Going into reverse mostly and sometimes into Drive the drive shaft is clunking hard. Not all the time. I adjusted the kickdown, seems to have helped slightly.
Driving at around 50 mph, I start hearing rattles, like ball bearings almost.
I drop into nuetral, no sound, put it back in gear, sound returns.
Rattle/bearing noise just started up the other day.
Happened today, I pulled over b/c the rattle was pretty constant, put in nuetral, back in Drive, no noise. Drove home, no noise.
Trans temps are around 125 in the pan.
I had a similar experience a few years back, thought trans was toast, but it was just a crack in the exhaust. Welded it shut, no more rattle.
This sounds different
No rhyme or reason to it. I can't recreate it, but it just shows up.
Twice on steep down grades.
I'm going to drop transmission pan and tighten bands, change fluid.
I checked trans fluid by letting some out of the drain plug. Some metal, but no huge chunks, nothing that doesn't look like normal wear. Fluid is still red mostly.
Will also change fluid in differentials.
No oil on oil stick, I checked if it was KDP, everything looks solid up by the gear cover by the radiator?
Any thoughts?

 

Clunk going into reverse and drive I would set the idle down. adjusting the kickdown should have nothing to do with the clunking into drive or reverse.

 

I would check the rear axle for excessive end play and other issues. The hard clunking is normally rear axle end play. Your sig is showing about the milage where Dana's start showing bearing problems. You also have a set of gears in that truck that are hard to find.

 

Like Phillip said. I would get the rear checked out before you toast something and potentially destroy it. Assuming that you have a 3.08 ratio rear they are hard find gears for.



Before I did that I would really check over the U joints for any kind of play and the carrier bearing if your truck is CC. Trans in neutral and the rear axle SAFELY blocked up rotate the drive shaft back and forth looking and listening for any play in the joints. Doesn't hurt to put a screwdriver or small pry bar between the yoke and joint and nudge it back and forth to check for play.
When you remove the diff cover, if the gear oil looks like the Tin Man did something naughty in it, its a good indication that a rebuild is in order.

 

Ended up being a dry zirc fitting on the front end of the drive shaft, the good news is that the mechanic I took it too was honest and told my the trans is fine. The bad news is that I had him replace all the bearings and seals in the front and back (I figured i'd give him some business for taking the time to look things over at no charge, and I was busy moving across country). The rear seals have started leaking, I should have never had them touched, but I was trying to do the right thing keeping up on 25 year old truck maintenance. The drivers side rear leaked for a while and then stopped. Now the passanger rear seal leaks but the drivers side doesn't. Every time I check the differential, it has enough oil so it's not a huge mess. But I may have to take it apart and do the speedy sleeve. Always something with these trucks.

 

There used to be a moderator here called Faith. She said to check my differential spider gears when I came across that clunk.

Dead nuts. They were toast. Lasted about 160,000 miles or so, then the clunk started. Replaced them (as the clutches in the spider gear assembly are wear items) and no more clunk.

If you have dodge's power lock rear differential (limited slip Dana 70), then that's what I would look into. I did a thread on them, and lots of pictures. It wasn't really hard to do, but I bought the housing spreader which made it very easy.

If it wasn't for that tip, I would have blown that rear apart as she did to hers.

 

These trucks are a labor of love man!
Sad thing is that you can get a new PLoc on Fleabay for about a $100 more than you can buy the spider gear/side gear/pin kit for. + $70 for the clutches.