T6 B Front Control Arm Issue

[Phil Planck]

Going through the control arms on Foam Car I noticed that the passenger lower had a short needle bearing race, meaning it is a C arm. All 3 others are B and the axle tubes have the double row, flanged bearing. But, the passenger lower has just one, loose 20mm needle bearing. Loose because the end of the axle tube is deformed, but only about the outer 20mm. I can get a 51.8mm socket to fit pretty snug and it bottoms out on the ridge in the tube which I assume is a secondary stop for the original bearing. But, with just one 20mm bearing, what locates the bearing? Does the C tube have a similar ridge to accommodate just one bearing? I would like to try to reshape the end of the tube back to round. One way would be to heat the deformed area red and try to pull it in place with the muffler clamp shown below. If that is not strong enough, possibly use the socket as a dolly and hammer the end back to round. If that works, I would like to put 2 20mm bearings and the spacer Stoddard sells in, but would need a B lower arm or B bearing race to put on the C arm. EASY has not lower arms; I took a bunch of measurements of the upper and lower tubes(pic below) but not sure that helps except to show that the outer part of the upper has some slop in it's diameter(.014" I think). If no B arms are available, I will have to use the C arm with one bearing, which Jim at EASY thought would be okay. I suppose I could still drive 2 bearings in with the spacer and use the C arm. That way the working bearing would be in the right location.

All opinions/advice welcome.

Thanks - Phil

[Martin Benade]

I have no info to help you but wondered, are the arms the same, just a different sleeve pressed on?

[Vic Skirmants]

Yes; arms are identical except for the sleeve.

[Dave Erickson]

Phil, I assume the metal is actually stretched, from the looks of it. I think you may need to shrink the socket once you get it round. Getting it round should not be difficult, you can hammer it using a steel mandrel that is a tight fit inside the control arm socket. However, I would be surprised if the i.d. you end up with is going to be within specs. There are methods to shrink tubing that could be applicable, e.g. an external roller burnisher, but it may not be easy to find someone with the capability to do it on your car's front end.

-Dave

[Phil Planck]

Thanks Dave

Yes, I was able to get it looking round, but you are right, it appears stretched, as the old 20mm bearing slides right in. I have ordered 2 new 20mm bearings to see if one will be a tighter fit, as the old bearing O.D. is only 51.9mm. I have located a used 40mm bearing also which worst case may be tight on the inner row of needles and maybe I can wrap the outer end with shim stock. You were right Vic, heat and the muffler clamp did not work.

[Dave Erickson]

Phil, is the outside of the needle bearing a solid cylinder? I've had mine out but I forgot...

The reason being, if it is solid, you could use loctite to position the bearing and take up the clearance. e.g. loctite 680. I would recommend contacting loctite and speaking to an engineer to identify the correct product.

[Phil Planck]

Dave
Yes, the outside is solid cylinder. Not sure how big a gap the Loctite will fill. I have some and will check.
Thanks for the tip.

Phil

[Dave Erickson]

There are many types of loctite. 680 is designed for installing bearings/bushings and other radial fits that are not press fits. However I do not know if it is designed for the type of side thrusts you would get from the control arm. I use it for installing bushings in Solex 40PIIs, and similar applications which are a lot different from this one.

[Phil Planck]

I have used the site: allmetalshaping.com for advice on a lot of the sheet metal issues I have had with Foam Car, so posted my problem there and got some good tips. The main one I used was to get a shaft collar that would fit around the outside of the tube. The good tubes OD is slightly greater than 2.25" so I got a 2.25" collar. It took some work, and the use of some shim stock over the distorted area but was able to get the tube compression shrunk back to it's original diameter. Also, located an original used bearing and was able to drive that in. It was a good interference fit, and the control arm is tighter than the other 3, but easy to rotate by hand. I suspect it will loosen up after a few road bumps. The work involved hammering on the collars with a large brass hammer and slowly tightening the collar down.

[Ron LaDow]

Phil, I was willing to bet we were gonna see some more of your very talented tin-work, replacing the outer end of the tube and part of the upright. I'm sure you are, and should be, proud of THAT solution.