VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Pinion and Ring gear replacement

I have tried to add to my previous post but it keeps knocking me out so here is a new topic on an old post.

My "second mechanic" is putting the new ring, pinion, and bearings assembly into the rear dif and discovered that there is a lot of play with the pinion shaft rear bearing 5.484.

He is not sure if this is correct as he suspects its to much play and the book doesn't really show it.

Interesting the old/damaged bearing that was just recently installed and purchased from the Filling Station as a kit was the same with and the snap ring? that held it together had come apart and was just spinning on the pinion shaft.
is there about 1/4 play back and forth?
see pics

The same bearing, Hayatt #OR-1506 was used from 1937-1954.
Is it the same width as the old bearing?
No, it should be snug against the snap ring.
Is that a new pinion gear. Is the space between the snap ring and actual gear the same as the original.?

Either the bearing is the wrong width or the spacing on the pinion gear is incorrect IF IT IS A NEW PINION GEAR.

Shoot who knows if it is the same bearing as the original old one? It appears to be the same that the first mechanic put in after he rebuilt the rear end. Snap ring? Not sure where that is? and I'm not sure about the spacing either. All I know is that the 2nd mechanic thought it was odd or incorrect to have that play back and forth as shown in the pictures.
Yes new pinion and ring gear.

Just an FYI here, the 5.484 is not a part number.
Instead, it is a "group number", or the physical location, within the GM parts catalog, where the various pinion bearings are listed.

It has been over a year since I rebuilt my rear axle differential assy but I believe I had the same clearance. When installing the pinion into the case the bearing had to be tapped to seat it so I do know that it was not tightly locked in place but I can not verify the amount of clearance.

Same clearance?
Are you talking about the bearing play back and forth like the pictures?

There should be no "PLAY" OR MOVEMENT BACK AND FORTH.
The bearing is driven back as far as it can go and the grove for the snap ring should be visable so the ring can be installed.

Is this a new ring gear and pinion?

Yes everything is new again

#1-compare the space between the snap ring grove and the actual pinion gear. In other words the area covered by the bearing. Measure old and new. My guess is the snap ring grove is in the wrong location on the new gear and the space is too wide.
If your "mechanic" was sharp he would figure this out.

While I agree that there should be no "back and forth" movement my repair manual shows spacer tool # J-4050 to set the pinion to bearing clearance which to me indicates that there is space between the bearing and pinion though it does not specify that space or clearance. If someone has that tool perhaps they could tell us it's thickness. The pinion lateral movement is set by the front pinion spacer and bearings so no lateral thrust should be on the bearing closest to the pinion gear. This is not stated in my repair manual but is my opinion. I do agree that the space in the above photo looks excessive however the clearance to the pinion needs to be checked when installed.

we have the tool FYI, and my mechanic is talking to the Filling Station as we now think the bearing is wrong width? and or the pinion was made wrong?
again the "old one" original if you will is long gone, as everything was replaced about a year ago from the Filling Station replacements
now the second set does match the 1st replacement set, so maybe that's why the bearing blew apart and caused all the ring and pinion gear damage as well.
Bottom line is that play is toooo much and we need to figure this out. Sounds like we need the replacement bearing SKF R1506EL and the one that comes in the kit is to narrow?
more to come I'm sure.

The width should be .748. My sources tell me that the OR 1506 Hyatt original bearing is NOT a thrust bearing. When the pinion is installed and the three locking screws tightened it forces the spacer against the front bearings and locks them in place. After that process THEN the rear pinion bearing clearance is checked. The SKF number listed is the same width (.748)as the hyatt original OR1506. There also was a change in the differential housings about June of 1951 and the front pinion bearing bore depth was changed so the shim requirement was changed. Prior to June, 1951 required two shims and the later required only one. Do you have an axle serial number?

This is what I would recommend for your protection.
If the space AFTER THE SNAP RING IS INSTALLED MORE THAN .750" I WOULD CONTACT THE PERSON YOU BOUGHT THE GEARS FROM AND GET HIS RECOMENDATION. GET IT I WRITING SO IF A PROBLEM DOES ARISE HE WILL REPLACE THE PART AND PAY FOR THE LABOR.

END OF STORY.....

that would be the Filling station and I have my guy talking to them about it.

thanks!

may just end up "tubing" it and dropping a big HEMI and new rear end with huge wide slicks on it?
and a roll cage of course!

NOW YOUR ROLLING, EXCEPT USE A 572 bbc WITH AUTO, 720 hp , THATS 295 HP MORE THAN A 426 HEMIIIIII .. DON'T FORGET TO ORDER A PARACHUTE TO STOP IT...............LMAO

MIKE LYNCH..............

It's the responsibility of the "mechanic" to determine if the part is correct or not and if he can not then find someone that can.

Got a call from mechanic number two late today as he firgured it out with the help of Steve? At the filling station. I'll know more tomorrow the "T" is ready to be picked up. Guess I'll be re installing the whole rear end this weekend. Not looking forward to those leaf springs!

Stopped by mechanic number one today, thinking he may have the "original" set of bearings from almost a year ago now to compare to the second set replacements. No such luck. However I told him why and he felt real bad and asked me why I didn't take the car back to him as it would have been under warranty.
I said after the Oakie bushing re install and getting what 20 feet away from you door and letting off on the gas and hearing a sound that sounded like the whole rear end fell off. Then learning that you didn't test drive the car after dropping the whole rear end and torque tube. And then you realized you didn't screw in the third member bearing retaining bolts which you should have known most likely would cause one heck of a problem to the ring and pinion gears. Then you told me a couple of days later when I went a second time to pick the car up you said "has the rear end always had that hum?" And just drive it about 1500 miles or so and see if it goes way as it may need to seat.
Well let's just say I lost confidence in you.
He agreed he screwed up and offered to pay for the new parts (currently around $1000). But not the labor as he could have done the work.
I'll be working on my bill for removal and the re install of the complete rear end. Mechanic number twos labor bill. And the parts bill. And the second Uber driver bill and pictures, time lines, etc and will see if he steps up and makes it right. If not we are off to small claims court.

I am sure Steve will help you get the problem solved.

Keep us posted.

I have overhauled one 1937 Chev 1/2 ton rear end and two 1940 Chev 1/2 ton rear ends, and can say that there is, indeed, axial clearance on the rear pinion bearing. I don't know for sure, but my guess is that this applies to all mid-30'and up Chevrolet passenger and 1/2 ton truck torque tube type rear ends. With the rear pinion bearing installed on the pinion shaft and the circular bearing retaining ring installed in its groove, there is about 1/8" axial movement of the bearing between the front face of the pinion gear and the lock ring. Because the rear pinion bearing is for radial loads only, and the front pinion bearing absorbs the axial loading, the pinion shaft is allowed to "float" axially in the rear bearing.

When assembling the propeller shaft/pinion assembly into the torque tube and differential housing, Kent Moore tool number J-4050 is used to locate the rear pinion bearing axially. I didn't have a J-4050, so I made one out of 1/8" flat stock, which worked fine. The J-4050 insures axial clearance between the outer race of the rear bearing and the front face of the pinion gear. If you don't use the tool, or a facsimile thereof, the front face of the pinion gear will contact the outer race of the rear pinion bearing as the propeller shaft assembly is driven into position and will rub against the bearing, resulting in a potential problem when put in service.

I could have sworn there was a photo and reference to the use of the J-4050 in the shop manuals, but it's not in the 1937 or 1940 shop manual, so it must have been in the Service Bulletins.

I have found the best way to install the propeller shaft assembly into the torque tube/differential housing is to stand the torque tube up vertically with the differential housing up. The front end of the torque tube must be blocked up to allow the propeller shaft to protrude about 1" in its final position. It's best to have a helper for this job. With the torque tube held up vertically, tap the back of the pinion down till it seats in its final position. Tap on the center of the pinion--not on the gear teeth. By having the torque tube vertical, the forward pinion bearing lock ring falls into position, allowing you to install the three lock bolts without having to fish around trying to get the lock ring into position. If you're using a home-made J-4050, it may bind up as the propeller shaft is driven into its final position, due to the tool being slightly too thick. If this happens, before tightening the lock ring bolts, simply tap the front of the propeller shaft back slightly to release the tool, then pull the propeller shaft assembly back into its final position by tightening the lock ring bolts. Tighten evenly to keep the lock ring squarely against the forward bearing. With everything locked down, you should see some axial clearance between the outer race of the rear pinion bearing and the front face of the pinion gear, and the propeller shaft should turn freely with no binding.

Mark

Thanks Mark,
Very detailed description of something way above my comfort level. I have the tool ( comes in the kit) and my mechanic guy has the rest of this assembly down.

I'll have all I can handle trying to reinstall the rear end myself with a small garage and floor jacks.

Marks description of the process is right on. The tool is shown in the rear axle overhaul manual I have dated 1952. The only thing I would add is that after tapping on the pinion to seat it the rear bearing outer race may need to be tapped with a punch to seat it and gain the space required for the J-4050 tool.

I just tried to open the '49 to '53 Chevy Service Manual on Hardy's site ..... no go.
It directed me to a site for instructions ... in order to open the Hardy site, I presume, but that NEW site didn't work for me.

Did Keith Hardy make a change, as to who may view his collection ?

I think the posted shop manual is online again. The website or server has been experiencing some down time recently, but hopefully it is back to normal.

http://chevy.oldcarmanualproject.com/shop/1949_53/index.htm

Thanks Dana, hope you're doing well.
Bob.