Press-on or heat diff bearings?

[ASJT3]

Hey guys,

I grenaded the stock rear differential a few days ago (from the parts I removed, looks like the 8mm locking screw completely backed out, then the center pin flew out).

I bought a Detroit Trutrac to replace. I don't have an H-press, but I've seen people heat up the bearings and because of thermal expansion they can just drop them on. Do you guys see this as an acceptable method of putting the bearings on the diff?

-Alex

[gmtech1]

My opinion is no. If you don't have access to the proper pullers and installers, take the parts to a machine shop and have them do it.

[ASJT3]

Originally Posted by gmtech1

My opinion is no. If you don't have access to the proper pullers and installers, take the parts to a machine shop and have them do it.

Well the bearings and diff arrived today and I just couldn't help myself! I went ahead and cooked 'em at 450 for 20 minutes, and they dropped on pretty easily. They were pretty charred with burnt gear oil though, so I re-lubed and turned them to clean them up.

Hopefully this should be OK; incidentally one of my master chiefs told me they used to cook bearings on the ship to install them.

Thanks,

Alex

[Blue Bowtie]

I know this is a little late to the game, and I hope your axle is working well, but I use a bearing heater for almost all larger bearings. The better ones have a magnetic thermocouple to monitor temperature to prevent damage to plastic ball carriers, elastomer seals, and those shielded or sealed bearing packed with lubricant.

[DeltaP]

For reasons BBT mentions I usually wont pre heat bearings over 300-350' for a close interference fit. Probably not for sealed/shielded bearings. If that's not enough then you'd best have the pullers,press, (what I usually use), or a machine shop. I once put a shaft in the freezer and installed a bearing that way.

[j cAT]

Originally Posted by DeltaP

For reasons BBT mentions I usually wont pre heat bearings over 300-350' for a close interference fit. Much less for sealed/shielded bearings. If thats not enough then you'd best have the pullers,press, (what I usually use), or a machine shop.

shrink fit bearings I have done a few times. this is obviously with bearings designed to be heated . the ones I did was 400 deg f. used a electric stove with a thick piece of sheet metal and a temp gauge on the bearing. worked good. these had grease fittings in the housing ,so after install the bearings were greased.

the bearings came clean no grease...to be heated and make a mess..