C1('62) Rear Axle Question

[rkew]

After sitting around relatively inactive for 20 years, the seals on the rear axle of my '62 are shot, particularly the seals at the left rear wheel and the one behind the yoke. Is replacing the seals at the wheels as easy as removing the carrier from the axle, popping off a couple c-clips, and sliding each axle shaft out of the axle? None of the reference material I have speaks to the assembly and disassembly process of the axle itself.

Additionally, are there any tricks associated with removing the carrier and/or re-inserting it, or is it as easy as removing the bolts around its edge and sliding it out of the pumpkin area (and then back in for re-installation)? It's not a posi rear end if that makes a difference.

Thank you,

Ryan

 

[John Mcgraw]

Ryan,

You do not need to remove the center section on a C1 like you do on later GM cars. There are no C-clips holding the axles in. The axles are retained by four bolts on the end of each axle tube just like a Ford rearend. just remove the bolts and slide the axle and retainer out of the rearend. The bad news is that at this point, you have to take it to a machine shop to have the seals changed since it requires the bearings to be pressed off to change the seals.
While we are on the subject of seals, there is a good reason that the seals seem to go away after only 10-20 K miles. The seals that have been sold for the last 30 years or so, have the seals configured incorrectly for use as C1 axle bearings! The original bearings were open to the rearend and had a seal on the outboard side of the bearing with the lip set to seal from the inside out. The current bearings have a dust shield on one side and a seal on the other, but are configured to heep contamination out of the bearing. The failure mode is as follows: The bearing is factory lubricated and will serve well until the bearing gets hot and grease begins to weep out of the bearing into the brake drum area. as the bearing runs hotter and hotter, more grease runs out the bearing until it gets so hot that the seal fails and allows rearend lube to run into the bearing. The bearing now gets the lube it was crying for, but unfortunately, the lube runs right through the dust shield and staurates the brakes!
You can convert the bearings to last a lifetime by preforming a couple of simple steps. 1. pry out the dust shield and discard it. 2. remove the seal and turn it around and re-install it in the opposite direction. 3. install the bearing with the sealed side of the bearing toward the brakes. This will allow the rearend lube to keep the bearings libricated and will make them last a long time! The only tricky part of this is getting the seal out without damaging it, but despair not, a new seal is available from your local auto parts store for a couple of bucks! I have had very good luck with using a small pin punch and driving the seal off by punching through between the balls in the bearing.
There are almost no mechanics or machine shops that are aware of this misconfiguration, and they just continue to install them as they come out of the box. The bearing works OK, but a few thousand miles later, you have a leaking seal again! All of the old mechanics that used to know this information, are either retired or taking a dirt nap.
One other little item that you should be aware of: If you car has the original bearings in it, the bearings are only .90" wide and it will have a .10" spacer behind the bearing. The replacement bearings sold now are a full 1" thick and do not use the spacers. If you use the spacers behind replacement bearings, you will distort and ruin the bearing retainers when you torque the bolts down.
The pinion seal can be replaced without removing the carrier. just loosen the nut and remove the yoke and seal. When replacing the yoke after the seal replacement, remember to put some non-hardening sealer around the splines of the yoke before installing it. There are probably as many pinions leaking from around the splines as there are leaking around the seal! Be cafeful not to crush the crush sleeve any further when tightening the nut back on, as this is what sets the pinion preload. It will take a large breakover bar to tighten the nut with an equally lagre bar to prevent the flange from turning .
Regards, John McGraw

 

[maxphunn]

C1 rear axle.

Great info John. Thanks for posting it.

 

[rkew]

John,

Wow. Thank you for the very detailed answer.

The brake saturation thing is exactly what happened on the left rear. The reason I assumed the axle shafts are held in by c-clips is I already removed the four bolts on the end of one of the axle tubes and gave it a couple good yanks but it didn't budge. Are the four bolts you're referring to the same as the four bolts that secure the brake assembly backing plate to the axle tube? If so, are there any special tricks or techniques I should use to get the axle shaft out?

I have another question for you since you seem to be very knowledgable about rear axles. How much would you expect it to cost to have my non-positraction rear axle converted from it's current state (not sure about the ratio but I don't think it's a 3.70, more like 3.08 or 3.40) to a 3.70:1 positraction unit? Is that a job that's easy enough for the average weekend mechanic or does it require specialized tools and therefore should be handled by a professional?


Thank you,

Ryan

 

[Rowdy1]

Axles

John,

Wow. Thank you for the very detailed answer.

The brake saturation thing is exactly what happened on the left rear. The reason I assumed the axle shafts are held in by c-clips is I already removed the four bolts on the end of one of the axle tubes and gave it a couple good yanks but it didn't budge. Are the four bolts you're referring to the same as the four bolts that secure the brake assembly backing plate to the axle tube? If so, are there any special tricks or techniques I should use to get the axle shaft out?

I have another question for you since you seem to be very knowledgable about rear axles. How much would you expect it to cost to have my non-positraction rear axle converted from it's current state (not sure about the ratio but I don't think it's a 3.70, more like 3.08 or 3.40) to a 3.70:1 positraction unit? Is that a job that's easy enough for the average weekend mechanic or does it require specialized tools and therefore should be handled by a professional?


Thank you,

Ryan

Removing the four bolts on the axle plate will allow you to pull it. If you don't have the right puller, which I don't, what I do is take the brake drum, turn it around with the center out and slide it over the studs backwards from the way you would normally install them leaving a 1/2 inch of threads showing. Then take the wheel nuts or any flat nut with the same thread and run them up to the drum. This will allow you to slide the drum towards you and back to the hub acting as a puller. A few shots, they should come out, crude, but it works.
As for the posi, although I own a 62, I'm no pro, but I believe the housing for the posi is slightly larger inside and you will have to find a pumpkin with the large "P" on the outside and gear that. I'm sure John will know the exact reasons. Let us know how you make out.

 

[John Mcgraw]

Ryan,

A slide hammer axel puller is sometimes needed to get the axle out.
I would not reccomend building up a rear pumpkin if you have had no expreience doing so. There are a lot of tools and tricks of the trade that are only accumulated over years of experience. I would think that you would be well served by having someone build up a pumpkin for you and then you can install it.
If you are wanting to keep the car correct for flight judging, then you will have to find a Corvette Posi unit which differs slightly from a passenger car unit. The P on the case is a different size and shape. A passenger case will work fine, it will just be noticeable at judging. There is another alternative. There is a company called US Gear that makes a new posi unit that I understand will fit in an standard open carrier. This way you could have a posi rear with out getting a deduct for the wrong casting, and nobody will even know that you have a posi! A correct, rebuilt, original, positrac unit will tear the hell out of $1000.
Regards, John McGraw

 

[rkew]

John,

I'm not restoring it for judging so fortunately I won't have to track down a Corvette posi-unit and incur the costs that accompany such a unit.

Just to make sure I understand your message correctly, are you saying that posi carriers (and non-posi carriers) from GM vehicles of that era with the same rear axle setup will fit the axle on my '62 (i.e., a posi carrier from a '62 Impala will bolt right up to my axle)?

Assuming that's the case, do you have any recommendations on cost-effective ways to get my hands on a quality positraction carrier that fits my axle? I'm guessing there are a number of suppliers on the web that offer rebuilt units.??? I guess there's always the path of finding one at the ol' salvage yard and taking it to the local axle-man for a rebuild? Any ideas what positraction rebuild using parts from a dependable manufacturer should cost?

Thank you,

Ryan

 

[Rowdy1]

Not Too Many Left

I've seen them on eBay going for $400 and up but that's an as is, it could be shot, you're actually buying the pumpkin. They're out there, but not falling off of tree's and NOT cheap. Plan on having one rebuilt if you do find one, you can look at Summit racing online to price out the parts, then figure in the labor. It does make a big difference in traction, also a lot more impressive when you do a


Good Luck

 

[studiog]

Ryan,

You do not need to remove the center section on a C1 like you do on later GM cars. There are no C-clips holding the axles in. The axles are retained by four bolts on the end of each axle tube just like a Ford rearend. just remove the bolts and slide the axle and retainer out of the rearend. The bad news is that at this point, you have to take it to a machine shop to have the seals changed since it requires the bearings to be pressed off to change the seals.
While we are on the subject of seals, there is a good reason that the seals seem to go away after only 10-20 K miles. The seals that have been sold for the last 30 years or so, have the seals configured incorrectly for use as C1 axle bearings! The original bearings were open to the rearend and had a seal on the outboard side of the bearing with the lip set to seal from the inside out. The current bearings have a dust shield on one side and a seal on the other, but are configured to heep contamination out of the bearing. The failure mode is as follows: The bearing is factory lubricated and will serve well until the bearing gets hot and grease begins to weep out of the bearing into the brake drum area. as the bearing runs hotter and hotter, more grease runs out the bearing until it gets so hot that the seal fails and allows rearend lube to run into the bearing. The bearing now gets the lube it was crying for, but unfortunately, the lube runs right through the dust shield and staurates the brakes!
You can convert the bearings to last a lifetime by preforming a couple of simple steps. 1. pry out the dust shield and discard it. 2. remove the seal and turn it around and re-install it in the opposite direction. 3. install the bearing with the sealed side of the bearing toward the brakes. This will allow the rearend lube to keep the bearings libricated and will make them last a long time! The only tricky part of this is getting the seal out without damaging it, but despair not, a new seal is available from your local auto parts store for a couple of bucks! I have had very good luck with using a small pin punch and driving the seal off by punching through between the balls in the bearing.
There are almost no mechanics or machine shops that are aware of this misconfiguration, and they just continue to install them as they come out of the box. The bearing works OK, but a few thousand miles later, you have a leaking seal again! All of the old mechanics that used to know this information, are either retired or taking a dirt nap.
One other little item that you should be aware of: If you car has the original bearings in it, the bearings are only .90" wide and it will have a .10" spacer behind the bearing. The replacement bearings sold now are a full 1" thick and do not use the spacers. If you use the spacers behind replacement bearings, you will distort and ruin the bearing retainers when you torque the bolts down.
The pinion seal can be replaced without removing the carrier. just loosen the nut and remove the yoke and seal. When replacing the yoke after the seal replacement, remember to put some non-hardening sealer around the splines of the yoke before installing it. There are probably as many pinions leaking from around the splines as there are leaking around the seal! Be cafeful not to crush the crush sleeve any further when tightening the nut back on, as this is what sets the pinion preload. It will take a large breakover bar to tighten the nut with an equally lagre bar to prevent the flange from turning .
Regards, John McGraw

WOW John This is great info and if you don't mind I would like to copy & file it with all my other tech info I have gathered for my "61

 

[rkew]

John (or anybody else out there),

Any ideas on where I can get my hands on a new carrier gasket and yoke and axle seals for a '62 rear end? Mid-America and Ecklers don't seem to go back past '63 on those parts, a guy I talked to at NAPA claims they don't carry them, and another local auto parts store was only able to locate the carrier gasket and the pinion seal (not the axle seals). Any help would be greatly appreciated.

Thank you,

Ryan

p.s. - FYI, I found a local shop who says they're familiar with the older rear ends and shold be able to replace the gasket and seals in roughly an hour if I bring in the axle out of the car (which I've already removed). If the bearings are still in good shape, which they said they'll check when the pull the axle shafts, I'm looking at roughly $50 plus the cost of the gasket and seals ($20 or so). I was pleasantly shocked. Hopefully the bearings and everything else inside is in good shape.