jackshaft bearings

[sevenmilebridge]

Does anyone have any ideas on removing and replacing the jackshaft bearings or do I have to get a machinist to do it

[Habitat.pat]

I’ve always had the machinist do it, it requires a special tool.

Peace,,
Pat

[Gregs672000]

I know this sounds crazy, but unless those bearings are showing clear wear, they don't always need to be replaced. Per my previous very thorough engine guy, they are not under a lot of load ever. While I did go ahead and have them replaced in this last engine as it was at the machine shop for a bore and hone anyway (different block than before), I'm confident the previous motor saw at least 300k miles over 34 years, some years of daily driving. Your mileage may vary as they say, but for what it's worth I think their replacement CAN be optional.

[Habitat.pat]

Greg,
I agree up to a point. In the “older days”, when everything was hot vatted, the acid was guaranteed to kill the bearings. Since hot vats are now few & far between, the bearings are much more likely to still be good, but personally, I’d rather pay an extra $75 for bearings & installation than have to pull the engine again & do a rebuild because a reused bearing let go.

I’m finally getting ready to reassemble my engine & will be checking with tool lenders/renters to see I can find the tool set so I can install the bearings myself. It’s not that difficult to do.

Peace,
Pat

[Gregs672000]

Agreed, it was more of an option in case he was worried that they had not been done, or that it would be a special trip to the shop only for the bearings. Of course, new is (almost) always better!

[redroadster]

The Babbitt type bearings are pulled in by a bolt fixture or a driver and mallet like doing cam bearings in the car
This usually mushrooms them a bit so then a adjustable 5-6 blade cutter is used to mill back even ... I'd bet it's hard to rent though

[SLOroadster]

The front jackshaft bearing does see a lot of load. The two times I've rebuilt my engine, the first one has shown a lot of wear, the other two, looked better. It might have something to do with running a higher lift cam, and stronger valve springs, and turning it faster than most people do. Still, they aren't that expensive, and why take the risk of reusing them when everything is apart anyway? That front bearing does see a lot of sheer load from the timing components.

Will

[johnscf]

is there anything unique about the bearings that makes it better if you get them for the shop or are they something any machine shop will be able to source. i’m sure the place that has my block has probably never done a roadster,

[sevenmilebridge]

Well I just bit the bullet and had the machine shop do it had a local guy that had the right tools just took a few minuets to do.

[redroadster]

Heck You've won the lottery if you can find a machine shop that isn't swamped with diesel fleet work $$$$ $
and will be interested in your tiny $ project