Transmission rear seal

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Rolexus

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Hi All! Re: 05 Tahoe, 5.3 litre, 4WD: Recently replaced the transfer case motor ‘encoder sensor ring’ with great success (thanks YouTube!), can now use dash selector to change between all options - previously stuck in 2 WD only.

While under there, noticed rear Transmission seal is a bit wet.

If I proceed with replacing this seal, and after removing the driveshaft, is this a fairly straightforward procedure, only needing to replace the seal? Or are there more items to consider?

Also, Is aftermarket rear seal okay? Or should I be ordering OEM from dealer?

Any advice most welcome, Cheers, Dwayne
 

rockola1971

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Hi All! Re: 05 Tahoe, 5.3 litre, 4WD: Recently replaced the transfer case motor ‘encoder sensor ring’ with great success (thanks YouTube!), can now use dash selector to change between all options - previously stuck in 2 WD only.

While under there, noticed rear Transmission seal is a bit wet.

If I proceed with replacing this seal, and after removing the driveshaft, is this a fairly straightforward procedure, only needing to replace the seal? Or are there more items to consider?

Also, Is aftermarket rear seal okay? Or should I be ordering OEM from dealer?

Any advice most welcome, Cheers, Dwayne
You mean Tcase rear seal? There are 2 types. One flat a stereotypical seal and the other is like a boot and is real thick. Make sure you replace your seal with the same type that is installed now. They are easy to replace. Pry out with a screwdriver after dinking the side of the seal with a hammer and screwdriver or punch. Be very careful not to damage the inner diameter of the case where the seal pops into.
 
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Rolexus

Rolexus

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No, the main transmission rear seal is what’s leaking
 
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I imagine that once the main driveshaft is removed, then it’s just using TLC to remove the existing seal, with caution not to damage the main trans rear housing?
 

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Seems like the front of the main driveshaft would connect to the transfer case. Is it leaking there, or closer to the engine between the transmission and the transfer case?
 
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Rolexus

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Yes, you are correct, the leaky seal is at the front of the main driveshaft, which connects the differential to the transfer case
 

rockola1971

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Yes, you are correct, the leaky seal is at the front of the main driveshaft, which connects the differential to the transfer case
There is no rear transmission seal on a 4wd chevy. There is a seal that goes between the Tranny and Tcase. Most just put silicone gasket maker there. There is a rear seal on the Tcase that the REAR driveshaft goes into when it enters the rear of the TCASE. A 2wd transmission has a rear seal that the driveshaft goes into but the driveshaft does not attach to a 4wd tranny. It attaches to the rear of the Tcase.
Power from the engine travels in this order in a 4wd. Torque Converter, Transmission, Tcase, Driveshaft, Rearend Differential, Rear Axles, Tires(rims).
 
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Rolexus

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There is no rear transmission seal on a 4wd chevy. There is a seal that goes between the Tranny and Tcase. Most just put silicone gasket maker there. There is a rear seal on the Tcase that the REAR driveshaft goes into when it enters the rear of the TCASE. A 2wd transmission has a rear seal that the driveshaft goes into but the driveshaft does not attach to a 4wd tranny. It attaches to the rear of the Tcase.
Power from the engine travels in this order in a 4wd. Torque Converter, Transmission, Tcase, Driveshaft, Rearend Differential, Rear Axles, Tires(rims).
Thanks! Yup, I got a little confused, crawling under the truck (unjacked); the seal in question is the back end of the T Case.

So to replace the seal, no big whoop, I’m hoping. Just remove the driveshaft, gently remove the seal, reinstall carefully, then reattached the drive shaft.

Any tricks that Will make this swap a bit smother- any lubricant, etc.?
 

rockola1971

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Thanks! Yup, I got a little confused, crawling under the truck (unjacked); the seal in question is the back end of the T Case.

So to replace the seal, no big whoop, I’m hoping. Just remove the driveshaft, gently remove the seal, reinstall carefully, then reattached the drive shaft.

Any tricks that Will make this swap a bit smother- any lubricant, etc.?
Wipe tranny fluid on lips of new seal where it meets the driveshaft yoke before installing the seal. Remember there are 2 types of seals and you have to install the same type that was originally installed.
 
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Rolexus

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Wipe tranny fluid on lips of new seal where it meets the driveshaft yoke before installing the seal. Remember there are 2 types of seals and you have to install the same type that was originally installed.
Thank you!
 

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