Trailing Arm Rebuild Advice

[Jack O.]

Hi Everyone,
I have my trailing arms at Bair's and was told today I need spindles. They offer new USA made for $149 each or reconditioned originals for $100 each. I'm leaning
toward the reconditioned ones but thought I would ask the forum as I always get good, insightful perspectives. I was also asked how I wanted certain parts finished
since NCRS sometimes changes its standards. I found all but the the spindle supports in my Judging Guide (3rd edition) and wanted to double check here: spindle
supports (natural?), rear caliper mounting brackets (low gloss black?), axle flange (natural?).

Thanks in advance,
Jack

[Joe L.]

Re: Trailing Arm Rebuild Advice

Hi Everyone,
I have my trailing arms at Bair's and was told today I need spindles. They offer new USA made for $149 each or reconditioned originals for $100 each. I'm leaning
toward the reconditioned ones but thought I would ask the forum as I always get good, insightful perspectives. I was also asked how I wanted certain parts finished
since NCRS sometimes changes its standards. I found all but the the spindle supports in my Judging Guide (3rd edition) and wanted to double check here: spindle
supports (natural?), rear caliper mounting brackets (low gloss black?), axle flange (natural?).

Thanks in advance,
Jack

Jack------

I don't know what they mean by "reconditioned original spindles". I really don't see how a spindle can be "reconditioned". Keep in mind that many original spindles have excessive runout on the spindle flange relative to the spindle shaft. This is because GM riveted the brake rotor to the spindle flange and trued the rotor to the spindle shaft. So, minimal runout on the spindle, as machined, was not important to them. This same problem affected GM SERVICE spindles, too, even though they never had a rotor attached to them. So, if the new USA manufactured spindles they offer guarantee minimal runout on the spindle flange (like .002", or less), that's the way I'd go.

Spindle supports were natural finish as were 1/2 shaft u-joint flanges and the splined spindle flange.

[Bill W.]

Re: Trailing Arm Rebuild Advice

Jack unless I missed it you didnt say what year . The fifth edition 65 manual says the spindle support should be painted semi gloss black before machining . I would go with a new spindle If it is the quality Joe would like to see .

[Gene M.]

Re: Trailing Arm Rebuild Advice

Even .002" runout on the spindle flange may not be good enough to maintain the rotor to under .005" runout. The diameter multiplies the runout at the rotor edge. You may have to "index" the rotor around till runout is within spec. Also consider shims on the wheel studs to achieve spec. Remember the rotor is not manufactured perfect neither.

[Jack O.]

Re: Trailing Arm Rebuild Advice

Thanks Joe, thanks Bill. It's a '69 - sorry about that. I believe what Ed (at Bair's) means by reconditioned is that they cleanup, and paint if you request it, the non-machined part of the spindle, i.e. for appearances only. Not worth taking a chance when I'm already spending all this money so I'll go with the new ones.

By the way, what Ed said was done to my spindles (not by me I might add) was that they were polished or "worked" somehow such that the bearing could be put on without having to be pressed on. As a result the whole bearing assembly was spinning on the spindle - not a good thing.

Jack

[Gary R.]

Re: Trailing Arm Rebuild Advice

Jack,
You had slip fit spindles, not a good idea. I see a lot of them that come in. Bairs will do a good job. Reconditioned probably means a good GM spindle is cleaned up. I do that to every spindle I reuse. The threads & splines are checked. The shaft is polished but not undersized. I don't like to cut the flange as long as I see the original facing marks on them but the area around the rivet and stud holes is dressed to remove high spots. Once these are done they are fine to reuse. If the application is high HP then I won't use a GM or aftermarket 17 spline axle as they do break under load.

The new spindles Bairs sells are also very good, I have used a lot of them as well. Much better then some of the "new" spindles sold elsewhere.

Runout is the norm, doesn't matter if you have new or used spindles or rotors. They either need to be riveted and machined as one or shimmed to dial in the runout under .0025". 005" is too much in my opinion. I prefer to bolt them on and shim if needed. I rather not turn a chip if I don't have to.

Keep in mind there is rotor runout and spindle endplay. The endplay is in the bearings and the spec is 001-008" at 003" you will feel movement in the spindle by hand. It will work but I like to get it down to -0- lateral play and the endplay will fall in about 0015"

Gary