Clutch Judder 1st Gear when hot

[344739lv]

Hi all, some help with a diagnosis if possible.
I have a newly rebuilt 1969 Etype Series 2 open top. Full resto included gearbox rebuild and new clutch, new master, new slave etc etc. Car drives nicely when cool but once it gets hot there is very bad clutch judder on 1st and reverse. It’s particularly bad on a hill start. We have bled and re-bled the system, adjusted the clutch to take up free play - made sure the clutch return spring on the slave is correct and in place - but can’t seem to eradicate it. Given it only happens when hot I am hoping it’s not a problem with the new clutch itself - but would be interested in your experience.

If it is relevant the car is still on an old fashioned rope seal for the rear main - despite my asking the engine rebuilder to upgrade it! That’s for another day - but wondered if it is possible for that to be leaking so that oil gets onto the clutch plate? I would add that it doesn’t slip or give any symptoms- just thought I’d throw it out there.....

Is it another engine and box out on a fresh resto (please say no!) help?!

[piman]

Hello 244739lv,

I've worked on all my cars for decades but had no experience of clutch judder so these are just my feelings.

Going from what you wrote I would be inclined to live with it for a while, but minimising the effect as much as possible by adpting your driving style. If gently easing the clutch makes the judder worse, then I suggest going the other way and release the clutch quicker which will need more engine speed, the idea being to wear the clutch in a bit. What is the idle speed, it should be 700 rpm or so. I know it's been rebuilt but what are the engine mounts like?
The rope type oil seal is not automatically a source of trouble and should there be some oil leaking there it will be on the back of the flywheel and so be flung outward and away from the clutch face. Such a leak will show up as a drip from the bottom of the bell housing.

Alec

[344739lv]

Alec,

Thanks for the response.

The idle is circa 750rpm and it runs pretty sweetly nice tick over etc.

Funnily enough I have had a Morning on it today and checked the engine mounts which are spot on.

It is a rope seal and the drip is exactly how you describe it - and not that significant- so I was clutch at straws.

Today I have bled the system for the umpteen millionth time and we also adjusted the clutch to give it a little more free play.

We have got to a place where hill starts involve a more pronounced shudder as do quick or high revs pull away. In both instances only when hot.

I have kond of got to the same place as you - in that my intention is to drive through it and see. If you use low revs and gently pull away - it’s very light in terms of judder.

Thanks again

Best wishes

Tim

[piman]

Hello Tim,

good luck and hopefuully it will bed in with time? If there is any air in the hydraulics you will find it difficult to get it into gear at rest. Did you find that the clearance was nil or near that when hot?

Alec

[344739lv]

Alec,

Good insight on the “air in system” symptom. Pretty confident there isn’t any now anyway. Gear change and selection is pretty much perfect all the time. Reverse can cause a crunch but I have taken to selecting first then reverse and it goes in without issue.

You mention “clearance” if I understand the question (forgive my somewhat amateur grasp of terminology) There was a very small amount of free play prior to adjusting- but not too much. We have dialled in more free play and it certainly reduced the problem - although it still exists as per previous posts when hot. I am loath to dial any more in as we are pretty much at the outer edge of adjustment.

Tim

[piman]

Hello Tim,

yes, frre play, clearance, are the same thing, I'm assumiong the E Type clutch is not self adjusting then? As it has adjustment I would guess not. As long as there is some then that's all that matters although too much will give engagement problems as there is not enough clutch throw in that situation. As a clutch wears then the clearance decreases.

Alec

[344739lv]

Alec,

Makes sense - thanks for the advice.

I’ll put some miles on it and report back.

Best wishes

Tim

[3.8etypephil]

Check the condition of the gearbox mounting, and the adjustment of the stabiliser between the bulkhead and the bellhousing.

[344739lv]

Phil,

Thanks for that - I’ll check it over the next week or so and report back.....

Tim

[344739lv]

Phil,

Just to report back - stabiliser and engines mounts all fine (new) and correctly tightened.

So I am going to try putting some miles on it.

It’s 3000 since rebuild - issues started at 2000

Tim

[jlimonjagi689]

344, Im breaking in my 67 coupe.
I went crazy on this drivers as Ive had and driven etypes for over 30 years, ON A DAILY BASIS!
If you GREASED the input shaft and the throwout bearing wasnt chipped another issue is......THE FLUID!
I tried MT90 REDLINE,Everyone said its the model way to go.
It was TERRIBLE. It shifted fine except for 1 st and reverse BUT made tons of noise.
I went back to old CATROL 75/90 but it is now gl5 with synthetic , It was alot better but.....not right.
I then got turned on toe PENN TRANSMISSION FLUID , 80/90 OLD GL4 /NON SYNTHETIC.
It transformed the car, the pressures the pedal feel. The noises were all gone!
What fluid are you running, it makes a big difference on the old 4 speed.
Good luck
gtjoey1314
1,000 miles in 2 weeks
Drive for awhile as everything has to bed in.......everyone else is right as well.

[344739lv]

Jlimonjag,

WELL YOU ARE 100% CORRECT!

I actually went down this route myself and was just logging in to update everyone and then saw your post. So I FULLY AGREE.......

IT WAS THE FLUID AND IT IS NOW 100% SOLVED !!

Thanks all

Tim

[piman]

Hello Tim,

good to hear you have had a result, I assume by fluid you are talking about the gearbox oil?

What oil did you end up using?

Alec

[344739lv]

Alec,

Sorry mate - on re- reading the posts I can see the previous post meant transmission fluid.

I was actually referring to Brake and Clutch fluid.

I went with Millers Racing Brake Fluid 300+ Mainly because it has a much higher boiling point. Anyway it absolutely fixed it on first application.

So all good at the moment.

I will try the transmission fluid upgrade in about 1500 miles when I would normally change the oils anyway - but in a quick internet search the Penn fluid was out of stock everywhere- so any advice welcome.

The standard Jaguar 4 speed box runs quite hot (it has been rebuilt) and has a few odd noises sometime but does the job with nice precise and linear changes including 1st and reverse - but I don’t mind investing in the best oils.....so feel free to call out any preferences.

Tim

[jlimonjagi689]

Happy to help...….This club is wonderful AND always having driving fun.
Its refreshing , I might ship the ETYPE over for the Geneva run with the Porter group and all.
Hopefully they will be better times by then.
Back on the transmission, I tweeked the adjustment rod back and forth and marked it as I tried it from cold to hot.
Enjoy the ride!
GTJOEY1314