What's needed for a rearend?

[mont974x4]

From looking at my service manual and the LMC catalog I have determined that I have the 9" 10 bolt removable-carrier type axle's. The problem is there are no tags or anything to let me know what gears I have now. How can I tell if I have the 2 pinion gear, 4 pinion gear, or Trac-Lok ? If I rebuild the rear end does it matter? Can I just go with the parts for the Trac-Lok if I change everything?

[DuckRyder]

This should keep you busy.

http://www.kevinstang.com/Ninecase.htm



and yes you can replace it with a true trac, Detroit Locker or Trac Lok. You only need count the axle splines (probably 28 ) and select the proper one.

[mont974x4]

Everything I wanted to know but was afraid to ask. :lol thanks

[DuckRyder]

A shimmy is hard to diagnose without feeling it. It is hard to explain but back in the dealership, I could drive a car and pretty much call it from the feel. Probably lost my touch sine I do not do it EVERY day anymore.

That said it would be HIGHLY unlikely for it to be the rear end itself without some other indication. (Leak, Noise)

Based on your description, driveshaft would be my first guess. you might be able to find a weight slung off of it, or try putting a hose clamp near the existing weights and see it rotating it slightly smoothes it out. (Not a permanent solution.)

You should be able to find a driveline service that can rebuild and balance it or exchange it.

[mont974x4]

I didn't see anyplace where I slunga weight, but I'll look again. I do have a hub seal leak. It feels like a u-joint beginning to go.




I may look into a new driveshaft anyways. thanks for the idea I won't tell the wife where I got it.

[FORDification]

...and definitely get your wheels checked for straightness. If they'd ever hit a curb or large pothole, they could be bent. I once bought a car for $100 that wouldn't hold the road at all, all over the place, vibrating, etc. Replaced two U-joints and two bent rims and then it rode smooth as glass.

[mont974x4]

shouldn't the tire shop have tried to sell me new wheels if I need them when I bought new tires last fall?


I suppose getting an alignment done would be a good thing to do.

[FORDification]

Not if you had somebody who didn't know to check for that...or thought the tiny bit of runout wasn't in excess. I'm not saying that's what it is, but it's a quick check, and would at least eliminate that as a possibility. Personally, I'd MUCH rather have a bad rim than a bad rearend.

I agree with DuckRyder though...going through U-joints that fast likely means your driveshaft is either bent or missing some balancing weights.

[mont974x4]

Ball park, what's drive shaft cost?

[FORDification]

To replace or balance? Is it a one-piece or two?

[mont974x4]

2 piece

balance and new? just for comparison

[FORDification]

It's been a few years since I had a one-piece driveshaft balanced, but then it was about $25-$30 at the local machine shop. I think I recall someone mentioning before that the two-piece shafts have to be balanced together. I'm not sure about replacement costs or availability.

One more thing that just crossed my mind....when you installed the new U-joints, did you ensure that the U-joints were phased properly? That is, when one U-joint is positioned so that there's a top, left, right, and bottom cap, the other one should be in an identical position. Both yokes need to be be in the same plane. If the second U-joint is installed out of phase, like maybe pointing out at a 45-degree angle when compared to the first, it'll cause that vibration.

There's some good reading on the subject at the following link:

http://www.chicagolandmgclub.com/drivel ... hafts.html

[mont974x4]

uh oh I think I'm about to learn a lesson on u-joint replacement. I didn't even check how the joints ligned up when I installed them. Would that be enough vibration to wear out my new u-joints?

[FORDification]

Absolutely! It'll cause vibration, and it's the vibration that'll kill your U-joints. Any time you replace a driveshaft you need to make sure that the yokes on both ends are positioned the same, and if you disassemble a two-piece driveshaft, you need to mark their position so that when reassembled the U-joints are phased together.

Do a Google search for "driveshaft phasing" and you'll get an education.

[hardtailjohn]

A pothole in Montana???? Surely you jest!!!
Seriously, another thing to check out is the pinion angle. The angle of the yoke on the pinion should to be the same as the next yoke forward.. ie: parallel.... or at least close, or if not parallel, equal degrees apart. We run into this on big trucks alot, and it can drive ya nuts trying to get it to settle down back there, and get everyone lined up, as you're dealing with an extra driveline between the rearends. I've attached a scan from Kenworth's manual for single rearends..it explains it better than I can... But I'd be betting that Keith's hit the nail on the head when he suggested out of phase u-joints.
John H.