Clutch fork travel

[frdfver]

Is the input shaft bearing retainer snout to long and hitting up against the clutch discs?

[lippy]

Originally Posted by frdfver

Is the input shaft bearing retainer snout to long and hitting up against the clutch discs?

It's possible. And it's a dual disc clutch, so maybe it's taller. What would the solution be if it were - a spacer plate?

[frdfver]

Should be easy to measure. If that's it I would just machine the required amount off the snout of the retainer. I would measure the total length of the input shaft and make sure you have enough depth in the crank hole to.

[Dominik]

A spacer plate which will give you that gap, yes that might be your solution. Like the ones between block and bellhousing for the FE engines. Bur for trying, use 2 shims under each bellhousing bolt?

Can your disks be reversed, resulting in too much height? Isn't the one side of the disk assembly tapered where the transmission input shaft sits and the other side flat? They should be marked "towards engine" or something.

[tkb289]

Sorry to hear the clutch is still not working as it should. Maybe a spacer is the way to go, it does not find the root cause of the issue, but it does solve the problem.

If you have the time and patience, stay the course a bit longer and try some of the ideas mentioned, to find out what is causing the clutch not to work properly.

One way or another you will get it to work ...

[tkb289]

Another thought ...

One way to try and find an interference is to put a small amount of grease on a suspect part, reinstall the transmission and bolt it down. Pull the transmission out and see if any grease has transferred to the other part. You can also use small bits of silly putty or clay to look for interference points.

[DanEC]

Lippy - sorry to hear this. Putting one of those in by yourself from the topside is a real job. If it is the length of the transmission bearing retainer, I think rather than using a spacer, I would remove the retainer and shorten it enough to clear. The length is un-important contingent upon it being long enough to support the full stroke of the throw out bearing.

From every thing you have described it almost is a sure thing it has to be the bearing retainer hiting the back clutch disc hub. It sounds like removal of 3/32" from the length will do it and that does absolutely no harm to anything else.

[lippy]

I'm not sure I understand how the bearing retainer would prevent the clutch from releasing. Could anyone take a shot at trying to explain in a bit more detail? I'd really appreciate it. Thanks again.

[DanEC]

Originally Posted by lippy

I'm not sure I understand how the bearing retainer would prevent the clutch from releasing. Could anyone take a shot at trying to explain in a bit more detail? I'd really appreciate it. Thanks again.

The bearing retainer includes the sleeve over the input shaft that the throw out bearing slides on. It extends into the pressure plate area so that the full travel of the throw out bearing is guided. The clutch disk splined hub rides on the input splines just past the end of the bearing retainer sleeve (normally). It sounds like your retainer sleeve is in contact with the splined hub on the rear pressure plate. As you tighten the transmission bolts in forces the two disks forward into full contact with the itermediate plate and the flywheel - thus locking the thing up tight to the engine. The bearing is activating the pressure plate but the disks are forced into contact with the flywheel so nothing will give. When you back off the transmission bolts the retainer sleeve releases the clutch disks and it then works normally.

[lippy]

Originally Posted by DanEC

The bearing retainer includes the sleeve over the input shaft that the throw out bearing slides on. It extends into the pressure plate area so that the full travel of the throw out bearing is guided. The clutch disk splined hub rides on the input splines just past the end of the bearing retainer sleeve (normally). It sounds like your retainer sleeve is in contact with the splined hub on the rear pressure plate. As you tighten the transmission bolts in forces the two disks forward into full contact with the itermediate plate and the flywheel - thus locking the thing up tight to the engine. The bearing is activating the pressure plate but the disks are forced into contact with the flywheel so nothing will give. When you back off the transmission bolts the retainer sleeve releases the clutch disks and it then works normally.

Dan, very helpful. Now I understand. Is this common?

[Jerry Clayton]

if too long the bearing retainer can/might push against the clutch hub center---it doesn't have to touch in a static or non release position but only restrict the movement back from the flywheel of the discs---keep in mind that the static clearance of the snot to disc hub needs to be greater that the total released clearance of two clutch discs plus a floater--total of 4 spaces------

If you have even slightly let the weight of the trans transfer to the disc hub via the input shaft while installing the trans, you will have possibly bent the disc and ruint it as it will be wrauped and will rub the flywheel/floater/pressure plate---

I haven't read the whole thread but with the fact of 3/32 comes the question---do you have a plate between the bell housing and block???

sorry for the slow typing while you and Dan were reading

[DanEC]

Originally Posted by lippy

Dan, very helpful. Now I understand. Is this common?

Not in my somewhat limited experience but other than new cars I have never had a dual plate clutch. I know dual disk clutches are a little thicker in section than a single disk clutch and that seems to be what is working against you. I'm kind of surprised that McLeod or Tremic don't say something about checking for this interference in any of their installation guides or that Tremic hasn't shortened their bearing retainer a little.

[lippy]

Thanks Jerry. I do have a 1/8" spacer. Also, I checked the disk during install and it spun freely, per the McLeod instructions. I even spoke with their tech support to make sure I was interpreting correctly. Then when I installed the trans I used two dowels made from bolts to guide it on. I did have to work it quite a bit, but the trans was always supported by at least those dowels, and most of the time a jack underneath also.

[Jerry Clayton]

If the dowels are long enough to support the trans before the splines reach the engage starting point--put trans in whatever gear is direct one to one ratio and use a drive shaft snout on the tailshaft to gently rotate the trans shaft for spline alignment---

If you take it all apart again---put machinest dye (blueing) on every part/surface that could possibly touch so you will have witness marks for the contact points---

And I would suggest shortening that snot hub some---------

[lippy]

I spoke with Tremec, McLeod, and Brent. The consensus seems to be that the bearing retainer is too long, as several here have suggested. If it works with the trans pulled 3/32" - as it is now (I will double check) - then I need to cut it back that amount, plus another 0.100" for clutch wear. So a total of maybe 1/4" or 5/16". PITA. I have to pull this trans again and bring the retainer to a machine shop.

[maurice19]

Lippy,
I have been following your situation with the clutch.

Do you have a shortened input shaft, and if so,were the splines also cut longer to make up for the shorter travel.

I had to get a different input shaft with longer splines,so that the shaft would insert all the way into the pilot bearing. If the splines aren`t lengthened a like amount, the input shaft can bottom out on the clutch disc.

My original Ram with tko 600 and shortened shaft was ok.

My McLeod replacement needed more spline length

Just a thought, as I haven`t seen it mentioned before.

Maurice

[lippy]

Originally Posted by maurice19

Lippy,
I have been following your situation with the clutch.

Do you have a shortened input shaft, and if so,were the splines also cut longer to make up for the shorter travel.

I had to get a different input shaft with longer splines,so that the shaft would insert all the way into the pilot bearing. If the splines aren`t lengthened a like amount, the input shaft can bottom out on the pressure plate .

My original Ram with tko 600 and shortened shaft was ok.

My McLeod replacement needed more spline length

Just a thought, as I haven`t seen it mentioned before.

Maurice

Maurice,
It's not a shorter input shaft. It's the standard one. I think it's ok - I double checked the clearances at the pilot bushing surface, and at the crank - and they seem to be fine. The guys at McLeod and Tremec seem to think that taking a bit off the bearing retainer will do the trick. I'll try that and see if it solves the problem. Thanks.

[frdfver]

When the trans is removed again I would take the time to measure everything , total length on input shat, spline depth-length, bearing snout to disc using the bell housing face and trans face as reference points to find out what is really binding up. So that the trans only has to go 1 more time, save the back...best of luck...

Paul T.

[DanEC]

Lippy - I went back and skimmed this entire thread and I didn't see where the type of flywheel you are using was mentioned. I'm kind of assuming it's a McLeod flywheel that is typically paired up with this dual-disk clutch. But, there are several quality aluminum flywheels out there that various builders get attached to. I remember reading that sometimes dual disk clutches are paired with flywheels that are thinner than what is usually used for a singe disc clutch - to offset the additional thickness of the pressure plate and disk assembly. It's possible the root cause of this is a flywheel that is possibly a little too thick for use with this clutch - which would set the clutch pack to the rear in the car - thus possible interference with the bearing retainer. Even if this is so, by shortning the retainer the problem should be solved.

I don't envy you having to muscle that transmission out and back in again.

[ERA Chas]

Got the Thinking Cap on eh Dan?-Great thought.