Humming sound continues, in OD, out of OD, in 2H, 4H and 4L, forward or reverse.

I thought I would lift the truck again (rear only) drop it in Drive and do double, tripple checking where the sound is coming from.

Questions:

The smaller drive shaft from the Transfer Case to the front of the truck...will it spin if the vehicle is in gear, NOT in 4x4 while the rear of the truck is lifted?

Should the sound come from inside the transfer case, would it be a good idea to then drop the case out, open it and check if anything obvious is making the sound like a bearing etc., then go ahead and get parts needed or a whole rebuild kit instead of buying a used case that will last who-knows-how-long?

Which fluid do you use in the transfer case?

I read about input and output shaft length could differ as two different models of the 231 D T-case were made? How can I find out which one I need?
One has a longer input/output shaft than the other?

Will a 231 D out of a 1999 1500 Dodge Ram fit?
How about those made in previous years? 1994 and such?

If any of these questions are silly, sorry, but so be it.
Need to get this issue fixed, it's getting to me.

I am planning to even head into Mexico and hit a couple of salvage yards and want to make sure I know what I am looking for.

 

1. If you are fully dis-engaged from 4X4 then the front will not spin. This is very dangerous and hard on the rear differential so only do it slowly!

2. If the sound is in fact the T-case, remove the drive line, then remove the few bolts on the end of the rear extension housing and ensure the snap ring is still in place and not slipped out of it's grove on the main shaft. If it is ok drain the T-case and pull it out and have a look. At this point you can try and find the source of the vibration such as a bad bearing. They are actually just a simple gear box. If you are not good at it take it to a shop and have it rebuilt and re-install. You are smart to rebuild then go to a junker...+1

3. ATF+4 transmission fluid. Valvoline ATF+4 Fully Synthetic is a good fluid.

4. I seriously doubt you will need to replace the shaft. I wouldn't worry about it until you find it broken or worn. If you do in fact need one the dealer can tell you which one it is or a good parts warehouse like www.sixstates.com

5. Yes it should. Now sure on the years, but they changed the Ram in 1999 so I would look 1999-2000. Dakota would be 1997-2000. Or Durango 1998-1999.


These are all great questions, thanks for asking.

I always say:
There is no stupid question if you don't know the answer to it.

 

Thank you for your help and responses. All this info is useful to me as I get to know my truck/SUV closer. I printed out Transfer Case Diagrams with a parts-list, and have a good understanding now what it looks like inside, NOT how it all works with each other...but it's like having a cheat - sheet for a puzzle.

Now, i want to do more with this truck than just have it stock. It is important to have this issue taken care of in order to move on to the next level.

Hydra (or anybody else willing to respond)...I am sitting in my vehicle, windows closed, driving and CLEARLY hearing the humming sound coming from the back and I want to say, definately from the Differential. I do believe that IF the sound was coming from the T-Case I would HEAR it inside the vehicle coming FROM the T-Case, the middle, where I sit...but nothing...it is all coming from the back.

Even though we had the Differential open and replaced a couple of bearings and cleaned it all up, I really believe it is something else that is causing this sound from the Differential. When we had the Diff. open we saw small marks on the (watch out...here I go) big metal tooth ring inside. Could those marks make such sounds? this sound did not just happen it gradually got louder of a good period of time (1-1 1/2 month).

It is a Limited Slip ( I think it is called)...is there any adjustments to that which might eliminate the sound? (It has the additive). Should anything be replaced maybe?

Anyways, I will have the drive-shaft disconnected from the rear differential this sunday and gonna spin the rear-wheels to see if I can get the sound to show up.


This has taken long enough and once I figure out what it is and what we did i will make sure I take all these messages and make an article of it for the next owner of a 1999 Dodge Durango 5.9L 4x4. This thing has been my wish for some time, expecially the body-style, size and power. The condition of this truck is absolutely fantastic, beautiful to look at. Carfax record shows constant care as it was scheduled and I am planning on keeping it that way. It will get a lift, wheels, nerf-bars, cow pusher (or whatever it's called).






IT'S DRIVING ME NUUUUTS!!!

 

We had a similar issue with my moms tahoe. The problem was that the nut on the crush sleeve was torqued correctly to spec, but the sleeve wasn't crushed at all. The tech at the dealership said just take an impact and crush it slightly then set your backlash. I don't know if I explained this worth a crap but I was only 13 when we did this and I didn't know much (anything) then about diffs at that time.

 

I read that post like three times and still couldn't repeat. Don't even know what any of that means. But it will lead to me finding out.

At 13 and you remember all this? Nice...

What I will do is use this, do research online, get info to my mechanic JUST in case he doesn't already know and well, see what can be done.

 

Well I would wait for hydra to wade back in on this, but yeah we had a very annoying droning noise and a whine. We put in axel shaft bearings (bearings were shot) and seals, but that was the issue when it was put back together we still had the whining noise. That was only 5yrs ago.

 

Okay, from what you are saying, me "knowing" where this sound is coming from (rear of vehicle, differential) plus an article (with pictures) of someone rebuilding his differential from a 1500 Dodge Ram I am now very, VERY sure it IS from inside the differential.

Is it hard to get to the cruch sleeve? I believe someone DID work on the differential before and they might never, well, crushed the sleeve?

I even found the name of the part I tried to describe by making a sad drawing. What we found inside the fluid were parts of a pack alignment clip. These apparently hold the clutch packs together. One must have fallen out or whatever and got destroyed somehow. Just can't imagine them to fall out 'just like that'.

Going to see how much was replaced now by my mechanic.

Now I gotta find what kind of clutch pack to look for (1999 Dodge Durango 4x4, 5.9L, 12 hole Differential Cover, Limited Slip, not sure about the bloodtype) and where to get em IF they are needed...


(I learned something new again...teehee)

 

Did the clutch packs get replaced when these pieces where found? They should have been other wise with that piece gone they aren't functioning the way they should be. Also did the mechanic replace the axel bearings, cause any floating debris would most likely make them fail (and any other bearing in there) and they will make a droning grinding noise. When the bearings go everything else starts to wear and go out premature, its the domino effect and it is better to take care of it now.

 

The axle bearing were changed, yes.
The packs, I would say, are from another differential and were installed WITH the clips in place. I saw before it was installed.

The whole was cleaned to remove and debris, metal flakes. (see what I did there? clever, eh?)

Maybe some damage was done to a bearing somewhere behind that big tooth-thing sitting in the differential.

I think a closer look at ALL gears and bearings will probably reveal more.
And to teh crush sleeve...I drove this truck for maybe 3-4 thousand miles before this sound (a low hum at low speed to a whine at higher speed) would make itself known. Could it be that someone worked on the Diff. before I bought it but was drunk or whatever and did not put everything back together as it is supposed to be and a clip came off, got eaten and now left a mark somewhere...maybe bit a bearing further inside the Diff. towards the drive shaft?

I mean, shoot...anything in the differential is better than a transfer case replacement...

I live along the Mex.-US border and a lot of SUVs etc are being left in the desert by those coyotes or drug-smugglers. I can get a Differential anytime.

Laughter aside...gonna get to be evaluat'n the Diff. more on sunday...

 

The big tooth things are the ring and pinion set. The one attached to the driveshaft is the pinion and the other is the ring. The crush sleeve is in front of the pinion, but there is a pinion bearing that could easily be the culprit. If it is damaged it will start getting metal in the oil and undo all the work you just had done.