VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 pinion bearings

Hi one and all
Re-assembling pinion/drive shaft with new bearings,38 HB coupe.
When the 3 tapered collar bolts are tightened the pinion locks up.
I have gone plus and minus on the shims but neither seems to make a change.
Logic tells me it is tight because the double row bearing is pulling the pinion head back into the housing ?
Do I keep adding shims ? have gone .018 " with no change .
Maybe a width issue with the double row bearing ??
I don't really want to strip to check unless last resort..that pin in the driveshaft was a mission..

thanks for any advice ..

Ollie

You add one .015" and one .018" shims for starters and go from there. Usually close with those two.
If you are installing a newer ND 5306/X1730A New Departure bearing, the ball loading slot must go to the front of the car, the original before 1953 went to the rear.
The bearing fit 1937-1954 and a change was made about 1953..

I had a similar problem with my 51 and the problem was that the bearing was not seated properly. A couple taps with the three pounder resolved the issue.

Curious....what made you decide it was time to replace the bearings? Noise?

Green, A bad front pinion bearing will make a howling noise on acceleration. The rear bearing on de-acceleration.

I have two cochlear implants, and they amplify everything at once, so I will need to have someone like you who can isolate specific sounds...

I have to drop the rear axle anyway to replace the leaf spring bushings & seals, axle gaskets, and will put an Oakie bushing in the shaft, and planned to follow the owner's manual at using feeler gauges to determine whether the bearings need to be replaced....what do you suggest?

Thanks Gene
Was just a matter of "tapping" the end of the Pinion with a Nylon hammer as the tapers were snigged up..first time on a torque-tube for me.
Bearing from FS has no ball feed slot so hopefully it is not direction specific.

thanks

Ollie

Green 42
Noisy diff .. turns out carrier bearings loosing surface coating,front pinion bearing a little ropey and the lateral bearing gets replace any way .. 1/8" backlash probably not helping.
Oakie bushing was fun (not) Check before you decide..if its ok ..leave it alone.. save money from the swear jar ..

Ollie

I've got my axle out and in pieces except for the carrier housing/shaft.

What did you use to replace the 4 rivets that hold the shaft tube on the diff housing?

I did a search and some folks use rivet bolts from FS...if that's what you used, do you recall what size?

What is a shaft tube on the housing????

My bad, wrong wording.

I meant the rivets that hold the propeller shaft housing to the differential carrier:

I have never heard of any one taking that apart. I would not advise taking it apart and can think of no reason to do so. The torque tube is pressed into the casting as well as riveted.
The two parts were not sold seperately also.

Someone told me that I need to take those two apart in order to get the pinion out....are you saying I don't need to do that?

What would I need to do in order to get the pinion out? Tap a hammer on the other side of the shaft?

That or pry from the rear. Can be difficult.

Once you have all the "guts" out of the housing just drive the pinion out from the ujoint end. You might want to get a copy of the axle overhaul manual or better yet a complete service manual reprint. Reinstalling was covered in another post so you might also do a search for that.

The easiest way I have found to remove the pinion shaft and propeller shaft (they're pinned together as an assembly) is to stand the torque tube and differential housing up vertically with the differential housing up, then raise the assembly about 6 inches and drop it straight down onto a 2X6 or other suitable piece of wood. You may have to repeat the process a time or two to dislodge the pinion bearings from their bores Be sure you have removed the three lock ring screws that hold the forward pinion bearing onto its seat before you try the above procedure. Once the bearings are dislodged, the pinion and propeller shaft will slide out the back end of the differential housing. After removal, it's a good idea to remove the shims (normally two) from the bore for the forward pinion bearing. This will prevent them from being accidentally lost if they fall out when handling the torque tube assembly. Make sure you reinstall the same shims when reassembling.

Mark

+ 1 for what Mark says .. when you re assemble I had problems re seating the pinion bearings in the housing also . the 3 bolts in the housing have a taper that pulls in the assembly and locks in place .. I used a Nylon headed hammer to seat the pinion . needs hit / tighten hit hit hit /tighten etc until it locks against the housing ...
Not right and the depth into the crown wheel will be off .. set back lash and off you go .. have fun

Thanks, guys, great info. I have a few manuals, all pretty much show how to work on the pinion but none really say how to get it out.

Got the pinion out using Mark's method, went a lot easier than I thought.

Looks like I have to remove the pinion from the shaft in order to get the pinion nut out of the way and remove all bearings.

Is the pin (highlighted in yellow) one piece? Can it be hammered out of one side and put back in the same way?








The rear bearing shows some twisting movement, but the front one seems to be very tight.

The pin can be driven out. A new one must be used.
The front doubvle row ball bearing was common to fail. The rear roller bearing seldom failed.
Don't loose the two shims.
See the 1938 shop manual for seating the rear bearing with a punch.

Ollie,

Check out this article for how to remove the bushings and seal with common, inexpensive hardware store items.

https://vccachat.org/ubbthreads.php/topics/334876/1936_Chevy_3.55_rear_gear_conv

There is no need to use an "Oakie" bushing. The real GM parts show up all the time on ebay. Also notice what I wrote about getting a quality, made in USA seal. The seal ID should be 1 1/32" (not 1 1/16" as sold by the restoration parts suppliers). How can a seal with the wrong ID seal properly?

Also seating the pinion bearings is easy without any hammering using a piece of exhaust tubing on the transmission end of the inverted torque tube and thumping the whole inverted assembly against a wood block. Inertia seats the bearings. We can easily outsmart this and other inanimate objects.

Green 427,

The pin that holds the pinion into the driveshaft is a rivet. Drill off one end and it will tap out easily. A replacement is easily made from the unthreaded portion of a soft hardware store bolt. All that rivet does is position the pinion on the driveshaft. Torque is transmitted by the splines.

The project described in my article was a fun one and the 3.55 gears are a huge improvement. My stock '36 engine pulls that gear ratio easily, even on a long 11% grade near my home, and the reduced interior noise is very nice.

Ray W raywaldbaum@gmail.com

brino,
do you know of a source for that seal? I think that may be a problem.

Thanks for the tip! Before I had a chance to read your post, I had already surmised that the ends of the pin were spread out by looking at the punch marks, and drilled one end out. Used a pointed chisel and it came out with a few whacks.

I would love to convert the ratios, but that is above my pay grade right now, and my goal is to get this '38 roadworthy first so that my Dad can enjoy it before he can't.

The rear pinion bearing, the thinner, taller one, can be moved up & down the shaft by about 1/2", is that normal?

"brino,
do you know of a source for that seal? I think that may be a problem."


Old216,

The Timken seal I used was in stock at a local bearing supplier. Since I live in a rural area I interpret that to mean is's a very common seal.

"Thanks for the tip! Before I had a chance to read your post, I had already surmised that the ends of the pin were spread out by looking at the punch marks, and drilled one end out. Used a pointed chisel and it came out with a few whacks."

You're very welcome.

"I would love to convert the ratios, but that is above my pay grade right now, and my goal is to get this '38 roadworthy first so that my Dad can enjoy it before he can't."

Jim, I understand that. If you read my article my conversion was only a big deal because I had to actually change rear axle to accommodate the 3.55 gears that are hypoid. You wouldn't have to do that. The only change you would be making, other then the gears themselves, is taking the 10-spline socket out of the back of the '38 driveshaft and putting in a 17-spline socket from a '40 and up car. Any machinist can do that. I did it in my home shop and I'm no machinist.

"The rear pinion bearing, the thinner, taller one, can be moved up & down the shaft by about 1/2", is that normal?"

I don't know off the top of my head since I'm not an "Expert". I do have the 4.11 gears that came out of the donor '37 car rear end I used for my 3.55 conversion and I can check. Please let me know if you want me to do that, preferably by email:
raywaldbaum@gmail.com

Ray W

Pictures of my bearing swap-out. Replaced all bearings, including carrier bearings & wheel bearings.

















Used a piece of PVC pipe to press the new bearing in place.









Drilled out shaft bushing dowel.






Used slide hammer to remove bushing.






View of shaft and rear bushing that remains in place.





Old bushing vs new Oakie bushing.