Technical Gearbox Bellhousing Oil Seal

[Vitesse]

Does anyone know how to get to the oil seal on the bell-housing that the main shaft goes through. It is accessed from the clutch side of the bell-housing rather that the gearbox side and sits behind the mount that the thrust/release bearing slides along. There is a 10mm bolt that holds the mount to the bell-housing, do you then just prise the mount off to get to the oil seal?

See picture below.

 

[fiat500]

KNO_8563 by peterthompson, on Flickr

KNO_8596 by peterthompson, on Flickr

I found it quite tricky to lever and wiggle that housing out. Then I think I gathered some handy old screwdrivers and drifts and and levered and whacked the seal out whilst gently supported on the vice facing down.. It's all a bit hazy in memory now but you have to get at it from the inside of the housing.

Thinking about it, I think you can lever the seal out easy enough once the part is off. It would be the bronze bush I struggled with. That was a waste of time because the new one was a looser fit on the shaft than the original; so I replaced it after all that effort.

PS. I may have had to take the input shaft off which isn't hard to do. Use the input shaft, if it is off, to align the clutch perfectly on the flywheel.

 

[Vitesse]

So are you saying Peter to knock the housing off from the gearbox side using an old screw driver through the hole where the shaft sits. I don't want to touch the bush if I can help it? There doesn't seem to be a lot of purchase on the bell-housing side to get a screw driver behind it.

 

[fiat500]

Now you're asking!!!
I should know it as it was only about a year ago, but you know what it's like with age etc. (or maybe you don't).
The more I think about it the less clearly I remember what I did.
I don't know how I got the housing started to move because it is a really tight fit, it must have involved some very careful tapping. I may have used the hooked end of tyre levers to apply equal pressure to lever against the gearbox casing once I had enough of a gap to insert them.

I think that because the bush obscures access to the seal both items had to come out. In fact I'm not sure what I'm seeing on your photo but the arrangement seems a little different from mine. Is that the seal in the very end of the tube You can see on mine that whole length of tube has an internal diameter almost the same as the shaft and you wouldn't see the seal from that angle.

We need an expert here. Come back Mr. Hobbler.

 

[Vitesse]

The bronze bush sits at the very end of the tube in my picture and then the oil seal sits just in front of the mount that the input shaft goes through.

I took the easy way out. I had a few taps try to lever it out from the gearbox size but as I suspected there wasn't any leverage. As there was no sign of any oil leaks on that seal, I decided to leave it with the original seal in place.

If I had attempted to knock the mount out using a screw driver from the gearbox side I would have probably ended up destroying the oils seal and if I couldn't get the mount out I would have been stuffed. I can't see this being a major oil leak problem as any oil has to get passed the bush and the seal first. It's much more likely to leak out via the driveshafts.

 

[fiat500]

Sensible man; discretion being the better part of valour and all that... Also, I think that tiny hole is a return weep hole to encourage any oil that gets in there to drain back.

 

[Vitesse]

I used your tip on removing the input shaft to align the clutch. It did take a bit of working out where the little pin was behind the clip. It is already to go back together now. I just need to pimp the tin work.

 

[nzbobc]

Sorry for the late addition to this post. I know that you decided not to remove yours Tony, but if I can add to this thread for folks that may be facing this in the future:

First, Sean mentioned how he removed the seal in a concurrent thread:
https://www.fiatforum.com/500-classic/345169-franko-1971-500l-18.html?p=4028356

I was able to knock the seal housing off of the gearbox from the inside as Peter mentioned but it took some doing as RTV or similar product had been used to seal between the two.

I read elsewhere that rather than remove the seal from the housing, it's easier to just replace the whole unit (housing, seal, and bushing). But, I had the bushing and seal in hand...

Similar to Sean, I was able to just knock the bushing out with a drift pin but struggled with the seal. In the first photo, the metal ring of the oil seal sits down against a flange in the bushing. I tried to use a small drift pin inserted in hole highlighted in red to push the seal out from the other side (Second photo). But, the seal was in solid and the edge of the metal ring just bent. Unfortunately, the hole doesn't line up with the outer edge of the seal either so, when pounding on it, the metal ring just bends. But, by bending it, it created a void between the metal ring and the housing that I was able to get an "L" shaped hook in between the two and by simply prying in the four quadrants of the seal, I was able to get it out fairly easily. In the first photo, the metal ring of the old seal in on the right-hand side of the photo. This is what you're up against.