I'm reassembling a midyear rear spindle assembly (on the bench) and the shop manual states just to "press it on", nothing else. But HOW MUCH should I press it? The last time I pressed it on too much and the trailing arm wouldn't spin in the vise, and I had to loosen it up a little. The spindle nut is torqued to 100 ft. lbs, but if the bearing was NOT pressed on enough, will the nut torque press the bearing in and compensate for the slack? I want to be able to get an accurate measurement on the bearing end play. Does this sound logical or am I mixing apples and oranges? What is a good rule of thumb to use? Any suggestions would be welcome. Thanks, Patrick
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Re: Pressing Inner Bearing On The Rear Spindle....
Patrick-----
I must tell you, Patrick, that I'm a little worried about the outcome of all this given my understanding of what you've described. In any event, I'll offer this:
The rear spindle should be pulled into the bearings using the special tool available from Kent-Moore and described in the Chevrolet Service Manual. In this operation, the spindle is first pulled through the outer bearing until the spindle "seats" on the inner race of the outer bearing. Then, the inner bearing is pressed onto the spindle until the inner race of the inner bearing seats against the selective thickness shim and spacer assembly. When this occurs, the tool is removed and the spindle nut is torqued to 100 ft/lbs (+ additional torque necessary to align the cotter pin with the hole in the spindle). That's it! If you do it this way, there is no way that you can "lock up" the spindle by pre-loading the bearings. Also, if you use the installation tool properly and install the spindle nut to the specified torque, the bearings will be drawn into the proper and final positions.
Now, all of this presumes that you have selected the proper selective fit shim to establish the .001-.008" end play (.001"-.002", much preferred). To do this, you must use the special shim selector tool and PROPER MEASUREMENT TECHNIQUE to determine the appropriate shim. If you install a shim which is too thin, you will put the bearings into pre-load and "lock-up" the spindle when you install the spindle nut. Under such conditions, your rear bearings will fail catastrophically very soon after you put them into service. If you select too thick of a shim, you will have too much end play in the rear bearing assembly. This will create excessive rotor runout and, also, cause the bearings to lead a short, but exciting, life.In Appreciation of John Hinckley -
Re: Pressing Inner Bearing On The Rear Spindle....
Joe, I think you told me what I wanted to know. I should have mentioned that these are new bearings with a new spacer and shims, 3 months old, with 300 miles and no evidence of damage or wear. I also think the key word to your message was "when the spindle seats", so the 100 ft. lbs. of torque on the nut really is a moot point, regarding pulling the spindle into the bearings. When I pulled the inner bearing on 3 months ago, the spindle did lock up, apparently because the was no runout clearance, but I think now that was a result of using a pre-load shim that was not thick enough. I will just have to experiment with differnt size shims.
Incidently, on your advice, I did disassemble the whole works, because of a scraping noise in the rear wheel and the "metallic dust" I mentioned turned out to be yellow overspray from a touchup in the inner fender lip. Fortuately, I had enough sense to investigate this promptly. I had the rotor turned today, because it was a little rough, which may have caused the parking brake shoe pad to shear, and somehow, this seems to be what the noise was. This has been a really weird experience, but I think now I've finally got the hang of it. Thanks, PatrickComment
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Re: Pressing Inner Bearing On The Rear Spindle....
Patrick, Joe is absolutely correct and you can thank all of the "others" who have had an opinion on other posts about "how easy" it is to replace rear spindle bearings for your problem. I never have and never will recommend anyone replace there own bearings without the proper tools and I haven't heard anyone say they have the tools. All bearings and cups have a "+ -" tolerance. Therefore, new bearings and cups can have significantly diiferent dimensions from the ones that you are replacing. The selection of shims, therefore, will most likely be different from what you have, so if you don't have a selection of shims, you may be out of luck. Send the spindle assy. to one of the rebuilders and have them do it.Comment
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Re: Pressing Inner Bearing On The Rear Spindle....
Rob-----
I totally agree. I NEVER recommend that anyone get into this job without the proper tools and the EXPERIENCE. I learned how to do this through a VERY DIFFICULT and EXPENSIVE process. The "expensive" part of it had to do with all of the parts that I destroyed getting my "education". The "difficult" part involved the innumerable "redos" that I had to perform before I got it right. Then, of course, when I realized that you had to have the proper tools, I purchased a complete, new set of ALL of the Kent-Moore tools necessary for this service operation. That set me back about another $1,000.
Of course, like you, I've heard all of the assertions about "how easy" this job is and how much folks get "ripped off" when they have a professional do it. Bear in mind, though, that just about anyone can do this job and have the bearings/spindle last for 500 miles. But, doing this job and having it last for more than 100,000 miles.......that seperates the men from the boys. Remember, too, that catastrophic failure of this assembly can be the "proximal cause" of the loss of large sections of rear quarter panel fiberglass and, in some extreme cases, result in severe injury or death due to loss of control of the car.
Now considering that my involvement with Corvettes is strictly at a hobbyist level and I NEVER, EVER work on anyone elses Corvette, why did I go through all of the expense and frustration to learn this procedure and purchase the tools just for my own personal use? That's a good question. A VERY GOOD question.In Appreciation of John HinckleyComment
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At least buy the right tools!
Patrick,
I too would suggest you take Rob and Joe's advise.
But if you are stubborn, and can't talk Joe into borrowing his tools , buy your own !! Maybe you could sell them to someone else when you finish.
The removal, installation, and set-up tools are available from International Axle & Mfg (612)425-5515 for about $300. You can also get an assortment of shims with more sizes than GM offers. You will also need a dial indicator.
Good luck whatever you do!
Wild BillComment
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Re: At least buy the right tools!
You can make a set-up tool out of an old axle. Just turn down the bearing journal a little. A special tool for installation is not absolutely necessary either. Just seat the bearing before you install and use a flat punch to seat the inner bearing. You have to be carefull but it works fine. Just before the axle is seated you can use a screwdriver to seat the outer seal. If the trailing arm is out of the car this operation is easily done on a press all in one operation.Comment
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Re: Turn down the axle!!!!!!!!....
Patrick!!!! If you have the axle all apart, take the axle and new parts to competant machine shop. Have them turn the axle on a lathe, you will also need to remove the wheel studs, so the bearing just slides on the axle shaft. You will need an assortment of shims. When they turn this in the lathe, you can get them to check that a) the shaft is straight b) the hub is at 90 degrees to the axle solving your runout problem too You can now mount it in a vice and trial fit till you get no more than .002 clearance, but try for .001. Doing it this way, which is the same way your front hub is assembled, you can take it apart when you want to check and lube. Use synthetic grease (mobil 1) to reassemble. It is fool proof and not noticeable. I have done Bloomington Gold cars this way, and race cars too Hope this helpsComment
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Re: Turn down the axle!!!!!!!!.... Yes, Yes...
I "turned mine down with a strip of emery cloth 35000 miles ago (slowly, evenly, and carefully to a .001 interference fit). It made setup much easier. I made a fixture for an old dial indicator to check for end play and runout (both of which I constrain to .001-.003). The whole process is part of the joy of maintenance. If you are not enjoying the learning experience of which Joe Lucia spoke, try reading "Zen And The Art Of Motocycle Maintenance". - Dave.... P.S.Dial indicators are cheap now. Even JCWhitney and harbor frieght Tools sell them. They will tell every thing from cylinder bore distotion to brake rotor runout. Ditto for dial calipers, etcetra.Comment
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Re: Turn down the axle!!!!!!!!.... Yes, Yes...
Dave ....This is quite common, doing it this way. But the way I describe,everthing is square. Your way makes maintanance easy, but the wheel stud surface may not be straight (perpendicular). This will leave the rotor (Brake) with runnout, possibly causing problems.Comment
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Re: Turn down the axle!!!!!!!!.... Yes, Yes...
Bruce, et al------
The "slip fit" type rear spindle bearing design was actually used by GM. When the 1963 Corvette first appeared, the first ones had this type of set-up. GM changed the design to the interference fit in mid-model year.
Of course, this change greatly complicated (and increased the expense of) GM's own trailing arm assembly manufacturing operation, necessitated the GM design and Kent-Moore manufacture of a series of special service tools, necessitated a vastly more complicated service manual procedure, and required dealers to purchase the special tools and mechanics to learn the service procedure.
Now, do you all suppose that GM would have done all this if the first design worked just as well as the second design? I don't fully understand what their reason was for this change, but I'm certain that the engineers that designed it and the managers that approved the substantial additional costs did. Often, when GM makes a change like this, they don't explain their reasons. But, if one chooses to disregard the engineering changes, sometimes one gets to find out for themselves what the reasons are.In Appreciation of John HinckleyComment
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Rear spindle pack design changes
The '63 Corvette shop manual calls for a rear bearing repack every 30K miles, and this applies to the original "slip fit" design, however, there was a problem with "excessive wear" on early cars, so the design was changed to what we all know and love, but the good news is that the maintenance requirement was eliminated. There were several interim changes in production during November '62 and the final design went into production December 3. Chevrolet documented all this in Bulletin No. DR #599, June 10,1963. It was published in Vette Vues magazine back in the eighties.
DukeComment
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Re: Turn down the axle!!!!!!!!.... NEVER
Joe --- Duke has identified the design change document (dated June '63), also reprinted in an early RESTORER (winter '79). The REAL reason they went to full interference spindle fit was to prevent "INNER RACES ROTATING ON THE SPINDLE" (GM's words, caps mine). This is a catastrophic design error, and could result in the axle melting due to friction, and the rear wheel passing the car, especially on pre-disc brake cars. GM kind of buried this major "OOPS" by calling it a design improvement to minimize wear (some wear !), and deletion of the 30K mile lube interval (another big "THANK YOU").
Seriously, I thought all shops stopped doing this "slip-fit" business 2 decades ago (either BOTH or INNER-only slips), due to liability concerns.Comment
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Re: Turn down the axle!!!!!!!!.... Yes, Yes...
Joe ...no doubt GM has more money to spend on development and engineering than you and I. I learned of this procedure in the ealy 80's. I worked in the racing field for a few years in the late 80's in Corvettes and Trans Am racing. I believe the Greenwood cars used this procedure and alot of other racers did too. I think if it's good for 200mph+, that should just about cover all the cars that will need it in NCRS!!! But....to each their own. I was just trying to help out, in a way that I KNOW works. I think that's what this board is about. BruceComment
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Re: Turn down the axle!! ... Seriously????
Wayne...... There weren't too many shops that thought about, or had the experienced mechanics to know of this procedure. Hey.. you 're not the first one to not believe in it. I' ve been told "It won't work, thats impossible!!" To remember too, the Corvette was your basic mechanics nightmare. Not too many dealerships had mechanics lined up to work on Vettes, because they couldn't beat the book time to repair them. Now how would you think I got started fixing them, just that reason and of course owning one.Comment
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