CJ2A with GPW Drivetrain, Crossroads

1945 - 196*, Willys CJ series, questions, discussions, regarding anything related to the post war jeep.®
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rusty_pinto
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CJ2A with GPW Drivetrain, Crossroads

Post by rusty_pinto » Sat Jan 10, 2026 3:45 pm

Hello all, i'm new here. I have a 1946 CJ2A that I bought last spring and i've been slowly correcting many mechanical issues.
CJ2A_Camel1.jpeg
CJ2A_Camel1.jpeg (34.76 KiB) Viewed 555 times
I've been battling heavy drive train and RMS oil-leaks, and overall loudness when driving. I recently pulled the drivetrain for inspection and discovered an early Model 18 "C-18-15-10-1" transfer case with 0.75" intermediate shaft (no data plate, some bolts are script "f" marked) and GPW 7008-marked T-84 transmission.

The transfer case seals, bearings, and shafts were worn. The intermediate gear's smaller section was overheated and burned. There is also a 0.983" hole on the shift-tower side of the TC-case, an apparent failed mod of some sort (no idea, I don't think they made 1" )? Other gears were in so-so condition.
TC_gears2.jpeg
TC_gears2.jpeg (37.65 KiB) Viewed 555 times
Int_shaft_shift-side2.jpeg
Int_shaft_shift-side2.jpeg (51.35 KiB) Viewed 555 times
xfer_case_cast2.jpeg
xfer_case_cast2.jpeg (48.73 KiB) Viewed 555 times
The transmission shifted fine in use, I put ~50-miles on it. I only noticed harsh shifting into 2nd gear sometimes, the others always shifted good. When I pulled it, the input shaft was pretty loose, so i'm sure its in need of a simple rebuild. Some gears appear to be in good shape, other have minor pitting and chips and may need replacement.
GPW_T84.jpeg
GPW_T84.jpeg (49.91 KiB) Viewed 555 times
T84_top.jpeg
T84_top.jpeg (30.2 KiB) Viewed 555 times
I went into this assuming that I would need a basic re-build of TC+transmission, but its looking like the TC is a loss with the odd case modification. It seems possible to upgrade the TC to 1-1/4" with additional machining work and continue with the T-84, but its not clear if this is worth the cost. Ideally, I would like to upgrade to a 1-1/4" Dana 18 with T-90.

Thoughts?
1946 CJ2A "Camel"

rusty_pinto
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Re: CJ2A with GPW Drivetrain, Crossroads

Post by rusty_pinto » Sun Jan 11, 2026 2:11 pm

More numbers after wire-wheeling:

Transfer case mounting flange, transmission side (52/10665, PT112):
GPW_TC_numbers2.jpeg
GPW_TC_numbers2.jpeg (24.81 KiB) Viewed 522 times
Some plate by the intermediate shaft (5-3):
GPW_TC_numbers3.jpeg
GPW_TC_numbers3.jpeg (41.56 KiB) Viewed 522 times
Rear output cover (which has a E-brake "contracting" band):
GPW_TC_Rear_Cap.jpeg
GPW_TC_Rear_Cap.jpeg (38.2 KiB) Viewed 522 times
Front output cover/shift-tower:
GPW_TC_shift_tower.jpeg
GPW_TC_shift_tower.jpeg (34.91 KiB) Viewed 522 times
Main transfer case data plate was lost at some point.

Looks like the first, very thin, paint coat was OD-green, followed by Navy grey-blue.
1946 CJ2A "Camel"

parker007
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Re: CJ2A with GPW Drivetrain, Crossroads

Post by parker007 » Sun Jan 11, 2026 6:10 pm

i would ditch the t84 and go back to a t90 much beter tranny and it came with.

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Re: CJ2A with GPW Drivetrain, Crossroads

Post by rusty_pinto » Mon Jan 12, 2026 4:38 pm

parker007 wrote:
Sun Jan 11, 2026 6:10 pm
i would ditch the t84 and go back to a t90 much beter tranny and it came with.
I am certainly leaning in that direction. Complete GPW drivetrain with damaged transfer case housing may be appearing in the classifieds.
1946 CJ2A "Camel"

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dpcd67
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Re: CJ2A with GPW Drivetrain, Crossroads

Post by dpcd67 » Thu Jan 22, 2026 10:22 am

There is a reason we went to the T90 on all jeeps after WW2; the T84 was a weak toy car transmission. You can get a complete T90 and D18 easily.
Hell, bring yours up and I will trade you; I have a few of them....
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rusty_pinto
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Re: CJ2A with GPW Drivetrain, Crossroads

Post by rusty_pinto » Sat Jan 24, 2026 1:20 pm

dpcd67 wrote:
Thu Jan 22, 2026 10:22 am
There is a reason we went to the T90 on all jeeps after WW2; the T84 was a weak toy car transmission. You can get a complete T90 and D18 easily.
Hell, bring yours up and I will trade you; I have a few of them....
OK, I posted the T84 for trade here: viewtopic.php?t=345154, i'd be interested in what you have
1946 CJ2A "Camel"

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