I am now done with the VBP front suspension, and have th rear spring, smart struts, and brackets in, and have done the wheel bearings on the driver side rear with all new bearings and new spindles from Tom's. Here's the question.

I took everything apart and cleaned, sandblasted, painted, then put in my new races, then used the bearing setup tool with the housing on clamped in the vice to set up my bearings so that when I would pry up on the end of the setup tool I would get .001 play using my dial indicator. So I put in the outer bearing and seal, packed with grease, then I used the spindle installation tool to put the shims, innner bearing, and axle flange in and pull it all together. I got it together and it was hard to turn. Too hard for any wheel bearing I've ever seen. So I had to rip it apart again, and use a new outer seal and bearing because I had to use a bearing splitter to pull the bearing off of the spindle and I didn't want to use a bearing that was pulled on that hard again. I set it up again, this time on the car (same setup though) and used a shim that was .0025 thicker, which gave me play of about 3 to 3.5 thousandths. I put it back together and it's easier to turn, but still a little stiff. I am thinking it will loosen up a bit after being run, as most wheel bearings do, but what I want to know is what is the upper tolerance of the endplay on the bearing setup according to GM? I used Monty's paper and it says to go to .001", which has to be the lower tolerance, because that's getting right down there for any mechanics using any type of dial indicator. My guess is that it's supposed to be something like .001-.003 or .004 inch. Correct?

 

Here are the specs from the factory manual.

Front
http://temp.corvetteforum.net/c3/pau...earing_002.jpg

Rear
http://temp.corvetteforum.net/c3/pau...arings_002.jpg


[Modified by paul79, 9:29 AM 3/2/2003]


[Modified by paul79, 9:29 AM 3/2/2003]

 

Use Monty's numbers. The lower the slop back there, the better.

 

Justin,
I just read your post. You shouldn't have any binding in the bearings at all.
Here is how I set up my rear bearings:

Once disassembled and cleaned check all parts to see what needs to be replaced. I'll take it that everything is good except for the bearings.

Using the spindle set up tool make sure the new bearings are a slip fit- they
should be. Use the old spindle nut during setup. I use a new nut when rebuilding.
Install the new races,they're different for the inner/outer.
Use machine light spindle oil on the races,setup tool, and bearings. Do not use the seals at this point.
Install the setup tool,bearings,original shim, and spacer into the housing,install the washer and nut.
Torque the nut, while holding the tool, to 100 ft/lbs.
The spindle should rotate without binding.
Now mount an indicator to the spindle. This part is important,there can be no movement in the indicator otherwise your measurement will be off. I have a plate I made up,per the advice of Tom454 last year, that will allow the indicator and housing to be held tight. I can send you a picture of it if you like. I'm sure you'll be able to make one at your shop.
I like to take a reading before I start the rebuild to compare the difference in bearings. Trying to get the reading can be tricky too. According to the book you're supposed to apply froce in/out and check the indicator for movement.Well if you get 5 guys you'll have 5 different readings! You get a average strength guy vs a muscle man and you'll get different readings. So again be sure the indicator and housing don't move and apply force by hand. I experimented with this last year and it worked the best by hand. Also my fixture holds he setup tool in the vertical position which holds them in better alignment,this again is credited to Tom454.
When you get a accurate reading then you'll know how much shim you need. Usually, there's about .010" difference. I use a surface grinder to dial in the shim to the exact size I want to bring them in to .001" endplay. If you don't have use of a surface grinder,not a bench grinder, you'll have to use the shims to try and get them as close as possible.Some people have hand lapped the shims to fit. You can try this too but be sure you have the shim on a flat surface.
You should try to keep the end play under.003" the last ones I did were .00157" to be exact. I checked them with a digital indicator and the regular dial indicator. They have worked great the 1200 miles I ran the car last summer. I have since disassembled hte front of the car from the tranny forward to rebuild everything.
Once you have the correct endplay then you install the seal on the spindle, then the greased bearings,shim,spacer,hub,inner seal. I used a bearing greaser and then went over them by hand. When pressing them in, the outer seal will not press in the housing. You have to go back and use a round rod or screwdriver to press the seal into the housing. Be careful pressing the bearing on. Watch that everything is aligned. I made the exact same spindle installation tool sold in all the catalogs and never used it. I prefer the press, I think I used some eletrical EMT to make tubes to press the bearings on with.

I used new Tom's spindles last year and found them to have too much run out in the flange- .005" with the rotor on. I had to shim the flange to rotor to cut down the runout to .001-.002" that didn't cause a problem with the brakes.
I used Mobil 1 red grease in the bearings and housing,don't over pack the housing. Try to pack them about 80%. There should be a well cast into the later housings,which I think you have. I found a 65 housing on the left rear T arm on my 69. The early housings didn't have the well in them, just a straight bore.
Does this help anwser your questions? I probably won't be back on the forum until tomorrow AM.
Gary


[Modified by gtr1999, 8:43 PM 3/2/2003]

 

You are very thorough gtr1999. Like you steering box you go to great lenghts to get things right.
Dalannex. Check all clearnaces without shims or grease. Light oil will not hurt but definitely no seals and no grease, I do mine dry. I also have a inner slid fit bearing. I polish the spindle until the inner bearing is a easy fit. Anyway set up end play then take apart again and install the seals and grease and re assemble like before. It will turn hard. I made the mistake once of doing like you and taking it all back apart and increasing the shim thickness and I end up with too much end play. After a few thousand miles I had to take it back apart and redue.
So check all clearance without seals, without oil or a light oil and use sparingly, set clearnance to around .001, then take apart and reassemble with seals and grease and doing worry about the drag. It will go away.
My son does fittings like this for a living and he taught me, I doubted him on my rearend when I found the final assembly too hard to turn and corrected it . I ended up sorry that I didn't listen the first time. He was right.
Have a nice day.

 

Thanks Norval, but I just had to edit that post because of some typo's :bb
Justin let us know how you make out,good luck,
Gary :thumbs:

 

Thaks guys. I kind of assumed that the bearings would loosen up once they were run for a while, but wasn't sure. That one sure did turn hard. It just didn't seem right. I still have to do the passenger side. I just got done setting up the driver side, hooking up the new rear spring and mounting the sway bar end link bracket on the trailing arm. The thing about it now is that if I run it a little bit and don't like it I can always take it apart easy enough and redo it. I think I may consider making that inner bearing a slip fit. That would allow me to take it back apart without knocking that outer seal out.

Norval, When you thought it was too tight and took it apart to add a little shim, then it was too loose, what did you have for enplay after adding a little shim, and what did you have once it loosened up?

GTR, did you notice your bearings feeling unusually tight after you put them together with grease?

 

.001-.008 is correct then. I thought that seemed kind of loose to me. But I see why you added the page on front wheel bearings. I have always done them wrong. I usually tighten them up until it feels like it takes the right amount of force to spin the wheel, just a slight bit of drag. The method that GM recommends seems awful loose to me. I guess I spent too many years running CNC machines where we measured down to ten thousadths. :D I think I got it right now. Not sure, but I think so. I would still like to know how much it will loosen up after driving a few miles. I mean, if I set it up for .001-.004 and it turns over a little hard, what will my endplay measure after I run it a little while? I assume still .001-.004? Maybe I worry too much too. :crazy: :yesnod:

-Justin


[Modified by Dalannex, 9:26 PM 3/2/2003]

 

Justin,
The bearings shouldn't feel tight after greasing. They might be a little snug but not tight. I can move them easily with one finger on the rotor. I haven't checked them over the 1200 miles of use to see if they loosened up.
Gary

 

gtr1999, I can probably rotate them with one finger, but it'll take a little bit of effort. When I checked my endplay this last time I didn't use any type of tool to push on the bearing setup tool. I just grabbed it and pushed it all the way out, then gave it a little rotation to be sure the bearings were seated, then did the same thing the other way and watched the difference on my dial indicator. The first time I used a bar to lift up on the setup tool. I think that made for too tight of a setup. What do you think of the setup procedure for the front bearings in the page that Paul listed above? I mean the tighten to 12 ft. lbs., then back it off, then go hand tight while turning the wheel and that's good?????????

-Justin

 

Justin I never used a torque wrench to adjust the front bearings. I was taught to tighten them while rotating the wheel to seat the bearings then back off and hand tighten until the nut gets snug then until the cotter pin hole lines up. I'll have to try the torque wrench procedure one day to see how it is.
I too tried using different leverage approaches on the rear bearings until I reread the GM procedure and set them by hand pressure.
Gary

 

The reason i asked is I noticed when I put my front springs in that I have a wheel seal leaking on the front. I suppose i might as well take care of that right away too. Those only have a couple thousand miles on them too. I must have bent the seal a little when I put it in.

-Justin