Bevel Gear Rear End V-Bearing Question

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Rustynut
Posts: 11
Joined: October 31st, 2020, 11:06 pm
Body Type: C-Cab
Model Year: 1930
Location: Campbell, CA

Bevel Gear Rear End V-Bearing Question

Post by Rustynut » February 20th, 2021, 1:11 pm

Wondering if anyone has run into this before:
I purchased a new V-Bearing for my bevel gear end from Snyders (they only had one in stock), so proceeded to assemble the rear end gears with one original bearing in good shape, and the new bearing from Snyders. However once assembled, I noticed a difference between the new & original bearings - see photos below.
The original bearing is ford part number AA-4421E (as far as can tell from the stamped number), and has 20 roller bearings in the assembly.
The new part from Snyders is labeled 4421B and has 22 roller bearings in the assembly.
This is the only difference I can determine, micrometer measurements of the OD are with-in 0.003" as best as I can measure.
I have not been able to find any documentation on this type of revision. The June 1937 Chassis Parts List only lists part "BB-4221-AR" for 1930 - 1934 trucks, and part "BB-4221-B" for 1934 - 1937 trucks, but no specific info on the detailed designs of the bearings.
Has anyone seen this type of bearing revision, and do you know if using one of each would cause any issues? :?:
As far as I can tell, the only difference is in the number of roller bearings in the assembly which I assume would not be an issue...but I would like to be certain before proceeding with wiring the housing bolts together & final assembly.
Attachments
Bevel Gear Bearings 1.png
Bevel Gear Bearings 1.png (1.3 MiB) Viewed 174 times
Bevel Gear Bearings 2.png
Bevel Gear Bearings 2.png (1.19 MiB) Viewed 174 times

KimVanOrder
Posts: 709
Joined: August 11th, 2013, 4:25 pm
Body Type: 82-A Platform
Model Year: 1928
Location: Hamilton, Mich.

Re: Bevel Gear Rear End V-Bearing Question

Post by KimVanOrder » February 20th, 2021, 3:21 pm

I'm no expert, but I would use it. I can see no reason not to.. I would think the new bearing is an "improvement" that was Made..
KVO
Dec. '28 AA

Bob C
Posts: 1350
Joined: April 24th, 2003, 11:50 am
Body Type: Mail truck, Stake tr
Model Year: 1931
Location: SO CAL

Re: Bevel Gear Rear End V-Bearing Question

Post by Bob C » February 20th, 2021, 6:05 pm

I have two new sets of Timken 3982 carrier bearings. The older looking set has 20 rollers and the newer looking set has 22.

Rustynut
Posts: 11
Joined: October 31st, 2020, 11:06 pm
Body Type: C-Cab
Model Year: 1930
Location: Campbell, CA

Re: Bevel Gear Rear End V-Bearing Question

Post by Rustynut » February 23rd, 2021, 11:44 pm

Appreciate the input, don't see any reason there would be an issue with the (assumed) newer 22 roller bearing assembly paired with the original, so moving ahead with assembly.
BTW, presetting the pinion assembly end play with the recommended "free rolling to 0.002 loose" and using the same number of shims between the pinion housing sleeve & axle housing as originally found (none in my case), resulted in good ring to pinion gear contact, to the best of my ability to determine. Trying to accurately measure the backlash between the ring gear & pinion to confirm it measures between 0.003" - 0.008" as described in the service bulletin for the bevel gear axle was nearly impossible w/o preassembling the axle housing, so used gear marking compound to check initial alignment (see pic below). The contact markings look reasonably centered to me, will do final check with backlash measurement after final assembly...
Attachments
IMG_5346.jpg
Ring to Pinion Gear Contact Test
IMG_5346.jpg (514.23 KiB) Viewed 119 times

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