I took the Mini out for a run yesterday as its been a couple of months since driving it, when parking the car back in the garage I remembered about the clutch Judder/Shudder it has in reverse only and only when hot, clutch feels as per normal and take up point is the same. last time the engine was out I put a new minispares lightened flywheel and back plate, still using the double grey diaphragm and AP organic plate, which does a great job, I made sure the spring was flat when it was assembled and for the past year or so it has been fine, but has slowing started to shudder in reverse only when slowly releasing the clutch, parking situations.

any thoughts? Might just be time to pull it out and have a looksy I guess.

thanks all

Grant

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100% Pure A Series Turbo
Morris - The Original RedBull Racing

Does it have an oil leak at that end of the motor? Clutch plate might be oily

don't believe so, plus this would make it slip also and even on big boost it holds well.
no oil on the ground just the normal BMC sweat from working so hard haha.

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100% Pure A Series Turbo
Morris - The Original RedBull Racing

It would not necessarily make it slip, it's still clamped up tight.

When you are slowly releasing the clutch (slipping the clutch) and causing friction between the plate and flywheel it shudders.


Either way it sounds like a pull apart job

Sometimes crook engine mounts or stabilisers will make it seem worse

I'd look at the engine steady rubbers...

my clutch is working well now, and I'm sitting at a wooden desk, so I'm going to go out on a limb and say "no oil leaks"

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did I tell you that I won a trophy?

+1 for checking the engine is held in tight. Check stabiliser bar rubbers and engine mounts

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1969 Cooper "S"
1967 Mini Deluxe
1973 Clubman Van (the fleet spare)
1978 ex 1275 LS ("Wizard" Eaton Supercharged)
2015 HSV GenF GTS(occasional drive & tow car)
2019 MINI F55 Cooper S

Hi, clutch shudder is one of those very annoying intermittent , only does it to some cars ,seems worse in rod change cars in reverse , and that has been around since the 70s. maybe late 60s ....early 60s I can't answer for
The problems listed above only help make it worse, not cause it, and I don't know if a definite cause has ever been found...At Link in the first lot of years we tried all sorts of things, and refused to use certain brands of clutch plates , trued and aligned flywheels etc etc...did lots of clutch jobs twice.....Leyland came out with a cure of the floating thrust bearing...but I don't think anything was a guaranteed cure.... some drivers could actually drive around it...I think the Verto clutch with its sprung clutch plate seems to have solved the problem though ...It will be interesting to hear the answers from other experienced long time mini people ....
On the specific car above I would be betting the lightweight backplate is not flat any more and maybe a tiny bit of oil ...but would then only be hoping for no clutch shudder
I also am personally not convinced on a ground finish on the flywheel and back plate ..I prefer to machine them in a lathe
cheers Lindsay

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1959 Austin A40 Farina fun car
1965 Mk1 Cooper S restored
1970 Colt 1100F SS restored
2014 Mitsubishi Imiev fully electric daily driver
1948 Allard M coupe Olds 215 v8 project
1971 Twin cam Escort ex Uk championship winning rally car project

If you try the same conditions in first and reverse (especially the incline and release speed) and you're only getting the shuddering in reverse I would definitely try to eliminate all factors outside the gearbox first. As others have said, check all of your mounts and steadies to make sure they are in good order. I would also check your inner CV's, outer CV's, wheel bearings, tie bar bushes, lower control arm bushes, top arm bearing play, make sure your brakes (front and rear) aren't binding in some strange way, and basically anything else that is also loaded when you are going backwards.

Obviously if you eliminate all of that and you're still having issues then it's probably an engine out job - but then you already knew that. But it would be a shame to jump straight to that conclusion and find you haven't solved your issue once it's all back together.

ok,
top engine steady poly bushes are new, lower stead is good nick not too old, new remote shifter rear mount, main engine mounts are not new but not soft either.
engine is ROCK SOLID believe me the car shakes when it judders not the engine, I have also just converted to inner CV's from uni joint hardy spicer type and new outer CV's also.

I believe it has to be in the clutch setup, as it was all virtually new I should see witness marks if there is a problem with the diaphragm locating etc.

its ok for now so I will leave it for a bit yet, I will pull it apart one day when I have the time to spend on it.

thanks all
Grant

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100% Pure A Series Turbo
Morris - The Original RedBull Racing

Is the flywheel to light not balanced properly.

Good to hear all your mounts are in good condition. But then I still find it odd that it would only be shuddering in reverse - The clutch works the same no matter which way you're going

Anyway, I'm sure you'll get it sussed one way or another if you pull it all down and inspect it

Good luck and happy hunting.

That's what makes me think it is mounts or something similar. The clutch operates and spins the same way for all gears and reverse, and will apply torque to the engine in the same way. The only difference in reverse is that the driveshafts will be applying torque in the opposite direction to all the forward gears.

given the symptoms, only, reverse, only when hot. i would be inclined to say that the drum brakes may be dragging slightly. when you drive the car forward the pads drag a bit and heat up but because of the rotation direction they don't bind, when you go in reverse the pad has expanded a small amount from the heat and bind due to the opposite direction of rotation. they don't bind enough to stop the car but enough to labour the engine at low rpm causing the shudder. might be worth checking as its fairly simple to diagnose (jack up check, free spin of wheels) and fix (back off a notch)

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2015 Ducati 899 Panigale

Sometimes if the clutch has had a bit of a work out the you can get either hot spots on flywheel/pressure plate or the plate itself can get warped. This can cause a minor problem that may only be obvious in the lower reverse gear. I think there was 2 different plates ??? One was a solid disc and the other was a disc with like a flattish flower petal looking bit holding linings.