Pinion Seal leak - ZR-1 Net Registry Forums

We Gone · 03-24-2014

Can I just replace the seal? or do I need a new yoke? If I do the yoke do I have to change the crush sleeve and have it re-shimmed and set up? It has a new seal and gears in it now as I just had the gears changed have put about 6-7 hundred miles on it.

mike100 · 03-24-2014

I would probably want to at least check the backlash if you just pop a new seal in there on the old crush sleeve. Kind of taking your chances on the re-torque of the pinion nut.

That said, I had a good leak on mine using synthetic lube, but solved it by filling it with conventional 80w-90 when it was a pint low. That seemed to have done a good job at conditioning the seal and the leak stopped. It has been great for the last year and a half.

We Gone · 03-24-2014

Thanks Mike, may give it a try first as it was filled with Amsoil synthetic when done.

WVZR-1 · 03-25-2014

Is it actually the seal or is it "seeping" from the splines past the nut. I would have thought if you needed a pinion flange it would have been brought to your attention when the build was done. It's possible though that even though "new" the pinion seal could have been very old and created an issue.

The 80W90 conventional "top-off" is a thought but if you thought the synthetic a possible cause I'd just do a complete change to the 80W90 and add the LS additive. Did you have a drain added?

Jagdpanzer · 03-25-2014

Changed my pinion seal last year.
Jacked up the rear wheels so they turned freely.
Pulled the C beam and drive shaft.
Before loosening the pinion nut I measured the torque required to rotate the pinion slowly. Then I R&R the pinion seal and tightened the pinion nut to achieve the same rotation torque value as before.

We Gone · 03-25-2014

Thanks guys, I'll get it up and see. Just want to get it fixed so I can drive it to BG this year it is leaking bad enough that when I drive it you can smell the fluid burning on the exhaust. . Everything was replaced when the gears were done, and yes I did have the drain plug installed. Jagdpanzer, not sure how you measure the toque, was this done with a toque wrench?

Thanks again

Jagdpanzer · 03-25-2014

I used a inch/pound torque wrench set up like shown here but with the yoke still installed and the rear end under the car.

WVZR-1 · 03-25-2014

You can count threads and also mark the pinion nut if you want to use the same one. I generally suggest replacing the pinion nut just because it's a prevailing torque nut and is inexpensive. I would think it unusual but it's possible that the spring that creates tension on the sealing lip of the seal was dislodged when yoke installed or maybe it's just failed.

Count threads and confirm the rotational drag but you might need to get creative when figuring out how to hold the yoke in position to tighten the nut appropriately.

If it's leaking badly enough to sling fluid to the exhaust it certainly hints the spring failure and not a typical pinion seal leak. It's possible that when the spring fails it will pump more fluid out when using reverse. The ring gear throws more fluid towards the pinion.

We Gone · 03-25-2014

Thanks again guys I love this forum, It was leaking within the first 75 miles.

03-24-2014	#1
We Gone Join Date: Apr 2004 Location: Atlanta, GA Posts: 2,168	Pinion Seal leak Can I just replace the seal? or do I need a new yoke? If I do the yoke do I have to change the crush sleeve and have it re-shimmed and set up? It has a new seal and gears in it now as I just had the gears changed have put about 6-7 hundred miles on it. __________________ Steve 1990 Steel Blue/Black #2355 1990 Red/Red #1473 1991 Quasar /Black #118 Sold 1991 Turquoise/Black #766 Parted Out 1993 Yellow/White #179 Sold 1990 Black/Gray #1361 Headers/4:10s Sold

03-24-2014	#2
mike100 Join Date: Feb 2011 Location: San Marcos CA Posts: 1,801	Re: Pinion Seal leak I would probably want to at least check the backlash if you just pop a new seal in there on the old crush sleeve. Kind of taking your chances on the re-torque of the pinion nut. That said, I had a good leak on mine using synthetic lube, but solved it by filling it with conventional 80w-90 when it was a pint low. That seemed to have done a good job at conditioning the seal and the leak stopped. It has been great for the last year and a half.

03-24-2014	#3
We Gone Join Date: Apr 2004 Location: Atlanta, GA Posts: 2,168	Re: Pinion Seal leak Thanks Mike, may give it a try first as it was filled with Amsoil synthetic when done. __________________ Steve 1990 Steel Blue/Black #2355 1990 Red/Red #1473 1991 Quasar /Black #118 Sold 1991 Turquoise/Black #766 Parted Out 1993 Yellow/White #179 Sold 1990 Black/Gray #1361 Headers/4:10s Sold

03-25-2014	#4
WVZR-1 Join Date: Oct 2004 Posts: 1,889	Re: Pinion Seal leak Is it actually the seal or is it "seeping" from the splines past the nut. I would have thought if you needed a pinion flange it would have been brought to your attention when the build was done. It's possible though that even though "new" the pinion seal could have been very old and created an issue. The 80W90 conventional "top-off" is a thought but if you thought the synthetic a possible cause I'd just do a complete change to the 80W90 and add the LS additive. Did you have a drain added?

03-25-2014	#5
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,662	Re: Pinion Seal leak Changed my pinion seal last year. Jacked up the rear wheels so they turned freely. Pulled the C beam and drive shaft. Before loosening the pinion nut I measured the torque required to rotate the pinion slowly. Then I R&R the pinion seal and tightened the pinion nut to achieve the same rotation torque value as before. __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake

03-25-2014	#6
We Gone Join Date: Apr 2004 Location: Atlanta, GA Posts: 2,168	Re: Pinion Seal leak Thanks guys, I'll get it up and see. Just want to get it fixed so I can drive it to BG this year it is leaking bad enough that when I drive it you can smell the fluid burning on the exhaust. . Everything was replaced when the gears were done, and yes I did have the drain plug installed. Jagdpanzer, not sure how you measure the toque, was this done with a toque wrench? Thanks again __________________ Steve 1990 Steel Blue/Black #2355 1990 Red/Red #1473 1991 Quasar /Black #118 Sold 1991 Turquoise/Black #766 Parted Out 1993 Yellow/White #179 Sold 1990 Black/Gray #1361 Headers/4:10s Sold

03-25-2014	#7
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,662	Re: Pinion Seal leak I used a inch/pound torque wrench set up like shown here but with the yoke still installed and the rear end under the car. __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake

03-25-2014	#8
WVZR-1 Join Date: Oct 2004 Posts: 1,889	Re: Pinion Seal leak You can count threads and also mark the pinion nut if you want to use the same one. I generally suggest replacing the pinion nut just because it's a prevailing torque nut and is inexpensive. I would think it unusual but it's possible that the spring that creates tension on the sealing lip of the seal was dislodged when yoke installed or maybe it's just failed. Count threads and confirm the rotational drag but you might need to get creative when figuring out how to hold the yoke in position to tighten the nut appropriately. If it's leaking badly enough to sling fluid to the exhaust it certainly hints the spring failure and not a typical pinion seal leak. It's possible that when the spring fails it will pump more fluid out when using reverse. The ring gear throws more fluid towards the pinion. Last edited by WVZR-1; 03-25-2014 at 08:28 PM.

03-25-2014	#9
We Gone Join Date: Apr 2004 Location: Atlanta, GA Posts: 2,168	Re: Pinion Seal leak Thanks again guys I love this forum, It was leaking within the first 75 miles. __________________ Steve 1990 Steel Blue/Black #2355 1990 Red/Red #1473 1991 Quasar /Black #118 Sold 1991 Turquoise/Black #766 Parted Out 1993 Yellow/White #179 Sold 1990 Black/Gray #1361 Headers/4:10s Sold