SO let me ask everyone this and then I'll shut up for a bit......I'm going to replace motor mounts, trans mounts, flex discs and driveshaft center bearing. Which job would be best to tackle first, the trans and motor mounts all at one time, or the flex discs and center bearing?

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2012 Mercedes ML350 Bluetec 91K (hers)
2005 Corvette 55K (fun car)
2002 VW Jetta TDI 231K (mine)
1998 Volvo S70 T5 Turbo 196K (kids)
1994 Ford F150 4WD 249K (firewood hauler)
1983 Mercedes 300D 376K (diesel commuter)

Motor mounts and trans mount are first - because you want the engine in solid position before you install your refurb'd driveshaft. Part of this reinstall is the adjustment of the driveshaft's length. You want the engine solidly tied down before you do this...(!)

You can remove complete driveshaft as one unit, including flexdisks, if you're well-organized. I did it this way, though my exhaust system was out at the time...

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'83 300 SD
'68 Triumph TR 250 - The only car I ever loved more than the Mercedes; who needs electricity, anyway? - Damn, why did I sell it?!
'59 Jaguar 3.4 'Le Chat Noir' - Damn, why did I sell it?!

It's difficult to make predictions, especially about the future.
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You indeed want to have the new motor mounts and the transmission mount in place before you start connecting up the flex discs and the centre propshaft bearing...

...however I think the better order of torquing / tightening is first the flex disc bolts and the mount for the centre bearing on the propshaft. Leave the large nut on the propshaft loose.

Next wiggle the engine and the transmission into a preferred position. Make sure it is sitting correctly in the centre of the vehicle - it is possible to make the engine and the transmission sit askew. If you look at the transmission mount resting on the transmission mount cross member you can see if the small M8 bolt holes are aligned correctly with the slots in the cross member. Once you are sure it is all good tighten the motor mounts and then fit the bolts to the transmission mount.

It is then best to put the car on its wheels and push it around a bit (transmission in neutral!) - backwards and forwards - so the flex discs find their best position and the propshaft splines find their preferred place. With the weight still on the wheels tighten the big nut on the propshaft.

I know this is all a pain in the arse but it reduces the chances of drive line vibration problems.

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

In addition to new mounts, disks, and center bearing you should probably take the shaft in to a drive line shop and have the ujoint replaced / shaft balanced. This is generally not a DYI due to the pressed flanges / yolks vs clip retainers. Although some here have managed. But the shaft still needs to be rebalanced using special equipment.

Even a small undetectable (manually) amount of wear in the ujoint will cause your very description (vibration). Even when my drive shaft was out I could not detect any "notches" or slop in the ujoint. And I've personally R&R'd many a ujoint over the years. Apparently it needed some torque to get offset.

Prior to having the shaft ujoint replaced I replaced the motor mounts, trans mount, flex disks, center bearing and carrier, differential mounts only to still have the same vibration at 35mph to 55mph.

Drive shaft rebuild cost me about $265. Now the car runs smooth as silk.

I'm betting the true source of your vibration is a slightly worn ujoint. That said probably caused by worn engine mounts, trans mount, center bearing / mount, and or flex disk etc.

Don’t forget to do the “roll back and forth” procedure mentioned above prior to torqueing up the trans mount, motor mounts, and center bearing mount.

P.S my car is a W126 SDL

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1986 300SDL 440,xxx

When I remove the Drive Line, I leave the Flex Disks on the Trans end and on the Diff. end. Then slide the whole unit out towards the rear of the vehicle, down and out.

Be sure to mark the two halves with some paint (before removing) incase it separates.

I think it would be near impossible to remove it with the Disks on.
Maybe if the two halves were separated, then it could be done.

Every MB Drive Line I have removed, the U-Joints have had that notchy feel to them. They don`t get flexed much, they really just smooth out any slight vibrations in the drivetrain.

I had both the 80 240D and 85 300D U-Joints replaced by San Jose DL Cost was $300. They machine them out and replace with a grease able joint.

Use good U-Joints and Engine Mounts, not the crappy URO one`s.
The shop must have used a China made center Support. 30K miles later I had a vibration, and the rubber was about totally gone.
replaced it with a Fibi, and made in China sticker on the box.

Ask ALABASSI about his 91 560SEL when the front Disk came apart and destroyed his car.


Charlie

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there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

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