Clutch Pedal Vibration
Discussion
Wondering if anyone else has experienced the same as this ?
When accelerating slowly and gently I can change gear at any speed and any revs and it’s all smooth as butter. However when giving it a solid bit of throttle any gear change above around 4000rpm results in some very noticeable vibration through the pedal. This only happens up in the rev range. Boot it and change at say 3000rpm and it’s still all good.
The clutch only has around 250 miles on it since being changed. The master, slave, fork, pivot, throw out and pilot and pedal clevis pin were all changed around the same time.
So far I’ve been trying to break in the clutch correctly. No full power runs, being gentle, plenty of stop start traffic etc. When I say ‘booting’ above I mean no more than 3/4 throttle and I’ve only started raising the revs to above 4k and going above half throttle within the last 20-30 miles.
These specific/intermittent issues do my head in !!! If it was all the time then fine, if at certain revs great, I’d have a direction to go in. But this ONLY occurs at higher revs WITH solid application of throttle. Gentle acceleration it’s perfect.
When accelerating slowly and gently I can change gear at any speed and any revs and it’s all smooth as butter. However when giving it a solid bit of throttle any gear change above around 4000rpm results in some very noticeable vibration through the pedal. This only happens up in the rev range. Boot it and change at say 3000rpm and it’s still all good.
The clutch only has around 250 miles on it since being changed. The master, slave, fork, pivot, throw out and pilot and pedal clevis pin were all changed around the same time.
So far I’ve been trying to break in the clutch correctly. No full power runs, being gentle, plenty of stop start traffic etc. When I say ‘booting’ above I mean no more than 3/4 throttle and I’ve only started raising the revs to above 4k and going above half throttle within the last 20-30 miles.
These specific/intermittent issues do my head in !!! If it was all the time then fine, if at certain revs great, I’d have a direction to go in. But this ONLY occurs at higher revs WITH solid application of throttle. Gentle acceleration it’s perfect.
Having replaced the clutch and brake hydraulics myself, the only thing I can think is that it needs tightening up - check all bolts:
Four bolts the secure the pedal box to the inner wing
Two bolts connecting the pedal box to the wheel arch
Two bolts mounting the clutch master cylinder to the pedal box
Four bolts mounting brake servo to pedal box
The pedal on its own arm is adjustable, that might be loose (though mine was impossible to undo)
The hinge that the pedal arms hang off - not a bolt fitting, but might have developed play (not sure what can be done for this without taking it all out again)
Are you familiar with the way it works?
The pedals are not directly connected to the clutch and gearbox, they only operate master cylinders mounted on the back of the pedal box.
The next connection is fluid pipes that go to an alloy block mounted in the bulkhead (you can see it on the inside wall of the footwell, also by looking down the side of the inner wing under the bonnet.
That block connects to further pipes that then run to the clutch slave cylinder and the brake callipers.
I could be completely wrong, but have definitely fixed a couple of vibrations by finding loosened bolts.
Especially if you've had underbody seal applied - has been known to lubricate bolts that you may not want it to...
Four bolts the secure the pedal box to the inner wing
Two bolts connecting the pedal box to the wheel arch
Two bolts mounting the clutch master cylinder to the pedal box
Four bolts mounting brake servo to pedal box
The pedal on its own arm is adjustable, that might be loose (though mine was impossible to undo)
The hinge that the pedal arms hang off - not a bolt fitting, but might have developed play (not sure what can be done for this without taking it all out again)
Are you familiar with the way it works?
The pedals are not directly connected to the clutch and gearbox, they only operate master cylinders mounted on the back of the pedal box.
The next connection is fluid pipes that go to an alloy block mounted in the bulkhead (you can see it on the inside wall of the footwell, also by looking down the side of the inner wing under the bonnet.
That block connects to further pipes that then run to the clutch slave cylinder and the brake callipers.
I could be completely wrong, but have definitely fixed a couple of vibrations by finding loosened bolts.
Especially if you've had underbody seal applied - has been known to lubricate bolts that you may not want it to...
Thanks Pablo. Yes I'm all good on how it all works and goes together. One of the benefits of doing a body off a few years ago 
But you're absolutely right, will go over everything again and make sure its all good. Just puzzling me at the moment as to why it occurs with such a specific set of circumstances/manner of driving.
But you're absolutely right, will go over everything again and make sure its all good. Just puzzling me at the moment as to why it occurs with such a specific set of circumstances/manner of driving.
Nice!
Your car should be awesome then!
Just sounds like a bit of time checking stuff over and tightening things up - mine had a body resto a few years back by the previous owner.
I started to notice a bit of play in the steering, and when I took a proper look, then entire rack had come loose on its mounting bolts. It was moving side to side. Sorted that, then found it still had a little play, and discovered a slightly loose bolt on one of the steering column UJs.
Steering is tight as a nun's crotch now.
Your car should be awesome then!
Just sounds like a bit of time checking stuff over and tightening things up - mine had a body resto a few years back by the previous owner.
I started to notice a bit of play in the steering, and when I took a proper look, then entire rack had come loose on its mounting bolts. It was moving side to side. Sorted that, then found it still had a little play, and discovered a slightly loose bolt on one of the steering column UJs.
Steering is tight as a nun's crotch now.
PabloGee said:
Nice!
Your car should be awesome then!
Just sounds like a bit of time checking stuff over and tightening things up - mine had a body resto a few years back by the previous owner.
I started to notice a bit of play in the steering, and when I took a proper look, then entire rack had come loose on its mounting bolts. It was moving side to side. Sorted that, then found it still had a little play, and discovered a slightly loose bolt on one of the steering column UJs.
Steering is tight as a nun's crotch now.
Has your car had a body off or steering rack out? Your car should be awesome then!
Just sounds like a bit of time checking stuff over and tightening things up - mine had a body resto a few years back by the previous owner.
I started to notice a bit of play in the steering, and when I took a proper look, then entire rack had come loose on its mounting bolts. It was moving side to side. Sorted that, then found it still had a little play, and discovered a slightly loose bolt on one of the steering column UJs.
Steering is tight as a nun's crotch now.
Out of all the jobs the one you defenitely don’t want to forget is to do up the bolts on the rack and steering shafts.
All 4 bolts loose on rack suggests they weren’t done up tight in the first place.
Saying that I seem to remember the rack bolts are only about 8ft lb on a torque wrench in any case.
Fixed now though
kris450 said:
Wondering if anyone else has experienced the same as this ?
When accelerating slowly and gently I can change gear at any speed and any revs and it’s all smooth as butter. However when giving it a solid bit of throttle any gear change above around 4000rpm results in some very noticeable vibration through the pedal. This only happens up in the rev range. Boot it and change at say 3000rpm and it’s still all good.
The clutch only has around 250 miles on it since being changed. The master, slave, fork, pivot, throw out and pilot and pedal clevis pin were all changed around the same time.
So far I’ve been trying to break in the clutch correctly. No full power runs, being gentle, plenty of stop start traffic etc. When I say ‘booting’ above I mean no more than 3/4 throttle and I’ve only started raising the revs to above 4k and going above half throttle within the last 20-30 miles.
These specific/intermittent issues do my head in !!! If it was all the time then fine, if at certain revs great, I’d have a direction to go in. But this ONLY occurs at higher revs WITH solid application of throttle. Gentle acceleration it’s perfect.
What make of clutch is it and was it a full 3 piece clutch. When accelerating slowly and gently I can change gear at any speed and any revs and it’s all smooth as butter. However when giving it a solid bit of throttle any gear change above around 4000rpm results in some very noticeable vibration through the pedal. This only happens up in the rev range. Boot it and change at say 3000rpm and it’s still all good.
The clutch only has around 250 miles on it since being changed. The master, slave, fork, pivot, throw out and pilot and pedal clevis pin were all changed around the same time.
So far I’ve been trying to break in the clutch correctly. No full power runs, being gentle, plenty of stop start traffic etc. When I say ‘booting’ above I mean no more than 3/4 throttle and I’ve only started raising the revs to above 4k and going above half throttle within the last 20-30 miles.
These specific/intermittent issues do my head in !!! If it was all the time then fine, if at certain revs great, I’d have a direction to go in. But this ONLY occurs at higher revs WITH solid application of throttle. Gentle acceleration it’s perfect.
I’ve never considered you needed to break a clutch in so that’s a new one on me. Can’t do any harm
Did you fit the clutch?
Classic Chim said:
What make of clutch is it and was it a full 3 piece clutch.
I’ve never considered you needed to break a clutch in so that’s a new one on me. Can’t do any harm
Did you fit the clutch?
An LOF clutch that the major TVR sellers stock (Racetech, Motaclan etc). It was the full works, so pressure plate, friction disc, pilot and release bearings. The flywheel was also reskimmed.I’ve never considered you needed to break a clutch in so that’s a new one on me. Can’t do any harm
Did you fit the clutch?
Yes I fit it myself and there never appeared to any issues, and I've fitted clutches too cars before so fairly happy with the procedures needed.. As far as I'm aware fitting a clutch and then ragging on it is a bad idea. Can end up glazing the surfaces. Sure it needs to be used, but gently, thus city/stop start traffic is ideal (although not something I want to do loads of in a TVR haha).
The issue is the clutch works perfectly. Except when you give it some strong throttle. Only then does the pedal vibrate. And when I say vibrate its properly noticeable. Accelerate gently to high revs and theres no issue. Thats the part thats stumping me. I can't figure out why theres such a noticeable problem with such a specific circumstance.
Classic Chim said:
Has your car had a body off or steering rack out?
Out of all the jobs the one you defenitely don’t want to forget is to do up the bolts on the rack and steering shafts.
All 4 bolts loose on rack suggests they weren’t done up tight in the first place.
Saying that I seem to remember the rack bolts are only about 8ft lb on a torque wrench in any case.
Fixed now though
In my case, yes, the steering rack was refurbished by Lawfield Engineering, whilst the chassis had new outriggers and powder coating amongst many other things.Out of all the jobs the one you defenitely don’t want to forget is to do up the bolts on the rack and steering shafts.
All 4 bolts loose on rack suggests they weren’t done up tight in the first place.
Saying that I seem to remember the rack bolts are only about 8ft lb on a torque wrench in any case.
Fixed now though
I refitted with new stainless bolts, with serrated heads and a spring washer, and some loctite.
It may never come out again, but I really was alarmed by how loose it was having driven it on the motorway in that state!
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