Removing old rubber grommet/seal from aluminum

[hannibal]

As I am reassembling my engine, I decided to replace the kick starter shaft grommet/seal in the clutch cover. I thought I could just pop out the old one and install the new one. But the old grommet is frozen onto the aluminum cover. In hindsight, I should have re-used to old grommet as I had no leaks from it. But since I already tore it trying to get it out, I have to finish removing it. Due to its shape and location, I have no more mechanical options (razor, thin screwdriver, or even a pin can't get into the area where the hardened grommet sits).

I did some googling and found two general options: using chemicals to eat away at it or a flame to melt/burn it. I just bought some acetone and a propane torch. I'm really scared of using heat to melt it even though I've read several suggestions about it. The guy at the auto repair shop up the street suggested too and he's helped me out with random things in the past so I trust his opinion.

What would you guys suggest to remove this 40 year old rubber grommet without harming the cover?

 

[Rijko]

Heat is a very effective tool and does no damage if applied carefully.

I used to force oil seals from front fork legs, making marks on the outer
rings and bending screwdrivers or using pry bars in the process.
Lots of force.

I discovered a few seconds of a small torch applied to the seals makes them real
supple and i can remove them with the smallest screwdriver with ease.

So i would prefer heat over chemicals.

But since it's real easy to remove the clutch cover and a new gasket is cheap,
why would you not go that way ?
That would make removing the old seal and installing the new one a simple job.

 

[bwringer]

I seem to dimly recall that the seal installs from the back; you have to remove the clutch cover to replace the seal.

However, that's a vague and unreliable memory from long, long ago. Apologies in advance if that is incorrect or doesn't explain your trouble...

 

[hannibal]

Still struggling with this. I've tried heat several times and was able to scrape more of the old grommet out but what remains is like petrified rubber.

I gave it one more shot this evening. I'm ready to spend the money on a used one on Ebay. Here's pic of what I'm dealing with.



And a link to the only cover I could on Ebay without the grommet.
http://m.ebay.com/itm/77-78-SUZUKI-...%3Ac92cedc415d0a88f52e705e7ffff91d3%7Ciid%3A1

Looks to me like he Dremeled out that dark colored ridge you can see in my pic. Or is that supposed to come out? I haven't try to pull the ridge out with a needle nose. Any thoughts?

 

[Rijko]

if you place the new seal on top of the old one, does it fit inside that ridge ?
Using a small screwdriver and drive it into the old seal, can you deform it so it bends inwards ?

 

[hannibal]

Inside the ridge is tremendously thin. Can't fit a razor in there since it's so thin and curved. I've been using a push pin to scrape the old gasket away. I'm going try to pull that ridge out but 99% sure it's part if the cover.

With the 1 exception I posted above, every clutch cover I've seen on Ebay has the old grommet installed. Leads me to believe I should have never touched it. Haven't seen a person on the forum who's replaced it.

Forgot the pic. New gasket sitting where it should go once the old one is gone.

 

[Rijko]

sorry for my earlier post making it sound easy to remove, but i did replace one decades ago and it was so unimpressively easy to do i forgot how i did it. I was lucky.
Maybe your old seal rotted to the cover, po superglued it, it seems yours is badly stuck.

Looking at the pic, the new seal cannot be fitted with the ridge in place.
Is that ridge made of aluminium ?
If the ridge is that thin and curved, it cannot be part of the aluminium clutch cover.
It looks like it is the metal body part of the old oil seal and should come out.
If you can scrape rubber from the seal and uncover more of the ridge, that confirms it. Looks like the bottom of the seal still has rubber on the ridge.

Maybe using a large screwdriver you can drive it out by going in through the tunnel and tapping it outwards.
Cover upside down on the workbench, supported by wood so the seal has room to come out. Extra pair of hands to hold the cover. Use a big flat tip, a small screwdriver will go through the ridge and shear it off.
Drive the tip through the rubber so you hit the ridge properly, tap it a few times, move the tip half an inch and repeat. Circle the ridge that way and hopefully it comes out.
I think that's how i did it back then.

 

[hannibal]

I think the ridge is supppsed to be there. The seal is U shaped in profile and I believe it goes in with the U shape facing toward the motor and sits over the ridge. With that said, the only pic of the cover that I've seen with the seal has no ridge.

Also the new seal has a metallic ring in the bottom of the U. I'm beginning to think the ridge I described was part of the old seal and the metallic ring in the new seal replaces the old ridge. I've already butchered this cover trying to remove the old seal. I brought the cover with me to work today. Gonna try to remove that ring when I get some time.

There are some decent used covers on Ebay dor $20-30. At this point, I'm just gonna buy one and hope the seal is in decent shape. I just wanna get back on the road.

 

[hannibal]

I am so freaking stupid. I just put together a motor from bare cases but couldn't figure out how to remove a rubber seal. One tap and the ridge fell out. Will post a pic in a moment. Thanks for talking me through it Rijko!

Canceling happy hour plans and putting my baby back together as soon as I get home!

 

[hannibal]

Pic. Can't believe I wasted 2 weeks on this!

 

[Rijko]

haha just see it as a learning experience, we have all been there.

Great you got it out !!

 

[Rijko]

oh, and you can use the old seal on top of the new one to gently tap it in, less chance of damaging the new seal that way.

And make the shaft and oil seal nice and wet with engine oil before mounting the cover back on. That prevents damage to the seal dry mounting sometimes causes.