Hey Guys,
First off I want to say I am not trying to sell anything here or reference anyone in particular. I have been reading lately about comments on rebuilding TA's and how simple it is. This is found more on social media sites where, for whatever reason, common sense and corvette repair work just doesn't go together.

I am in favor of an owner rebuilding their car if they understand how things should be done rather than just relying on what a website may advertise or what their buddy told them because he did his and it lasted 1000 miles.

This thread is really just information on what I saw with a set of arms that were recently done. This is about the 3rd or 4th time in the past year I have seen arms with Chinese bearings in them. Now this is not a China bashing thread either, if a manufacturer follows ISO procedures, using quality metal and assembly you can make parts just about anywhere.

Maybe these builds are showing up now after short usage. I would have to ask the owners of those I worked on to see if mileage and time frames were close. I do know 2 of them were in the same date and mileage range.

However, the bearing shown today came in and was binding in spots. It was not burned or impacted from what I saw, the set appeared to be as good looking as any. After removing them I noticed play in the cage more so than I have seen with USA Timken's. I had an original NDH bearing I removed from my 72 years ago and use it as check gage for the bell spacers. I put it on one axle and the Chinese one on another, side by side and clearly there was a huge amount of play in the rollers and cage with the Chinese bearing. The cage on the Chinese one was not only looser but hung lower. Now the bearing should ride on the rollers and the cage should float but that is the only thing I saw different with this set.

The set of Chinese bearings I found in a rebuilt set of 63 TA's fell apart when I removed them. The rollers literally came off under slight pressure. I didn't think much about it at the time until I saw the present set and saw the play in them.

Around here the local parts stores including NAPA carry all imported bearings, some are brand name some are not. I don't use them but many of those I see posting how cheap and easy it is to setup bearings seem to think it's ok, and for them that's their choice. Same for you I just wanted to point it out as something to think about if you do the work or if you have it done. I suspect most experienced shops would not use imported bearings, but you never know. The guy I saw on the social media site today really had no idea what he was doing yet alone advising someone else on how to set them up.

The stripped threads on the axle are also common on mid C3 axles because there is a common stake mark on some original axles. The mark is the same on all the axles I have seen, and that is a few of them. If the nut is backed off without addressing the stake you will see the result. Sometimes it can't be avoided or has been previously worked on. This is the type of thing those social media guys have no clue or experience with and could be a $200 mistake. The threads can be dressed several ways.

Good luck

 

With luck the Russian military has been buying Chinese bearings.

 

Is the stake mark on the nut, staking it into the axle threads, or on the axle thread, staking it into the nut?
Looking at the picture above I'd guess the stake is on the nut, and it messes up the threads as the nut is removed.
And how do you remove the stake? Small file? Or can you un-stake it with a hammer and punch?

 

The staking of the threads I have seen on the mid 70's axles is shown in the picture. The first one I saw I just figured it was the handy work of some previous guy but more and more I see the same indent in the same place. A small file may work, I have several chasing tools and the die for those axles. A chamfer can be cut into the end as well but most times I don't have to do that unless it's really bad and it's the last attempt to save an original axle. Now with previous work all bets are off as many are mushroomed over not staked because the correct hammer tool wasn't used. These pictures show the threads after I restored them and how they should look.

threads restored

Threads staked

 

Damn Gary, you do beautiful work. When you decide to shut down the shop for the last time, this hobby will lose one of its’ best folks.

 

What brand of bearings are not Imports these days, So I know what to look for?
Where are you finding USA Timkens? Timken has almost all their automotive components made by a Japanese company and have for years. This is what their engineering Dept in Cleveland told me about 10 years ago while I was working there. They made the decision to focus on the industrial market while making royalties off the Japanese company making their automotive stuff which was a much less profitable division for them. Not to say the japanese made stuff isnt superior to the chinese stuff but its still imported.

 

I seem to find that on most videos the tighter bearing clearance the better and the person who can get it tightest is the best person doing it. They generally don't bother to show just how they got to these clearances. I have done 2 or 3 sets of these myself in the last year or so. ( once word spreads you can do them you gain more friends ) So the only way I can see to do this correctly is to start making custom sized spacers using a surface grinder. I doubt many people have one let alone know how to use one alone how much extra time this takes. On the ones I have done as of late, are all for trailer queens or garage trophies and I was able to get the clearance down to .0004 or so by juggling the parts I had in front of me. This was done with just the Oil that came on the bearings. 2 of them I used Timkens via Zip and the last one I SKF via Napa at twice the price. Oddly I have found Randy's Ring and Pinion a good supplier and they flat out only had sealed bearings in there data base and despite telling them 82 and older don't use them. I work in the Marine Industry and when we rebuild one of the ABB Turbochargers, we send the Bearings n to be rebuilt. Yes rebuilt. How do you rebuild a bearing i have always wondered? The core exchange is worth 4k so we send them in. Figure the Turbo Compressor Wheel is about the size of a Corvette wheel and its turning at 33,000 RPM in a hot exhaust environment. The true test of a good bearing.

 

I machine fit every set of rear bearings I dial in, using a surface grinder.

Steve, thank you for the complement. I should mention the picture of the rolled threaded axle is not the same axle I cleaned the threads on. That rolled axle was junk. The one I cleaned up would have been junk but I dressed it before and after removing the nut.

As for getting USA Timken bearings for arms and diff's, I still have them on my shelf. Pretty much all I ever used with a few exceptions over the years. I would check with a bearing house over an auto parts source. You will find them, but they cost more. Remember, cheap and quality don't go together- today more than ever. I no longer list my procedures or sources as some have used my techniques and build names in the past to supply an inferior build to unsuspecting people and I won't support those efforts.

Since we are speaking of arms, here is a set of Tom's 31's I have. Whoever worked on them truly should not be working on corvette parts. There were missing parts, seals not installed correctly, and they were clueless on how to install ARP wheel studs. Those that understand this will see the story the pictures tell. Really a shame because these are the best rear axles for a corvette, now backordered, these should not have been treated as they were but will be back in shape soon.

 

Wow! What did they do? beat them in with a hammer?
If I did work like that I'd be fired!

 

Yeah, these were the best parts you can get- Toms arms, axles, complete set up and the person who attempted to assemble them just had no idea what he/she were doing. I don't know who that was, this is the condition I got them in to correct them.

 

Gary, thank you for another insightful thread. It's kind of funny, when I was a kid we made fun of Japanese parts - now they make great quality. But many of the parts, tools, etc. that are being made in China are complete junk. I redid the TAs and front inners/outers last year and made certain I found USA Timken's. They're still out there. I sure with this country hadn't exported so much of our manufacturing capabilities - in so many areas.

Best, Paul

 

Gary,
I did& and do all my work, but HATE what you have to do. I loved the old third members that were easy to adjust, but there is defenatly expertice in what you do "shimming and set up.
Now about bearings .I have over 200 A6 compressors out and so far so good. Here is what I noticed. First a respected forum member endorsed the pulley bearings I get that I am using.
I had 2 customers say that they got some oil out of the comp, but no long term loss of gas.
Well, back in the 60's I greased bearings with a gun and then the bearings were replaced with sealed bearings. Sealed bearings can be over packed and back then we were given a choice on the amount of grease was in the sealed bearing.
Well, what I get in sealed bearings are over packed bearings and the 2 in question were caused by overpacking which I learned was from heat caused from a over packed bearing. Well time told the story as the oil that seperated from the grease stopped and all was good.
I know you do not use sealed bearings, but my point was that the packing was not equal back when they came out (sealed). Now we get what they sell.
Note, that I have a 5 gallon container (plastic) of common grease. Bucket got a crack and the Palm Springs heat caused almost a qt of oil to seperate.
Nothing to do with your great post but was about the parts wer have to stand behind.

Dom

 

Hi Dom
Hope you're well. I probably should have titled it TA bearings as today's bearings is a general statement.
Grease sealed bearing do fail, no question about it. Depending on application. My first job out of trade school was rebuilding and servicing Bridgeport Mills. This was a great job for a kid to learn about machinery and bearings are a huge part of any machine. They are nothing more than anchors without them. The J & 2J heads used some open and sealed bearings and it was common to find noisy bearings that were grease sealed.

 

When I need a dif, you will be the guy. Perhaps I should say, I do not want to do your job. I did it at Chevy and , NO NOT easy.....
Takes a expert like you. Some things are not easy and ring & pinion are on the top of the list. Thanks from all for your work.

Dom

 

Now I'm really taking advantage of the thread. The Brake on my J Head Bridgeport is not holding anymore, and I am wondering what preventative maintenance I should be doing while I'm in there. I'm using the phrase " maintenance " quite loosely because in the 25 years I have owned it I havn't done a thing to it other that Oil it with Spindle Oil. Its of coarse being used by a hobbiest and not a production shop.

 

Gale,
I've had a copy of Bridgeport (Enco) I bought new about 30 years ago. Brake never worked on it. Was going to take it apart, but not a bearing and I just decided to live with it since.

Dom

 

ok a slight change of information
A J head is one with a v-belt on the pulleys
A 2J is the variable speed, first came with a 1.5hp motor then about 1980 a 2 hp motor. The motor pulley bushings are a common problem with them. I used to change them out a lot on field calls.

The brake on a j head is a fiber block. To replace it you need to take the top of the head off and break it down, 3 shoulder bolts hold the block in place. A common wear item.

2J brakes look like vette parking brakes, small shoes. Again the top half of the head needs to come off.

There have been a lot of imported copies of Bridgeports, most were junk but since Bridgeport closed 30 years ago have improved. New Bridgeport's are sold but they are imports with the name on them. There used to be a business here in CT that did the heads, but I don't know if they're still around. I lost track of it.

I have a J head on a 1955 Round ram Bridgeport with 7" riser block. Works great for vette work, not a cnc by any means, you still have to use your head to set up jobs but it works. I rebuilt the head 30 years ago at a cost of $2000 in parts at the time, way more than the machine is worth but $2000 over 30 years is a good investment. The upper sealed bearings are starting to go but I will keep it running. Bearings for mills and machine tools are a LOT more than any corvette tapered bearing.

 

Mine is a V-belt J Head with a 1Hp Motor. Hardened ways and a Mitutoyo DRO. with BP Power Feed. Bought at an auction from an Aerospace manufacture. The Auction was huge a couple of days long at more than one location. Mostly CNC The people I was bidding against flew in on their company Jets. They were bidding 5k on a mill only worth its weight in scrap. I didn't stand a chance. On the second day the site was much smaller and no place to land a Jet. I figured this Mill was the best one they had and would go to a big shot for 10k I got it for $2500. After 25+ years I think I have got my money's worth. Same Mill I had in High School Machine Shop class. I believe the serial number makes it out to be a 1977. Back in the good old days I could buy End Mills and Drill bits at Boeing Surplus for $5 a pound. I have a bad Tool addiction I have bought most every BP attachment made over the years. In the above thread I realized If I had a Magnetic Base, I could use it to surface grind Spindle Shims, so I better start looking for one. Last Year the DRO finally gave up and I installed a Newall to replace it. On the rare day when I get to run my Bridgeport is always a day well spent.