Clutch grabs, releases, grabs, releases when engaging. Hydraulic clutch modification?

[Superthermal]

Hello all, My M813 is a bit odd, with the clutch. When attempting to slip the clutch to ease my rig into gear the clutch with grab then release then grab harder and release.
Example: Trying to back up very cautiously along the side of my house which is uphill slightly, as I let out the clutch, with the intention to slip the clutch, it will engage and then release then come back harder and almost fully lock in and jerk my rig backwards when it was unintended.
I have thought that maybe the flex between the motor/transmission and t-case inside the frame rails may be just enough that the play is sufficient to allow for movement to physically shift in the frame and shift the clutch mechanical linkage between the cab mounted pedal and the motor/trans/t-case.
I haven't closely inspected the mounts for this but I am guessing they are OK. If so and the flex is just getting in the way the only way I see fixing this is to replace the manual linkage with a hydraulic master/slave setup.
Anyone else experiencing this issue?

 

[NDT]

Sounds like the friction material is breaking up.

 

[Mullaney]

Hello all, My M813 is a bit odd, with the clutch. When attempting to slip the clutch to ease my rig into gear the clutch with grab then release then grab harder and release.
Example: Trying to back up very cautiously along the side of my house which is uphill slightly, as I let out the clutch, with the intention to slip the clutch, it will engage and then release then come back harder and almost fully lock in and jerk my rig backwards when it was unintended.
I have thought that maybe the flex between the motor/transmission and t-case inside the frame rails may be just enough that the play is sufficient to allow for movement to physically shift in the frame and shift the clutch mechanical linkage between the cab mounted pedal and the motor/trans/t-case.
I haven't closely inspected the mounts for this but I am guessing they are OK. If so and the flex is just getting in the way the only way I see fixing this is to replace the manual linkage with a hydraulic master/slave setup.
Anyone else experiencing this issue?

.
Another question for you is with the hydraulic clutch - Did you bleed the system? Almost like you push down on the peddle a little less or more because their is air in the system?

 

[Superthermal]

.
Another question for you is with the hydraulic clutch - Did you bleed the system? Almost like you push down on the peddle a little less or more because their is air in the system?

Thanks for the response Mullaney,
Currently the clutch system is linkage. I have only theorized of putting in a clutch hydraulic system to remove the physical shifting problem between the cab and the engine/trans/t-case that could cause this type of issue. In the old days my friends had CJ5 jeeps that had this very issue due to the jeeps very flexible frame and the motor moving around the body. The Jeeps were notorious for "auto disengaging" the clutch when the jeep was put into a severe twisting of the frame. I had never had the problem with my V8 Fj40 because it used a hydraulic master/slave so there was never a linkage issue when the frame or motor was flexing around.
I want to say I read a thread on SS where someone used a hydraulic clutch setup when they did an Eaton transmission swap, but when searching I couldn't find it again.

 

[NY Tom]

Sounds like the friction material is breaking up.

They stretch and twist these trucks pretty harshly in every test I have seen. I find it odd that you would be having this problem and it relating to the linkage moving. I tend to agree with NDT here unfortunately. Something is likely wrong with the clutch unless it's history is known to you.

 

[GopherHill]

Best go ahead and replace the clutch. Flywheel likely will need resurfacing at that time. Hydraulic clutch won't help your difficulty.