So, I've been getting this vibration at speeds betweet 0-5, and very, very, slightly between 20-40 MPH. I took apart the 9" today to have a look and see if was a ring & pinion problem. Didn't find much; the gears seem to be in good shape as well as all the bearings. There's no play in the pinion-ring gear set-up. The only things I found were some loose retainer bolts at the axle flange and my ARB o-rings are gonna need replacement soon as I found some gear oil in the lines. I bolted everything back up, add gear oil, top off my t-case too, and tighten down the transmission bolts (a little loose nothing major).

Start driving and NO difference what so ever. It feels some what like a u-joint but they're brand spankin new. I dissasemlbed the shaft and inspected the CV and yoke joint with nothing wrong with it.

It's a very distinctive vibration usually only when I am slowing down between 5-0 MPH. I can idle the Jeep and get the same results so it's not the brakes. The gears and ARB have about 13,000 miles on them. Could this be a ring/pinion problem? I wouldn't think it would be the front roller bearings but?? Any differential shop workers out there that could tell me if this is in fact a differential problem?

1983 CJ7
1979 (ford econoline) Banjo Style Ford 9"
4.0L engine, AW4 4 SPD auto
Flat Dana 300 T-case
CV Rear Drive Shaft
Dana 30 Front

Since I don't list my rigs stats anymore there they are for the people that were about to tell me to do so.

Chris

Bogger I once had a tire that was slightly egg shaped and it gave me a similiar fit!
Another time I had a gob of clay clinging to the inside wof ONE wheel... was days figguring that out.
Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" />

if your dif had problems you'd see filings in the oil (grey oil). bad difs usually make very distinctive audio noise.

BJ pretty much covered what I would say.

I hate having tires replaced. Never a cheap thing to do.... But every time I get new tires, all the vibrations and little wiggles seem to go away.

Check them for balance and true spin. I'm lucky enough to have a store at the corner (only store within 30 minutes) that has a wheel balanceing rack outside that is available any time.... This will tell you if your wheel/tire is balanced, but won't give you the spin deal to see if there is any wobble. shade-twig way of checking this is would be put all four corners up on jack stands on a good surface, crank her up and idle in first and second gears, have second set of eyes on the ground watching the wheels through various ranges of speeds. I seriously wouldn't get up to more than 20 MPH or you might wind up in a pond or through a wall if the stands aren't that sturdy.

Clean the wheels insides. I know my front ones have a nasty tendancy to collect goo from the lube points and dirt/sand/mud from the roads around here.... Rear isn't much better, just no grease to attract even more stuff....

This could be two tires that act strange at different speeds. Could be a loose suspension component. Could be a bad bushing or shock....

Only questions other than the contents of the insides of your rims would be... does this happen at all positions of your steering or just straight rolling? Does it happen only in 2WD or also on 4WD?

Good luck and keep us posted!

differential problems would be raising cane from
start to stop not at certain speeds.