M38 Front Axle Knuckle King Pin Bearing Change

Rotorhead · Post by **Rotorhead** » Wed Mar 25, 2015 8:26 am

Hello everyone, I'll be replacing front axle knuckle king pin bearings on my M38. Can anyone tell me what other parts should be changed while I've got it all apart? Wheel hub bearings, axle seal, knuckle felt seals, etc, etc? The brakes and brake parts are all new, so I'll reinstall same. And any tips for changing the king pin bearings? Can this be done without any special tooling? I'd rather not have to pull the axle to give to someone else to to:) Thanks!

Post by **wesk** » Wed Mar 25, 2015 9:40 am

Just follow the instructions in the manual. Be sure to refer to all 4 manuals. (TM 9-8012, TM 9-1804B, ORD 9 SNL G-740 and the CJ manual in my photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php) You should always replace all seals and any worn parts. You should use a scotchbrite red pad on the spheres that the seal rubs on. You will need a spring scale to set the pre-load on the two bearings. The pre-load is adjusted by shims under the bearing plates. Rear the cj manually carefully on the set-up of the steering knuckle stub axles. This procedure differs significantly based on weather you have Rzeppa, Bendix or Spicer (Cardon) type.

Rotorhead · Post by **Rotorhead** » Thu Mar 26, 2015 9:47 am

Thank you, Wes. Will I need a puller to remove the hubs? Any other special tools required?

Post by **wesk** » Thu Mar 26, 2015 10:38 am

Most of the time the hub drive plates pop right off. The small caps come off with a pair of channel lock pliers. The main thing are the spring scale, axle nut wrench/socket and it helps to have a nice bushing/bearing driver set. A set of brass punches help also.

Rotorhead · Post by **Rotorhead** » Sat Mar 28, 2015 11:33 pm

Thank you! I 'm ready for the axle nut socket/wrench - it appears to be just over 2". The search commences. I've got everything else. I can already feel the play in the king pin bearings.

Post by **wesk** » Sun Mar 29, 2015 12:10 am

From my photo album:

$13.99 http://www.kaiserwillys.com/product/153 ... ccessories

$9.99 http://www.jeep4x4center.com/spindle-nu ... a692n.html

$9.99 http://www.quadratec.com/products/98001_00.htm

This Auto-Zone 2 3/32" would also probably fit.

Rotorhead · Post by **Rotorhead** » Sat Apr 04, 2015 9:02 am

OK. I'm putting it all back together - Knuckles are installed with proper pre-load on bearings. Does anyone have the latest and greatest formula/mix for oil-grease lube inside the knuckle? I've found a bunch of info on the net, but am hoping to get your input here. I'd like to have as much 'splash' for the upper king pin bearing's sake, but realize that this might lead to leaking if I go too thin.

Post by **wesk** » Sat Apr 04, 2015 7:23 pm

That is the oldest jeep question in the world. Just search this web site the same way you searched the rest of the web. There are at least a dozen discussions here that we all participated in. That will save another post getting 25 postings of opinions. In the end no matter how much BS or fact is posted you will have to make your own choice.

Here's the results of my "Search" for the Topic "Knuckle Pudding" on our tech board:
http://www.willysmjeeps.com/v2/modules. ... 89&start=0

And gere's the google search results:
https://www.google.com/webhp?sourceid=c ... n%20mjeeps

There is just no sense in rumbling through all the replies over and over again.

Rotorhead · Post by **Rotorhead** » Mon May 25, 2015 11:01 am

Well they're done. And the wobble is gone. One side had a couple rollers missing - they were sitting in the bottom of the knuckle! Fortunately they didn't get into anything. Easy job. Wheel bearing nut torque - went by feel, nice and tight, free-spinning with wheel on. Thanks for your input!

Post by **wesk** » Mon May 25, 2015 3:29 pm

Thanks for coming back and telling us the outcome. Very few folks think to do that!

M38 Front Axle Knuckle King Pin Bearing Change

M38 Front Axle Knuckle King Pin Bearing Change

M38 Knuckles