FancyFarmSS

iTrader: (5)

I installed a new rear main seal over the weekend during my clutch install. I noticed at the time that I had ever so slightly nicked the crankshaft during removal, but it was very small, so I didn't think too much about it (sorry, no pictures). Best I can do is say it's about 1/2-3/4 the length of the letter "l" on my screen, and about the same width. Didn't seem to be very deep, but then again, I don't know how much is too much.

The more I've thought about it, I wonder if I should have done anything about it? What are the chances of a very small nick like this causing leaks? And what can I do about it? I've heard of using crocus cloth. Luckily, the transmission is not installed yet, but I would have to take the bellhousing, clutch, and flywheel back off. What should I do?

mark21742

That's a hard call....is it where the seal rides, and do YOU think it will tear the new seal after running it for a while....I guess just go with your gut and if you feel it might cause a problem you could cut the edge five on it with a fine file, or cloth...but if you do mess with it, just touch it up, do not go hog wild on it and cause a divit

FancyFarmSS

iTrader: (5)

Hmm, where exactly does the seal ride? Do you mean the entire "polished" portion of the crankshaft? I would say the nick begins approximately 1/4" from the back part of the crankshaft (end where bolt holes are) and runs straight back. All I did to check for leaks is idle it for 2-3 minutes with the flywheel on, then removed flywheel and it was dry. But I guess this doesn't mean it won't cause problems down the road.

mark21742

The seal rides on the outer rim of the crank...should have been a slightly more shiny ring around this area....if you nicked it behind that area you will be fine.

FancyFarmSS

iTrader: (5)

Don't recall seeing a more shiny area, but wasn't really looking for one either. So is the entire width of the seal not involved in the sealing process? How far in (towards the engine) from the outer rim would you say the seal rides? If it's somewhere between the rim (beginning where it tapers up) and the 1/4" mark, I might be OK. Does it make any difference that I installed the reverse lip (newer) style seal?

gMAG

iTrader: (1)

I'm looking at a new, uninstalled seal-GM89060436
The inner ring, or sealing surface on the seal is a bit over 3/16 in width. Within the 3/16", it has 4 or 5 concentric rubber ribs, and is coated with grease. The inner ring is cone-shaped>>>the inner diameter of the inner ring is less than the outer diameter.
The cone shape gives the seal a tighter grip toward the outer (outside) edge of the 3/16, but it looks like the entire 3/16" does participate in the seal after the seal is installed. When the seal is installed, the cone shape will now conform to the shape of the shaft.

FancyFarmSS

iTrader: (5)

If I do decide to go back in and very gently polish the nick, what should I use? Crocus cloth (I guess it comes in different grits like sandpaper?), extremely fine wet/dry sandpaper (I think I've got some 2000 grit)...What can I use on the crankshaft sealing surface that definitely won't make the problem worse?

Also, I read somewhere somebody recommended putting a little JB weld in the nick, let it harden, then polish that down. How does that sound?

redtail2426

iTrader: (10)

yeah use some 2000 grit wet and just take off the raised part of the nick.If its large enough to hold some jb weld than do that first

gMAG

iTrader: (1)

I've used a dremel with 1/2" polishing wheel & polishing compound.