Differential tooth differences in Detail

[Florence]

Hello, after a very long time I'm back in and underneath the Dodge ...
Had done a house moving and now have to move in a new garage soon and wanted to have checked all the little leaky points on the CC before.
Last week I just wanted my mechanic to do the leaky points on the rear Diff and transfer case and now we have a lot work.

The rear diff is dissasambled now and we will rebuild it. Got all parts NOS and found out that my drive gear (both front and rear axle) are dated 1941 and have 44 tooth. Most available repair sets of the Drive Gear and pinion matched set 922847 seem to have a 35 tooth gear with the 6 tooth drive pinion.

When do they change from 44 to 35 tooth on the first model two pinion differential?


Kindest regards
Sylvia

[Gordon_M]

Welcome back Sylvia

I'm not sure, but I suspect your truck has the early small diffs. If you have a 44-tooth ring gear and 9-tooth pinion, then someone has swapped-out both diffs for half-ton WC units with the 4.89 axle ratio.

May well be if they are 1941-dated as 3/4 ton production didn't really start till September 1941 I think.

[Kaegi]

Hello, after a very long time I'm back in and underneath the Dodge ...
Had done a house moving and now have to move in a new garage soon and wanted to have checked all the little leaky points on the CC before.
Last week I just wanted my mechanic to do the leaky points on the rear Diff and transfer case and now we have a lot work.

The rear diff is dissasambled now and we will rebuild it. Got all parts NOS and found out that my drive gear (both front and rear axle) are dated 1941 and have 44 tooth. Most available repair sets of the Drive Gear and pinion matched set 922847 seem to have a 35 tooth gear with the 6 tooth drive pinion.

When do they change from 44 to 35 tooth on the first model two pinion differential?


Kindest regards
Sylvia

like Gordon said the ratio of the sets if different. are they same size or are the new gears much larger? 3/4 tons have 3 different set ups. 1. 8 & 3/4" with 2 pinion spider gears. 2. 8 & 3/4" with 4 pinion spider gears. 3. 9 & 5/8" with 4 pinion spider gears. Nothing of the 8 & 3/4" differentials will interchange with the 9 & 5/8" set up

[Florence]

Thanks Gordon and Kaegi!

1/2ton was what I thought first also, but on a 1942 Truck in a 3/4ton axle?
Here is a pic of the Date (?) 1941:


We are now want to use the old 44 tooth ring with matching old 9 tooth pinion on a new case.
Pics follow ...

Sylvia

[Florence]

As far as I know my mechanic allready assambled the Diff and the rear axle today!
He said everything fits, we did not drive the Dodge already.
Anything what could be wrong with the case CC 922416 and 44 tooth ring / 9 tooth pinion together?

Just wanted to know for interest when they changed the rings and now new questions ...

9 tooth pinion:
.


44 tooth and 35 tooth ring:
.


44 tooth Diff on front axle, still in good condition:
.


44 tooth Diff on rear axle, worn out and now taken apart:
.


Case old but pinns broken out and worn out:
.


Case for replace the old one, the 44 tooth ring and all the small stuff fits!?
.



Kindest regards
Sylvia

[Florence]

Hi again Gordon,

thanks for the hint - yes the number 856122 is from the 1/2 ton!
Most parts have the same part number, except the side gear.

Am I correct with my assumption that only the base of the side gear is different and the "working" part with the teeth is identical? As the Diff pinion has the same part number for 1/2 and 3/4 ton.

Edit:
After comparing all Differential part numbers in the Master parts list I'm nearly sure it is ok. All smaller items except the side gear (and of course the complete set and case) have the same number for T207/T211/T215/T214.

Tomorrow afternoon we will make the test drive.

Greetings
Sylvia

[Dozerman51]

Hello Florence,
The booklet you need to purchase if you want to learn about Dodge third members is one entitled: "TM 9-1808C Ordnance Maintenance-Power Trains and Interchanges: Military/Civilian Trucks 1941-1971 (Dodge)". This booklet was originally authored by John Zentmeyer in 1981. Vintage Power Wagons sells it. A must have item for third member Identification and Interchange of Dodge trucks.
Joe Giraud
41' WC-12 (Original serial number 8682297, frame butchered beyond repair, present serial number 8676966).
40' Cat D2/3J Serial #4103

[Fred Coldwell]

Hi Sylvia:

I restored your WC-58 command car in Denver CO a few decades ago. Being an early 3/4 ton CC, it came from the factory with the smaller 8-3/4 inch axles housings. I had the 3rd members rebuilt using WC 1/2 ton 4.89 gear sets (ring and pinon) for faster highway speeds with 900-16 tires. I did not plan to do much off-road 4-wheeling with it so did not use the 5.83 gear set in a smaller 8-3/4 inch diameter. The beauty of the smaller early WC 3/4 ton axle housings is that one can install brand new surplus WC 1/2-ton 4.89 gear sets without incurring the greater expense of buying 4.89 gears in the larger and more expensive 9-5/8 diameter gear set as is necessary for later production WC 3/4 tons with the larger 9-5/8 inch axle housings.

I used WC 3/4 ton side gears in the third members to accept the slightly larger (than WC 1/2 ton) diameter WC 3/4 ton axles shafts to keep those original CC parts. In essence, it was a groovy 1980's re-mix of Dodge's greatest drive train hits (with a tip of the hat to Don Cornelius)

[Florence]

Thank you Joe, for the book tip!
Will get that in the near future

Sylvia

[Florence]

Hello Fred,

thanks a lot for that very helpful and interesting info!

Just came home from the first test drive with the redone rear axle Differential.
My mechanic showed me the four pinion set up wich was inside the old housing.
And the "new" two pinion set up in the newly bought NOS housing.
I was surprised about the 1/2 ton ring and pinion on the four pinion case.

With your info it makes sense too me.

The Dodge runs very nice without any noises from the rear axle/diff.
We used the 44 tooth ring and 9 tooth pinion again (to have it the same as on the front axle) on the new two pinion case.
So am I right that this mixture is ok, also?


Greetings
Sylvia

[Kaegi]

I would run the 4 pinion carrier. they upgraded because the 2 pinion is too weak for such a heavy truck.

[Florence]

Hello Kaegi,

yes, we know that but on the other hand that is what I have now already assambled and I will not do any offroad driving or tow a very heavy loaded Trailer for example.
Of course long distances on roads again yes!

If it will broke in the future because it is too weak from the factory I can change it again. What I don't want is a brake down because we made a mistake with non matching parts. I realy trust my mechanic, and it all looks, feel and drives excellent now ... just a bit maybe much over nervous regarding my beloved Dodge

Sylvia

[Ian Jamieson]

WOW!!! The person who originally restored the Command Car in the USA is able to post to the current owner, in Germany, how good is THAT!

Ian

[Fred Coldwell]

Hi Sylvia:

As Kaegi said, I used the 4 pinon differential because it is stronger than the 2 pinon differential. I followed John Zentmyer's recommendations in his 1981 book "TM 9-1808C Ordnance Maintenance-Power Trains and Interchanges: Military/Civilian Trucks 1941-1971 (Dodge)" that Joe mentioned to build the strongest 8-3/4 inch 4.89-geared third member possible. Commander George will run OK with the 2 pinon differential and the 44/9 ring and pinon in the rear axle, but that axle is always being used as opposed to the front axle which is infrequently engaged. When you get the opportunity, I'd move the 2 pinon 4.89 third member to the front axle and put a 4 pinon 4.89 third member in the rear axle. The custom-built 4.89 third members are just one reason why Commander George is a very special Dodge radio command car. I'm glad he found a wonderful home.

[Florence]

THANK YOU Fred!
I'm so glad you read my post. What a wonderful international Dodge world.

Commander George will run OK with the 2 pinon differential and the 44/9 ring and pinon in the rear axle, but that axle is always being used as opposed to the front axle which is infrequently engaged. When you get the opportunity, I'd move the 2 pinon 4.89 third member to the front axle and put a 4 pinon 4.89 third member in the rear axle.

Great, will search for the items but with no hurry to get the best available.
And in the meantime have some fun driving Commander George!

The custom-built 4.89 third members are just one reason why Commander George is a very special Dodge radio command car.

Another reason to change it one day - have that custom-built "original" Diff again

Latest pics from yesterday evening/night:
Test drive ...


Ready to go back to winter sleep (salt here on the roads) ...


Part remnants ...


Kindest regards
Sylvia