Leaking differential

Bjorn Nilson

Bjorn Nilson

True Classic
My differential is leaking and it seems like final drive shaft sealings need replacement. Is it possible to replace those without dismantling the gearbox? There is a top cover on one side (the leaking side) on the final drive unit. If I remove that, would it give me access to at least one of the sealings? Workshop manual is not very clear in this matter so an advice would be much appreciated.
It is a 5-speed gearbox.
 
Changing the seal is easy.

Step 1: Remove the CV axle. Most likely, you will have to remove the six allen head screws that retain the inner CV to the Stub Shaft that provides drive to the axle.

Step 2: use a slide hammer or pry bar (Slide hammer preferred) to remove the stub shaft from the transmission. You now have access to the seal.

Step 3: Use a seal puller or small pry bar to lever out the seal. Be careful not to mar the sides of the seal carrier.

Step 4: Use a seal driver or large socket and hammer to drive the new seal into place. Note that that the seals are not identical side to side. You will want to ensure you have the correct seal. I would suggest replacing both.

Step 5: Insert the stub shaft into the case. Be sure to rotate the shaft slightly in each direction until you are sure you have the splines fully engaged. Then drive the shaft into place with a mallet. It should only take one firm blow to seat the snap ring. You DO NOT have to drive it in with multiple blows.

Step 6: Re-assemble the CV axle. Be sure to properly torque the allen head screws.
 
Steve Hoelscher said:
Note that that the seals are not identical side to side.
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Steve, you just got me thinking. Some time ago I ordered all of the basic components needed to go through two X gear boxes. But I haven't begun the actual work on them yet. Off hand I don't recall now if I ordered two different seals for the output shafts. I may have but for some reason I think possibly not. Guess I'll have to go check the box of parts to check.
 
Many thanks. I didn't expect to have an answer that quickly. This forum is world class :).
The engine and tranny is out of the car so this will be an easy job.
A (drained) X1/9 gearbox was included in my UT engine deal and I was told it should be ok so I decided to go for that one instead of my old gearbox. I had the new clutch fitted, gearbox mounted and filled up with Redline oil a month ago and it has been sitting since then. But yesterday I was working on the engine and noticed the tiny leaks.
If someone have the part numbers I would be happy for that information as well.
 
Dr.Jeff said:
Steve, you just got me thinking. Some time ago I ordered all of the basic components needed to go through two X gear boxes. But I haven't begun the actual work on them yet. Off hand I don't recall now if I ordered two different seals for the output shafts. I may have but for some reason I think possibly not. Guess I'll have to go check the box of parts to check.
Click to expand...

HA!

You can buy the seals from Midwest-Bayless if needed. I never bothered to get part numbers. I typically buy them in pairs from Midwest-Bayless. I recently found an industrial seal company that is local to me. They have a massive inventory. I buy all of the metal clad seals and O-rings from them in quantity. Its also super convenient to just drop by their place anytime I am in town. They're about 20 minutes from my house.
 
Steve Hoelscher said:
found an industrial seal company that is local to me
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I have a similar resource, only not quite as close to me. However it depends on how many I need of a particular item. Some items are worth buying bulk, others not. But they do sell some items (O-rings for example) in small quantities (even singles). So it's different for each need. Another thing I find odd is the selection of sizes they carry; in certain items they may not have a lot of SAE sizes while in other items not a lot of metric sizes. I'm sure it has to do with demand, but often it seems counter intuitive.
If you don't need something any time soon there are great deals to be found online also.

I still need to go check what I already bought for those trans seals.
 
Yeah, you can buy most anything online. My source is great because I can walk in with an odd seal and they can usually match it on the spot. Way easier than trying to make detailed measurements and hope I got it right. I bought enough o-rings to keep me stocked for pretty much ever. I didn't want to have to go back and I wanted to make it as worth while as I could to sell me stuff direct.

They likely don't make enough money off me to make it worth their time but they are nice and always take time to find the stuff I need. So I order as much as I think I would ever need. Or in the case of axle seals, all they had in stock at the time.
 
Ya, the people at the place out here are really nice also...despite me being such a small buyer overall.

By the way I just checked, I got all the right seals. After thinking about it I remembered that I ordered these by part number, not by dimension.
 
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I would add to check the axle bolt torque after a few miles. I made the mistake of torquing the bolts with the CV surfaces not clean and it resulted in working loose after a few miles. Lost the driver's side shaft at low speed and thankfully it didnt destroy the transmission.
 
Conda said:
I would add to check the axle bolt torque after a few miles. I made the mistake of torquing the bolts with the CV surfaces not clean and it resulted in working loose after a few miles. Lost the driver's side shaft at low speed and thankfully it didnt destroy the transmission.
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Yes, that seems to be a problem specially when going +180 hp. I'll try to keep the threads clean and use Locktite. Not an easy job as the CV joints are greasy.
New shaft seals ordered and on its way from UK. I am looking forward to have the new UT engine in place.
 
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