So about a week after buying this truck I noticed something. I hoped I might have chased it away when I changed differential fluid, but no luck.

I get a vibration - it feels like I'm driving over the notched pavement which is commonly at the shoulder of a freeway.

The problem only occurs:

When starting from a dead stop, turning (right as far as I can tell, only when turning right), up a hill.

Once I am straight the problem goes away. I'm not certain the problem will happen if I make the turn excessively wide. basically I have to be turning right lane to right lane.

The problem does not occur turning right on level ground.

The problem does not occur turning right down hill.

The problem does not occur when starting from a dead stop going straight forward, under any circumstance.

I have never noticed the problem at higher speeds, but you don't typically turn sharply at higher speeds, for obvious reasons.

I wouldn't take it as gospel that the problem does not occur during left turns. In normal traffic left turns are typically a bit wider.

I appreciate any thoughts about what is going on here. There are no other issues to speak of. Truck runs well, I've discussed before that the take off from dead stop is a little slow - but I assume that is due to the 285/75/16 - 33" tires.

1999 Ram 2500 V10 4x4 3.55, 47RE - 74K miles.

I read a few things that mentioned LSD chatter and the need for friction modifier. I hoped the issue would go away after I changed the rear diff oil. It did not. I've put oil/filter (that's another story, found the wrong oil filter on it when I changed the oil...the kind of filter you use in a old Dakota V6).

Appreciate any input/ideas/tests I can try.

-Ray

 

Only on turns, normally I would suggest the u-joints on the axle ends.... but, up or down hill shouldn't matter if that were it. Wouldn't hurt to check 'em anyway though......

I suspect something is binding, but, no idea what it would be. May have to wait for the condition to get worse.... might make it easier to find. (or, it might just go away, as you break things in again.)

 

Well I'll be under the truck again in a few days...last 2 bits of maintenance fluids, because I don't know when they were done last:
Transfer case - drain and fill
Auto transmission fluid/filter drain/fill and adjusting the bands (I read some place better to let an 'expert' do that, but I've read the procedure and it looks pretty stupid easy...if you have a torque wrench and can measure 1/8 of a turn, it seems easy to do.)

Neither of those do I suspect will affect this symptom...which is why I went with diff drain and fill first...figured it had a chance.

When I'm down there. What would look 'bad' while I'm there? Nothing is obviously damaged (bent/broken/loose) that I have seen so far. This symptom is part of why I'm chasing lubrication points in the other thread.

 

Don't expect it to be clean. Basically, if everything looks good, then, it's all good. The t-case fluid will likely look nasty, so, don't be surprised. Let it drain for a while, and then refill. Also, pull the FILL plug first. Just to make sure it comes out nice. Be a bummer to drain it, and then not be able to re-fill it.

 

Read someone's differential story about that happening, and did as much on both of those. From now till I die... check I can fill it, before I empty it.

 

You could take the drive shaft off and grease the splines. Sometimes they stick. Check your u-joints while the shaft is off. If they feel rough or dry, replace them. On our Dodges the axle shafts are bolted to the hub, so everything is always spinning in the front axle. You could possibly have a bad axle shaft u-joint. Just because they are tight, doesn't mean they aren't dry, and beginning to fail. Also, jack the front up and spin the hubs. You could have a bad front wheel bearing. See if they spin smoothly and easily with the tire off.

 

And turn the wheels slightly as well. That'll tell ya if the u-joints are dry.

 

actually - that was the first fluid I got into that looked brand new...clearly someone had changed it...nice and red...however, at that point I had already taken off the skid plate...found my hand transfer pump to get new fluid in there...a 10mm allen wrench (that would fit between the exhaust and drain plug, my 10mm allen wrench ratchet adapter was not going to fit in there, so I went on a hunt through ever tool box I own to my 10mm key)...so I went ahead and swapped it, and I know I won't have to visit again for a while.

While the fluid itself looked pretty darn nice, the transfer case itself has some caked on crap light dirt and mud...I'm guessing it's had some fluid on the surface of it, which made dust and crap stick to it.
While I was down there I noticed something.

The transfer case connection to the drive shaft, going towards the rear differential, has a rubber seal around it, and what looks like the ability for the drive axle to play a little bit in and out of the transfer case. The rubber seal, which looks more like a sleeve than a seal, has a hole in it.

Am I suppose to be putting lube in there? I manipulated it in my fingers a bit, it's quite soft, I don't know if this hole is original, or if someone squired lube in there using the same needle attachment I mentioned previously.

I haven't had a chance to try the other things you guys mentioned. I just discovered that my floor jack doesn't elevate enough with the bigger wheel, to get the tires to clear the ground. Going to have to drop a little money on a new jack. Looks like the cheapest route is about $70 for a 3 ton floor jack that will do it. Looks like it will get 20" off the ground, which should get my 33" tires off the ground.

The only other thing I did while I was down there for the diff was look at the drive shaft and U joints from front diff to transfer case to rear diff. Nothing is obviously wrong to my very untrained eye. The only thing I noted was that in the front drive shaft where it meets the front differential I do have some play when I grab it and pull back end forth, not much, but contrary to the rear drive shaft where I have no play - I can grab the shaft with one hand and pull left right or up/down and feel it move. However, since the problem occurs when I'm in 2WD/RWD I can't imagine this is an issue. Also, I don't know what the tolerances are for the front drive shaft play. Some where I read that if you are chasing a vibration - doing that in the rear should yield no perceivable play...but this made no mention of 4wd vehicles.

 

The seal is actually further inside, what you are seeing there is just a dust boot. The hole is to drain any fluids that happen to collect in there. (like going thru deep water.)

The fact that things under there are dirty really isn't a surprise. That's all stuff that hangs out under the truck.... one trip down a dirt road will make it look like it hasn't be cleaned since it was new... (which it probably hasn't. )

If you are curious if the play in the front shaft might be your issue, remove the shaft, and then go for a drive. Do the things that usually bring on the problem you are looking for, and see if it's still there. Driving without the front shaft won't hurt anything.

 

Since I was advised to get wheels of the ground soon them and listen... have a listen with me...

https://youtu.be/fPBnuOzIfik

No noise when steering. Not sure if the noise I hear when spinning the tires isn't just normal.