The 1980 300TD that I have been helping a friend with is being a pain. I was wondering what could cause the following: When accelerating quickly ( regardless of being a 1980, it is a turbo diesel, and is very capable of doing so) from a slow roll or a stop, the car shakes/ shutters/vibrates. I thought it was the RR Axle, due to torn boot, and dirt/wear, but replacing it has not helped. Now I am thinking it may be one of the following, but do nto want to play the narrow it down game while replacing parts.: tranny mount, drive shaft, rear end mount. When I let off the pedal a little it subsides to a large degree, and it does not do it at higher speeds, mostly when lots of torque is applied at low speeds. Any suggestions on what to check and how? thanks a lot! John

__________________
Wilmington, NC. Board member of Cape Fear Biofuels.
www.capefearbiofuels.com
1982 Rabbit on WVO (sold)
1979 300TD on biodiesel
1985 F-350 6.9 on WVO and Biodiesel
1983 Factory Turbo Diesel Rabbit.
1985 300SD 252,000 for sale (sold)

Does the frequency of the "shake" increase with the cars speed, or is it just random vibration that is independent of speed? For example, the "clunk-clunk" of a bad CV joint will usually occur once per wheel revolution and can be heard to increase as the car speeds up. Is there any way to reproduce this on a lift or jack-stands (safely)? For example, if you applied power while holding the brakes with the rear wheels off the ground would you be able to hunt it down? Just some thoughts.

You really ought to try to isolate it as being either the engine (or related mounts) or further along in the drive train. From your description, it almost sounds fuel related, but I wouldn't go there without making sure it wasn't in the drive train somewhere.

Wes

I am going to put it on stands today, and run it as described. It is definately speed/rpm related, and I can promise is not fuel related. If you rode in the car you would understand. It only does it under hard accleration, and is worst at the higher rpms, right before the shift. After you are at steady MPH, or high MPH high gear it no longer does it. I am fairly certain it is not in the engine mounts, but I will look into it. Thanks for the advice. John

__________________
Wilmington, NC. Board member of Cape Fear Biofuels.
www.capefearbiofuels.com
1982 Rabbit on WVO (sold)
1979 300TD on biodiesel
1985 F-350 6.9 on WVO and Biodiesel
1983 Factory Turbo Diesel Rabbit.
1985 300SD 252,000 for sale (sold)

shocks that are worn can cause a vibration under load - are yours new(er) or ready to be replaced?

John

__________________
John Hughes, was in Landstuhl, Germany but currently in San Antonio, TX


1978 280CE Astral Silver now 59,xxx miles and counting "Silber-Kugel"
1986 300E Black Pearl Metallic 143,xxx miles 5-spd daily driver w/ blk leather "Schwarz-Schönheit"
1989 190E 2.6 (euro) 5-spd Desert Taupe 112,xxx kms Had to leave behind in Germany!!! "Helga"
1983 300D Pastel Beige now 312,xxx + miles SOLD

OBK#24

If it's in the driveshaft you will want to know before it goes! That could be an ugly mess. If certain parts like the flex discs need to be replaced, though, I understand it's not too bad a job provided you get to it before total failure occurs. You probably already know all that, though.

Hope you're able to figure out what the problem is today.

__________________
Ralph

1985 300D Turbo, CA model
248,650 miles and counting...

sounds like some driveshaft wobble to me;
if it begins when you are under load (beginning up hills, etc.) and then subsides (after a few seconds) once you let off.

had similar symptoms and it was part of the driveshaft setup.
thanks omegaman, that was my exact repair as well.. could only remember it was cheap.

I just replaced a driveshaft support for a customer because of the exact same simptoms and it fixed it. The support was only $16 I think.