Rear radius arm needle bearing size.

Started by tsumini, March 10, 2020, 10:04:20 PM

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tsumini

I asked this on the MK1 FB forum and got silence.
Can some one tell me the OD of the ATJ4098 REAR TRAILING ARM ROLLER (needle) BEARING?
I have a set of radius arms that have bronze bushings both ends and was wondering
if I use the needle bearing do I have to enlarge the hole. Photo makes it looks the OD is larger than the bushing. The bushings are 15/16 OD.

MiniDave

I can a little later, I have an appt at 10 but when I get back I'll dig one out and measure it for you
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

jedduh01

From memory the Needle bearings are larger than the bushings = When refurbishing arms you cant swap them mistakenly.

if your arms are Bronze both inner and outer they are very early and original....  Wouldn't hurt to keep them that way too.  They made it this long. 60 Years.

MiniDave

But are the inner and outer bushings different sizes on those old arms?
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

tsumini

Quote from: jedduh01 on March 11, 2020, 07:54:37 AM
From memory the Needle bearings are larger than the bushings = When refurbishing arms you cant swap them mistakenly.

if your arms are Bronze both inner and outer they are very early and original....  Wouldn't hurt to keep them that way too.  They made it this long. 60 Years.
Yeah I didn't change them on my 60 Austin they were good. The arms I have are from a 60 Morris and had some brackets welded on which I removed. They are the old welded type with bushings both ends. I wasn't going to enlarge the hole to adapt the needle bearing but wasn't sure of the size. Parts store say to order additional bushings separately. Since I haven't done any I wasn't sure.
Anyway I was going to refurbish the arms and offer up for sale but don't know what they're worth. Refurded from parts store are pretty dear.

MiniDave

#5
Could you post a close up of those, especially the end that the knuckle joint and push rod for the cone goes into?

BTW, OD on the roller bearing is 1 1/16", on the bushing it's .943-.945, a little more than 15/16" (.9375)
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

tsumini

Ok here's 4 pics of the arms. Knuckle hole is 1 1/8 Dia. Casting numbers are 17038 and 17039.
I suspected the needle bearing OD was over 1 inch. I've ordered the kit plus three extra bushings (one for inevitable screw up). I don't hvae the trumpets either but have the rest of the parts to build up complete to the brakes and hubs. Rear bearings are good shape and run smooth.

MiniDave

Wow, those are some gnarly looking welds.....
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

tsumini

Quote from: MiniDave on March 11, 2020, 05:34:56 PM
Wow, those are some gnarly looking welds.....
Oops I didn't dress them to well.

MiniDave

Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

tsumini

Quote from: MiniDave on March 11, 2020, 09:53:46 PM
Not yours, the OEM ones....
Oh OK LOL I think those are resistance welds you're referring to. Huge for resistance welding.

MPlayle

I have a set of stock trumpets left over from putting hi-lo's into a Mini.  I think they are the longer Van ones.

I would be willing to let go of them for cost of shipping.

I can look into finding something to ship them in and get an estimate if you provide a destination zip code.

(I can also deliver them to the Spring Drive in April if you will be there.)


CooperTune

#12
When I machined up the reamed guide bushings for doing rear swing arms I set up to do early welded swing arms. They have the same steel backed bushing in board and out. On my vintage car I machined oil-lite bushings for the
inner ends of my cast rear swing arms. Just seemed like a good idea at the time. Steve (CTR)

The early welded swing arms also had steel welded trumpets front and rear.

tsumini

Quote from: MPlayle on March 12, 2020, 07:52:24 AM
I have a set of stock trumpets left over from putting hi-lo's into a Mini.  I think they are the longer Van ones.

I would be willing to let go of them for cost of shipping.

I can look into finding something to ship them in and get an estimate if you provide a destination zip code.

(I can also deliver them to the Spring Drive in April if you will be there.)
Thanks for the generous offer.  I can offer them with the arms. Not sure of the Spring drive. Was wanting to go but the carona virus may preclude that. Also the engine is still stumbling at idle Keep chasing that with little success. Right now it's too unrelaible to trust with a 100 mile drive. Zip code is 75757 but we can hold off shipping. Again thanks.

tsumini

Quote from: CooperTune on March 12, 2020, 08:03:02 AM
When I machined up the reamed guide bushings for doing rear swing arms I set up to do early welded swing arms. They have the same steel backed bushing in board and out. On my vintage car I machined oil-lite bushings for the
inner ends of my cast rear swing arms. Just seemed like a good idea at the time. Steve (CTR)

The early welded swing arms also had steel welded trumpets front and rear.
Had to google oill lite. Did they not work well?

CooperTune

Yes, they worked just like any two bushing arm. I don't like the needle bearing, they are better rotating. The swing arm travel is so small the needles tend to wear a small area. I have a fair collection of rear swing arms. It seems the inner bearing is the problem. All the damaged arms have issues with the bearing. I'm not sure I ever read that the correct repair is driving finishing nails around to tighten. The reason I say this is I have several sets with the nail repair and they did not all come off the same car.  A correct repair is to bore the housing and press a sleeve in. I have even machined a new end cut the damage away and weld a fresh end on.

In regard my inner bush I did cut some shallow grooves to allow grease to lube.

Another thing that bothers me is the plastic tube supplied with repair kits. They split very easy with a grease gun. I always try very hard to remove the old metal tube if possible. I secure the arm in my big vise. Drive the needle bearing out from the inside. Next drive the outer bushing with a proper bushing driver into the arm pushing the tube out ahead of it. Steve (CTR)

tsumini

Quote from: MiniDave on March 11, 2020, 08:31:13 AM
But are the inner and outer bushings different sizes on those old arms?
No they are the same size.

tsumini

Quote from: CooperTune on March 13, 2020, 07:36:32 AM
Yes, they worked just like any two bushing arm. I don't like the needle bearing, they are better rotating. The swing arm travel is so small the needles tend to wear a small area. I have a fair collection of rear swing arms. It seems the inner bearing is the problem. All the damaged arms have issues with the bearing. I'm not sure I ever read that the correct repair is driving finishing nails around to tighten. The reason I say this is I have several sets with the nail repair and they did not all come off the same car.  A correct repair is to bore the housing and press a sleeve in. I have even machined a new end cut the damage away and weld a fresh end on.

In regard my inner bush I did cut some shallow grooves to allow grease to lube.

Another thing that bothers me is the plastic tube supplied with repair kits. They split very easy with a grease gun. I always try very hard to remove the old metal tube if possible. I secure the arm in my big vise. Drive the needle bearing out from the inside. Next drive the outer bushing with a proper bushing driver into the arm pushing the tube out ahead of it. Steve (CTR)
Yeah not a fan of the needle bearing. Saw one with wear you describe. Not a good application for oscillating motion. Bushing should be better.
Steel tubes were still inside. Got one out but the other has corrosion on OD and prevents it from coming out so I left it in.

tsumini

Just got the kit. Without checking th fit I installed one bushing. Had to pound it in. Once I got so far I could't get it back out without cutting it so left it tight. It reamed out OK.
I went back and checked the fit. It looks like I've got .006T fit. Way too tight for a bushing that size. I measured them ( 0.938 Dia arm hole - 0.942 bushing OD)
Now I'm not sure how to correct it and need some opinions.
1. Ream out the arm hole to 0.940 (0.002T should be sufficient.
2. Turn the bushing OD to 0.940
3. Try to widen the seperation of the bushing with a dremel.
I believe this is the first bushing replacement these arms have seen.
For those that have done these, how do the bushings fit?

94touring

Widen the separation of the bushing?  Not sure I follow.

I haven't done an early arm or bothered to measure bushing vs arm diameter on the later arms, but they are tight and I use my press.

MiniDave

#20
They'll wear in!   ;D ;D ;D

He means widen the gap in the sleeve itself....

Are you sure the bores are clean and straight that the bushing fits into? No burrs or leftover rust?

I've done a few that I thought were just a tiny bit tight, but like I said - they wear in OK, never had one bind up or make noise....as long as you can turn the shaft they should be OK. Make sure you tighten the nuts on either end good and tight so the shaft can't turn once they're installed in the car.
Complete failure at retirement

1989 Cooper Racing Green
2009 Clubman S
2014 Audi Allroad

94touring

To echo Dave, they'll wear in.  I'd rather have it on the tight side and wear in than loose and sloppy.  So long as it moves as it should without binding.  It is important that they are reamed straight, but that's easy to determine if it slides in one end easy but binds on the other side.

tsumini

Ok I guess they're made to fit that tight. Wouldn't have guessed they would be that tight. I can press them in with a threaded rod.
Dave I have a set of adjustable reamers that I used to clean up the holes prior to installing bushing. I may give it another thousandths cleanup.
Sorry about the confusion of the bushing split. Dave got it.