I have a whole lot of shakin' goin' on!!!

I replaced the driveshaft, flex disks and center support...

Now when the car approaches 65 to 70, it still shakes. I had a tire/wheel rotate and balance, and no change in the shaking.

Can the rear diff mount and/or subframe bushing be the cause? The car does have 292,000 on it.

Thanks!

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

06 VW Jetta TDI 156K miles-replaced the other '06 that quit after 300k miles. (did not catch the bad cam in time)

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

You replaced the drive shaft?

Or the flex disks on the drive (prop) shaft?

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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!

I replaced the driveshaft (due to bad ujoint), replaced the flex disks, and replaced the center support bearing assembly.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

06 VW Jetta TDI 156K miles-replaced the other '06 that quit after 300k miles. (did not catch the bad cam in time)

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Did you replace both driveshafts? Why not replace just the u-joint?

The driveshaft on your car should consist of two pieces. They are balanced together! If you take it apart and don't mark where they fit together, you will have an unbalanced condition. If you replace one piece or the other, they must be rebalanced to each other.

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Own:
1970 Mercedes 250c, 1976 International Scout II, 1982 Mercedes 240d, 1997 Honda Accord Wagon, 1998 Acura Integra Type-R, 2009 Mazda5.
Owned:
1974 International 100 pickup, 1975 International Scout II, 1981 Mercedes 240d, 1985 Mercedes 300SD, 1988 Honda Accord, 1988 Ford Thunderbird, 1991 Honda Accord, 1996 Geo Metro, 1996 Ford F150, 1996 Dodge Grand Caravan, 1997 Honda Accord, 2003 Acura TL-S, 2003 Yamaha V-star.

^^^ Indeed are you certain the propshaft is OK? (Did you have a different thread for the propshaft U joint problem?)

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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!

could be an axle shaft...

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John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
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My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Yes, there was a different thread. I replaced both sections with a full rebuilt driveshaft.

VSTECH, I hope it's not an axle shaft. They are original from what I can see, but the boots are not even split.

I do need to crawl uner it an make sure nothing came loose on it.

I notoced today when I sped up to 70, is shook pretty good, and when I let off the pedal, is shook even harder at first, then smoothed out just as quick.

I am also wondering if it could be worn shocks or even bad tires, like a slipped belt.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

06 VW Jetta TDI 156K miles-replaced the other '06 that quit after 300k miles. (did not catch the bad cam in time)

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Anyone have any other ideas?

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

06 VW Jetta TDI 156K miles-replaced the other '06 that quit after 300k miles. (did not catch the bad cam in time)

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

I would be guessing right now considering what you have done and the info we have. Here are some guesses:

Trans mount

engine mounts

driveshaft clamping nut

trailing arm bushings / worn front suspension / tie rods

Flex disk nuts / bolts

Wheel bearings


5hit, buddy... anything that moves.

However, you can make a really good guess at whats going on by driving certain ways. When you are on the highway, focus on the characteristics of the engine and road speed.

Make it shake, then immediately lay off the pedal... what happens? RPMs change by about 500 or so, but the driveline rpm will remain mostly the same.

Try to determine if the load on the driveshaft from the engine has an effect also.


Next step would be to start prying on suspension parts and find the culprit.

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A bad tire belt will be a low speed vibration

A worn diff mount, I believe, will mostly only cause highway wandering and lack of control (think: sloppy a55), but if its totally gone... I guess it might.

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Re-reading your posts, I am thinking trans mount right now. Can you get the car to wiggle at slower deceleration speeds? The feeling is similar to warped rotors except you may not feel it in the steering wheel.

JT, come to think about it, the engine mounts and tranny mount are getting weak. The car does not have wandering tendancies. No wiggling at lower speeds either.

I was wondering if weak engine and tranny mounts could cause that...

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

06 VW Jetta TDI 156K miles-replaced the other '06 that quit after 300k miles. (did not catch the bad cam in time)

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

It sure would be an easy fix! (fingers crossed)

You would know best, I am not really sure about what magnitude of shaking they might be responsible for... but certainly they will allow some at highway speeds.

I wouldn't discount the diff mount either. If you suspect driveline vibrations, that mount is responsible for absorbing them along with the trans mount and center bearing.

Good luck. I am dealing with one myself... lots of trial and error.

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