Is the rear bearing preload on a 75 determined by the spacer on the spindle??

 

No preload is used on the bearings. The end-play is set by shim selection. 100lb/ft. torque is applied to the nut to maintain integrity of the assembly.

 

OK, is the spacer you refer to on the spindle in the center of the bearings??

 

Yes. You have an inner and an outer bearing. The distance they are held apart is determined by spacers. This sets the free play in the bearing assembly. It should be at only .001 or .002 even though the factory says it can be up to .008

 

OK, why is everyone saying that onece you take the bearings out you need to replace them?? I have the proper tools and mine came right out, can I just grease them and put them back together or what?? the bearings have 38,000 original miles on them, I've had bearings in my other cars well over 150,000 miles and just keep greasing them.

 

The bearings are pressed fit on the spindle and usually require about 20 tons of force to remove. If properly setup the bearings should go 100k miles without greasing. The bearings cost about $30 per side,replace them.

As Norval said,the end-play and rotor runout are the important things to check. You need a setup tool that is slip fit and several spacers or access to a surface grinder to fit the spacer,not the reducing sleeve, to get the .001-.002" fit. This must be done dry fit and the spindle torqued to 100 ft/lbs.
I will be rebuilding a set of trailing arms this week. I can take some pictures to show I do the job if that helps.
Gary

 

my thing is... I got these apart with no problem with the proper tools, I have the press and the proper fixture, the bearings seem fine, they are factory, should I just greese them and put them back together with the factory spacers for preload?? This car sat for 7 years.

 

No do not re-use the original bearings. Buy new Timkens,seals and set up the end play & runout to under .002"
Gary

 

Gary Id be very interested to see your trailing arm rebuild if its not too much trouble. Im waiting to hear from Van Steel so I can order a pair of offest arms and a bunch of rear end parts. The more info I have on building the arms the better.
Thanks in advance for any help.

 

ttt

 

I still don't get it

 

[QUOTE=gtr1999]bearings The bearings cost about $30 per side so if you were able to remove them without wrecking them it's not worth it to replace them.


??? then why not use them over??

 

Even with the right tools, when you remove the bearings, you use the rollers & seats as "pressure points" The bearings were not designed to be used as "pressure points".... i.e.- pressure is applied directly on the rollers & seats/cage in the removal process. These procedures make re-use of the bearings questionable due to potential unseen damage. Because the job is so involved, it's considered a "wise" move to replace the bearings instead of re-using them. Except for any obvious cage deformation, you really do not not know if you damaged the bearings or not by a visual inspection.... ergo... replace them. In a shop that does this work professionally and guarantees the work, there is no question....they are replaced. Done in your own garage, to your own car, you can try reusing them, but you are playing the odds. Your time has to be worth something if you have to tear it all down again.

By the way... the "assembly" tools that "pull" the assembly together also place stress on the bearings & seats.... I do not use them... I press only on the INNER races of the bearings and never stress the rollers/seats/cages during the assembly process.

 

the tools I have don't put ANY pressure on the rollers, you can still spin the bearing freely while your pulling it off!! I don't get it?? I've repacked bearings on cars with over 200,000 miles on them, I've never seen a bearing go bad unless it ran out of grease. I know they're cheap enough, I'm just trying to find out why people say they can't be repacked.
Thanks guys.

 

"you can still spin the bearing freely while your pulling it off"

You cannot disassemble the rear wheel bearings without exerting pressure on the rollers/seats.... just because it still spins while you are removing it does not mean you aren't putting pressure on it or damaging it.

Disassembly begins by removing the spindle nut, washer & flange.
At this point, the end of the spindle is exposed, along with the inner bearing.

Next, you need to
a) press on the threaded spindle to push it out of the spindle support -or-
b) pull on the spindle flange to pull the spindle out of the support.

Either way you do it, you MUST exert pressure on the inner bearing rollers & race to overcome the interference press fit between the inner-bearing inner-race on the spindle.

There is no other way..... unless you use a torch & cut it out.

The bearing inner race is pressed onto the spindle... to get it off, it is necessary to put pressure on the rollers & seat because there is no way to just grab a hold of the bearing inner race directly to pull it off the spindle. After the spindle is out, it is possible to rip the OUTER bearing apart (rollers & cage) and then pull the inner race off separately. Both bearings have the same issue.... you cannot grip the inner race to pull them off.

One exception.... if the spindle has previously been turned down for a "slip fit" on the inner bearing... it just slides off... no tools needed.
My C2 is set up this way.
My C3 is not.

 

If your putting the pressure on the center of the bearing how is it putting pressure on the rollers or the cage, if the pressure was on the rollers, how would it be able to spin?? If what you say was the case, you would destroy them putting them back in because the pressure used to put them in is applied in the same place on the bearing, the inner part...

 

When you push on the spindle, the spindle being a press fit to the inner race, it is pulling on the inner race. The reason it comes out is the outer race is hitting the hub and holding it there. The outer race is stopped and the inner race want to go with the spindle.

When you assemble it your only pressing on the inner race which is the press fit part, before the outer race bottoms out to the hub your clearance, spacer and bushings stop it.The outer bearing is now bottomed out. But this bottom out is stricly from inner race to inner race.

For your other cars I doubt you regreased the rear bearings. These aren't front bearing sets we're talking about.

If you want, re-use them. At least change the seals. I think gtr1999 Is a typo. I took it that way.
For the amount of money spent replace them. I would take a hard look at the spindles too to make sure they aren't all crapped up. The press fit can score up the spindle. The bearing can also spin like my right side did.

 

OK, one final stupid question. If you dont have a setup tool, ow do you get the bearing off to change the shim for the correct runout? Wouldn't that destroy the bearing, and wouldn't a new one possibly different?

 

Thats what I don't get. You would have to throw them out every time..

 

Thanks Techno, you are correct I did not type was I was thinking
I have edited the post. Bottom line, replace the bearings when doing this job.
The setup tool is ground undersize so the new bearings will slip on and off without any force.

Gary