Rear differential swap help

[Alex_htx]

Hello everyone i have searched this forum for answers but no luck so my question is I have a 02 Tahoe LS & the diff is going bad & im wondering if i could swap one from a 2004 z71 Tahoe & if it needs any modifications to fit if needed thanks

 

[Saucy_Walnuts]

It will work as long as they are the same gearing. I just swapped a 01 tahoe axle in my 03 Yukon. I did a write up on all tools and the process of it. You will need to pull the diff cover off to check gearing if the axle is un known. But I personally would. I added 80/90 and a new pinion seal and diff cover gasket in while I had it apart. It took me by myself about 5hrs to swap. The hardest part was getting the new axle alined to put the bolts in. Constant moving the axle back and forth. But others could do it in about 1.5hrs im sure without servicing it.

 

[Alex_htx]

It will work as long as they are the same gearing. I just swapped a 01 tahoe axle in my 03 Yukon. I did a write up on all tools and the process of it. You will need to pull the diff cover off to check gearing if the axle is un known. But I personally would. I added 80/90 and a new pinion seal and diff cover gasket in while I had it apart. It took me by myself about 5hrs to swap. The hardest part was getting the new axle alined to put the bolts in. Constant moving the axle back and forth. But others could do it in about 1.5hrs im sure without servicing it.

Would different gearing cause problems?

 

[Saucy_Walnuts]

Would different gearing cause problems?

4x4 definitely you will destroy your tcase or front diff and most everything in between the moment you put it into 4x4. Non 4x4 your speed may be off some it's not a very big deal.

 

[Marky Dissod]

Would different gearing cause problems?

4x4 definitely you will destroy your tcase or front diff and most everything in between the moment you put it into 4x4.
Non 4x4 your speed may be off some it's not a very big deal.

Although I am of the opinion that the mathematically superior axle would break the mathematically inferior axle,
YES, different gearing will cause DESTRUCTION in 4Lo or 4Hi, including the part time mode the moment it engages.

 

[Alex_htx]

4x4 definitely you will destroy your tcase or front diff and most everything in between the moment you put it into 4x4. Non 4x4 your speed may be off some it's not a very big deal.

The 02 that I want to put the diff on doesn’t have 4x4 it’s a 2wd getting a diff from a 4x4

 

[Marky Dissod]

The 02 that I want to put the REAR AXLE on doesn’t have 4x4, it’s a 2wd. getting a REAR AXLE from a 4x4.

Thanks for clarity.

In that case, you should seriously consider it an opportunity to upgrade.
Although it'd need reprogramming to correct the speedo and protect WOT shifts,
3.73 should have been the lowest axle GM ever offered on the GMT800,
& 4.10 should have been far more common.

 

[Saucy_Walnuts]

Thanks for clarity.

In that case, you should seriously consider it an opportunity to upgrade.
Although it'd need reprogramming to correct the speedo and protect WOT shifts,
3.73 should have been the lowest axle GM ever offered on the GMT800,
& 4.10 should have been far more common.

Yes as Mark said it will need programed. I was mistaken i didn't think about it affecting the WOT shifts. Any dealership or most larger shops could program it for you. And I was not aware that the 4:10s were more common.

 

[Marky Dissod]

Yes as Marky said it will need reprogramed. I was mistaken i didn't think about it affecting the WOT shifts.
Any dealership or most larger shops could program it for you. And I was not aware that 4.10 were more common.

4.10 should have been far more common.

4.10 was very rare in 1500 2WD suburbans, even rarer in 4WD Tahoes.
4.10 was much more common with 2500 & 3500 GMT800, but those were not 10-bolt rear axles.

GM was trying to improve their Corporate Average Fuel Economy score in the early / mid noughts;
4.10 became less and less common, 3.42 became far more common (far TOO common);
GM even had the gall to introduce 3.23 (& a lower front fascia) in '05 & '06,
to gain 1MpG on their CAFE score ... making those 4L60E less reliable.

Re WOT shifts: if pcm thinks more gear than actual, WOT shifts will be fine with lesser gears,
but
if pcm thinks less gear than actual, WOT shifts may not be accurate,
because RpMs will change quicker than pcm expects.

 

[Alex_htx]

Interesting apart reprogramming the truck itself would it bolt right up or is there hardware differences