jmgtp

I had another thread going about determining if my click sound was wheel bearings or teflon washer related.

I found some confusing things. First, of all I think that my click sound is the stub axle moving around inside the hub splines. I determined this because beneath the car if I push up on the 1/2 shaft I hear my noise and I can SEE the abs ring moving! Granted this was after I had removed the large nut on the end of the axle but before I had loosened anything else. My work progressed and in under an our I had the wheel bearing sitting on my work bench.

Here are my questions:

1) the stub axle fits extremely loose in the hub, the splines have a ton of play and it pulled right out of the hub, effortlessly with my hands - is it normal for such a loose fit? On other cars I've had to press them out.

2) the teflon washer was no where to be found! I suppose in its past ownership someone could have been in there before and not reinstalled the washer, is it possible that it disintegrated?

3) the wheel bearing - it feels tight, without any play, and no bad noises. However, after I pulled the stub axle out I noticed grease around the bearing race and a big blob of bright green grease pooled in one spot. Has the seal failed or is that normal? I imagine this means the bearing needs to be replaced.

4) how do you separate the wheel bearing from the aluminum piece that is sandwiched between bearing flange and spindle?

This is the wheel bearing and the grease I see. (I've only pulled drivers side so far)


this is all that came out of the assembled unit, teflon washer MIA. Unless it is the reddish dust that is on the grease blob in the above pic.

Sidney004

3) In my experience, the leaking grease is a kiss of death. I've found it leaking when the hub assembly falls apart not the through a leaking seal.

4) Use a plastic hammer and pound it out.

xrav22

It looks like the splines in your bearing are stripped. check my garage I have a schematic

Klyde

What year is your car? On most if not all the bearing and hub are one piece. They do not come apart and you replace it as a single unit. I replaced mine on my 96' last spring and the spline pulled out easily. I used WBI tapered bearing rear hubs and put never seize on the Teflon washer and the splines so they can move freely. The WBI tapered hubs are supposed to be heavier duty but some racers say they only last a little longer. These are guys who go through a set every season so who knows. For every day use I recommend the WBI units because they help with sideways forces which the originals don't. WBI makes almost all the hubs (not the bearings) for all cars in the US and added a tapered bearing to their hub just for the C4's.

I also think your hub splines are worn. I wonder if a past owner might have replaced the hubs with a lesser priced unit. The seals are toasted and the splines are worn plus the washers are missing showing signs of someone being there before you.

jmgtp

Car is a 94 - and yes they are sealed units, have to replace whole hub not just bearing. That said, I agree that all signs point to someone has been in there before.

I've concluded new bearings are in order. I've placed an order for 2 SKF rear bearings, they are of the ball bearing variety. I contacted the parts house to see if they could tell me whether or not the SKFs were manufactured in the USA or overseas. They couldn't and noted bearings are manufactured globaly and they don't have any country of manufacture info. Heres to hoping USA, but Google reveals SKF does some (maybe most?) manufacturing in Mexico. Has to be better than the junk bearings coming out of China.

I don't track the car and do most of my spirited driving in a straight line. The literature for the bearing claims an expected 100k mile service life. I already have a set of new Teflon washers to install and I need to clean up the mating surface on the stub axle where the washer would reside since it looked a bit galled. In person the splines on my old hubs don't really look worn to my untrained eye but the stub axle does fit surprisingly loose. I ordered a set of poly bushings for the trailing arms too, the original rubber set is completely trashed.

In case anyone is interested, the part number for the SKF rear bearings for the C4 is BR930024. Once received I'll post if there is any indication to where the bearing was manufactured.

Klyde

I've read good things about the SKF's so you should be good to go. I bought the tapers because I like to sprint through the turns. I don't race either but I like to use the car for what it is. With the size tires these use the rear bearing get a lot of side force and is why they are well known for them going bad. I'm old enough not to want to replace them ever again so I choose the tapers hoping they last the rest of my life. Only time will tell. When you replace the rubber bushings make sure you coat the poly's heavily with never-seize. It stops the squeaks.

WW7

I've had SKFs in my 89 for 6 years/42,000 miles without any problems.. Just make sure you put the teflon washer in the correct way, the picture below will show how it goes in, the lip should face outward...Also make sure you tighten the large outside nut to the correct torque, don't guess, use a torque wrench......WW

http://forums.corvetteforum.com/1585368450-post5.html

jmgtp

Can anyone explain why torqueing the 36mm nut on the wheel bearing is so critical for bearing preload on a sealed bearing/hub assembly? I fully intend on using a torque wrench to hit the specified torque, but if you look at what it is torqueing down it doesn’t seem like it can possibly be the preload on the bearing. The applied torque is on the inner race of the bearing and it seems that it would only impact the preload on the Teflon washer as it is sandwiched between the hub and stub axle. Does my logic make sense? The preload on the bearing is performed during production of the hub and cannot be altered by the installer. That said, I could see the need for a certain torque spec as under-torqueing could be a problem with a loose fitting stub axle and over-torqueing could deform the inner race of the bearing. But I don’t see how it can preload the bearing. Again, this is a curiosity thing – I’ll be using a torque wrench.

Older cars with servicable wheel bearings, yes, the torque on that nut certainly would be setting preload. My arguement is that in sealed hub/bearings, such is the C4, the torque on the nut is not effecting bearing preload.

WVZR-1

The intention is NOT preload as such regarding the bearing but "securing" the hub/bearing assembly to the splined spindle shaft which sees "severe" duty in just daily driving. A loose nut creates an issue that will tolerate the travel of the hub/bearing "laterally" on the splined shaft. The torque procedure makes good sense to me and I can't see any argument that could debate that. Your images I believe satisfy what I've mentioned.

Sidney004

I agree with you, I don't think it has any effect on preload. I've destroyed at least a half dozen sets of rear hubs as a result of road racing my 94 on slicks at Laguna Seca, Thunderhill and Sears Point. When a hub failed on mine, there was of course excessive play but the spindle nut was always loose or sometimes finger tight and that was not a result of undertorqueing the nut but the hub assy structure falling apart. The components of the hub assy would literally fall apart upon disassembly. This was common to all brands that I encountered.

WW7

I have seen on a few Corvette sites, including this one where people have said the new torque settings for the nut are (195-200) ft lbs ....I have never used these new torque settings because I could never find an update or notice from GM saying these new torque numbers were correct, I still use the GM (164 ft lbs)...But, I do know a few guys who use the higher settings......WW

Crepitus

maby a retork would be a good idea after everything has had a chance to settle in. These wheel bearings are the only thing I really despise about these cars.

Crepitus

What is a WBI bearing?

Klyde

Wheel Bearing Incorporated. They manufacture almost all the bearing hubs/housing for the US market. They sell one of their hubs with a tapered bearing for the C4's. The tapered bearing has up/down as well as side ways race way. It uses cylindrical/roller bearings instead of ball bearings. The C4's have a lot of sideways force on a ball bearing that has no sideways race surfaces so it tears them apart. At the time these cars were made they had no tapered bearings that would fit in the hubs confined space. WBI made a hub that would except a modern tapered bearing and still maintain the outer dimensions. They are priced really nice too and are an exact replacement including the speed sensor gear. The WBI part number for my 96' is WBI-513020HD. The normal ball bearing style is WBI-513020. The price I paid last spring was $133.00 each. I bought them through MIBearings.com. Summit also sells them, just search for WBI-513020HD but they are a few dollars more. Here is a Summit Link:

http://www.summitracing.com/parts/WBI-513020HD/

And a pic of it installed in the rear knuckle:

jmgtp

I received the SKF wheel bearings and couldn't find any documentation regarding where they were manufactured. They do seem like a quality set and are EXTREMELY tight, difficult to rotate by hand. Maybe its from the seals? Maybe its the preload. Not sure. I'm still looking for my FSM which I need before I can reassemble as I have been unable to find all the torque specs that I need. It's been missing since we moved in June, hopefully I can find it soon.

WVZR-1

If they were in SKF packaging I would think the package would indicate COO (Country Of Origin). The SKF Torque Guide still shows the 164 spec for torque all '84 - '96 C4. I've never seen a TSB that suggested a change in that. A '94 FSM confirms that. I've never seen it mentioned but I always thought that the torque needed to be established with "clean & dry" threads.

If you need torque specs use the email option for me and give me your email. I'll snapshot the '94 and send them. I can likely do any that you need. Just ask!!

Crepitus

Thanks!

Gale Banks 80'

This post might a bit old but since I'm right into this very thing I thought I would bring it back up. I'm in the process of installing the Street Shop C6 Brake conversion and the Bearing Spacer Washer needs to be a custom width. Mine is an 86, and my OEM washer is Steel, I'm reading here about a Nylon one, it must be used in the later Years. There is no mention of what if any Washer is Used with the WBI 513020 HD Bearing, shall we assume that is uses the same Steel Shim washer as the early years, and the nylon one when ever that came to be ? I see that with the Timken Bearing fits all C4's with the same part number, shall we assume that all the Axle Parts are interchangeable, and that a Nylon Washer could be used in the earlier cars as well ?

QCVette

I never heard of a nylon washer used.

The factory ones are teflon coated steel and the part # is 14076924. I think all C4 years used it.

Gale Banks 80'

OK, so my rusty old steel washers had a Teflon coating when they left Bowling Green. And I will assume that all the C4's probably have interchangeable Bearings and Axles, except the 84-5's didn't have the ABS Vanes.
I think I will go with the WBI513020HD unless somebody has had an issue.