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Rear Bearing Removal

I had a Thunder Tiger 40 with a rear bearing that just would not come out. I did a search of this newsgroup. After looking through a lot of threads that end at "heat in oven and the bearing should come out when you bang the case on a piece of wood", I came across a thread in Sept

15, 2002 with some more agressive techniques. Although I wasn't ready to heat the case with a torch or cut the bearing with a dremel tool, there was a suggestion from Fred McClellan that did the trick. He suggested heating the case in an oven and then chilling the bearing with a quick spray of Brakleen auto brake cleaner (I used STP). I tried it and the bearing popped out on the second bang.

Thanks Fred, Bert

Reply to
Bert
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I had a Thunder Tiger 40 with a rear bearing that just would not come out. I did a search of this newsgroup. After looking through a lot of threads that end at "heat in oven and the bearing should come out when you bang the case on a piece of wood", I came across a thread in Sept

15, 2002 with some more agressive techniques. Although I wasn't ready to heat the case with a torch or cut the bearing with a dremel tool, there was a suggestion from Fred McClellan that did the trick. He suggested heating the case in an oven and then chilling the bearing with a quick spray of Brakleen auto brake cleaner (I used STP). I tried it and the bearing popped out on the second bang.

Thanks Fred, Bert

Reply to
Bert

Good ole Fred comes to the rescue again!

Reply to
Paul McIntosh

I often use a piece of wooden dowel, either slighltly tapered, or padded out with a bit of masking tape, to form a slight interference fit in the inner bore.

Heat the crankcase gently with a gas torch whilst pulling gently on the dowel - works every time for me.

CW

Reply to
C W

CAUTION! Never heat the case with a torch because you you cannot accurately control the heat distribution and this will cause warpage of the casting. And the result in many engines will be premature wearing of the bearings, piston, or liner. Use the oven(20min@300). Torches are for welding, soldering, and heatin' coffee.

PHIL AMA609

C W wrote:

Reply to
pcoopy

I wholeheartedly agree with that. Also, heating the castings above 350 F can cause irreversable changes in the castings.

Reply to
Paul McIntosh

Well I guess I must have 7-8 engines with warped crankcases over a 27 year period then - I don't really think so..... they all run fine, and the bearings, crank and liners/pistons have shown no subsequent problems.

Keep the flame low, and move it all over the case so the main heating is actually `hot air'. A paint stripper type heat gun might work for looser fits. By pulling on the bearing witha a dowel it releases the moment the crankcase is hot enough - ie no overheating.

The problem with the `Tapping' method is if the bearing comes out partially through gunge and gets stuck on the skew. Then if the crankcase cools as you try to remove the stuck/skewed bearing it really does get distorted !

You pays your money and takes your choice.

CW

Reply to
C W

Boy I guess ya can't tell you newbies nuthin'. LOL

Phil AMA609

C W wrote:

Reply to
pcoopy

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