Severe judder in 1st or reverse

[mmarks]

Hi all,

Firstly let me say hello as this is my 1st post and I only puchased my TR7 (2 litre, 5 speed, 1977)this weekend!

Love the car but it has a severe judder when setting off in either 1st or reverse. The car has been recommisioned by the previous owner and had thousands spent on it, including new engine and gearbox mounts.

If I set off in 2nd gear, the judder doesn't seem to be there but this is not practical up a hill!

Any suggestions?

Mike

[Beans]

First thought is some thing clutch related;
- worn or dirty (oil) clutch plate;
- worn splines (on plate hub or input shaft);
- worn crankshaft pilot bearing;
But that's solely based on own experience ie what caused a judder in one of my cars in the past.
Also I don't know how the car judders and how you drive off.
Always difficult to judge these problems from a written account.

Could also be loose engine/gearbox mountings.



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1981 TR7 DHC (not very well known yet, but back on the road)
Also a 1980 TR7 DHC, 1980 TR7 DHC FI, 1981 TR7 FHC
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[TR Tony]

Yes difficult to diagnose really Mike.

Does the problem ocur all the time, or only when first pulling away (engine/gearbox cold)? Is there any unusual noise (whining or rumbling or whirring) from the clutch/gearbox? Can you change gear OK once on the move?

If your car is a 1977 then that would be early to have a 5 speed box - there were some built with the 5 speed LT77 box at that time but the box was in short supply so many were still built with the 4 speed box. Has yours been converted from a 4 speed car (perfectly OK if done correctly) or has it always been 5 speed?

Tony

<font size="1">1981 2L FHC Cavalry Blue - very original & not rusty!
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[mmarks]

Hi there,

Don't know if the car was always 5 speed or converted.
The judder happens whether warm or cold.

Once on the move, all gear changes are smooth and no judder and if I try to set off in 2nd it doesn't seem to judder so this has confused me - just 1st and reverse gear from standstill. Also, 1st gear is fine once the car is moving.

Mike

[Howard722]

<font face="Comic Sans MS">Likely that the rear g/box mount is now soft from oil contamination -esp. if the rear seal is weeping which can be a niggle- and this certainly can allow the box to move about under take off!</font id="Comic Sans MS">

Enjoy& regards

[mmarks]

Would that not still exhibit the same symptoms when setting off in 2nd gear though?

[Hasbeen]

Mike, I had a similar noise to yours in one of my 7 some yeays ago.
It was only when taking off in first, with a few revs on. Not when
taking off very gently, & I don't recall it in reverse.

In Oz our 7s have CV joints at both ends of the tail shaft, not as
in the book, with a UJ at one end, so I'm not sure if one of those
would respond the same way.

I thought it was a CV joint noise, so as I had 2 TR7s, I swapped
tailshafts, from car to car, to see if the noise went with the tail
shaft. To my surprise, there was no noise in either car, except when
I did a full racing take off in the car, with the suspect shaft, so
I suspect your tail shaft CV joint. That tailshaft did another
5/6000Km before it got noisy again, in its new home.

A new one, or a repair is too expensive to do, unless you know that
is the problem. I think, from memory, that you can end for end the 7
tail shaft, so I'd try that, & see if it makes a difference to your
noise. It should, if that is the problem.

Hasbeen

[aeroshadow]

The "books" say that launch judder is caused by a bad u-joint or out of spec.u-joint working angle. It's worse in first gear due to more torque.
I've experienced and cured both causes on other cars (with spicer type u-joints), so I tend to think hasbeen's ideas are the best place to begin.
Alex

[John Clancy]

Check the timing and the points gap. Lack of power at the low end can cause judder when pulling away.

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[gaz]

I know this is an old post but......... up until this morning mine was behaving just the same and as our John Clancy says " check the timing and points gap "
It worked for me new points and condenser all seems to be well [:D]



It rides again..... and again wehey!!!!!!!
http://mytr7.weebly.com/tr-drivers-club ... -wend.html