Rear differential noise

[rupert's]

That the rhythm does not stop friends! Today I have solved 3 problems that I had in the mutt .... I thought it was over and suddenly !!!! Oh no! What sounds there? Something weird sounds ... This car is never finished

I have the car raised with the wheels raised, I have put a gear and I have noticed that there is a noise in the rear differential ...
Maybe a bearing? Has anyone ever dreamed of the differential like this? Can you give me trouble if you left it like this?
He left you the link to the video
https://youtu.be/K6reOTqUucw

[m3a1]

I'm going to take a couple of guesses which will probably make you feel just a little better.

I believe you may have said you were dealing with some issues with the drive shafts between the differential and the wheel hubs.

Problems with those shafts will sometimes cause other problems, especially creating problems with the yokes on the differential (to which they attach).

These shafts must be capable of smoothly lengthening and compressing to allow the suspension to travel up and down.

Shafts that have been poorly maintained can cause the yoke to go out of specification and the yokes then begin to be loose on the splined output shaft to which they are attached. When this occurs, no amount of tightening of the center bolt that holds the yoke on will make any improvement and any declination of the drive-shafts will move it.

I am pleased to say that the sound I am hearing does NOT sound like something that is immersed in gear oil. Thus, I suspect it is something other than the rear end itself (assuming that the rear and is fully lubricated).

I am going to suggest a couple of independent steps to help you diagnose this problem-

I will begin by pointing out that (in the video) your suspension is hanging all the way down which is at the position of full travel and the position of greatest declination which is also the angle of greatest resistance against those universal joints.

1. Put a long solid rod, or long screwdriver to your ear and listen while simultaneously touching the opposite end to the stationary surface of the differential housing and also each hub housing. Obviously, you should NOT touch it to any component that is in motion. In this way you can listen to determine the general area that is making the noise.

2. Support the body/chassis. Lift only one rear control arm up at a time and if necessary, perhaps both at the same time and see if the noise remains constant. Next, with the engine off and as each side is raised, give each shaft a good, firm shake. Does it wobble even in the very least? It should not.

3. If you have an idea which side is making the noise, remove the shaft on that side and check again to see if the noise persists. While the shaft is off, and with the engine is off, check the yoke on the output shaft of the differential. If it wobbles in the least, it will have to be replaced. Discard any yokes that are out of specification. They cannot be repaired. They are inexpensive and exceptionally easy to remove and replace.

4. With each shaft removed, check the rear wheel and see if it wobbles. Even a slight wobble indicates that your bearings may require servicing or you may have an actual bearing problem. Poor adjustment and poor lubrication at the bearings can produce the same symptoms as a bad bearing so, if you have a wobble, do not assume the worst. A visual inspection of your bearings and races will have to be performed.

Cheers,
TJ

[rickf]

TJ, remember that Rupert is in Spain so parts may not be as easy to get as they are here. His suspension is not fully extended since it is sitting on jackstands under the control arms. I can see the issue, Watch the main drive shaft wobbling, I would venture a guess that either the pinion bearing is bad or the transmission output bearing is bad or a u-joint is bad or loose. Since the differential is not leaking I doubt it is the pinion but that is a serious wobble and it is in sync with the noise.

Rupert, there IS oil in that diff isn't there?!!! It kind of sounds like a dry differential.

[rupert's]

I'm going to take a couple of guesses which will probably make you feel just a little better.

I believe you may have said you were dealing with some issues with the drive shafts between the differential and the wheel hubs.

Problems with those shafts will sometimes cause other problems, especially creating problems with the yokes on the differential (to which they attach).

These shafts must be capable of smoothly lengthening and compressing to allow the suspension to travel up and down.

Shafts that have been poorly maintained can cause the yoke to go out of specification and the yokes then begin to be loose on the splined output shaft to which they are attached. When this occurs, no amount of tightening of the center bolt that holds the yoke on will make any improvement and any declination of the drive-shafts will move it.

I am pleased to say that the sound I am hearing does NOT sound like something that is immersed in gear oil. Thus, I suspect it is something other than the rear end itself (assuming that the rear and is fully lubricated).

I am going to suggest a couple of independent steps to help you diagnose this problem-

I will begin by pointing out that (in the video) your suspension is hanging all the way down which is at the position of full travel and the position of greatest declination which is also the angle of greatest resistance against those universal joints.

1. Put a long solid rod, or long screwdriver to your ear and listen while simultaneously touching the opposite end to the stationary surface of the differential housing and also each hub housing. Obviously, you should NOT touch it to any component that is in motion. In this way you can listen to determine the general area that is making the noise.

2. Support the body/chassis. Lift only one rear control arm up at a time and if necessary, perhaps both at the same time and see if the noise remains constant. Next, with the engine off and as each side is raised, give each shaft a good, firm shake. Does it wobble even in the very least? It should not.

3. If you have an idea which side is making the noise, remove the shaft on that side and check again to see if the noise persists. While the shaft is off, and with the engine is off, check the yoke on the output shaft of the differential. If it wobbles in the least, it will have to be replaced. Discard any yokes that are out of specification. They cannot be repaired. They are inexpensive and exceptionally easy to remove and replace.

4. With each shaft removed, check the rear wheel and see if it wobbles. Even a slight wobble indicates that your bearings may require servicing or you may have an actual bearing problem. Poor adjustment and poor lubrication at the bearings can produce the same symptoms as a bad bearing so, if you have a wobble, do not assume the worst. A visual inspection of your bearings and races will have to be performed.

Cheers,
TJ

Wow! There are several possible culprits ... I'm going to start by lifting a wheel and see what happens, let's see if I can identify which side the noise comes from, it's not that it bothers me, but I don't want it to cause me something worse ... I'm going to grease the transmission arms, I remember that I disassembled them cleaned and greased but maybe I put little grease.

TJ, remember that Rupert is in Spain so parts may not be as easy to get as they are here. His suspension is not fully extended since it is sitting on jackstands under the control arms. I can see the issue, Watch the main drive shaft wobbling, I would venture a guess that either the pinion bearing is bad or the transmission output bearing is bad or a u-joint is bad or loose. Since the differential is not leaking I doubt it is the pinion but that is a serious wobble and it is in sync with the noise.

Rupert, there IS oil in that diff isn't there?!!! It kind of sounds like a dry differential.

Parts ... In Spain there aren't any, everything is imported, there are few mutts on the street and the army hasn't used them, that's why there are no parts.
Very observant Rickf, the main stream has a bun. I took the transmissions to a workshop to put the transmission spreaders, and the workshop mechanic told me that this bun would not affect at all, that nothing was wrong. That's why I haven't said anything ...
https://www.youtube.com/watch?v=UB3qPdcvl-I
https://www.youtube.com/watch?v=X-QQk0YBcoA

It seemed strange to me, I have seen that the shaft has metal pieces on the tips that seem to be to balance it, I thought that if it had to be balanced it was strange that a bun did not affect the operation, but ... he is mechanical, I trusted on his word
Do you think the problem could be that? Do I have to get that bun out?

[m3a1]

Whatever it is, you will be able to identify it by listening, I am quite sure of that.

Any you may be in Spain where parts are few and far between but you have friends all over the world, here on the G838. If you can't get any help from them, you have bigger problems than just a noisy rear end.

[rickf]

That driveshaft not only has a dent (bun ?) But it is also bent and that is going to take out both the u-joint and the pinion bearing. This dent is usually caused when the vehicle is picked up with a forklift. I had the same thing on mine. Here it was simple to just get a new shaft but there it will probably be easier and cheaper to get the driveshaft rebuilt, they will cut the ends off and put them on a new tube. Is that a factory u-joint at the rear? Something looks strange but it might just be the spinning and light.

[rupert's]

That driveshaft not only has a dent (bun ?) But it is also bent and that is going to take out both the u-joint and the pinion bearing. This dent is usually caused when the vehicle is picked up with a forklift. I had the same thing on mine. Here it was simple to just get a new shaft but there it will probably be easier and cheaper to get the driveshaft rebuilt, they will cut the ends off and put them on a new tube. Is that a factory u-joint at the rear? Something looks strange but it might just be the spinning and light.

Yes, it is an original and new U-joint, this week I want to take that bun and see if it is completely straight ... I keep you posted

[svramselaar]

hi

i agree with rickf if the u jounts are good bend drive shaft
look also if the nut from the flange is not loose
i see the a large gap between the diff and the flange

cheap shaft parts number 7368801
https://webwinkel.truckpartstrading.nl/ ... ller-shaft

george

[rickf]

For 145.00 I would just get the new shaft! It is going to cost you at least that much to have this one straightened and I am sure there are no guarantees. With 4.88 gears that shaft is really spinning and needs to be perfect.

[rupert's]

Jorge! encontraste el mas economico de todas las webs europeas! Al menos de las que yo conozco...
I have asked for repair in 2 specialized companies ... and yes, they ask me between 150 and 200 to repair.
I'm going to buy a new one and finish faster and better. It's a shame, I have put the 2 new spreaders on this bar

Even so I think the noise will remain I think there is orgura between the differential and the wheel transmissions ... it will be seen in a short time and I will tell you how it progresses.

saludos

[m3a1]

No comments on the actual, identifiable source of the noise.....

[rupert's]

Classmates! In the end I put in a new rear transmission ... I don't know if the noise from the differential will continue because now I can't start the engine, later I will tell you if the noise from the differential continues.
But I have seen this gap in the gearbox outlet. This is so? Or on the contrary ... Is there something wrong?

All the best!

[rickf]

That looks a little further out than normal. What does the gap on the front output shaft look like? They should be equal. Was this vehicle ever cut? If the front gap is very close then you will need to loosen the transmission and motor mounts and try to move the powerpak back just a hair.

[rupert's]

No, this car has never been cut, the solution will be to pull back the powerpack, I don't know why I had not thought of that solution before ...
Thanks rickf

[rickf]

You will not be able to move it much, the mounts are designed to pretty much place it in the correct position as they sit. Is the gap at the front shaft too close?