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MG Midget and Sprite Technical - Clutch engagement
|Can anyone explain how my clutch works fine when the pedal is almost fully depressed but when pushed all the way to the floor I can't select gears without it crunching . Its a 1275 model and this may not have just happened as I have only manouvered the car a few times since I put it all back together? I notice there is a bolt on the back of the pedal that hits the footwell wall when you push the clutch down, shall I just adjust that or is there a bigger problem!|
|Did you fit any new clutch components?|
It is possible to have too much travel, although I've only experienced it in my race cars.
On the old yellow midget that I bought from Ashley, I put a new clutch in it and only got it back together the night before heading off to Mondello Park. When I found the problem, it was too late to try and do anything, so when I got to Mondello, I just taped a piece of wood to the bulkhead. Worked fine.
On the red Sprite, I initially had an F3 clutch and experienced the same problem. I made an aluminium spacer and bolted it to the bulkhead behind the pedal. I think it was still like that when I changed to a conventional Midget clutch.
|Hi Dave, the engine with clutch came out of a road car that I had and I have put it into my old race car, that was originally a 1098 (1966) but that has had another 1275 in it since the 80s. I seem to remember the PO had fitted a 1275 slave on the bellhousing- I might just go for thick carpets!|
|Too much travel results in the release ring in the diaphragm contacting the driven plate, and pushing it on to the flywheel - hence the drag you are getting.|
Causes are either the wrong size hydraulic cylinders (doesn't sound as though that's the case if they haven't been changed) or driven plate linings incorrect thickness. If they are a bit too thick (and it doesn't need to be much) than the centre of the diaphragm sits further forward than usual.
|The 1275 used a smaller diameter slave than the 1098 so will overthrow the clutch. Maybe the previous 1275 had been fitted with an early style slave to correct ly match to the early master.|
|Guy - it's the other way round: 948 & 1098 had a 7/8 slave, 1275 had a 1" slave.|
|Thanks for comments so far, the car has the original 1098 twin master cylinder and looks like it has the 1098 slave on second look. The car had a 1275 engine in for a long time albeit a different one, should I just experiment with pedal travel? Incidentally did the early clutch pedals have an adjustment bolt on the back that hits the footwell wall or did the PO weld one on because of this problem?|
I was going from my memory (not good!). Before I fitted my concentric slave I had problems with an overthrowing clutch on my 1275. I eventually tracked down to a mis-matched master/ slave combination - just got the sizes the wrong way round. In my case, I had used a second hand slave that I came across and only subsequently found out it was off an early car.
Presumably then, if Mike's car master has been replaced with a 1275 variety, but now has an early 7/8 slave then this would cause it.
|IWhen I saw your post Guy I thought it was my memory, it's dodgy too! But having examples of both in stock I was able to cheat :-)|
I think the 1098 master cylinder is 3/4 (now I'm relying on my memory!), certainly the 1275 is 0.7" - if so the 1098 master cylinder will lead to about 12% more travel than intended even if used with the 1275 slave. However, it should be near enough to give it a try, and maybe limit pedal travel if it doesn't work.
I don't recall seeing a bolt, I'd say it is a PO thing.
|edited to delete rubbbish - was thinking brakes not clutch !!|
This thread was discussed between 22/04/2012 and 23/04/2012
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