Leak...leak...leak...

After repairing my diff (hopefully for the last time) I've had a gear lube leak coming out the bottom of the bell housing. At first I thought it was the O rings on the bottom of the bell housing around quill shaft and "lube transfer tube" that go through the rear gearbox cover. It wasn't. Then, I thought maybe the RTV I used on the back gearbox cover didn't cure correctly. That wasn't it. Then, I saw the culprit. The input shaft seal was leaking pretty bad. I removed the throw out bearing and replaced the seal with a Timken that cross referenced to the seal I had. The O ring around the outside of the TO housing looked good. Since I couldn't find a replacement for that O ring locally, I just coated it with a little RTV to be safe. I reassembled and drove it. No more leak. I drove it again the next day and for the entire drive, no leak. Then I got home. gush. coming from the same spot.

Any ideas why this failed after about 20 miles? I think I'm gonna have to order the F seal and O ring to be sure.

I know I replaced this seal about 13 years ago. It was a National seal made in Mexico. And for 13 years it worked.


Crap!!! I can't drive it...STILL.... because the gear lube will turn my dry clutch into a wet clutch that should be a dry clutch.

 

Doing an engine rebuild on one that just had a clutch done along with a new input shaft seal elsewhere. It was pouring gear oil out at an alarming rate and here's what I found.
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After a clutch change I also had a drip out of the bottom of the bell housing. I bought a complete set of o rings form vendor 'X'. The next set of rings I bought from Recambi. There was a visual difference between some of the rings. 16 months later, no leaks. The seals that were different were: #24 (times 2) and #25 were different. Seal # 28 was super stiff from the fist batch, but slid like butter from Recambi. IIRC your car is an earlier TR and does not have this seal.

Im going off of the diagram below.

CLUTCH CONTROLS (STARTING FROM CAR NO. 80095 - 80146 CH - 80177 US) - Ricambi America, Inc.

I also put gasket maker on the clutch housing around o rings #50 and #10. I hear after the fact it was not necessary. I was also REALLY careful installing seal number #26.

Hope this helps.

Christian

 

Wow Paul! Are you sure that seal is bad? Looks reusable.

 

Maybe this is one of those times when the rule "You get what you pay for" is true. The seal I bought was $5. Ricambi wants $47?!? Really?? It's just a seal!

 

On a slightly unrelated area, I would also add caution on OEM #21 (139440) which has some bad batches. The rings were a little too small and failed after a couple of cycles, requiring a further two attempts to get it right. Hill Engineering produces good quality alternatives which are also cheaper. Mine has been running on their seal for 4000 miles with no issues.

 

It's perfectly reusable but as a precaution I applied 2 tubes of orange silicone for added insurance.

 

Dang....
you should have used Hylomar!!!
problems await

 

Now you tell me!

 

I thought the same thing trying to save a few bucks. But when I had to redo it after visually inspecting the O rings, all I could think was, 'Hey dummy, at least you saved XXX.'

 

Paul, I can now relate to your picture very well. I ordered the $45 seal from Truts and it's different enough in I.D. dimension from the $5 Timken seal to suspect it was the culprit. I'm surprised that original $5 seal I've had in there lasted so many years. A brand new Timken seal with the same spec'd dimensions as the F seal is actually about .3mm larger I.D.

Anyway, the F seal is so much smaller that I managed to pinch it during installation. Another $50 gone poof because I didn't think to rotate the shaft while sliding it in place.

But when I pulled it back off, I could see how someone could easily have installed it that way and instantly shredded it upon first start up. How your previous clutch installer guy didn't see the instant flood of gear lube dripping out the bottom of the bell housing after he drove it is a bit concerning...

Fortunately, while reassembling, I couldn't get the input shaft to mate with the clutch disks. That led me to a bound up input shaft which led me to the seal folded over, probably looking like yours did before it was driven. I hadn't trashed the rubber part of the seal yet, just the spring. If I had driven it, it would have looked just like yours for sure. And I would have probably driven the F'ing car into the Pacific out of frustration.

So, Truts here I come again.

And, anybody have any tricks for making sure that seal slides over the input shaft correctly when reinstalling?

 

put a liitle grease on the seal, that always works fine

 

Scott, was the ferrari seal damaged? I have put in cam seals where it twisted on itself during installation (not an f-car) and didn't slide correectly, and just straightened out the seal and did it again with no issues. The seal was still fine.


Did your seal get cut? I understand not wanting to use it "just in case." But it might be ok unless its obviously deformed...

 

Very little taper on the shaft and seal damage is very common. Best method is to pull the shaft and install seal housing and shaft as a unit.

The original seals seldom leak. The problems start when it is replaced just because or when a leak in the bell housing is misdiagnosed. 90% of clutch shaft seals I have replaced are to replace damaged replacement seals.

 

Why are the replacement seals getting damaged?

Poor install technique? Installed off kilter?

What happens if someone doesn't oil the shaft when they slide it on? Does it self lubricate within a couple rotations, or does the seal burn up? Someone mentioned grease, could that hurt the seal?

Bo

 

Gets caught on the edge of the shaft during install and folds the lip over.

 

Personally, I lightly fill the seals (like cam seals and presumably like #26) on their backsides and especially fill the mating surface of the seal with a synthetic grease like the one shown below.

Is this seal a candidate for the cam seal 'business card' mounting technique? Any downside or other complications when pulling the shaft per Rifledriver?

Life Is Good,
Vincenzo
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grease...
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Seal is being installed blind behind a housing. There is no way to use a shim to guide the lip over the step on the shaft with the shaft installed. Down side? I don't know, they did it that way in Maranello when they built them. Ask the factory guys if there is a downside.

I never touch them unless they are leaking and that almost never happens.

 

That makes it easy to understand the problematic installations (blind side)... thanks for the clarification!

Life Is Good,
vincenzo

 

Why not just use a smidge of loctite anaerobic sealer around the outside of the seal? Granted, that makes it a bit tougher to get out next time....

 

I've installed thousands of seals in my life. When you can see it, it's easy. When it's blind, it's a crap shoot. I'd never be stupid enough to install it dry. I lubed the shaft and the seal with gear lube. It pinched and crushed the spring. The rubber is OK but the spring is trash.

Brian's idea sounds best. I guess it can't be too hard to remove the input shaft from the drop gears.....I hope!

 

I usually oil any oil seal when I put it in... makes sense to me...

Interestingly, Victor Reinz (manufacturer) says that some seals should be put in DRY. They also say that using grease to install damages the seal. They seem to be reffering to seals with PTFE edge? I have no idea what kind of edge ferrari seals have. I assume ferrari just uses regular rubber seals?

They also say the seals are designed to have a 1 micron gap to the cam. So technically, they aren't really touching... I assume again that this gap occurs through the initial engine rotations rubbing on the seal. I fid it hard to believe a 1 micron gap can be made via the manufacturing process....

Any one know?

Oil Seals - VICTOR REINZ

Another philosophical question. If the oil seal isn't really touching the cam, it should never - in theory - wear...

 

Gotta love Trutlands. They always treat me well. Dave sent me 2 seals overnight just in case I do it again. He had pity on me so he's charging me cost. Thanks Dave!!!!!

 

Hey Brian. Can you give me quick instruct on removing that input shaft from the drop gears?