Turning the "C's" on D30

What a fricken day I had yesterday. My buddy, Rick, came over to help me try to turn the outer "C's" on my front axle. We got the passenger side done in about 10 minutes. The driver side.......about 4 hours. That prick would not turn. We even had it almost red hot and both of us hitting on it with 20lb doublejacks. Not a budge. In the end we pressed it off the axle with my 12 ton press. Even then I almost broke the press. Apparently the C had some rough spots on the inside that goes over the axle tube. When it was originally pressed on those rough spots scored groves into the tube and acted almost like splines to keep it from turning. I got them all buffed off yesterday and plan to get it hammered back on today. What a b#tch! Hopefully that's my last BIG NIGHTMARE on this project.

 

Sounds like a brutal day! Keep at it we want to see the "new" Posi on the trails this year!

 

How did you get a passenger drop high pinion 30? What did ti come out of?

 

Yes, thanks, Jim. Rant over!

It's a standard pinion D30 from a '73 CJ5. Might look high pinion in the photo though.

 

oh its upside down hahhaa......................

 

Hi John,
Just checked out all your pictures again. Your jeep is looking great. Man that's alot of work just to get the caster right( or camber....can't remember which is which)

 

Well, once I got the pinion angle where I liked it, I had almost 7* positive castor. That was definitely not going to work. All shims would do is move the pinion back down where it was before. I already was real close to binding the upper u-joint on the front driveshaft before. This way I have a pretty straight shot from the pinion to the t-case output.

 

A couple words of advice here. Before putting the "c"'s back on put them in the oven for about an hour at 350*. This will allow them to expand to slip on much easier. Put punch marks on the tubes and the knuckles to help with initial alignment. It makes it much easier for initial alignment.

Do you mean 7* negative caster? Typically we build the fronts with between 5-7* positive caster for more stability with larger tires. Takes some of the wander out of the vehicle on rutted pavement. Much more than this accelerates tire wear and can cause high speed instability. Remember positive caster is when the top of the knuckle is tilted backward (toward the rear of the vehicle) from 0*. Negative caster is when the top is tilted towards the front of the vehicle.

 

Please provide us with some background on your axle project (is this your SOA effort?). Many of us have converted to Dana 30s, but never took the C's off the axle tubes. Castor shims are frequently used, but there's little said about front drive line angle. Thanks.

 

My bad, nickmil. I got that backwards. The pass. side C turned without having to take it off. I put the driver side out in the sun and warmed it up, almost too hot to touch. The Sun is pretty intense here at 6500 ft. It went on with a little coaxing from a 4lb hammer. I set both sides to 7* positive castor.

 

Yes, this is part of the SOA. I turned the pinion up to within 2* of straight to the t-case output yoke. I have a couple of degrees in there to keep the u-joints working so they don't seize up from lack of lubrication. I have a set of Chevy flatop knuckles with high steer arms that are going on as soon as I get the axle back from the welder. Then I can start working on the steering. I'm using a new to me frame (M38A1) so I don't have the steering box mounted yet. This is a prime example of one of those 3 month projects that's become 10 months, with at least two more to go. I'm getting the impression that "Jeep project escalation syndrome" just goes hand in hand with doing anything to a Jeep.

 

I'm afraid that gouging must have happened on my scout 44. I can't get them to budge with a 8 lb sledge. How'd you get the axle housing in the press?

 

Dang, I didn't take a picture of it on the press. I had to pull one bolt on each side of the brace between the bottoms of the legs, then I was able to swing it out of the way. Then we set the whole press up on a couple of cinder blocks to get it high enough in the air for the end of the axle to hang down. I had so much pressure on the press that the support piece that you adjust up or dowm, actually was bowed quite noticeably. I had a piece of tubing that was about the same diameter as the axle tube I cut a 1" piece off of and put a piece of 1/2" plate on top of that for the press to push on. I ended up bending that 1/2" plate, but, using my torch to heat the C it finally let go. Lots of heat. My 12 ton press was really not enough for the job. If I had it to do again, I'd take it to a machine shop and have them press it off. Once it's off you can clean up the inside of the C (just a little) and take care of any burrs on the tube. You want it to still fit tight when you put it back on. It's really the burrs and gouges that keep the C from turning, not the tightness of the fit. For reference, you might as well use a flyswater. My buddy and I each had a 20 lb hammer, one of us hit the top arm of the C while the other hit the bottom arm and we used heat too. It didn't budge. Funny thing is the pass. side was no big deal and we turned it with a couple of 4 lb hammers and some heat. I used the pre-heat flame from a cutting torch to heat it. Also using two hammers at the same time keeps the C from getting cocked and binding up. Also, I had to remove one of the spacer/brace pieces out of the press support so I could slip the axle tube between the rails. Wish I had taken pics, but after 4 hours of beating on that thing, all we were interested in was getting it done.

 

I think I'll take mine to a machine shop.