VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Pinion gear and bearings Q and A

I had a roaring sound whenever I let off the throttle. I found that the pinion gear in my ‘46 coupe has a broken tooth. I have several questions. First, I assume that I can remove the pinion and torque tube as an assembly, but I read that to remove the pinion I must drill out the rivet to allow the assembly to be removed from the rear in order to remove the pinion gear from the shaft, does the rivet have to be removed? And the pinion bearings, who manufactured them (Timken,?)and what are the numbers for front and rear? And what other damage should I look for?

Also, is there any difference in pinion gear, shaft and tube from a ‘46 and a ‘50? Including length. Both are from manual transmission drivetrains.

The above parts are the same from 1941-1954.
Good time to install a 3.70 assembly from a 1953 or 1954 stick or a 3.55 from a 1950-1954 Power Glide.

The1950 stick will be a 4.11, same as what you have.

So, the shaft and tube are the same length? If so, then this problem won’t be as bad as I had feared. Also, can you shed any light on my earlier questions?

The pinion and ring gears are a matched set and best to replace both at the same time or you may end up with the same 'howl" you now have. If you get the numbers off the old bearings then you can search local suppliers or online. The brand is not as important as using a quality supplier and known manufacturer. Most bearings are determined by size, type, and capacity and with the number from the bearing any good supplier will be able to help. To remove the rivet grind the head on one side and drive it out with a punch.

I Would like to have numbers and manufacturers before I start to do the tear down so I can have all parts on hand. I can go to the local parts store where they actually know how to open the books, and do! I was just hoping that someone had them readily available. And the rivet doesn’t intimidate me except perhaps the replacement and peening there of.

GRP 5.447 frt pin brg ND5309 Chev# 954455 GRP 5.484 Rear Pinion brg OR1506 Hyatt Chev 125630 Grp5.536 Diff carrier Brg A11360hyatt and 11360Z hyatt cup and cones Two ea. Chev# 127861. I suggest you disassemble and inspect all parts first so all parts needed can be sourced at the same time and if further damage is found it may be better to replace with a used unit. Also do not use it now as further damage can result .

correct newer number for front pinion bearing is ND5306W X1730A, Chev #954780.Also the bearing has the notch for ball loading go to the front of the car original went to rear.This is a very expensive double row ball bearing so check price first.
The side carrier and rear piion bearings ae roller bearings.There is no rivet but rather a pin that can be driven out with a punch. Later change.
You will need a new pin and pinion nut for sure.
The front pinion bering will howl on acceleration and rear on slowing down. Side carrier bering make noise at steady speed, a low speed grumbling noise.
If a tooth broke off on the pinion gear something else caused this as it is not a common problem.I expect it will be cheaper and easier to find a different rear end and rebuild it as the front and rear pinion bearings can run over $120.

Thanks guys. This car is a junkyard rescue and is only recently being put back in service. I’m replacing things as needed. Try it, if it works great! If not, repair or replace. I appreciate all your help.

Just to weigh in on the conversation I'll go back to Gene's comment about "time to install a 3.70 assembly from a 1953 or 1954 stick or a 3.55 from a 1950-1954 Power Glide". Also, to answer your question, yes, the tube and shaft are the same length. Since the entire assembly, from the rear of the transmission to the face of the rear axle housing is a direct bolt in exchange, find a replacement assembly as indicated, take the rear housing cover off the 46, slide the axles out, and install the replacement assembly. While the axles are out, change the rear axle seals. If the seal area on the axles is pitted or worn, cover it with a speedi-sleeve. If you're not paying someone to do the work, your only risk is a later rebuild on the newer assembly. Driving a 41-48 on the highway with the higher gear ratio is a dramatic improvement.

Yes, the 370 would be ideal. I would just have to find a way to haul the entire assembly. Perhaps just the pinion and differential. The later model rear end would be a great improvement with the Bendix brakes as opposed to the Huck style. I’m planning to do that on my ‘50, I have the rear end from a ‘54 for that car. And the rear end is good under the ‘50, but it is a 411. I could pull what I need from the ‘50, but I would hate to have both down at the same time. I have 5 vehicles and only one driver, the ‘46 is supposed to be the next on the road, then the ‘55, then a Buick. Too many irons.

[quote=Rusty_Heaps]Yes, the 370 would be ideal. I would just have to find a way to haul the entire assembly. Perhaps just the pinion and differential. The later model rear end would be a great improvement with the Bendix brakes as opposed to the Huck style.

If we are still talking about your 46, it will have 16" wheels 6 bolt and whichever unit with Bendix brakes would have 15" wheels with 5 bolt pattern.. You don't need the complete rear assembly, just the torque tube and pumpkin containing the gears. Leave the banjo, axle housing, axles and hubs assembly where it is. Much easier to haul.

Dick

I will comment on the Speedi sleeve idea. I did this on one side of my 38 Master. In order to remove the c clips, the axles have to be pushed in from where they normally sit. A speedi sleeve will not fit inside the bearing. This means that the sleeve has to be installed so that part of that area is not occupied by the sleeve. However that is where the original style seals run on the shaft. However I was able to make it work with a modern seal that had it’s lip further towards the outer end and mated with the sleeve.

In addition to the wheel size and bolt pattern differences I would be cautious about having Bendix (self energizing) brakes on the rear of the car and Huck brakes on the front.

If the Bendix brakes are more efficient at converting line pressure to braking effort there will be a tendency for the rear brakes to lock especially under heavy braking situations. The last thing you want in a panic stop is for the rear end to be sliding and make the car rotate.

I always found the Huck brakes worked OK on the 1936-1948 models but not on the 1949 and 1950 and worse yet on the 1950 with Pwoer Glide which had less engine braking due to the 3.55 axle ratio and torque converter.
I noticed a little more pedal pressure was required on my 1939 when I switched from the 4.22 rear end to the 3.73.

The rear end is home now. It’s a 355:1 from a Powerglide car.I’m leaning towards putting it under the ‘50 even though it would mean pulling the rear end from the only drive able vintage car I have. The 355 would certainly help the old 216 on the highway. It might be a little harder on the clutch being here in hill country. Then I could pull the pinion and differential from the old one from the ‘50 to install in the ‘46. I think the logistics will be easier that way. Also, I’m already running 15” six lug rims on the ‘46. The ‘61 model 235 can handle higher rpms than the 216, anyway. Hopefully this will put that car on the road, too.