Trailing Arm Bearings Question
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Racer
Joined: May 2023
Posts: 372
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From: Williamsburg, Va
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Trailing Arm Bearings Question
I've just disassembled both trailing arms to replace bearings and bushings. It is a 60,000 mile car with original Timken bearings. When disassemblling the arms, both inner/outer bearings fell-off the spindle. Did not need to use a puller at all. The bearings had seen better days so I'm glad that I took the time to go through the arms.
The dimensions I’m sharing are identical for both spindles.
The OD of the outer bearing seat on the shaft is 1.375” and the ID of the new bearing is 1.374”. The OD of the inner bearing is 1.187” and the ID of the new bearing is 1.186”. I know that they need to be pressed-on but I’m not aware of what the interference dimension is the bearings to shaft. Usually, interference is .010” and I have .001” on both and I can press the bearings into place onto the shaft by hand. The bearings seat much like a front wheel bearings on the front spindle.
Doing some research, and I've learned that 1963 bearings were NOT press-on but fitted. 1964 onwards were press-fitted.
I'm not opposed to picking up new spindles, but if there's no harm by the bearings not needing to be pressed-on, I can redirect funds to other areas during the restoration.
Thoughts??
The dimensions I’m sharing are identical for both spindles.
The OD of the outer bearing seat on the shaft is 1.375” and the ID of the new bearing is 1.374”. The OD of the inner bearing is 1.187” and the ID of the new bearing is 1.186”. I know that they need to be pressed-on but I’m not aware of what the interference dimension is the bearings to shaft. Usually, interference is .010” and I have .001” on both and I can press the bearings into place onto the shaft by hand. The bearings seat much like a front wheel bearings on the front spindle.
Doing some research, and I've learned that 1963 bearings were NOT press-on but fitted. 1964 onwards were press-fitted.
I'm not opposed to picking up new spindles, but if there's no harm by the bearings not needing to be pressed-on, I can redirect funds to other areas during the restoration.
Thoughts??
Tech Contributor
Joined: Aug 1999
Posts: 15,156
Likes: 3,965
From: Connecticut, USA
I was just asked this question today, possibly the same car?
1- Timken bearings are not original, never were. C3 original bearings were NDH.
2- 001" press fit is all that is required and what GM had.
3- most likely the last guy that worked on the arms polished the bearings and axles. 1.375" and 1.187 are too loose. Axles should be 1.376 & 1.188
4- you get one shot at setting up press fit bearings. How you do it depends on your skill set and what reference materials you use. Many spec out 002" end play, some 001, some 003, etc. When all is said and done, there should be no rocking in the axle/rotor, there should not be noticeable endplay by hand/eye. The bearings should be correctly setup, greased and assembled and will last a long time.
5- There are both USA and imported axles sold today, some are good, some are junk. I use only Tom's NOS outer 17's, USA made and before Covid causes many production issues.
1- Timken bearings are not original, never were. C3 original bearings were NDH.
2- 001" press fit is all that is required and what GM had.
3- most likely the last guy that worked on the arms polished the bearings and axles. 1.375" and 1.187 are too loose. Axles should be 1.376 & 1.188
4- you get one shot at setting up press fit bearings. How you do it depends on your skill set and what reference materials you use. Many spec out 002" end play, some 001, some 003, etc. When all is said and done, there should be no rocking in the axle/rotor, there should not be noticeable endplay by hand/eye. The bearings should be correctly setup, greased and assembled and will last a long time.
5- There are both USA and imported axles sold today, some are good, some are junk. I use only Tom's NOS outer 17's, USA made and before Covid causes many production issues.
