I can't seem to find out what threads my rear spindles are. I need to find a die so I can clean the ends of the threads up. I replaced the bearings a couple years ago when I was redoing the chassis and had nice preload on them. It's since been on and off the trailer a few times and up and down the driveway and now they are lose. I had the trailing arms off and pressed them together and had nice preload. I guess I don't really understand that part of it. I've never seen bearings take a set that much and I work for Eaton that makes the rear limited slips and I install and test them. Done thousands of ring and pinion set ups and with different bearing preloads and haven't seen any of them get lose like these did. Weird. Anyway if someone could let me know what die I need it would be greatly appreciated. Thanks, Brad
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Re: 64' Rear Spindle Threads?
Brad,
3/4" 20
Regards,
JR -
Re: 64' Rear Spindle Threads?
Brad, I'm not sure I understand when you talk about preload here so you may already understand this but the rear wheel bearings are not adjusted for preload. The tapered roller spindle bearings are installed with end play of .001-.008, preferably closer to .001. This adjustment is made with shims and the assembly is torqued to 100 ft lbs. It should not come loose. Make sure your spindle threads are not damaged and the service manual suggests a new nut each time this is taken apart. You don't want this coming apart as you drive down the road.Comment
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Re: 64' Rear Spindle Threads?
I ordered some new nuts but but this end play is new to me. I didn't read that in any of the books I have. I take it you torque it to 100 ft/lbs and place a dial indicator on the end and rock it for your end play? That's interesting because I thought all tapered rolling bearings need a slight preload so they last. Thanks, BradComment
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Re: 64' Rear Spindle Threads?
Brad------
In Corvette (and, most other Chevrolet) wheel bearing applications ALL tapered roller bearing set-ups are specified with end play. This includes BOTH front and rear bearings. The procedure for adjusting the front wheel bearings, if followed, will ensure that the bearings end up with an end play of .001-.006".
For the Corvette rear wheel bearings, a spacer and appropriate thickness shim set the end play. It is measured essentially as you infer after the spindle nut is torqued to 100 ft/lbs (plus, additional torque necessary to install the cotter pin).
Running wheel bearings with less than .001" end play will usually result in significantly reduced bearing life. With wheel bearings set in pre-load, catastrophic bearing failure can result.In Appreciation of John HinckleyComment
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Re: 64' Rear Spindle Threads?
Could someone please explain this end play? Your telling me on the front wheels you don't use the age old procedure of spinning the wheel until it starts to tighten and then back off enough to get the cotten key in. I guess it's confusing when I don't know exactly what end play your talking about. Just makes sense to me since it's a tapered roller that it should be set up like a diff pinion gear of a set of preload of say 20 in/oz. Once those tapered bearings are drawn in with this preload then their isn't kind of play. I understand the select fit shims used in the back, I just would like to set them up with this correct "end Play". Thanks for all of your help. BradComment
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Re: 64' Rear Spindle Threads?
Brad-----
The end play for the front or rear Corvette wheel bearings is the same-----.001-.008". The bearing setting procedure for the front wheel bearings is to tighten the spindle nut to 12 ft/lbs while rotating the wheel. THEN, BACK OFF THE NUT 1 FLAT (and, any additional amount necessary to install the cotter pin). The backing off one flat ensures the .001-.008" end clearance. I've done some experiments with this and done some calculations---it will always work to ensure the .001-.008" end clearance IF THE PROCEDURE IS PERFORMED EXACTLY CORRECTLY.
For the rear, the bearing spacer and shim set the clearance. One must determine the correct shim to install by pre-set-up and measurement. Shims are available from GM in increments that ensure that the end-play IN THE SPECIFIED RANGE can be obtained. Shims in smaller increments (.001") are available in the aftermarket to enable setting the end play closer to the preferable .001-.002".
For the front wheel bearings, using the specified procedure will result in an end play WITHIN THE SPECIFIED RANGE. However, there is no control over WHERE in the specified range that the adjustment will end up, due to the fixed and limited number of positions that the cotter pin can be installed. As far as GM AND TIMKEN are concerned, as long as the adjustment falls within the specifed range, everything is fine---even if it's at .008". To improve upon this and achieve the .001-.002" preferable, one may have to PRECISION surface grind the special keyed washer used between the bearing and the nut.
The above is how it is. Any other setting or adjustment procedure is NOT as specified and approved by GM.In Appreciation of John HinckleyComment
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Re: 64' Rear Spindle Threads?
Thanks for the great information Lou. I appreciate it.Comment
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Re: 64' Rear Spindle Threads?
Very good post Joe. I have heard the "preload" thing argued for almost 40 years. At a former employer we had Timken service reps come in and do tech sessions on bearings and seals. Some old time mechanics could never understand the adjustment procedure you spelled out in your post was not preload. We finally had to take dial indicators to prove otherwise.Dick WhittingtonComment
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Re: 64' Rear Spindle Threads?
Remember that wheel bearings run in grease and rear ends in oil. The oil will lubricate and COOL the bearings more than grease.
JonComment
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