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Discussion Starter #1
I have a harsh change (slight thud) from drive to reverse, so got the wife to move the selector from D to R while i got under the car to see what was going on. My arse was twitching a bit i can tell you. Anyway when D OR R is selected the driveshaft moves around 2-2.5 inches (slack). Is that tranfer box chain stretch or a rear diff is it a problem?.
 

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Discussion Starter #3
I have done that 43 and no movement. Tranny is solid, engine is solid nothing else moves which is amazing with 120,000. Just like i say 2 inch of prop either way like its taking up slack. Other than that no bearing sound, Just like select R from D and after 0.5 sec you feel reverse with a kick.
 

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When i say moves. I mean turns 2-2.5 inches round before it takes up the slack?.
When you turn the shaft either way where is the noise coming from? It's probably from a slacked chain in the transfer case.

If you can't tell, mark both halves of the drive shaft (for reassembly) then remove the two u-clamps on the drive shaft to split it in half. Then turn each half to see where the slack is coming from.

Remember to hold the u-joint caps to prevent them from falling.
 

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Discussion Starter #7 (Edited)
Been thinking. If it is chain slack. There is quite alot of movement for chain stretch. Would it not be causing other problems like noise or something else?. I have no other issues. Does this happen to anyone else.
Anyone else got a wife you can trust to check it out.
 

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Discussion Starter #8
Been thinking. If it is chain slack. There is quite alot of movement for chain stretch. Would it not be causing other problems like noise or something else?. I have no other issues. Does this happen to anyone else.
Anyone else got a wife you can trust to check it out.
Come on. Is anyone going to get under their car for me and see how much slack they have in the driveshaft before i pull it apart. It may be slightly normal. Get your good lady to put it in reverse and in drive while you have a peek under the car, and see if the driveshaft has any movement. You trust her don't you.
 

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My thinking is that if the drive shaft is rotating than the slack has to be coming from the rear of the drive shaft. If the drive shaft could be held firm at the rear differential then it could not rotate, no matter what the transfer case or chain or center support bearing is doing. I think the slack, normal or not, is coming from the rear differential or universal and or the other universals connecting each rear wheel. There's lots of stuff rear of the drive shaft that could have play.
Mike
 

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Discussion Starter #10
My thinking is that if the drive shaft is rotating than the slack has to be coming from the rear of the drive shaft. If the drive shaft could be held firm at the rear differential then it could not rotate, no matter what the transfer case or chain or center support bearing is doing. I think the slack, normal or not, is coming from the rear differential or universal and or the other universals connecting each rear wheel. There's lots of stuff rear of the drive shaft that could have play.
Mike
Go on mike. I bet you have got a nice dry garage with one of those boards on wheels that you could scoot under and see what happens with yours for me. All i want to know is.
Is it slightly normal to have some play in the driveshaft when you engage drive and reverse. Maybe tranfer box has some play to stop major slam from reverse to forward. Until someone with a car with good amount of mileage like mine 120000 miles gets under and has a look, who has no real problems apart from a slight clunk/jerk, we will all not no if this thing is normal. If someone else has a look with low mileage and has no movement in the driveshaft what so ever, we may have a problem.
 

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mega, it's 2:19 AM in Manchester, what are you doing up reading Benzworld.
I would love to help but I don't have anyone here that can safely shift from drive to reverse to check the play. My 98ML (80K miles) is not here and my 05ML only has 58K miles. I will see if I can get under the ML tomorrow and see what I can do. However there is always some play in the drive train even when new. It's a question of how much is OK.
Mike
 

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Discussion Starter #13
mega, it's 2:19 AM in Manchester, what are you doing up reading Benzworld.
I would love to help but I don't have anyone here that can safely shift from drive to reverse to check the play. My 98ML (80K miles) is not here and my 05ML only has 58K miles. I will see if I can get under the ML tomorrow and see what I can do. However there is always some play in the drive train even when new. It's a question of how much is OK.
Mike
Hi mike. Yes it was late. Thanks for the offer. Thanks also to michael that looks about right for the play i have in the video. Shame its not with the engine running. From what i can remember yours was fine?. So guess this kind of play is normal.
 

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Discussion Starter #14 (Edited)
Still got this play in the driveshaft that bothers me. I turned the driveshaft with engine off in neutral with wheels removed. There is quite alot of slack both ways before the rotors turn. Its like you press the gas pedel and i get rpm then slight delay before slight kick and movement. Can feel it sometimes when i go round a sharp corner off gas then apply gas and get delay then kick. Seems to be getting worse.
How much slack can you get in the chain and can it be tightened?. Cv joints and bearing are fine. Then again dosn't the chain drive the front driveshaft.
Is there anything in the transfer case that can produce slack in this way?. Never heard of wear in the rear diff, but i was alone so could not hold driveshaft and turn rotors to test it.
 

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Discussion Starter #15
I did a bit of a test tonight. Went round a sharp long left at the supermarket. Just before long bend eased off the gas, coasted round the bend then hit the gas harder than usual and i could feel the pause before thud as power went to the propshaft. This seems like diff problem to me.
When at the lights i do not get any slack as its already taken up slack ready to move off. i.e let foot off brake and creep.
This happens when foot off the gas at any speed above creep, so no power to the transmission then apply power and i can feel slack taken up before movement. But it is worse when going round corners like diff or tranfer box problem. No sounds or anything that i can hear. Anyone had a similar thing.
 
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