Mcleod twin disc clutch trouble

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Have you adjusted the free-play until the pedal is hard at the top yet? Then back it off till you have about one inch of free-play at the top. After you do that then check your plate departure and install a positive stop so you don't put the fingers into the springs on the disc.
If you can't adjust it to zero free-play then something is wrong with your linkage or you need to adjust your spacing on the release bearing
Gus

I adjusted it for the one inch of free play and the clutch was going overcenter and actually beginning to re-engage the further you pushed the pedal down. The only way I can keep it from going overcenter is when the pedal is adjusted where its about only 2 inches from the floor. The linkage on the car is fine, its all brand new and the same exact setup I used on the other clutch that I had in my car and everything worked perfectly fine.

This is why I suggested a positive pedal stop. When I had a twin in my car I needed to install a stop because the fingers would actually touch the disc when the pedal was pushed all the way down.
I just adjusted the pedal stop so my air gap was .030 between the floater and the first disc.
Gus

Whats involved in installing the positive stop for the pedal and where can I get one., Ive never seen one in person before. Im at work now so Im not sure on the measurements, but I ordered the big block E body Z bar from brewers when I was installing everything so Im hoping that I received the right one.

Posted By: Sxrxrnr

Re: Mcleod twin disc clutch trouble - 06/29/14 04:34 AM

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Anyone?

What does McLeod advise?

Going back to your original thread where you thought that was transmission problem and indication initially was that you had not changed clutch or transmission(I am operating from memory) and could change gears with disconnected linkage, but not with shift linkage connected,,,the scenario changed to where you had also 'upgraded' to a double disk clutch and things got really confusing.

Perhaps you could give a blow by blow, step by step of all you have done. As in:

1. Car initially a 360 with automatic.

2. Pulled engine and transmission

3. Installed brand X clutch linkage

4......and so forth with each step and vendor products used,,,clutch fork, flywheel, bell housing, clutch pressure plate and disc(s), throw out bearing, shift linkage ,,,,,etc

I've believed from the beginning that shift issues was a clutch problem,,,now we must figure out just where things went astray,,,like warped discs, perhaps installed backward,,,easy to do on some cars,,,,clutch pivot ball(I'm thinking as in Chevy here,,,sorry)' pilot bearing, incorrect clutch linkage or improperly mounted,,,etc.

With Hemi engine upgrade, is there any possibility that engine is positioned out of spec as result of incorrect motor mounts causing clutch linkage 'throw' issues?

If pivot ball as in Chevy,,,,this would be my first best guess as cause.

With a complete blow by blow, we will figure it out

Posted By: 73cuda340

Re: Mcleod twin disc clutch trouble - 06/30/14 12:36 AM

The car started as a 340, 23 spline 4 speed and a hayes clutch. I put everything together and went through the transmission and everything worked fine in the car; clutch, transmission, shifter, etc. All new shifter linkage and rods, levers and clutch rod kit.

Next I put my hemi in the car with a 18 spline hemi 4 speed and a Mcleod rxt twin disc kit. Stock replacement bellhousing, new clutch linkage kit and pilot bushing from brewers performance. I used the same shifter linkage, mechanism, and rods that were on the car before and worked perfectly when I had them on there with the old motor and tranmission. When installing the clutch kit, I measured all the clearances with feeler gauges and everything was in spec that the gave me in the directions.

Now I have the problem with the clutch going overcenter when I push the pedal more than halfway down. The only way that I can adjust it so that it doesn't go overcenter and re-engage is when the clutch is adjusted to the point where the pedal is about 2-3 inches from the floor when it is all the way up and the 2-3 inches is all the travel that I have in the clutch.

I called the McLeod tech line three different times and the first two times the guys words were "I don't know what to tell you". The other time I was told that I can send it back and they would adjust the travel on the pressure plate fingers. However, I don't want to have to continuously take the clutch out, send it back, wait for them to adjust it, put it back in and find out that it needs more adjustment and repeat the whole process over and over. That is why I was asking and hoping to find some advice to make it work with what I have now.

Posted By: Sxrxrnr

Re: Mcleod twin disc clutch trouble - 06/30/14 02:01 AM

Not being Mopar wise in this particular area,,,does the clutch release(goes from external clutch linkage to throw out bearing) pivot on a ball just as with Chevy?

Is this pivot ball adjustable as with some Chevy balls( basically changing the angle of the fulcrum)' or are their different balls offered as certain GM configurations.

Is it possible to install either the throw out bearing or either clutch disc in backward,,,not suggesting that you did, just asking. It is possible on some cars to do this.

It is possible as I had mentioned in your other thread to severely distort a clutch disc if one leaves the transmission 'hanging' before trans main shaft is throughly ensconced into the pilot bearing,,,given all additional info now, doubt this is the problem.

Are you certain that is correct throw out bearing

Is it a Borg and Beck clutch or a diaphragm pressure plate. Is it possible that any fingers are compromised in some way,,,broken or distorted.

How does new clutch linkage compare dimensionally to that which you replaced?

You are certain that engine is properly placed via correct motor mounts and K member is all in place properly.

Did you replace flywheel and is it correct if you did,,,if thicker(or thinner) can throw off geometry of pivot ball, pressure plate and clutch release lever.

Assuming that you did not replace clutch pedal assembly and correct bell housing is used.

Damn, running out of ideas. McLeod's are the experts in the room, it is there clutch assembly(though not to insist it is there product at fault) surprised how they have shucked and jived you off with no solution. If it is happening to you, likely has happened to many who went before you so you would think that they would have seen this before.

Have you had the clutch out for a re-examination of all components since original installation to find if any damage to any?

Where earlier I said my dough was on the clutch as the cause of poor shift action, I now give even odds that is defective pressure plate or the geometry of the pivot ball,,,if this is used with Mopar too.

How's about a hydraulic clutch as a backup?

Posted By: RTSE4ME

Re: Mcleod twin disc clutch trouble - 06/30/14 02:33 AM

I have the same problem with my twin disc. When I adjust the pedal for an inch of free play the throwout bearing is depressing the clutch fingers.
I think there is not enough bell housing depth. What throwout bearing are you using?

Posted By: 73cuda340

Re: Mcleod twin disc clutch trouble - 06/30/14 02:53 AM

There isnt a ball, just the fork is on a bracket that is inside the bellhousing. However it only goes on one way so there's no adjustment.

The throwout bearing can only go in one way and it is possible to install the discs backwards, but they are labeled with a sticker from the factory showing which side is the pressure plate side and which is the flywheel side. I double checked that they were facing the right way when installing them.

I installed a throwout bearing from McLeod and according to the part number it was the correct one, it seemed to fit fine too.

The clutch is a borg and beck and the transmission never rested on the fingers during the install, so unless they were slightly bent from shipping, they should be fine.

The linkage is factory replacement and the only difference from the previous setup is that the adjusting rod is straight for the big block and angled for the small block.

For the motor mounts I used the Schumacher hemi conversion mounts and supposedly people have said that the motors position is slightly different from stock, but this shouldn't affect the amount of distance the throw is for the fork. If anything it might cause the linkage to bind from being at a different angle; however I don't have a binding problem, just too much travel.

The flywheel I used came with the clutch kit and is made specifically for that clutch setup.

I don't want to install a hydraulic setup if I don't have too.

I have yet to take the trans and clutch back out for inspection. Ive been looking it over hoping to find a stupid mistake and fix the problem, but Ive looked over this a hundred times and I cant come up with anything. I appreciate all that help that has been given but Im pretty much at a loss of what to do at this point. I cant find any other clutch that is rated for the power for my engine, if I did have to go down that road. My engine dynoed right at 700 hp and the only other kit that I can find that is close is only rated to 500 hp.

Posted By: Sxrxrnr

Re: Mcleod twin disc clutch trouble - 06/30/14 03:21 AM

Hanging transmission would distort clutch disc, not pressure plate fingers. Think heavy transmission shoved into disc splines but not into pilot hole. Think pull down on transmission and the damage that might ensue to clutch disc and the corruption to disc runout. Can be enough to keep clutch surfaces contacting both pressure plate and flywheel even though clutch pedal all the way down.

However sounding now more and more like somehow defective pressure plate or it's internal set up adjustments.

Minor suspicion motor mount positioning of engine, no options for clutch lever pivot, likely discard this.

Hate to say it but perhaps time to pull trans and clutch if all else is as you believe, in order.

I recently had to pull oil pan to resolve oil leaks on my 512 stroker 5 times to finally resolve a circus of missteps by 4 different so called reputable manufacturers and/vendors. And of course my fault in trusting each of them that they knew what they were doing or had the quality control to ensure that they did.

As I believe it was President Reagan was wont to say: 'Trust but verify'.

Posted By: jbc426

Re: Mcleod twin disc clutch trouble - 06/30/14 07:56 AM

Have you read this page thoroughly from Brewer's Transmissions?

http://www.brewersperformance.com/products.asp?cat=105

You did say you had a small block in the car didn't you and now you have a big block, but are using the same clutch linkage Z-bar?

Also, you are running a 700 hp hemi with a stock bellhousing? That's just plain crazy! Have you ever seen a car that had a clutch explode? it does happen.

http://www.youtube.com/watch?v=L9vpcyxvvC8

Posted By: 70HemiGTX

Re: Mcleod twin disc clutch trouble - 06/30/14 01:05 PM

Get rid of the over-center spring on the clutch pedal under the dash! That is the starting point. I had the same problems until I got rid of the spring in my Dart. After that it was cake to adjust. Feels like a normal clutch then also. Plus make sure your geometry is correct in your Z-bar and other linkage. It all works together.

Posted By: RTSE4ME

Re: Mcleod twin disc clutch trouble - 06/30/14 02:01 PM

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Next I put my hemi in the car with a 18 spline hemi 4 speed and a Mcleod rxt twin disc kit.

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The clutch is a borg and beck and the transmission never rested on the fingers during the install, so unless they were slightly bent from shipping, they should be fine.

I thought the RXT only came with a diaphragm pressure plate.
The RST/RXT pressure plates require less than.400" of bearing travel to fully release according to Mcleod.
I think the additional clutch height and the reduced pressure plate travel needed is causing the issue.

Not sure what the solution would be. Maybe you could use a longer clutch pedal to torque shaft rod to reduce travel? Just thinking out loud.

Posted By: dynorad

Re: Mcleod twin disc clutch trouble - 06/30/14 11:41 PM

You won't solve this until you get rid of the over center spring.

Posted By: 74RALLYE

Re: Mcleod twin disc clutch trouble - 07/01/14 04:15 AM

Here's an idea: Order a torque shaft replacement pin and mount it to the torque shaft leaver that actuates the clutch fork. Mount it at a position closer to the pivot point of the torque shaft. This will reduce the amount of travel and it will need all of that pedal travel to operate the clutch. This is just an idea to consider as I'm not a clutch expert.

http://brewersperformance.com/proddetail.asp?prod=TSP

Posted By: 73cuda340

Re: Mcleod twin disc clutch trouble - 07/01/14 10:17 PM

I did remove the overcenter spring from the pedal. It didn't make any difference. They do make the clutch kit in a borg and beck assembly. Here is the link to the one that I bought.

http://www.brewersperformance.com/proddetail.asp?prod=MC64408B

Posted By: 69Mcode440

Re: Mcleod twin disc clutch trouble - 07/03/14 04:01 AM

I am not an expert, but isn't this all a matter of pedal ratio, fork ratio to calculate pedal travel required to the travel of the clutch for disengagement. Maybe get out a tape measure and see what it figures out to be.

Posted By: General 68

Re: Mcleod twin disc clutch trouble - 07/03/14 09:24 AM

Does it require a lot of pressure to push the pedal through the release travel? I do not think you want to run the 3 finger original street twin without the over center spring. The original street twin also comes in a diphragm version and this one is tougher than the common 800hp and 1000hp twins. I run this diphragm 1200hp version and THIS clutch works well without the spring but is hard on the leg. It feels lik it requires twice the pedal effort we are used to from more modern cars. Mcleod describes the pedal effort to 'slightly heavier than stock' and that is for the diphragm version. I also might follow the idea of inproper pedal ratio - if the pedal is hard.
Lars

Posted By: 85_Ram_4speed

Re: Mcleod twin disc clutch trouble - 07/03/14 12:45 PM

No experience with a twin disk, but I set up my old Dartsport with a stop as was suggested previously and no overcenter spring. If you adjust the clutch right, there will actually be very little movement in clutch pedal travel to get the disk to release. Mopars have WAY to much travel in stock form. It took me having someone in the car pressing the pedal while I got underneath to see what was actually happening. I think I set my air gaps to be about .090 on the several different clutches I tried, anything much tighter and it was hard to shift at high speed---again, this is what I determined worked for me.

I'd be willing to bet if someone pressed the clutch for you while you under neath, measure your air gap and have the assistant note where the pedal started and stop to achieve that, you'd see it doesnt take much travel at all. My pedal actually was not any higher off the floor than my brake pedal--in fact it was lower---stock it was alot higher than the brake pedal. It doesn't matter which side of the pedal you limit, or both, you just need to limit it for a specified distance. And make sure the linkage geometry is right too.

Posted By: RTSE4ME

Re: Mcleod twin disc clutch trouble - 07/03/14 03:10 PM

The original Street Twin uses a Borg & Beck long pressure plate. This is a borg & beck hat with long style fingers. You have lower static pressure and they have c/w on fingers for lock up. It is kind of in between a B&B and diaphragm.
I think they make different diameter overcenter springs depending on static pressure. I would give Brewers a call.

I think a member(71TA) uses the same exact clutch with a Lakewood bell without any issues.

Posted By: RTSE4ME

Re: Mcleod twin disc clutch trouble - 07/03/14 03:17 PM

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Mopars have WAY to much travel in stock form.

I'd be willing to bet if someone pressed the clutch for you while you under neath, measure your air gap and have the assistant note where the pedal started and stop to achieve that, you'd see it doesnt take much travel at all. My pedal actually was not any higher off the floor than my brake pedal--in fact it was lower---stock it was alot higher than the brake pedal. It doesn't matter which side of the pedal you limit, or both, you just need to limit it for a specified distance. And make sure the linkage geometry is right too.

I would do this.

Posted By: 73cuda340

Re: Mcleod twin disc clutch trouble - 07/04/14 12:20 AM

I had a helper working the pedal while I was underneath. I just got it to the point where it will disengage. Im just going to live with the lower pedal. I got it to be about halfway now.

Mcleod twin disc clutch trouble