4L60E - extension housing seal (aka driveshaft yoke seal) (Page 1/2)
Raydar JUL 23, 07:31 PM
The Trailblazer (2WD) is leaking a bit of tranny fluid when parked pointed uphill. (First leak in 140,000 miles.)
I'm thinking its the extension housing seal, where the driveshaft plugs in.

Rockauto has three different seals available. The cheapest one has a flat flange around the outside. Looks like the flange butts up against the end of the housing to keep the seal flat, and perpendicular to the driveshaft.
The next one says "booted". but doesn't have the flat flange.
There is ~.003 inch difference in the sizes of the two.
The 3rd one is a lot more complex looking, and is twice the price of the other two.

Are these things specific replacements? Or are they generic, based upon the preferenc of the installer?

The Haynes book makes it sound easy.
Remove the driveshaft.
Pry out the old seal. Don't screw up the splines.
Hammer in the new seal. Get it straight and flat.
Reinstall the driveshaft.

A friend of a friend said that he could do the job for $300-500. I don't think so.

This looks straightforward for someone who knows what they're doing. Really doesn't look any harder than a Getrag axle seal.
Anyone?

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Raydar
88 Formula IMSA Fastback. 4.9, NVG T550

Praise the Lowered!

carnut122 JUL 23, 08:19 PM
$300-$500? Yep, I'd be doing that myself. Sorry, I can't help you with which one. Just don't park it on a hill.
Raydar JUL 23, 10:26 PM

quote
Originally posted by carnut122:
... Just don't park it on a hill.



Yup. That exact solution crossed my mind.

But i'm going to have it apart in the next few weeks, anyway. Bought a BellTech suspension kit for it.
The shocks are toast. Figured I install some lowering springs while I'm at it.
Probably will do the brakes too.
Will be really easy to pull the driveshaft at the same time.
carnut122 JUL 24, 07:08 PM

quote
Originally posted by Raydar:


Yup. That exact solution crossed my mind.

But i'm going to have it apart in the next few weeks, anyway. Bought a BellTech suspension kit for it.
The shocks are toast. Figured I install some lowering springs while I'm at it.
Probably will do the brakes too.
Will be really easy to pull the driveshaft at the same time.



Funny how these jobs grow...exponentially. If I regain possession of my S10, I think I'm going to lower it also.
Raydar JUL 24, 10:36 PM
What year S10? I still miss mine. It's the perfect commuter.
GreenPlatypus JUL 25, 04:29 PM
1st leak in 140k on a trailbalzer you are one of the lucky ones! And yes it is a fairly simple job ot do. Exactly as you stated. I'd suggest just going to Chevy for the seal, they'll go by the vin number and you are more likely to get the right part - although they do make mistakes sometimes And make sure the transmission isn't overfilled - pretty sure you know how to do that. And REALLY look at the driveshaft, make sure the old seal hasn't worn a groove in it. Hey, it happens. Good Luck!
Raydar JUL 25, 09:04 PM
Perfect! Thanks!
Darth Fiero AUG 03, 04:30 PM
The seal may not be the only problem. Check to make sure the yolk isn't worn in the sealing or bushing areas. Also check to make sure the bushing in the extension housing isn't worn out as well. Removing the extension housing from the trans should be easy, and replacing the bushing shouldn't be too difficult. With 140k miles on that thing, if it were mine, I would probably replace the bushing and the seal as long as the yolk looked ok. If the yolk has issues, I would replace it as well.

-ryan

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OVERKILL IS UNDERRATED

Custom GM OBD1 & OBD2 Tuning | Engine Conversions & more | www.gmtuners.com

Raydar AUG 03, 08:43 PM

quote
Originally posted by Darth Fiero:
...



Good info. I've also researched a little bit since I first posted.
In any event, this does not appear to be something that I should be afraid of tackling. Especially when someone else wants multiple hundreds of dollars to do it.

Having said that, I expect that the Haynes manual has over simplified the task, since it did the same thing with rear shock/spring replacement.
(Nothing horrible. Just neglected to mention that in order to get the rear axle to drop enough to get the springs out, the sway bar must be disconnected, in addition to the shocks.)
Darth Fiero AUG 03, 11:56 PM
On 2WD models, removing the extension housing should be very easy. The only thing you may have to contend with is if there is a transmission mount that bolts to this housing - in which case you'll need to jack up and support the transmission so you can remove the mount and then the housing. There's a square cut round seal that seals the housing to the transmission case but it is reusable and shouldn't require you to do much more than just make sure it is clean and free of dirt before reinstalling the housing onto the trans.

The bushing itself is pressed in but you can get a cheap seal driver kit and use it to drive out the old bushing and drive in the new one with a hammer. No big deal at all if you are mechanically inclined.