Guys I have a nagging problem that's got me a bit puzzled.
When cold, I easily and smoothly get engagement in all gears. This is so with the engine running and clutch disengaged, or engine off and clutch or no clutch. When it gets hot, either after hard driving or even easy driving on hot days, the shifting gradually gets fussier.
As things heat up, I can gradually feel it hang up a little when I shift and it eventually gets to the point where I can not get either reverse of first without grinding. The hotter, the more severe the grinding to the point where you wouldn't even try to engage. On the way to this point, it helps to engage 2nd before reaching for reverse, eventually this is of no help. If I shut the engine down when this is occurring I can smoothly and easily get any gear including 1st and reverse with or without clutch engaged. I can start the car in either first or reverse with the clutch disengaged (pedal down) and there is not even a hint of clutch drag; car doesn’t even twitch and the starter sounds as it’s at usual speed. This is the routine in parking lots and I take off in second at stop lights.
I have painstakingly adjusted the shift linkage per the usual procedure. It's absolutely centered fore and aft in the gate. I have it centered side to side and absolutely inline with 2nd and 3rd slots in the gate. I have experimented at what seems to be all point around neutrally centered. The linkage has been upgraded with Quella’s shift rod that uses a rod end in place of the stock trunion bearing. The ZF was rebuilt by Quella when he had the car doing the body work some years and 5k miles ago. This issue has always been present to varying degrees.
The car has a McLeod Twin Disc clutch (Long style Street Twin). Also has a long throw slave and aftermarket master cylinder. It has plenty of travel. I have recently bled the slave to make sure there wasn’t an air bubble being cooked in the circuit at temperature. I used to have a cover on the inspection window of the bell housing. I do not any more because removing it seemed to make it run cooler and help the problem.
All I can figure is there isn’t enough marcel (mar-sell) in the clutch plates or the floater plate hangs up when hot due to thermal expansion issues because I have an aluminum flywheel and the clutch housing is steel (floater slides on posts mounted to the flywheel). Perhaps with the dual discs there’s enough stick to prevent engagement but not enough to sense upon start up.
I’m looking for other thoughts on this. I’m going to put it up on my lift when it’s acting up next time to see if the engine is settling a bit in the mounts when the isolators heat up (yup they are rubber not urethane). I can’t really detect any shifting of the neutral position of the shifter hot or cold.
Any suggestions? Anyone else running a McLeod Street Twin?
Best,
Kelly
Original Post