This old thread gives the best advice:

https://www.rx7club.com/1st-gen-archive-71/drivetrain-replacing-rear-wheel-bearings-557114/

Two nights ago I was prepping a pair of used axles to put in my road racer by replacing the bearings, and changing the retaining plates from the 4 bolt drum to 3 bolt disc style.

I have a 20 ton hydraulic press that I use to change out bearings. Instead of following the advice in the above mentioned thread, I tried pressing the old bearings off (which has worked fine the previous 8 times I have replaced bearings.) However this time, the old collars did not want to move, and the outer race of the old bearings cracked and fragged. When 40,000 pounds of force moves a light weight steel part suddently, it picks up high velocity in a hurry. Two pieces of outer race frag grazed my fore head. Fortunately, my skull was harder than the bearing races, and only the skin was cut Pretty stupid on my part. From now on, I will cut the old collars off with a cutoff wheel.

 

are these the bearings that go bad at hum at like 45mph??

 

That hum is usually caused by bad u-joints.

 

If it increases in frequency the faster you go then it is a wheel bearing.

 

yes it increases in frequency the faster i go... but as soon as i let go of the gas it stops... then starts up again once i give it gas

 

i had that same problem once and i could never figure it out.
when the rust finally got too bad i parted it out. when i pulled the diff out it was missing some teeth on the ring gear.

 

PR84REX ---------- Your diff most likely needs adjusted/repaired with that sound

Max

 

you think so?? everything is fine when i drive... and the lsd seems to be working great also....

 

Yes, the sound you are describing is almost certainly coming from the differential. Either the rear pinion bearing is wearing out or there has been enough wear between the ring and pinion gears that the contact pattern between the ring and pinion gear teeth is no longer correct under load. The good news is that if the sound has come on gradually over a long period of time, the differential will likely continue to run for a long time in it's noisy condition. It wouldn't be a bad idea to change the dope in it...now!

 

i had a similar problem and it was the carrier bearings in the diff

 

Getting back to the problem of getting axle bearings off, the method I use is to get a cold chisel and a hammer and hit the locking collar in about 1/2 dozen places around the collar, maybe even some times in the same spot. You need to make sure that the ring is supported underneath by a block of steel or something that wont break when you hit the ring with force, normally the back of a vice is a good height to use. I have seen the collars crack after being hit which makes them a heap easier to get off but even if they dont crack they will generally come off when pressed with the bearing a lot easier. I have found that if I dont have a cold chisel and hit the collars with something not as good the outer race of the bearing does shatter.

Whether I have a cold chisel or not, I also learnt a lesson and now wrap a rag or cloth around the bearing when pressing it off.

That's how I do it anyway.

 

You do know that it's an Rx7club duty, to post pictures of Rotary inflicted wounds