Best Bearing/Bushing Installation Practices...

[blaat!]

Of course the cases are heated and the bearing or bushing is frozen, but do you press your bearings in with an arbor press or tap them in with a hammer and wood block?

[Jordan]

As the other side isn't flat, it'd be hard to properly set up to press in I think.
With care, the hammer method should be OK, maybe with a double diameter drift to have a better chance of the bush going in straight.
I'm slowly becoming more of a Loctite user - no interference fits needed, simplifies fitting.
When I make a bush with my amateur skills, I aim for the correct press fit, but use Loctite if I made it a bit small!

[double diamond]

I always have the press set up with the proper size tool to press the outer race of the bearing. Lubricate the bearing bore or you run the risk of galling the bore. Usually the frozen bearing will simply drop in by keeping it square with the bore. If the bearing starts to transfer heat and expand, you're ready to press it in the rest of the way. Keeping the bearing square in the bore is paramount. Bushings or valve guides require a shouldered drift; they're usually so thin/soft they mushroom easily as well as being difficult to keep square with the bore. I've made a plate that's drilled and tapped for 6mm allens in the same pattern as the bolt holes on side covers. Then you run different length allens in to support the case on the heads of the allens in the countersunk holes. Level the case with a bubble level across the gasket surface so you can press the bushing in square. BTW, don't remove the outer bearing race for the 1st gear/roller bearing on the countershaft (5-speed and late 4-speed) if you can avoid it. These are usually staked into the case and you'll get little chips out of the case if you press the race out. Be sure to dry the bearings with compressed air after instalation. Condensation will form on the bearings as they warm up and lead to rust if not dried and lubricated immediately.

[Jordan]

The special plate with adjustable supports is an interesting idea, probably more secure than using 3 or 4 screw jacks.
You must be doing a fair number of engines.

[blaat!]

I'm just about to pick up an arbor press to reinstall my bearings and bushings. I'm planning to buy the smallest one I can that will still fit the engine cases and have enough force. Amazon has a Jet brand one ton for $99 including shipping and a two ton for $189 including shipping. Seems like the force of the one ton will be plenty as I'll be heating the cases and freezing the bearings. The (throat) depth is 5" on the small one and 7-3/8" on the larger. Of course larger is better, but it is not a tool I will use often and I would rather save the money and storage space if possible. I have been looking used for a couple months and everything I come across is either too large for my needs or the same price as new. Anybody have recommendations?
Thanks!
-Jim

[wcorey]

Have you checked out Harbor Freight? They have a smallish 6 ton for $65, not sure if the dimensional capacity is ample enough though. Their stores literally surround you, Danvers, Braintree and Natick...


Bill

[blaat!]

Good suggestion, but I've stopped buying from Harbor Freight. I've had two bad experiences with their tools failing. The last time was three 12 ton bottle jacks I bought to straighten a house frame. The seals leaked on all three and I was past the return period by the time I got around to using them.

I think a mechanical press might give me a better feel for how much force I'm putting on the assembly, but it may just be that I don't have much experience using hydraulic presses. I know they can generate a rediculous amount of force depending on the tonnage.