early axle bearings

[Don B.]

I own what appears to be a '56 vette, but it is really made up of parts from several different years (ie, Frankenvette). Of the parts with casting numbers, it's relatively easy to figure out what year the particular part was manufactured. As an example, the frame is a '59 since the VIN is stamped into it and the differential is out of a '62 since the casting number says so. However, the rear axle housing is somewhat of a mystery, but is definitely out of a '59-'62 since it has the traction bar brackets installed. (The similar brackets on the frame were carefully cut off by some previous owner. Why?? Who knows!!) Recently I pulled the axles to have new bearings installed and found out that the bearing number correspond to those of a '57 vette (Timken #RW307R). This particular bearing is 0.905" thick and has a single O-ring. The Timken number for '58-'62 axles is RW607NR. A friend has a '62 apart and his bearing (double O-ring) is a little over 1.0" thick. He tells me that the thinner bearings will work as long as a spacer is also used in the axle housing. It appears that either I have the wrong bearings installed (expensive to replace) or that I need the spacers (approx. 0.090"T). My axle housing is about 0.910" deep where the bearings sit. Does anyone have any wisdom to pass on to me about this application??
TNX, Don

[Robert Willis]

Re: early axle bearings

Posi and non Posi Bearings ?????

http://members.kos.net/willisb/

[Don B.]

Re: early axle bearings

The differential is non-posi at the moment. What's the difference??

[Robert Willis]

Re: early axle bearings

I'm getting old and forgeting some things but I think there were ball bearings and the other type were a roller bearing. It gave a difference in width.

Bob

[Mike E.]

Re: early axle bearings

Right on--non-posi were ball bearing, posi were roller bearings. Posi bearings have been very difficult to locate for the past 25+ years. One is thinner, the other thicker--thinner with spacer will work--but, if I recall correctly, the thicker one is the non-posi and easier to find. I'm at work--don't have my books/resources with me here.

[Richard E.]

Re: early axle bearings

Did you say work? Hmmm, Any way, I recently put in roller bearings in my 62 Posi. As I recall,the roller bearings are 0.900" thick and require the 0.100" spacer. The open end of the rollers goes toward the differential. The roller bearings also have just one O ring, where the ball bearings have two O rings. The non-posi bearings are more readily available. Am I right remembering it this way Mike? Had another birthday and you know what that leads to...Regards, Dick

[James F.]

Re: early axle bearings

I remember it pretty much as Dick stated. The '65 bearings (narrow) required the .10 spacer ring which prevented the axle shaft from sliding out. In fact, a very early Corvette News suggests for race Corvettes tack weld this spacer in several places to the sxle. I guess the later and wider bearings did not require this spacer ring and the width of the inner bearing was sufficent to hold the bearing and axle together.

Prior to '56 axles Chevrolet expected the bearing to be open on the differential side and receive lubracation from the pumpkin. In '56 this thinking changed and the bearings need not receive diffeerential lubrication.

NAPA can supply correct '56 rear axle bearings. Regards

[Don B.]

Re: early axle bearings

Thanks for the information, all. It's still somewhat unclear to me, but at least I now know that I do need spacers and it's a matter of finding a pair. I'll start with NAPA.

The machine shop that replaced the bearings on my axles did so with exact replacements using the numbers. Interesting enough (but not surpisingly), the original bearings were 0.905" and had been installed in the housing without any spacers. This guy "Bubba" who I saw mentioned in a previous post certainly gets around when it comes to automotive repair.

TNX, Don

[John H.]

Re: early axle bearings

Don -

The original bearings were 0.9" thick and required the 0.1" spacer between the bearing and the housing; the replacement RW607 ball bearings are 1.0" thick and don't require the spacer. Both, however, require the pressed-on lock ring to retain the bearing on the axle.

[Don B.]

Re: early axle bearings

John,

Then, I must have the original style bearings installed since they are 0.9" thick - the only thing missing are the 0.1" spacers. With the spacers installed, the bearings will stick out of the housing about 0.1". I measured the depth of both ends of the axle housing where the bearings sit at 0.91" and that was also the depth measured in my friend's 62 housing. I notice that the retaining plates with the four bolts each are relieved to accommodate the bearings protruding from the houseing. The wisdom behind the engineering of this assembly is vague...

The bearings I have installed are RW307R and they are 0.9"T. These only have one O-ring. Do the RW607NR bearings at 1.0"T have one or two O-rings??

Yes, I do have the retaining rings installed. Thanks for your input to my situation.
Don

[John H.]

Re: early axle bearings

Don -

As I recall, the 1"-thick RW607 replacement bearings have two O-rings. Here's an original bearing installation instruction sheet for the 0.9"-thick Posi roller bearings from Hyatt, who supplied the production parts.

[Don B.]

Re: early axle bearings

John,

Fantastic! A drawing is worth a thousand words someone once said - true. There's a wealth of info in this picture. I definitely need the spacer rings mentioned in the assembly instructions (#6). I've contacted Timken and have asked for their PN for the spacers. Again, thanks!!

Don