M-38 with GPW axles

billybob · Post by **billybob** » Fri Feb 15, 2013 2:19 pm

My M-38 has a gpw front axle and it has the spicer shafts with normal type u-joints, but the axle shafts appear to be too small for the spindle bushings. Is this anything to worry about? If so where can I get smaller ones? Also the steering arms are part of the kingpins. the right one doesn't look normal to me. Do'es anyone have a top view of both the right and left steering arms? Can the knuckles from a cj-2a be used on my gpw axle? Thanks

Post by **wesk** » Fri Feb 15, 2013 6:53 pm

If you have the correct M38 model 41 or 44 rear axle the odds are the ratio is 5.38:1. If you truly have a GPW or MB front axle then you have two problems. 1-the ration is 4.88:1 and 2-The steering bellcrank is on the axle housing instead of the crossmember.

The WWII front knuckles and early CJ front knuckles had bolt on steering arms. Late CJ2A and on had the steering arm integral to the hub. Post some photo of what you have there.

The cardan style modern joint in the front axles was meant to be used in an unthreaded installation/hub.

Take a good look at the post WWII CJ service manual SM-1002 front axle chapter I have loaded here:
http://www.willysmjeeps.com/v2/modules. ... _album.php

billybob · Post by **billybob** » Sat Feb 16, 2013 7:08 am

Hello Wesk - I do believe it is a gpw axle. It has a 39 tooth ring gear with a 8 tooth pinion. The steering arms are part of the kingpin that bolt to the top of the knuckle. Will the late 2-a steering knuckles interchange with the gpw steering knuckles? Also the bellcrank is connected to the rear of the crossmember. It seemed to drive okay. It has the mount on the axle tube but it's not being used. The main thing I'm conserned with is that the spindle bushings appear to be too large for the axle shaft. Again it seemed to drive ok with this setup.

Post by **wesk** » Sat Feb 16, 2013 12:32 pm

If you read that chapter in SM 1002 (Pgs 206 & 207) closely it discusses that bushing in great detail. That's why I asked you to post photos of what you have. It's easier then using this 20 questions method.

1-Are the ends of your axle shafts threaded?
2-Are both of your shafts Bendix, Rzeppa or Spicer/Cardan.
3-Is your spindle bushing straight or shouldered?

The 4.88 in the front and 5.38's in the rear will be rough on your transfer case in 4 wheel drive.

The later Model 25 knuckle with integral steering arm will replace the early bolt on arm knuckle but you must be care which p[arts you use and which assembly/adjustment instructions you use. Finally you must adjust the steering stops to the correct limit angle which depends on which of the trhee axle shafts you are using on that side.

Do read the SM-1002 chapter closely and ignore the two military manuals.

billybob · Post by **billybob** » Sat Feb 16, 2013 8:39 pm

Wesk, I'm sorry to cause you so much trouble. I don't have any pictures. I did some more reading and I think I have it now. Now to answer your 3 questions- 1- both of the axle shafts are spicer/cardan without threads, just a groove for a snapring. The new spindle bushings both have shoulders. Both front and rear axles have 4-88 gears. I won't have any trouble setting the steering stops. I don't have the angle in my head right now but I know where to find it Thanks again for all your help.

Post by **wesk** » Sat Feb 16, 2013 9:17 pm

Billy,

It's not trouble. It's called learning the jeep and sharing information.

Then I will assume you have figured out that the snap ring type late axles do not require the thrust washer but you can still leave it there. You should not have any problem with the later knuckles. Note the later knuckles only shim the lower king pin.

Those 4.88 gears prefer a 6.00x16 tire vs the M38's 7.00x16 tire. The 7.00 will make the engine's lack of power more obvious to you.

billybob · Post by **billybob** » Sat Feb 16, 2013 9:29 pm

Thanks for the info on the shims, I haven't got that far yet.

Post by **wesk** » Sat Feb 16, 2013 9:34 pm

Stay with the civvy manual.