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SPXTrader
11-27-2007, 12:48 AM
Short and sweet...this just started this past weekend on a road trip.

up to 60 mph OK
61 to 69 mph bad vibration and rumbling. Like driving on the rumble strips on the side of the interstate. With slight pressure on the gas pedal, it diminishes slightly. When 100% off throttle, and rpm's drop below 1700, vibration and noise stop...smooth as silk.
71 mph plus slight vibration that decreases with a little pedal applied.

90,000 miles, 4" SuperLift, 33X10.5 BFG AT's.

I've checked the U joints and flanges and all are tight...

Any one else had this problem? Any suggestions?

Rollin Thunder
11-27-2007, 12:51 AM
im not positive what the tech did, but my 99 burban did that, it was never 100% fixed, even when i sold it, it first started when between 67 an 73 mph the entire car would shave rattle and bang all from the rear end, the fixed it for a while with new tires, then new rear shocks and struts, then new engine clamps. nothing really fixed it, was a stock except for tv's and 10 disc, nothing affecting preformace. FWIW

SPXTrader
11-27-2007, 12:57 AM
Did it come on all of a sudden as mine did, or was it something that started, then got worse over time?

Rollin Thunder
11-27-2007, 01:28 AM
one day i drove it and it was fine, the next it started, :skep:

they did a ton and finally before i sold it they said it was the carb's IM ase certeified and it stumbled me. im still stumbled and know it was never 100% fixed, they said the carb was sending too much fuel in and had to be rebuild, and that the shakeing and vibrations were from it trying to balance the use of fuel and send it back to the tank , i hardly belived this because it would not cause that much shakeing, would it??

Mike97
11-27-2007, 01:34 AM
Short and sweet...this just started this past weekend on a road trip.

up to 60 mph OK
61 to 69 mph bad vibration and rumbling. Like driving on the rumble strips on the side of the interstate. With slight pressure on the gas pedal, it diminishes slightly. When 100% off throttle, and rpm's drop below 1700, vibration and noise stop...smooth as silk.
71 mph plus slight vibration that decreases with a little pedal applied.

90,000 miles, 4" SuperLift, 33X10.5 BFG AT's.

I've checked the U joints and flanges and all are tight...

Any one else had this problem? Any suggestions?

My guess would be that you threw a wheel weight and now one of your wheels is out of balance. Either that or you have a tire that is separating. Either way, take it to the tire shop and have them check the balance.

What happens if you are at the speed where the problem occurs and then shift into neutral while at that speed? If it immediately goes away, that would pretty much eliminate a wheel or tire problem.

SPXTrader
11-27-2007, 01:36 AM
RT, the way mine vibrates it would have to be sending bowling balls back to the tank. But thanks for the info. I've got a friend that is a traveling mechanic for Pike Electric. He works on everything from their PU's to the big boom/cable trucks. He's off this week, so a ride up I81 is in the forcast.

Mike97, I never thought about a tread separation. I don't put a lot of miles on it...I bought it in 98 I think, with 58,000. It just went thru 90,000, and the BFG's have been on it for the entire time. The sidewalls look a little weak (surface cracks starting to show), but they've still got good tread depth left. I hate throwing away more $$$ on a new set of tires...but I'll check them out. Could this be a probable cause since the vibe/noise goes away, even at speed (60 or higher), once the tach drops below about 1700? This makes me fear it could be a TqC, tranny, or something I don't even want to think about: motor.

If anyone else has any opinions, I'm damn glad to hear them!

OSU_Tahoe
11-27-2007, 10:42 AM
Driveshafts are all balanced from the mfr. If the balance weight comes off it'll vibrate like crazy. Usually those are welded on but I've seen them epoxied on as well. Just another idea to look at.

JKmotorsports
11-27-2007, 11:01 AM
Unbalanced wheels/tires would vibrate regardless of engine rpm, and you said it goes away under 1700, which would normally also rule out the driveshaft and u-joints. At a steady vehicle speed, the only thing changing when the rpms drop is engine speed; everything else stays the same (driveline, tires, rear diff, etc). I would check the motor mounts, dampener on the crankshaft, and even the flexplate and torque converter possibly.

SPXTrader
11-27-2007, 11:12 AM
Thanks to all for the replies...guess its time to do some checking...

Mike97
11-27-2007, 11:40 AM
RT, the way mine vibrates it would have to be sending bowling balls back to the tank. But thanks for the info. I've got a friend that is a traveling mechanic for Pike Electric. He works on everything from their PU's to the big boom/cable trucks. He's off this week, so a ride up I81 is in the forcast.

Mike97, I never thought about a tread separation. I don't put a lot of miles on it...I bought it in 98 I think, with 58,000. It just went thru 90,000, and the BFG's have been on it for the entire time. The sidewalls look a little weak (surface cracks starting to show), but they've still got good tread depth left. I hate throwing away more $$$ on a new set of tires...but I'll check them out. Could this be a probable cause since the vibe/noise goes away, even at speed (60 or higher), once the tach drops below about 1700? This makes me fear it could be a TqC, tranny, or something I don't even want to think about: motor.

If anyone else has any opinions, I'm damn glad to hear them!

After thinking about it, if you had a tire separating it probably wouldn't get better when you speed up. I imagine it would only get worse the faster you go. But unbalanced wheels can actually smooth out when you speed up. I've experienced this.

Unbalanced wheels/tires would vibrate regardless of engine rpm, and you said it goes away under 1700, which would normally also rule out the driveshaft and u-joints. At a steady vehicle speed, the only thing changing when the rpms drop is engine speed; everything else stays the same (driveline, tires, rear diff, etc). I would check the motor mounts, dampener on the crankshaft, and even the flexplate and torque converter possibly.

If you are always in the same gear, it can appear to only happen at a certain rpm range. If you shift down while the thing is vibrating, you should be able to tell if it's engine related.

The original post does not say if he was always in the same gear or not. He did not say anything about maintaining a steady speed and dropping the rpm's, I suggested he try that.

SPXTrader
11-27-2007, 01:45 PM
Gear didn't seem to be an issue. While climbing the mountains in route to Kentucky, I encountered some long steep grades. It would kick out of OD as expected, and downshift to keep my speed up. So regardless of the gear, the vibe/noise was still there.

Summary: No change in vibe/noise regardless of gear. Speed and RPM dictated the problems.

I'm going to do a run up Bent Mountain tomorrow and play with the gear selector to see if it has any impact on the issue.

Thanks again for all the help...

SPX

EDIT: has anone seen a 1999 Surburban with the 4WD selector on the floor? It looks just like the one in my 89 K2500 PU...

Mike97
11-27-2007, 02:16 PM
Gear didn't seem to be an issue. While climbing the mountains in route to Kentucky, I encountered some long steep grades. It would kick out of OD as expected, and downshift to keep my speed up. So regardless of the gear, the vibe/noise was still there.

Summary: No change in vibe/noise regardless of gear. Speed and RPM dictated the problems.


You are contradicting yourself here. When you shift down, you change the engine rpm's. Are you saying that the vibration stays exactly the same when you shift out of overdrive? If that is the case, then your problem has to be after the transmission. Either in the driveline, axles, hubs, or wheels.

SPXTrader
11-27-2007, 02:24 PM
Mike, I guess I wasn't clear in my reply. Referencing the RPM, anything above 1700 or so and it starts...Climbing the mountains it did down shift out of OD. RPM went up, and the problem remained. Only when I got off the throttle completely did it smooth out. And that happened only below about 1700 RPM.

Sorry for the confusion...

Rollin Thunder
11-27-2007, 03:32 PM
Gear didn't seem to be an issue. While climbing the mountains in route to Kentucky, I encountered some long steep grades. It would kick out of OD as expected, and downshift to keep my speed up. So regardless of the gear, the vibe/noise was still there.

Summary: No change in vibe/noise regardless of gear. Speed and RPM dictated the problems.

I'm going to do a run up Bent Mountain tomorrow and play with the gear selector to see if it has any impact on the issue.

Thanks again for all the help...

SPX

EDIT: has anone seen a 1999 Surburban with the 4WD selector on the floor? It looks just like the one in my 89 K2500 PU...


i, but the suburban has electronic shifters, i think they stopped the mechnical shifters in the early 90's like 92, but whats funny is the 06 silverado base model has mechnical shifter encless you paid 500 to get electrionic. so NOPE i have never seen a 99 with mechnical shifters. sorry. but why do you ask??

Mike97
11-27-2007, 04:10 PM
Mike, I guess I wasn't clear in my reply. Referencing the RPM, anything above 1700 or so and it starts...Climbing the mountains it did down shift out of OD. RPM went up, and the problem remained. Only when I got off the throttle completely did it smooth out. And that happened only below about 1700 RPM.

Sorry for the confusion...

So If I understand you correctly, it isn't speed dependent. It is rpm dependent. From a stop, place the gear selector in low. Drive until your engine rpm's are at 1700. Do you still have the vibration at this speed? Your first post mentioned above 60 mph. Now you are talking about it being rpm dependent. It should be fairly easy to rule out one or the other.

SPXTrader
11-27-2007, 04:35 PM
RT...I looked at a 99 'burban LT today and the 4WD selector was on the floor! It was a beautiful truck, sapphire (?) white with barn doors! And only 78,000 miles...

Mike, I can't say for sure it's not speed dependent. Below 60 or so (driving around town), I can't feel it at all, even with the RPM's up...but I plan on a detection drive Thursday. I'll try the first, second and third gear to 4 grand ploy and see if it appears. If all else fails, I'll grab my mechanic buddy and take him for a jaunt up the interstate. I'll let you all know what I (hopefully) find.

Thanks again..........

SPX

Rollin Thunder
11-27-2007, 04:37 PM
RT...I looked at a 99 'burban LT today and the 4WD selector was on the floor! It was a beautiful truck, sapphire (?) white with barn doors! And only 78,000 miles...

Mike, I can't say for sure it's not speed dependent. Below 60 or so (driving around town), I can't feel it at all, even with the RPM's up...but I plan on a detection drive Thursday. I'll try the first, second and third gear to 4 grand ploy and see if it appears. If all else fails, I'll grab my mechanic buddy and take him for a jaunt up the interstate. I'll let you all know what I (hopefully) find.

Thanks again..........

SPX

ya sure it was a 99, sounds intresting that they did that so late in the game, i need to research that more. :confused:

Rollin Thunder
11-27-2007, 04:40 PM
i guess it was an option still, but push button 4wd was standard on an LT, still confusing, SOURCE, EDMONDS


1993 Chevrolet Tahoe: Electronic control for the automatic transmission was one of the few changes in Chevrolet's big wagon. The new automatic also added a second-gear start feature, for increased traction on slippery surfaces.


1994 Chevrolet Tahoe: A turbodiesel engine returned to the powertrain parade, as side door-guard beams and a center high-mounted stoplamp were installed.


1995 Chevrolet Tahoe: A driver-side airbag was added, in a redesigned interior with recontoured seats. The turbodiesel engine could now go into 1500-series models as well as the 2500 series, and the standard V8 lost 10 horsepower.


1996 Chevrolet Tahoe: More-potent Vortec engines debuted for '96. The 5.7-liter gas V8 leaped from 200 to 250 horsepower. The optional 7.4-liter V8 gained 60 horsepower (now 290). Pushbutton engagement for the 4-wheel-drive system became available, and daytime running lights were installed.


1997 Chevrolet Tahoe: A passenger-side airbag was installed on '97 models. Outboard seats in the middle row gained height-adjustable shoulder-belt anchors. The standard 5.7-liter engine added five horsepower.


1998 Chevrolet Tahoe: Suburban added an optional full-time 4WD system called Autotrac. This system can remain engaged on any road surface.


1999 Chevrolet Tahoe: GM's biggest wagon was all but unchanged for '99, pending the arrival of a redesigned 2000 model.

SPXTrader
11-27-2007, 04:52 PM
RT, sorry, my bad...it was a 96...

http://i118.photobucket.com/albums/o91/spxtrader/surburbanfloorshifter.jpg

http://i118.photobucket.com/albums/o91/spxtrader/surburbanfloorshifter2.jpg

Rollin Thunder
11-27-2007, 05:05 PM
lol, that makes more sense. nice looking though for a 96:cool2:

Bobc
12-12-2007, 11:36 PM
I have a 99 with 125K. same issue between 60-70 MPH (I have new tires and U joints-front and rear) Front U's did help a tad. Has gotten worse over time, but sometimes seems to be worse and then a little better even during an 2-3 hour trip. Not engine/rpm dependent and not Trans in that it continues even if you throw it in Nuetral at 65. So, I agree it seems to be rear diff, shaft, front diff or CV jount or axal related. question is where to look and how to ID?

Bobc
12-12-2007, 11:39 PM
Short and sweet...this just started this past weekend on a road trip.

up to 60 mph OK
61 to 69 mph bad vibration and rumbling. Like driving on the rumble strips on the side of the interstate. With slight pressure on the gas pedal, it diminishes slightly. When 100% off throttle, and rpm's drop below 1700, vibration and noise stop...smooth as silk.
71 mph plus slight vibration that decreases with a little pedal applied.

90,000 miles, 4" SuperLift, 33X10.5 BFG AT's.

I've checked the U joints and flanges and all are tight...

Any one else had this problem? Any suggestions?
I have a 99 with 125K. same issue between 60-70 MPH (I have new tires and U joints-front and rear) Front U's did help a tad. Has gotten worse over time, but sometimes seems to be worse and then a little better even during an 2-3 hour trip. Not engine/rpm dependent and not Trans in that it continues even if you throw it in Nuetral at 65. So, I agree it seems to be rear diff, shaft, front diff or CV jount or axal related. question is where to look and how to ID?

sterios
12-30-2007, 08:46 AM
I have a 96 Yukon and it shudders at 110 kph. Always has. On coloradok5 they say it's a bad torque converter that causes this.Common problem for this truck. Not worth fixing for me as I drive faster then 110 usually and the shudder goes away.

shanes98t
01-04-2008, 09:39 PM
had same problem as you to the tee on my 1998 Tahoe but mines fixed now I put it up on the rack and even after balancing the tires and rims together I could still see a barely perceptible wobble on the passenger rear tire after first over anylizing and much fear of cost I checked wheel and tire seperately and confirmed what my eyes and common sense told me.. the tire was bad since they wernt that great anyway I bought a new set of oem goodyear wranglers and the problem completely went away the same thing happened to my dads 1997 and his was a bent rim its almost always just a bad tire or rim check the runout on the rim if it is suspect have it checked without the tire

Sejo
01-24-2008, 03:52 PM
No.

I am having the same problem you are describing and it's not the tires, u-joints, or whatever. I had all that checked.

As someone may have mentioned earlier I am beginning to suspect the throttle body or maybe the injectors, maybe even the exhaust system. I had a hook break off not to long ago; just before the CATs.

I drive and everything is smooth until I had around 70MPH. Between 70MPH-80MPH the vibration gets respectively worse, but hit a bit above 80MPH the vibration seems to flatten out. The vibration I'm feeling is something that is felt thru the gas pedal. It's not the tires being out of whack or anything - those are easy fixes. On here and other forums I've seen people post about the same things.

Now I am starting to suspect the air/fuel system components b/c I realize that the vibration seems to simmer down after I Sea Foam the top end and/or use fuel system cleaner. On long trips when I have to reduce myself to using discount gasolines, b/c the next Top-Tier gasoline stations is miles away, the vibration is at its WORSE....seriously. It gets to the point of pissing me off because I do maintain the 'Hoe and use only the best, and to now that there is something you can't pinpoint is irritating. But neither her nor there.....I'm going to remove the throttle body and give it a good cleaning. If the pocket book permits I may change out Fuel Injectors, but those suckers are expensive. I've only done the Sea Foam top end clean twice, it may be that a few more cleanings will do the trick.

Something I'm less educated about is the EGR Valve. I read several places that they should be replaced with a high mileage maintenance intervals. Anyone ever change it out? Seems like it could be causing some of these vibrations issues.

http://autorepair.about.com/od/glossary/gr/def_egr-valve.htm

Pros
* The EGR valve is vital to your car's emission controls.
Cons
* When the EGR valve goes bad, it must be replaced.
Description
* EGR Valve = Exhaust Gas Recirculation Valve.
* The EGR valve controls formation of noxious emissions.
* Rough idle and poor acceleration can be caused by a faulty EGR valve.

EGR Valves aren't cheap either. If I replace it I'll post back here if there are any positive findings.

Slammed
01-24-2008, 07:49 PM
anybody check the hub bearings??? I also would check front axels (I know they have to be removed to check them)

sterios
01-24-2008, 10:55 PM
I had the same vibration on my 96 four door 4x4 Yukon. I just had the rear diff completely redone with new bearings and seals and the vibration is gone. Mechanic showed me the parts and all the bearings had pits and pieces missing. Had been making this vibration at exactly 110 kph since i've owned the truck two years now. After the work it's completly gone. Smooth and didn't even know how noisy it was on the highway till it was gone. Good luck

Sejo
01-25-2008, 03:37 PM
I had the same vibration on my 96 four door 4x4 Yukon. I just had the rear diff completely redone with new bearings and seals and the vibration is gone. Mechanic showed me the parts and all the bearings had pits and pieces missing. Had been making this vibration at exactly 110 kph since i've owned the truck two years now. After the work it's completly gone. Smooth and didn't even know how noisy it was on the highway till it was gone. Good luck

Was your problem a vibration or a shudder? Shudder where the entire truck shakes or a vibration you were feeling thru the gas pedal? My feeling is completely thru the gas pedal but I can tell it is affecting the performance of the truck. It's been cold in my area lately and on my way to work this morning I hit 70-80MPH and did not notice the vibration. I wonder now if it could have something to do with the MAF sensor?

Has anyone with an aftermarket intake unit, that eliminates the MAF Unit, experienced this vibration?

sterios
01-25-2008, 06:30 PM
Mine was a vibration you could feel through out the truck at exactly 110 kph. If you were going 120 and let off the gas as soon as I hit 110 ten you could feel the truck vibrating. It's completely gone now. good luck

mygreen98
01-28-2008, 03:59 PM
i had similar problem, only noticed it on highway, over 55 mph and only when giving it gas. changed front shaft ujoints. fixed problem. seems that at high speeds the shaft turns even when in 2wd. i would also check your front whell hub bearings. i changed mine a while ack they too caused a vibration.

madspeed
01-29-2008, 09:51 PM
mine was very similar and a new idler arm solved the problem!! Oh, and along with the tire guy finding that two of the dirrectional tires were mounted backwards!!!

Untitled415
01-31-2008, 07:32 PM
I hardly doubt its the wheels or steering... most of the time when wheels or a steering componets are bad there is just a vibration in the steering wheel which can most time only be noticed at high speeds.

This to me sound like a cracked flywheel, torque converter, or drive shaft probelm. I do not believe that the trans would make a vibration like the one you are referring to.

Stillakilla187
02-02-2008, 05:22 PM
Driveshafts are all balanced from the mfr. If the balance weight comes off it'll vibrate like crazy. Usually those are welded on but I've seen them epoxied on as well. Just another idea to look at.

You are right, the factory weight is welded on. However, the shaft can still rust and other things can happen to it to throw it off balance. Once this happens the symptoms are exactly the one described.

Stillakilla187
02-02-2008, 05:27 PM
and if not fixed the drive shaft will wobble all the components inside the tranfer case and/or transmission and will do SERIOUS damage. get it check out just in case. Getting it balance is like 100 bucks, thats a lot cheaper than getting a tranny rebuild.

SPXTrader
04-14-2008, 03:29 PM
Well, found the problem. Rear u-joints shot. The caps fell apart in my hand while replacing them. Funny part is that the DS was tight as a tick when trying to move it by hand. Decided to drop it anyway, just for grins. That's when I noticed the cracked u-joint caps. That problem solved!

http://i118.photobucket.com/albums/o91/spxtrader/Tahoe%20Pics/IMG_0074.jpg

http://i118.photobucket.com/albums/o91/spxtrader/Tahoe%20Pics/IMG_0075.jpg

New problem: Superlift front link bushings shot, I think. From time to time I get a BAD (and I mean BAD) wobble in the steering wheel when braking in a turn.

Oh well, it looks good!

GMCYukalade
04-14-2008, 10:44 PM
My factory U-Joint did the exact same thing.. and i drove it till the drive shaft fell out..

Black96
04-14-2008, 11:00 PM
wow, man someone should make a thread of just pictures of evey thing that has been broken on everyones tahoes on here and have it open too all the diff gen tahoes

GMCYukalade
04-14-2008, 11:08 PM
:) This is two different rearends both from the same Yukon

Black96
04-15-2008, 12:00 AM
dude i feel ur pain i did three so far haha, mine have all been the carrier brakin so i put a detriot tru trac and yukon gears in

SPXTrader
04-15-2008, 01:04 AM
My factory U-Joint did the exact same thing.. and i drove it till the drive shaft fell out..

What's funny is, like I said, you could yank, twist and shake the drive shaft till your hearts content and would have never known the joints were bad. Only after dropping the drive shaft did I find the severity of the problem.

I called a local place that does lifts (mine is lifted) and he confirmed that a set of u-joints in a lifted truck are only good for 2 or 3 years. I lifted mine in 1998, so this explains why this is the third set of joints since then. The other two sets that went bad came on gradually, and I knew what the problem was as it became more severe. This time, it went from OK to very bad in about 60 miles. Never experienced that before...

GMCYukalade
04-15-2008, 09:47 PM
ya, i didn't really know what mine was doing at all - all of a sudden it just started making a noise - when i jacked it up i could actually see the broken cups - but i couldn't move the drive shaft at all

Sejo
04-18-2008, 12:18 AM
How much are these U-joints/cups costing you guys and where are you getting them? Any special discount places?

I think I'm starting to have the same problem. Could this problem arise from over or under tightening? Just had some transmission work done and it only started vibrating recently. What are the torque specs for reinstalling the driveshaft?

SPXTrader
04-18-2008, 11:30 AM
About 5 bucks per joint at NAPA. Not too sure what the GM part costs. The cups (also called caps) are part of the u-joint.

Just had tranny work done and now a vibration, eh? Possible drive shaft index issue. Take it back to the shop and ask if they indexed the drive shaft properly when they re-installed it. Tell then it's vibrating now, where it wasn't before they dropped the DS, IF this is a true statement.

Sejo
04-18-2008, 01:53 PM
About 5 bucks per joint at NAPA. Not too sure what the GM part costs. The cups (also called caps) are part of the u-joint.

Just had tranny work done and now a vibration, eh? Possible drive shaft index issue. Take it back to the shop and ask if they indexed the drive shaft properly when they re-installed it. Tell then it's vibrating now, where it wasn't before they dropped the DS, IF this is a true statement.

So I just need to ask for the U-joint caps/cups; those are $5? Not the U-joint itself right?

I know it's something the Tranny Shop did, I'm already not really happy with their work so I'm a little weary about taking it back there for anything.

What all is involved with Driveshaft indexing?

SPXTrader
04-18-2008, 02:28 PM
So I just need to ask for the U-joint caps/cups; those are $5? Not the U-joint itself right?

I know it's something the Tranny Shop did, I'm already not really happy with their work so I'm a little weary about taking it back there for anything.

What all is involved with Driveshaft indexing?

The u-joints are a complete assembly. They come with the caps/cups.

When you had your tranny rebuilt, they had to drop the DS in order to remove it. From the factory, the DS itself is balanced. When installed, the whole drive line is then balanced, and index marks are made to note the proper placement of the DS to the yokes. These marks are on the yokes of the DS (both ends), output shaft, and rear end. When replacing the DS, you need to make sure these marks line up, or you may experience a vibration.

I'd take it back, tell them your problem and ask if the index marks were lined up when they re-installed the DS.

CRXMotorsports
05-05-2008, 11:44 AM
Hey SPXTrader (or anyone for that matter).

97 Yukon here, RWD, 157k miles... I have this incredible shudder throughout the entire truck, comes on in the 65-70mph range. Reading through this thread and a couple other Chevy truck threads, I'm thinking the $25 for a greasable, (supposedly supertough) U-joint makes sense to do. I'm sure it hasn't been replaced on this beast.

My question simply is this: Would a bad U-Joint made the truck shudder, and would it be consistant with a bad u-joint for the truck to shudder MUCH worse under a load, trailering approximately 4000lbs?

I notice a small vibration/shudder thoughout the truck at those speeds, but it becomes extremely pronounced and bothersome while towing the race car. In a 2WD Yuk, is there just 1 U-Joint on the driveshaft (yet to crawl under it to look)? Or are there multiple ones on it? one on each end, etc.

After this it is time for tie-rod ends and a fresh alignment, I replaced the pitman & idler arms, which helped a great deal for my previous steering issue, but this vibration is getting crazy and annoying.

Last bit of info: Only modifications to the truck is a power programmer, not lifted or lowered, new shocks all 4 corners, and air bags on the rear (just to help with towing, normally kept at 10-15lbs which is the minimum)

blk87brd
05-05-2008, 12:45 PM
Bad u-joints could well be the problem, however, they are usually accompanied by clunks and thumps when increasing or decreasing load on them. And, yes there are two. Without anything other than the description you have provided, my guess is you are looking at a transmission mount issue. I had a bad vibration in a pickup once, the mount looked okay. How I found it was by taking a racket strap around the tail shaft housing and to the cross member, tightening it up and going for a drive with the trailer attached. No vebration, (well, gratly reduced). Changed the mount and that was the end of the vibration.

CRXMotorsports
05-05-2008, 01:02 PM
No problem at all, I can easily do that while I'm under the truck, my thought process is that at over 11yrs. old, 157k miles, and most of it towing, the U-Joints are worth replacing regardless. The truck has clunks and thuds from a dead stop. The transmission was just rebuilt/replaced by a reputable shop within the last 10k miles, I am unsure if mounts were included in that. I may just do the U-Joints, see what I get, and put trans mounts on the list of 'next to do'.

telmd
05-05-2008, 03:59 PM
97 tahoe here with 187k. Noticed a vibration at highway speeds. Checked the tires once i stopped and noticed that two of them were warped/bubbled causing the vibration so you may check those....

CRXMotorsports
05-28-2008, 03:56 PM
Well, UJoints replaced, no better, still a bad shutter under towing (more noticable while towing anyway).

All steering components, tierod ends, sleeves, idler arm, pitman arm and alignment are done. I am at my wits end about. I am going tonight to have the wheels double-checked for balancing... The truck still gets a terrible shutter at 65-70mph, below that it is fine, above that it remains. I feel I'm running out of replacement items here! :mad:

Brakes are still crazy and terrible too (but that's discussed by many in plenty of other threads!)

Sejo
05-28-2008, 04:40 PM
Well, UJoints replaced, no better, still a bad shutter under towing (more noticable while towing anyway).

All steering components, tierod ends, sleeves, idler arm, pitman arm and alignment are done. I am at my wits end about. I am going tonight to have the wheels double-checked for balancing... The truck still gets a terrible shutter at 65-70mph, below that it is fine, above that it remains. I feel I'm running out of replacement items here! :mad:

Brakes are still crazy and terrible too (but that's discussed by many in plenty of other threads!)

I'm still getting a bit of vibration too. I'm starting to wonder if it's something in the tranny itself (Torque Converter), Oxygen Sensors, the intakes MAF (Mass Flow Sensor), maybe the throttle body is shot or needs good cleaning?

It just seems like it could be that the engine is sucking in bad air or not enough air.....? Just some thoughts.

The vibration comes and goes for me, sometimes it really bad to the point that I'm ready to burn the thing to the ground and at other times it's running great. Sometimes I think it gets worse towards the tail end of needing an oil change.

It irritates me either way.

PotentialTahoe
06-04-2008, 12:00 AM
i, but the suburban has electronic shifters, i think they stopped the mechnical shifters in the early 90's like 92, but whats funny is the 06 silverado base model has mechnical shifter encless you paid 500 to get electrionic. so NOPE i have never seen a 99 with mechnical shifters. sorry. but why do you ask??

I have a 99 Tahoe with floor shiftr 4x4.