What is the allowable for inner bearing wear on the front spindle?

[Tracy C.]

One of my front steering knuckles on my 63 is showing evidence of bearing wear near the base of the spindle. I whipped out my trusty 1-2 Lufkin micrometer and measured the area where the inner race of the bearing resides and got 1.243 top to bottom and 1.247 front to rear. The remaining shaft measures 1.250 before the taper starts.

I didn’t see anything in the service manual regarding an allowable amount of wear on the spindle. Does anyone have access to a blueprint noting the manufacturing tolerances on spindle diameters?

I’ve already sourced a replacement part, but I’m curious as the amount of wear that would deem the part unusable. If this thing is junk, I’m not going to keep it around.

Thanks,
tc

[Duke W.]

Re: What is the allowable for inner bearing wear on the front spindle?

I've never seen a spec, but if you can find a better one...

Do you know the mileage on that spindle?

Duke

[Tracy C.]

Re: What is the allowable for inner bearing wear on the front spindle?

Duke,

I don't know the mileage on this part. I bought it as part of a wheel hub assy years ago at a swap meet because my original spindle had gotten VERY hot at some point in it's life. My other side has only .002 wear.

I Just bought another pair of spindles off a 98K car and they measure out with only .001 wear. Typical wear patterns show mostly on the bottom of the spindle shaft. (makes sense)

I once had a 72 Olds with excessive spindle wear such that the inner bearing would chatter as the inner race rotated about the spindle. It was a very annoying vibration. The car had around 160K when I sold/gave it away.

I seem to remember reading somewhere the spec clearance for the spindle/bearing race should be .0005 to .002. I've googled the snot out my search, but can't find anything now.

tc

[Dick W.]

Re: What is the allowable for inner bearing wear on the front spindle?

Pin punch and green Loctite would be my choice.

[Timothy B.]

Re: What is the allowable for inner bearing wear on the front spindle?

Tracy,

Aren't these the same parts as full size Chevrolet in 63-4?

I think a industrial machine shop can fix it by machine for sleeve or a process called spray weld. I once had this done on a Gradall center pin that had corrosion where the O rings seperated the air/oil passages in the center pin. Worked great and saved me $$ for that center pin..

I was also told one time to slide a piece of cardboard in bottom to secure inner race. I have one like yours, Tracy

[Chuck S.]

Re: What is the allowable for inner bearing wear on the front spindle?

...I don't know the mileage on this part. I bought it as part of a wheel hub assy years ago at a swap meet because my original spindle had gotten VERY hot at some point in it's life. My other side has only .002 wear.

I Just bought another pair of spindles off a 98K car and they measure out with only .001 wear. Typical wear patterns show mostly on the bottom of the spindle shaft. (makes sense)...

...I seem to remember reading somewhere the spec clearance for the spindle/bearing race should be .0005 to .002. I've googled the snot out my search, but can't find anything now...

Maybe you're remembering right, but 1/2 a thou is an incredibly tight tolerance for most machinery including automotive (maybe crankshaft journals). I would expect allowable clearances in this case to be up to maybe a few thousandths, but less than 0.005".

At the insistence of a maintenance superintendent, I once had a coupling hub ground to 1/2 thou over mic'ed shaft fit diameter to avoid the mechanics having to use a coupling puller...it didn't work out well.

First, it took forever to install the hub because a human being can't align a male and female fit with that tight tolerance and simply slide it on. In this case, you will at least have the bearing piloted onto the smaller diameter, but alignment would still have to be perfect to get it started on the fit at 1/2 thou clearance.

Second, it didn't really help in our case anyway...even at a 1/2 thou clearance, the coupling hub fit on the shaft was fretted beyond all recognition in a few months. Mechanics finally gave it up, and a new shaft was made with a tapered fit for a new hydraulic coupling...that coupling was still running when I left there.

Tracy, as always, it depends on your objective...if you're fixing it up for a quick sale, maybe you look the other way, and put it back together. If I were going to keep the car for a while, I would replace the spindle. I suspect the inner race was turning on the shaft...I'm surprised this one doesn't show signs of getting too hot.

[Tracy C.]

Re: What is the allowable for inner bearing wear on the front spindle?

Appreciate the input,

Tim, according a previous post by Joe Lucia, this spindle p/n was also used as a service part for the 63/4 full size Chevys. At this point, reworking this one is off the table. I already have a replacement and I'm just going to use it instead.

Duke, Because you've never seen an allowable spec, and because Joe L, John H, and Micheal have remained silent, I'm convinced there is no such animal. I guess we all just use the TLAR method (That Looks About Right) to determine if a spindle is good enough...or not, to reuse on our cars.

Dick, I didn't want to confess this upfront, but before I got rid of that Cutlass, I did center punch the spindle several places under the bearing race. Don't know how long it silenced the problem, but I cant imagine that solution being a good one for a performance application such a Corvette back in the day when the cars were driven hard and put away wet.

Chuck, You are probably right on the "1/2 thou" info. Maybe it was .002 to .005 instead. Regardless, this part will go back in the spare parts pile. I hope I'll never need it.

If at some point anyone should stumble across something in the way of a specification, please share it with us.

Thanks again,
tc

[Dick W.]

Re: What is the allowable for inner bearing wear on the front spindle?

Appreciate the input,

Tim, according a previous post by Joe Lucia, this spindle p/n was also used as a service part for the 63/4 full size Chevys. At this point, reworking this one is off the table. I already have a replacement and I'm just going to use it instead.

Duke, Because you've never seen an allowable spec, and because Joe L, John H, and Micheal have remained silent, I'm convinced there is no such animal. I guess we all just use the TLAR method (That Looks About Right) to determine if a spindle is good enough...or not, to reuse on our cars.

Dick, I didn't want to confess this upfront, but before I got rid of that Cutlass, I did center punch the spindle several places under the bearing race. Don't know how long it silenced the problem, but I cant imagine that solution being a good one for a performance application such a Corvette back in the day when the cars were driven hard and put away wet.

Chuck, You are probably right on the "1/2 thou" info. Maybe it was .002 to .005 instead. Regardless, this part will go back in the spare parts pile. I hope I'll never need it.

If at some point anyone should stumble across something in the way of a specification, please share it with us.

Thanks again,
tc

There has been many a rear axle spindle and trailer axle spindle repaired with a ***** punch and green Loctite. Some have run several hundred thousand miles after those repairs. I did a few of them my self. I would have no qualms about a spindle, that had been magnafluxed, being repaired this way.