Transfer case replacement?

[twbauer]

OK guys... need some help. First time post here. I just purchased an 05 Yukon XL Denali just before Christmas. I took it in for an oil change, and the shop noticed a leak on the transfer case seal. To replace the seal, they needed to pull the entire rear drive shaft, so as long as they did that, I had them replace the fluids in both diffs, and the transfer case.

Problem # 1 - they found the transfer case did NOT have the Auto-Trak fluid, but instead had normal transmission fluid in it.

Problem #2 - The piece of the rear drive shaft (4-6 in) that goes into the transfer case had "rings" ground into it. It was obvious that there is metal on metal.

The shop told me that I should probably get the transfer case, along with the small shaft that goes into the transfer case (because of the ground rings) replaced. They quoted me 1500-1700 for the transfer case and 300 for JUST the small part of the rear drive shaft which inserts into the transfer case.

For now, I had them just replace the transfer case seal, put the correct fluids in, and put it all back together. So far, it has not leaked, and it does not really make any noise.

I have NOW found almost a brand new transfer case (21 miles on it) for $850 and an almost new complete rear drive shaft (also 21 miles) for $125. So I need to make a decision on what to do... OPTIONS....

1 - Do NOTHING, and let things ride until something starts to make noise and re-evaluate then.

2 - Get the new parts and keep them until something starts to make noise, and do the replacement when there seems like a reason to do so.

3 - Get the new parts and replace the transfer case and rear drive shaft now.

Couple other questions...
- Will not replacing the transfer case cause any negative affects on anything else on the truck? ie... the front/rear diffs?
- The gas mileage right now is not the greatest compared to my buddy's denali (same year). He's getting 15-16 combined highway/city, and I'm getting about 13. Could the obvious friction in the transfer case (ground rings) cause the lowered miles per gallon?

Thanks a lot for any help you can provide!!! I have a buddy going through the city that has the parts, so I have a window of time this weekend to make the purchase without having to pay for shipping.

 

[boostaholic]

I'd get the used one, just make sure the tailshafts are the same as well as the case itself (should have a tag from borg-warner on the rear cover). That could be hurting your mileage but not significantly, you may notice an increase in mileage from the fluid changes in the diffs however. The tcase shouldn't damage either differential although I have seen some crazy stuff when a tcase goes, I wouldn't worry about it just get the used case and you'll be fine.

 

[midwest]

My 03 calls for Dextron III in the transfer case. I'd just drive it.

 

[boostaholic]

The denali tcases require auto trak II overpriced blue fluid, nothing else will suffice.

 

[midwest]

The denali tcases require auto trak II overpriced blue fluid, nothing else will suffice.

Yep, I have read that here over and over. My 03 owner's manual doesn't mention it. It says use Dextron III. Is it a misprint?

 

[twbauer]

I just crawled under the darn thing to ensure that if I DO purchase the new transfer case, that it's the right one. The only thing I can find is the Borg Warner name, but no numbers, excep the AZ91D, which is apparently the magnesium alloy the case is made out of. It DOES have the NR3 option in the glove box, so can I assume this is truly a Bort Warner 4481 (which is what I see in most info I find)?

 

[twbauer]

One more thing... how does the prices that I was quoted sound? $850 for a 21 mile transfer case, and $125 for the rear drive shaft.

 

[boostaholic]

Sounds like a good price, I'd jump on it.