How to replace A arm internal bearing??

[Benno88]

Hi all I'm seeking some info about how you remove and replace the internal bearing of the rear A arm for my Stohr. Upon stripping the car we found ours had seized and all efforts to loosen it have failed. We have purchased a new bearing but I have no idea how you remove the old one and put a new one in? any secrets.

and please use layman's terms I'm only a driver not a mechanic

Cheers

[Mike B]

http://www.apexspeed.com/forums/show...ighlight=stake

Start reading around post #30.

[R. Pare]

Don't know how it is possible for a teflon lined spherical to 'seize" - it may be way to stiff because of too much press fit, but they cannot seize.

If it is because the press fit is way too much, a new bearing will be just as hard to turn once installed.

[R. Pare]

You might try putting the arm into an oven at about 200-225 degrees ( remove any brake lines) to heat and swell the teflon lining. Once it has come to temperature, remove it from the oven and quench in room-temp water.

This will cause the exposed edges of the teflon liner to solidify in place rapidly, leaving the area between the ball and the case to cool more slowly, shrinking the teflon in thickness, and releiving its pressure ( and therefore its friction) against the ball.

It might take a couple tries at this, and possibly a bit highr temp - I've never measured the teflon temp when we've heated it by spinning the ball in a drill press - it was always done by feel.

[jcorsico]

I agree with Richard that it sounds like there may be something wrong with the bearing housing in the a-arm. Regardless, if you want to remove it, the easiest way to do it is to buy a bearing removal tool from these guys:

http://www.cabcoindustries.com/

The tool goes on your drill press and will very carefully cut away the staked rim on the bearing. You can then push it out with a press or hammer.

You then should also get a tri-roller installation tool from Cabco. That will allow you to install the new bearing, again using your drill press.

None of this is cheap, mind you.

Good luck!
Jon

[R. Pare]

Also possible - if it indeed is a staked bearing - that the staking tool was made incorrectly and pressed the ID of the groove inwards ( as well as the outer wall), or that the installer used way too much pressure - in either case, squeezing the outer shell and the teflon hard on to the ball.

[Benno88]

Thanks for the info guys.

The bearing we very stiff (seized) I have tried to spin it with a drill to get it to loosen up but even after hours of trying and WD40 it has only become loose enough to move (with a large leaver) but still to stiff to be able to spin.

maybe if I use a drill press and start it in a really low gearing it may have enough torque to get the bearing to start spinning and heat up.

Im guessing for the oven temp you are talking about deg Fahrenheit not deg Celsius?

Cheers

[mousecatcher]

These guys may be cheaper than cabco.

hpve.com

[S Lathrop]

Thanks for the info guys.

The bearing we very stiff (seized) I have tried to spin it with a drill to get it to loosen up but even after hours of trying and WD40 it has only become loose enough to move (with a large leaver) but still to stiff to be able to spin.

maybe if I use a drill press and start it in a really low gearing it may have enough torque to get the bearing to start spinning and heat up.

Im guessing for the oven temp you are talking about deg Fahrenheit not deg Celsius?

Cheers

Spinning the ball with a drill press or mill is a good way to go. Have a wet rag available to quench the bearing once it gets hot.

I suggest that you hold the a-arm in you hand. You want to feel for the instance that the Teflon loosens and then quench the bearing a quick a possible. It is too easy to over do this and have a really loose bearing.

[R. Pare]

Yes, temps are F.

You can also pre-heat the joint by stuffing an alu rod into the ball, and heating the rod with a torch.

[Benno88]

Thanks for the help guys, it turns out the housing appears to have shrunk a tiny amount which was putting pressure on the bearing. a little clean out and the bearing fit back in perfectly.

Cheers

[Brian]

I have never had great luck with loosening ball joints in pressed in cups. I find it's usually down to the cup being warped after welding or bored to too tight a fit. I have resorted to honing and scraping egg-shaped bores and polishing the OD of a bearing to perfect the fit, then the new bearing presses in and is the right tension on the ball.

Brian

[S Lathrop]

I have never had great luck with loosening ball joints in pressed in cups. I find it's usually down to the cup being warped after welding or bored to too tight a fit. I have resorted to honing and scraping egg-shaped bores and polishing the OD of a bearing to perfect the fit, then the new bearing presses in and is the right tension on the ball.

Brian

You might try machining a brass plug exactly the diameter you want for the finished bore. Press the plug into the bearing retainer and then heat it with a torch.

I have found that using a brass plug in the bearing holder when I build the suspension part, will give me a finished part that the bearing will fit properly. If there is any error in this process, it tends to be that the bore might go over sizes a bit.