AMC 360 swap

[Roy]

Pressure plate heights are different respectively to diaphram and finger-style.
Throw-out bearings are made in several different heights to correspond.
Clutch release arms also have different travle/release ratios. Centerline of t/o brg to centerline of pivot point and centerline of pivot point to the centerline of the engagement point measurements will help determine the ratio. It sounds like you might need an adjustable pivot. Sometimes the ratio of the release arm requires an adjustable pivot so that the arm does'nt interfere with the bellhousing during release travel.

[Jester]

Pressure plate heights are different respectively to diaphram and finger-style.
Throw-out bearings are made in several different heights to correspond.
Clutch release arms also have different travle/release ratios. Centerline of t/o brg to centerline of pivot point and centerline of pivot point to the centerline of the engagement point measurements will help determine the ratio. It sounds like you might need an adjustable pivot. Sometimes the ratio of the release arm requires an adjustable pivot so that the arm does'nt interfere with the bellhousing during release travel.

All sounds logical (at least the part I understood)

The clutch, pressure plate and throwout were a kit. Would hope all those are matched up. The release arm is the stock one off the J-truck that was in the bellhousing to begin with. Did not mess with the pivot point. The old t-o and the new appeared to be identical.

The arm is not binding. I can look thru the hole in the bellhousing and see the pressure plate springs being compressed. The friction disc is just not releasing. Either something is binding on it or the friction disc is somehow binding on the pressure plate. Can't think of any explanation for either.

[Roy]

Did you have the flywheel resurfaced? Sometimes they remove enough material to cause a release issue. And...if you did not have it resurfaced it may be worn enough ( either convex or concave to not allow release too....

[Roy]

Also...is the release arm possibly bent or load-distorted?

[Roy]

Most clutches call for @ .060" of "free air space"....the distance between the flwheel and disc when released. We sometimes use a feeler gauge to check.

[Jester]

Had the FW resurfaced. If it was too thin wouldn't that create an issue with it not holding vs not releasing?

The FW also appeared flat when I put a straight edge on it.

The arm does not appear bent in anyway. The TO bearing is moving smoothly and engaging the fingers (at least what I can see thu the bellhousing hole).

Should I try backing off the pressure plate from the flywheel? Maybe spacing it as a test?

[Roy]

If the flywheel is "too thin" it actually moves the pressure plate towards the motor away from the throwout bearing. Depending on the ratio of the release arm it can make quite a bit of difference. Lets say the arm has a 3:1 ratio. You need to move the engagement point ( the end sticking out of the bellhousing) 3 inches in order to move the t/o bearing 1 inch.
We don't see the flywheel thickness being a problem most of the time. We do see hydraulic setups being much more sensitive to release arm pivot heights and travel ratios though......

Go to Novak Adapters website. They have some very detailed information on the subject of clutches and travel ratios, etc...

[Jester]

http://www.ifsja.org/forums/vb/showthread.php?t=20268

Interesting read here. Someone with a similar issue. The remedy one person recommended...

"Did you trim the pilot bushig even with the face and ream a slight chamfer on it?

Had the same prob with mine, rather than pull everything, I put a 1/16 body shim between the bell and trans (I know not recommended)"

Gonna space the bellhousing out tonight and see if that solves it. If so, at least I know the direction to head.

[fisherman]

I'll bet those problems will all be solved by just going with a diaphram type clutch. The 3 finger ones are very problematic and need to be installed just right. I've had the 3 finger type clutches before and I'll never use one again. I'd try a stock replacement diaphram type. Was the clutch that came out a 3 finger clutch?

[Jester]

I have a clutch!


I loosened the bellhousing from the motor, the spacer from the trans, the crossmember and the t-case.

Started in 4th gear, clutch in and allowed it to slip for a bit. Tightened everything back up and she seems happy now. Measured the amount of throw I needed and the hyro clutch is fine.

Need to bleed the brakes again and then should be ready for the first test drive.