Rear bearing endplay.....
#1
Melting Slicks
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Rear bearing endplay.....
I am putting my rearend back together and I want to make damn sure that I got everything right. I am at .002" and am only on the second shim. There was no play the first time, so I know that the shim was too small. I have all new parts including spindles. I can hear and feel the bearing setup tool move-although it is very minute. Someone say something to make me feel like I have it right. Thanks
#4
Melting Slicks
Re: Rear bearing endplay..... (79VetteMike)
I am not currently rebuiding. But it's on my "must do" list. I don't drive the car much due the excess play in the rear spindles. I can move my wheels and tires about 3/8" to 1/2" from side to side or up and down. All the play is in the bearings not the TA bushing. Soooo I need to just jump in and get it over with. Good luck
:chevy
Mark
:chevy
Mark
#5
Melting Slicks
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Re: Rear bearing endplay..... (mbeeman350)
Are you sure that you arent' feeling the play in the differential yokes? If you could feel as much play as you say, then the wheels would probably fall off within a mile.
#6
Melting Slicks
Re: Rear bearing endplay..... (79VetteMike)
With the car on stands, I can move or wobble the wheels side to side or up and down, not in or out. I am measuring from the the outer edge of the tire to get the 3/8" to 1/2" play. It is a '72 and most of the car is original except for the paint. So I would suspect the rear TA wheel bearings are original. That's why I don't drive it much!!!!!
Mark :cheers:
Mark :cheers:
#7
Safety Car
Re: Rear bearing endplay..... (79VetteMike)
As long as you give the spindle a little turn as you push it each way so make sure you measure every bit of endplay you should be alright. .002 is right in spec. When you put it back together you will find that the spindle is a little hard to turn. Don't worry about it. It will loosen up. Things just get a little tight after they are packed in grease.
-Justin
-Justin
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Re: Rear bearing endplay..... (79VetteMike)
If your measure .002 with a dial indicator and not just feel then you are fine. You could take a piece of fine emery paper, mask it to a flat surface and carefully draw the shim across it or the larger spacer and reduce it's length even further or .001 clearance. This is just being picky.
Like already said once the grease and seals are installed they will feel tight but that is normal.
I am assuming you are measuring dry bearings to get the .002?
Like already said once the grease and seals are installed they will feel tight but that is normal.
I am assuming you are measuring dry bearings to get the .002?
#10
Le Mans Master
Re: Rear bearing endplay..... (Ki m Le)
I believe GM spec is .001 to .008
I use .0010 to .0015 as my range because I do the work professionally and cannot allow the possibility of a "call-back" for both reputation and cost reasons.
At .003, you can feel a substantial amount of wobble even though it is within GM's spec. You can also measure camber & toe variance at .003. So... I always set them up at .0010 to .0015. Some guys even set them at zero, but I feel that this does not give the parts any room to breath when they expand due to heat.
.002 is a good number... should be fine.
One caveat here... it is virtually impossible to get a true "end-play" reading with the spindle support & spindle etc still mounted in the car. I have experimented with this system for over 25 years (since 1974) and have found that to get a "true" reading, you have to mount the whole mess in a custom made jig which holds the support vertical. The variation in surface correctness (parallellism) of the shim select tool itself is often more than .0015 to .0020 which introduces error before you even start to measure endplay. In addition, with the spindle support sideways, the spindle & bearings tend to "rock" rather than move perpendicular while measuring endplay... this introduces error as well. This is all based on 29 years of experience doing these bearings professionally and taking the time to use high qualilty dial gages in the process. Cheap gages are junk... they give numbers that are way off. By measuring sideways, and then using the jig, the measured numbers support the contentions without exception.
Just be aware that the GM methodology is not perfect and do the best you can with what resources are available. Also... if you haven't been taught by an "old-timer" how to properly hand grease a bearing, invest in the plastic bearing packing tool sold at autoparts stores... it works when used properly and it's cheap insurance.
Check the archives... there are many discussions on this topic, and several web sites.
Tom
I use .0010 to .0015 as my range because I do the work professionally and cannot allow the possibility of a "call-back" for both reputation and cost reasons.
At .003, you can feel a substantial amount of wobble even though it is within GM's spec. You can also measure camber & toe variance at .003. So... I always set them up at .0010 to .0015. Some guys even set them at zero, but I feel that this does not give the parts any room to breath when they expand due to heat.
.002 is a good number... should be fine.
One caveat here... it is virtually impossible to get a true "end-play" reading with the spindle support & spindle etc still mounted in the car. I have experimented with this system for over 25 years (since 1974) and have found that to get a "true" reading, you have to mount the whole mess in a custom made jig which holds the support vertical. The variation in surface correctness (parallellism) of the shim select tool itself is often more than .0015 to .0020 which introduces error before you even start to measure endplay. In addition, with the spindle support sideways, the spindle & bearings tend to "rock" rather than move perpendicular while measuring endplay... this introduces error as well. This is all based on 29 years of experience doing these bearings professionally and taking the time to use high qualilty dial gages in the process. Cheap gages are junk... they give numbers that are way off. By measuring sideways, and then using the jig, the measured numbers support the contentions without exception.
Just be aware that the GM methodology is not perfect and do the best you can with what resources are available. Also... if you haven't been taught by an "old-timer" how to properly hand grease a bearing, invest in the plastic bearing packing tool sold at autoparts stores... it works when used properly and it's cheap insurance.
Check the archives... there are many discussions on this topic, and several web sites.
Tom
#11
Re: Rear bearing endplay..... (79VetteMike)
I am putting my rearend back together and I want to make damn sure that I got everything right. I am at .002" and am only on the second shim. There was no play the first time, so I know that the shim was too small. I have all new parts including spindles. I can hear and feel the bearing setup tool move-although it is very minute. Someone say something to make me feel like I have it right. Thanks