either mount will work, maybe one is better? how much you wanna spend?
Is that the part which is(NOT) there?

__________________
1984 123.193 372,xxx miles, room for Seven.

1999 Dodge Durango Cummins 4BTAA 47RE 5k lb 4x4 getting 25+mpgs, room for Seven.

You are seeing flex disk failure. Stop driving the car until you replace the flex disk. You are lucky that the flex disk is giving you a pre failure warning.[/QUOTE]

I guess I am lucky. Strange how the center tranny mount is no longer on the car. Maybe I parked the car too close to a parts place one day.

Since it is a shame not to have a near carbon neutral GreaseCar on the road I ordered this part:
J6000-16023
Hope its the right one

Sucks driving my gas guzzeling 4 cyl. to work all week. Although I was HYPERMILING the hell out of it, I managed to squeeze 41.8 MPG out of "Raven".

bump

I'm replacing the flex disc (Front) What happens if the driveshaft orientation is not the same? never marked the way it was originally.

Don't I get a 50/50 chance of guessing right?

I done the same, never noticed a huge difference in vibration.

__________________
1987 VW Jetta Mk II - Daily Driver
1992 W201 2.3 - sold
1985 W126 380se - sold
1985 W123 OM617.952 - sold
1981 W123 OM617.912 - sold
1986 W201 2.3 - sold
1979 W123 OM 617.912 - sold

An unbalanced driveshaft will cause drivetrain vibration while moving. The vibration will wear out flex disks, center bearing, and maybe transmission mounts and rear transmission seal, probably roughly in that order.

Unless you want to wear out some of those more expensive parts, and be continually replacing the "cheaper" parts, you want to find and eliminate the cause of the vibration. If the car has always vibrated, the problem may be caused by nothing you did.

__________________
'83 300DTurbo http://badges.fuelly.com/images/smallsig-us/318559.png

Broadband: more lies faster.

Maybe the driveshaft has always been in wrong and I've been carefully putting it back together wrong........................... In this case two wrongs could make a right.

OK every one. Thanks for your help. It was the flex disc plate and the tail tranny mount has been replaced but the shaking on acceleration still exists. The car is in need of a valve job because it feels like I am always diving over pebbles. Have to admit the task seems a bit daunting to me. Between MercedesShop, GreaseCar and DieselGiant I may be able to pull it off some day................
Flex disc failure (front) 1984 300D after 1 year.

I could be wrong, but I don't think the driveshaft orientation at the flex plates matters- It's only if you pull the 2 halves of the driveshaft apart at the center bearing and universal joint.
Speaking of which, the vibration on acceleration you are left with may be due to a worn universal joint. I have that symptom remaining on my car as well, after replacing rear axles, rear wheel bearings, differential, tires, and center bearing support(all for different reasons).

__________________
'83 300D Turrrbo 295K miles

You've got a serious problem somewhere if that flexdisc is only one year old.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Thanks Kerry and rrgrassi for you correct suggestions. I have replaced the center tail housing tranny mount and front flex disc plate. There is still the same vibration during acceleation wich may mean I put the drive shaft orientation on wrong. But It always felt like I was driving over pebbles all the time anyway. Even worse when I hit the throttle. (Post IP screw tweek for more power)
The next step in troubleshooting the vibration will be to change out the tranny mount shocks. Having trouble getting this part number but expect to find the answer from a bloke from greasecars greaseboard, Friday.
Another this thats way over due is a valve job.