84 2wd rear diff - drive shaft play
 

I have an 84 2wd pickup, auto trans, with 322K+ miles on it. It has picked up a vibration at highway speeds when stepping on gas, as well as some pinging noise from I believe the rear differential. Guessing too much wear and tear. Checked the oil,it was a little low, but not much, guessing from the leaking driver side axle seal.

What type of kit would I need to get to fix the drive shaft - differential play? What else would I need to check for wear-wise? Guessing I should change out the UJoints and the drive shaft center bushing thing also, correct?

Curious. Why did they do a 2-part drive shaft with center bushing? Is there really that much flex in the frame that the 2-parts are needed?

Also, I have not worked on differentials before, but done just about everything else besides transmission work. Is differential work something better left to pro's, like transmission work?

It sounds like you probably have a bad pinion bearing in the differential. I personally have not set up differential gears before, but I have done axle work. With a bad pinion bearing, a leak in the axle seal, and 322K, I would rebuild the rear axle and possibly replace the brake shoes if gear oil has leaked on them.

I re-did the axle on my '88 2wd pickup, but I just bought a 3rd member from a 2004 Tacoma with low mileage and it bolted up. This would depend on if you have a 7.5 or 8 inch differential (most 2wd trucks are 7.5). I also bought the Marlin Crawler wheel bearing kit that included the bearings and seals. If I remember right, the wheel bearings are the same no matter if you have a 7.5 or 8 inch differential, or 2 or 4 wheel drive. I made a press to get the axle shafts off the bearings by cutting up on old axle housing to fit a bottle jack in it. There is a write-up on this somewhere online, but I do not remember where.

I would also check the U-joints and the carrier bearing for play, but it might not be necessary to replace them if they are still tight. It appears they used the carrier bearing in extended cabs due to the extra length. My standard cab trucks do not have carrier bearings. I think it has something to do with balancing too long of a driveshaft, but I am not sure about that.

If you are planning any performance upgrades, a Ford 8.8 rear end is suppose to be a fairly simple swap.

And the advantage of the ford axle is same bolt pattern..

if it is your pinion gear you can swap thirds pretty easy. Diff set up is kind of an art IMO..some guys say they can do it but I have seen street driven diffs grenade with in a few thousand miles.
Check out zuk's site at gearinstalls.com to get an idea of what is involved.

Thank you for the replies. First thing I'm doing is trying to get the truck fixed so that so the crooks stop trying to steal from my driveway. Stolen once a few years ago, and two attempts in the last month. Last attempt this past Tuesday, caught the guy trying to start it at 4:30am after he busted the ignition cylinder out. the ignition kill circuit made sure the truck didn't go anywhere, just need to do a few things to prevent them from even trying.