Rear differential noise

[rupert's]

Yes, it is very close, I remember that when I put it on I had to remove and put the front bar several times because one of the two crosspieces always did not fit me due to lack of space

I think that leaving the 4 screws of the engine and the Gearbox loose and also loosening the screws of the exhaust pipe will be enough for it to come a little behind.

[rickf]

As far as the exhaust, I would only loosen the clamp that holds the muffler to the body and leave everything else alone. Once you loosen those little donut clamps they never seal again. The very small amount you are going to move the engine will easily be absorbed by the exhaust with the muffler free to move. Once the mounts are tightened down give the exhaust a little shake and then tighten the muffler clamp and you should be good with no leaks.

[rupert's]

Today I spent the whole morning pulling the engine back a bit, I only had to go 5mm behind, but I couldn't, there is a 12mm gap in that flange and practically nothing in the front, and if this does not bring me problems in the future I will I'm going to leave like this

https://www.g838.org/download/file.php? ... &mode=view

I have also put the rear transmission new bar and it remains to test if the noise from the differential has been removed or on the contrary it is still there. I keep you informed. All the best

[rickf]

Is that the new drive shaft you bought? I wonder if they are making them and calling them NOS? Did you measure it and compare it to your old shaft?

[rupert's]

I have not measured it, but it must be NOS, the box was made of old cardboard, it was wrapped in old paper with red letters, and it also had rubber bands on the crosses that were broken from years of storage.
Do you think this separation can be a problem?

[rickf]

Only if the yoke is not engaged in the seal. It looks like it is probably close. Are you able to get the front shaft in and out? It just seems strange that there is that much room on the rear shaft and there would still be enough room to get the front shaft out. If it does not come out I don't really have a solution since that would mean that the powerpak is too far forward. If the front shaft has the normal amount of room then either the rear shaft is too short, the rear differential is too far back or the vehicle was cut and welded back in the wrong position. I don't think it is possible to move the rear differential and you say it was not cut and it is a NOS drive shaft so I don't have any answers for you.

[acudanut]

Differential noise seems to be a very common issue, but not really not a serious problem..... 2 cents.
I know this does not help you sleep better, but if it ain't broke, don't fix it. It goes with the hobby.

[m3a1]

The answer is, if all the adjustments have been made and it's still too far out, you're going to have to have a new drive shaft made.

[rupert's]

The correct answer is that the pwerpack is way ahead. I have tried to bring it back but have been unsuccessful. For now I'm going to leave it at that.

Rikf, I was able to put the front axle with a lot of work because there was no space, in the end I managed to put it but it took a long time. For this reason I know that the powerpak is way ahead.

Acudanut, if the noise persists I will follow your instructions ...

m3A1 ... the two transmission shafts are new, I don't buy anymore hahaha

[Mr. Recovery]

Rupert's, Check your front motor mounts, the bracket's that bolt to the block are different from right to left. I think they should have a part number on them, the right hand bracket should be part# 11630498, the left hand one should be part# 11630497

20210518_233908.jpg

dan-2beers.jpg

[rickf]

Never paid any attention to that! Learn something new every day. Does that move it forward and back or side to side? I have an engine in the yard with a set on it but it is going to be hot today and I also need to get a lot of other stuff done. If I have time I will check them out.

[Mr. Recovery]

Never paid any attention to that! Learn something new every day. Does that move it forward and back or side to side? I have an engine in the yard with a set on it but it is going to be hot today and I also need to get a lot of other stuff done. If I have time I will check them out.

Not sure how it affects the way the power pack sits in the rails if put on the wrong side but I put a set on wrong a long time ago and was having trouble lining the 4 mounts up and found them on the wrong side, I was only putting the pack in so don't know how it would have affected the drive shafts.

dan-2beers.jpg

[rupert's]

Puff an issue that I considered resolved is reborn ...
Today I saw that a bit of valves came out of the differential, right from the same place where the noise that gives this thread its name comes from ...
Almost nothing comes out, but I think it's better not to come out at all ...
I have removed the transmission cross from the wheel and I have seen that it has a little play.
I have tightened the screw to the maximum but it still has play.
Is this that you see in the video normal? Anyone know if I should do something?
I don't want to disassemble and open if I know what I'm looking for ...
I mean I leave the video so you can see what I mean.
https://m.youtube.com/watch?v=FsckLZihHUQ

[m3a1]

That is NOT normal and I'm betting that you have found your trouble.

The yoke is worn to the point where it will have to be replaced. The metal the output shaft is constructed of is far harder than the yoke so we may conclude that the splines of the yoke have been hammered out of tolerance by the shaft. I am guessing this was run for some time with bad universal joints in order for that to happen....

or

something else is out of tolerance such as the rear carrier bearing for the output shaft or perhaps also the shaft if the bearing is bad enough to cause unwanted wear on the output shaft. So be aware....If there is runout in that output shaft that might also be the culprit for that yoke being damaged.

This happens to yokes from time to time, especially on the M151 series of trucks and, as we all know, they have many, many yokes. Occasionally someone on this forum will write that a standard PM includes getting up under there, grabbing things and giving them a good hard shake. This is one of the reasons for it.

Happily, your troubles should soon be over!

Cheers,
TJ

[rupert's]

That is NOT normal and I'm betting that you have found your trouble.

The yoke is worn to the point where it will have to be replaced. The metal the output shaft is constructed of is far harder than the yoke so we may conclude that the splines of the yoke have been hammered out of tolerance by the shaft. I am guessing this was run for some time with bad universal joints in order for that to happen....

or

something else is out of tolerance such as the rear carrier bearing for the output shaft or perhaps also the shaft if the bearing is bad enough to cause unwanted wear on the output shaft. So be aware....If there is runout in that output shaft that might also be the culprit for that yoke being damaged.

This happens to yokes from time to time, especially on the M151 series of trucks and, as we all know, they have many, many yokes. Occasionally someone on this forum will write that a standard PM includes getting up under there, grabbing things and giving them a good hard shake. This is one of the reasons for it.

Happily, your troubles should soon be over!

Cheers,
TJ

Thanks for your help m3a1!
In the restoration I did a review of the differentials, and I changed this bearing because it was in bad condition, I suppose that this bearing will have caused the problem ...
Now I am days away from getting the documentation and being able to go out with the car to enjoy, this setback is very bad for me ...
What happens if I leave this like this for a while? Let's say ... 2 months, can I break something else?

Would the piece to order be number 4?

Greetings