Best way to pull a rear main seal on a 78

[lvacordian]

I'm in the process of replacing my clutch assembly and am also changing over my rear main seal since it appears to be leaking. This is my first time trying this and I have to say that I’ve appreciated the wealth of knowledge available to me via this forum since I couldn’t have come this far without any of this…

I’ve seen many threads about the different type’s rear seals as it relates to the earlier 70mm and later 74mm shafts, but I’m not finding any threads describing what the exact process is for pulling the old seal and installing a new one; suffice to say I’m already as far as having my flywheel off. I have a seal puller that I’m terrified of using it because I’m thinking I’ll likely gouge either the shaft or seal carrier’s surface and create an even bigger problem.

FIAT’s factory worship manual indicates that the seal carrier has to be off in order to install the rear main seal and so I’d like to know if this is the only way to replace the rear main seal. No doubt it’s probably the proper way, but it seems to be more work with all the gaskets. This is especially true since one would have to replace both the oil pan gasket and seal carrier gasket; please correct me if I’m wrong about that.

My last question is about “dressing” a flywheel with emory paper. Does anyone have any ideas on what that is? It sounds like it means to sand where the friction plate comes in contact with the flywheel, but then again sanding a flywheel sounds wrong.

[131]

Getting the seal out with the tool is quite easy, but as you say, be aware not to damage the crank end or seal carrier. I've always just popped them out with a screwdriver, it sounds easy, but again, beware of causing damage. I clean up the end of the crank, apply a light smear of oil, clean the carrier surface, apply sealant to the outside rim of the seal, fit the seal over the end of the crank and tap around the outer rim evenly with a small hammer until it sits flush with the carrier edge.
If you're replacing the clutch, get the flywheel machined, no ifs or buts.

[majicwrench]

Seal will came out like was said above by wedging a screwdriver in it and prying.
Damaging the crank surface is bad, damaging the outer seal carrier surface not a big deal.

Gonna disagree, no need to surface flywheel unless it is well gouged. Did clutch work reasonable well before with no serious chatter?
Every time you machine something like a flywheel or a head you start messing with the way things work. Who knows if it's been machined before?? Maybe twice?? Three times?? How much material has been removed?? A clutch is released by just a few thousands of clearance tween the disc, the plate, and the flywheel. Do you wish to start deviating from the design dimensions??

I've been a professional mechanic for over 35 years now, doing everything. Don't get to do a lot of clutch jobs, maybe 4-5 in an average year. Bet it has been at least 20 years since I have resurfaced a flywheel.
YMMV
Keith

[131]

It's a pain to have to pull a box out again if you have a clutch issue, not machining the flywheel is often a cause. If you go back to a vendor about clutch issues with a new clutch, the first thing they'll ask is if the flywheel was machined. Skimming a flywheel doesn't take much off it and it's cheap insurance to avoid problems.