63-82 Rear Trailing Arm Rebuilding
:crazy: Ok here is one job I get a lot of questions on. First thing I find is that a lot of guys are intimidated by this job. Once you understand corvette rear bearings the mystery will be gone. You'll be able to decide if you want to buy the tools and try the job or farm it out. Now the tool cost for a set of arms is more then farming them out so think about what your plans are. If you want to join the dozens of Arm Rebuilders out there buy the tools - but do the job right. This post will have pictures of various jobs I did so don't be surprised if the arms look different.
To do this job follow the GM manual procedures. I do some machining to my jobs that others don't. Take it for what it is and make your own choices. One thing I already know is guys have been asking questions now as opposed to just having the jobs done. Also ask your rebuilder if they supply any job reports and pictures on their work. I like to keep the car owners involved and make sure they know what was done with their arms.
Here are what your arms may look like once you get them out. I always rebuild them off the car but they can be done on the car. I would never do it that way unless I was stuck out of state on the road. Doing them on the car will not address the front bushing for dry rot and play. Trying to get an accurate setup will be difficult but getting a "good" job with GM specs up to 008" endplay is possible- if that is what you want ok, I like to dial them in much tighter so there is no lateral play and the bearings are smooth.
Here is a 64 arm. Remember the 63-64 and some 65's had drum brakes.
Look them over for rot, being bent, and look at the front bushing for dry rot.
I use one of those spindle protectors and either press or hammer the spindle out. If you hammer them out place something to catch the spindle. Don't worry about the bearings as they will be replaced anyway. If you have one that is really rusted the press and some heat may be the only way to go. Also the spindle nut should come off and the tool thread on without a problem. Many times these have been worked on before and the threads are already shot and a new spindle is needed.
REVISION- I have not used a press on any arms now in over 15 years. A 4-5 lb mini sledge and the spindle knock out tool should be all you need.
Here we have parts to one arm apart and cleaned up for inspection.
Here I found someone was in here before and installed the outer seal backwards.
Once stripped down, I remove the front bushing
Drill the flare out and use an chisel to remove. I used to put these in a Bridgeport mill but a large step drill works as well.
With the arm apart, I blast them to the metal and POR15 prep and paint them. I top coat with a satin black.
I use only rubber bushings, no poly for me. The rubber have to be compressed and then flared to correctly install them. I have found all kinds of crap work in this area, some have even left them unflared!
Here is the tool I made. Works good. There are a few on the market, some good -some junk.
Here are what mine look like
63-82 Rear Trailing Arm Rebuilding Part 2
Next look at your spindles. If you have threads like this replace the spindle.
Ok on to Bearings. I use only Timkens and CR/SKF seals. I could debate the fact other bearings are just as good or Timken are not made here anymore. You decide what you want. You can save $20 using imported bearings if you want. The Timkens I have are still stamped USA and I'll pay more for them.
The book calls for .001-.008 endplay in the bearings. I set them to .0015 -.002 +/- .0003" That is correct 3 tenths. Others may tell you otherwise which is ok for them, remember this is how I do them.
Here is the fixture I made to setup the endplay
Now here is the deal on this job. IF you want the BEST job done use a surface grinder to dial in the endplay. If a guy tells you he can dial in .002 endplay with just the common shim kits - walk away. I have never had one shim I could use without grinding it to size. Also you see those kits with the new spacers in them, total waste of your money. Unless the original spacer was burnt by an idiot with a torch they are still good and they do not fail in service. The thing with them is they are not parallel finshed. I always parallel grind them before even setting them up in the fixture. It is not uncommon to find them out .005 or more. This can change the endplay you setup on the setup tool to the final press on install. The amount of damage on the spacer faces will determine just how much I have to clean up before I can reuse them. Sometimes the large diameter is beat up pretty bad and once cleaned up the spacer is no good because the inside angle where it is tapered will hit the shoulder on the setup tool or spindle. This is important, if you miss it you will never dial in the endplay and the reading you get will be false. Once on the spindle or setup tool there should be no gap under the spacer, if you can slip a 001 shim in there then it's all done and you will need a new one with the full counter bore end.
OK with the spacers ground and in the fixture. I use a large shim to start. I have one that I use as a setup shim. I torque the tool to 100 ft/lbs and see how much endplay I have. Then grind a new shim to size and double check it. I only use light spindle oil on the bearings- no grease until you are done and ready to install the bearing in the press.
Use a micrometer over a dial caliper for this job. If your guy thinks a mic is a C clamp - walk away. Or even better as reported in a leading corvette magazine- "so and so has been rebuilding rear bearings for so long, he can feel the correct endplay"
When the endplay is set I install the prepped and painted parts on the arm.
It is much easier to install the parking shoes with the spindle out of the way.
Now before you install the spindle you have to remove the outer bearing. This should be done before you get to this point. Remove the bearing, clean the spindle, check the journals, replace the studs and I face the flange in a lathe as well.
Now if the threads are rolled a little you may be able to save them. I have a thread forming tool, thread file, lathe, but you can use the "old school way" of using an old nut and some very fine lapping compound to clean them up. BE sure the threads are good and you use a new nut before you get to the bearings.
63-82 Rear Trailing Arm Rebuilding Part 3
OK now we are up to assembling everything right?
The spindles are cleaned up, the arms painted, bushings installed,and bearing endplay set. One of the spindle preps I do is to remove the rivets and tap the hole 3/8-24. We'll explore this more when I get to the rotors.
Ok, so grease the outer bearing, I use Mobil 1. Install it in the housing, install the outer seal- I use Ultra Black on the OD and grease the rubber seal ID.
Place the spindle in there - it will be loose. Place the spindle on a support and install in the press and press on the outer bearing. Pack the inner housing with grease but leave room for expansion. Install the spacer and shim- you did have them parallel ground didn't you!:smack
Grease the inner bearing and put it on the spindle. Transfer to the press again and press the inner bearing on the spindle. Bring it back to the bench and install the inner seal- again RTV on the OD. I then usually re-use the shield and loctite it in place. With the yokes, I again grind them, clean them up and chase the threaded holes.
Torque the new nut to 100 ft/lbs and check the hole for the cotter pin. If needed you can tighten some more and install the new pin. If the hole is out a lot I grind the nut face to index it on the spindle. The spindle should spin snug but not tight. If you need two hand to rotate it there is something wrong. At .002 endplay you can feel movement,not much but you can feel it.
If something is wrong at this point you have to start over. Now here again is where the job differs as I have seen spindles so tight they could not be moved and so loose the endplay was over .004" Where did I see these works of art? - on tables at Carlisle for sale.
Now I countersink the rotors and bolt them on to the spindle flanges with 3/8-24 flat heads. Then setup an indictor and check the rotor runout. It doesn't matter if you have original rotors, new USA or new imported they will have runout. If over .002 I shim them to .000-.002" You can go to .003 ok. I wouldn't use anything over .003 and you should not accept anything other then that.
I do not like the procedure of using just the lug nuts to hold the rotors on. The runout can change everytime the wheel is removed that way. Many do it this way, I don't. I want the runout to stay where I dial it into.
OK so what do you think and did I answer your questions? Does the job still seem tough once you have the tools and procedures? Doing it my way will take longer but do you want this job rushed? Be honest with yourself and think it through before starting.
Excellent, very well done write-up! :cheers:
One other thing I would like to see added are the torque specs for the trailing arm bolts... wheel (lug) nuts....and I think that's about it.
hey Gary, thanks again for the kickass posts. I merged and stickied 'em for you.
This is quite a task to undertake, but with the right tools and great advice/pictures like this it makes it much easier! I did everything I could by my self, but left the rear spindles to a shop. Probably wasn't the best work ever, but maybe the next time I do the job I'll have the right tools.
As always, nice work :thumbsup:
Thanks Jason. It took me some time to get this info together tonight and I went back to check for spelling errors.
The only torque spec's for this job is the 100 ft/lbs. The spec for the lug nuts and front bolt are in the AIM. I don't konw them off hand. I never torque lugnuts - always use a large cross wrench to tighten them. Front bolt should have car weight on it when torquing.
GTR1999 ,Great info & pics.Would you mind if i posted a link to your post in another forum ?
Sure, but what forum? I think I have some procedures posted in Australia and soon Denmark as well at various vette club sites.
The forum is "Chevy Talk"
Theres a guy from "Iceland" looken for info on doing the bearings on his 78, this will help him out a lot !
I'm doing a 65 now and one arm has locked up spindle bearing. Thought you might want to take a look. The smell was something awful too. The spindle is wrecked but the support may still be good. I'll clean it up and mic the ID to see if the race spun and bored it open.
Here is the inner bearing with the flange off. Looks pretty good huh:laughing:
Here are what's left of the rollers. These were the original Hyatt bearings.
Here is the race. Look and you'll see it's coated with welded on roller metal.
Here is what is left of the bearing, the inner race.
Spindle is done.
Gary, That guy got his money's worth out of that bearing:laughing: I saw your comment above about poly bushings in trailing arm pivots. I have offsets that only come with poly bushings. Do you know if rubber bushings could be used instead?
Wonder how long that thing made total death defying hideous NOISE before it was finally pulled.....jeebus man, talk about instant DEATH...:crazy: :crazy: :WTF :cheers:
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