any M5OD experts out there.

[modelageek]

I have been having a clunking issue for a few years with my drivetrain....6 months ago I changed out the clutch , PP and slave.the clunk was still there. it seems to be getting worse. I have checked everything I can think off, u joints, suspension etc......I am starting to believe it is from inside the tranny.......it does not matter what gear it is in, even reverse. there is a clunk like a bad u-joint as you drive.....the truck shifts OK......I have looked at motormounts and tranny mount......is there one issue in the tranny that would give me this clunk no matter what gear it is in?.....I also got under the truck when it was in gear and sway it back and forth.....it seems to be traveling to far as iit goes back and forth.......I do have a slight bang on the front drivers side suspension when I go over a bump..the shock is new the upper control arm is new....I looked around for an issue but can't find one there either.......I don't think they are related but I thought I would mention it....TIA

 

[Dylan9302]

is clunk only when it is in gear.. and if so does it clunk stopped in gear. is it a constant clunk or every second when ur moving??

 

[modelageek]

It does not clunk every second. If I am driving in ANY Gear and I let off the gas and then step on the gas it clunks like there is slack in the drivetrain and when the slack is taken up it Bangs/clunks

 

[fastpakr]

Try unbolting the driveshaft from the rear axle. See how far the pinion rotates in either direction before catching. My first thought is that you have too much lash in the gear setup.

 

[modelageek]

Try unbolting the driveshaft from the rear axle. See how far the pinion rotates in either direction before catching. My first thought is that you have too much lash in the gear setup.

I will unbolt the DS and check, but for now I have this picture of where the driveshaft meets the diff housing. if I put the truck in neutral and crawl under there I can turn the DS about 3/8" in relationship to the diff housing.

 

[Dylan9302]

how many km/miles are on the truck.. has it ever had a diff service? my fathers truck does the edsact same thing and his has 300000 km.. i figured it was what fastpakr said and u have too much play in the rear diff.. he just drives it carfully and has never really given him any trouble

 

[modelageek]

how many km/miles are on the truck.. has it ever had a diff service? my fathers truck does the edsact same thing and his has 300000 km.. i figured it was what fastpakr said and u have too much play in the rear diff.. he just drives it carfully and has never really given him any trouble

I have 130k on it and as far as I know the diff has never been serviced..I bought it with 88k on it and it was a little neglected so I doubt it was serviced...I have added some gear oil before but that is all.....

 

[Dylan9302]

ya i dont really know how to fix the issue but sounds edsactly like my dads issue.. he doesnt really care about it.. i imagin you would have to rebuild the rear end or if theres someway to adjust it.. i just dont know.. hopfully a more experianced person on here will no.. then maybe i can fix his..

 

[Earl43P]

I will unbolt the DS and check, but for now I have this picture of where the driveshaft meets the diff housing. if I put the truck in neutral and crawl under there I can turn the DS about 3/8" in relationship to the diff housing.

I do believe you have FOUND your clunk!
No need to remove that driveshaft to check any further.

It may last for more YEARS like that, but I'd start looking for a replacement axle if it were mine. Might as well upgrade to a LS and the ratio of your choice (didn't notice if you are 4wd or not).

 

[Moreflying]

If you get this clunk while rolling off and on the gas while driving it isn't that uncommon. My 94 has had that same driveline lash since I bought the truck in 1995 brand new. It still has it to this day. You will have some amount of play in the driveline. 3/8 in around the radius isn't out of this world sloppy. Use the clutch more when you roll off the throttle. It may help.

 

[modelageek]

I do believe you have FOUND your clunk!
No need to remove that driveshaft to check any further.

It may last for more YEARS like that, but I'd start looking for a replacement axle if it were mine. Might as well upgrade to a LS and the ratio of your choice (didn't notice if you are 4wd or not).

I just noticed your post........so you think that is to much play? could I jut have the pinion nut/gear adjusted?..........I was just about to post this picture showing my DS without the harmonic balancer. It came lose a few years ago and I removed it. I was wondering if that could be the source of the clunk

 

[BRUTUS_T_HOG]

3/8" of slop is normal for the diff.

i'll revisit this when i get home.

 

[sloth69mustang]

i just rebuilt my rear dif.. well swapped then rebuilt. and all new unjoints and my truck has dont this for as long as i have owned it (80k). i have 180k on it now. its just the way they drive. its semi annoying sometimes and some days it feels like it doesnt do it as much but its just the way they drive.

 

[BRUTUS_T_HOG]

there will always be slack in the drivetrain. if the noise is really loud and the the bang is harsh then you might start worrying about it, but otherwise it should be considered normal.