Judder when setting off

[Ministrone]

Since I've owned my Dolomite (4 months now) I have had a problem of a judder through the whole car when pulling away from a standing start.
The problem mostly goes when I lift the clutch without pressing the accelerator pedal, then accelerating once I have taken up drive. This is much worse when in reverse or when the temperature is hot.

The cars suspension is fully polybushed, the clutch is relatively new and I have recently fitted new engine and gearbox mounts.

I have made a short video so I could see what was going on underneath the car.
https://www.youtube.com/watch?v=D6_NiKdgBj4

Has anyone any ideas how to cure this?

[mahony]

Looking at your video it looks to me that your propshaft centre bearing is shot as you can see the middle moving quite a bit on start up

http://www.rimmerbros.co.uk/Item--i-37H8019 ( think there cheaper on ebay but i cannot get ebay on my work pc )

[Mad Mart]

Great video. See how the diff. lifts up at the front. Must be your tie bar bushes.

[mahony]

Great video. See how the diff. lifts up at the front. Must be your tie bar bushes.

The axle does move as you say Mart but also the propshaft moves up and down quite a bit ( maybe a combination of both ).

[Jon Tilson]

Defo the tie bar bushes...

The prop is supposed to move in the rubber mount. Its not moving much at all....but the diff judder is obvious.

As they said....well shot vid. Must have scraped a few bits on the road filming that....not to mention the funny
looks from Joe Public...

"What's that man doing hanging out of the boot mummy..."

Lol...

Jonners

[trackerjack]

Triumph of innovative filming techniques

[HQentity]

Absolutely fantastic video!! My car next please!!

[tony g]

Im not convinced its rear end bushes. The diff will always rise under power as the crown wheel is "climbing " the pinion, so take off lift (of the diff nose) may be normal. My guess would be gearbox mount as the tail of the box is wagging back and forth slightly , which in turn will make the prop angle change slightly and cause a vibe. The fact you can pull off with no throttle (no torque to speak of) then floor the car without the vibe indicates its related the initial torque twist "encouraged" by the engine/gearbox to be able to twist when using power on take off. I'd check alignment of engine and box mountings or maybe even the hardness off the rubber mounts.
I once had a hybrid bmw with nissan turbo engine and box on custom mounts,and had a take off vibe. I cured it by lowering the box mounting 3mm.

BTW the vid is very nice and clear

Tony

[Jon Tilson]

Disagree...
That is a clear case of axle tramp, which the tie bars are supposed to fix but aren't cos the bushes at the axle end are shot...

I've changed these on a few cars and its one of the most marked changes you can make.

Jonners

[jikovron]

My car had exactly the same issue , normal pulling away caused the same horrible rubbery judder seen in your video and engaging at idle speed was smooth but impractical to keep doing and reverse was worse!

My car still wears its dodgy soft bushs and an old soggy prop centerbearing but i didnt believe it was that as i felt that with a smooth rise in torque into the propshaft when pulling away would always negate a sine wave esque judder regardless of the suspension condition (unless when axle tramping due to breaking traction)

So i removed the clutch and deglazed the flywheel and cover thoroughly and replaced the glazed friction plate and since i couldnt even provoke judder when trying to either in first,second or reverse!

[Ministrone]

Thanks for the advice and kind comments on my video technique.
I've had a good look round the car today and noticed that the rear suspension tie bars are only polybushes at the axle end with a standard (but good condition) rubber bush on the chassis end. My next step will be to track down a set of inner poly bushes and eliminate this possibility.

I also found that the engine stabiliser bar wasn't fully tight. This won't have helped either