TREMEC T56 Magnum S197 Transmission

rocky61201

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My experience is that slave cylinders/throw out bearings are hit and miss. I've had my 06Gt for 10 years/214k miles. Sometimes they last a couple years/sometimes a couple months. I've replaced mine about a half dozen times. But I drive in lots of traffic jams/stop and go traffic on hot SoCal days. So I imagine mine gets heated up good and is prone to earlier failure.

And when the throw out bearing is ready to pop it will have the same symptoms you're getting, getting stuck in gear or creeping forward at a stop light.
 
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rocky61201

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clutch master cylinder is at the top of pedal inside car

Yea, I know. I've replaced that too because the clevis is made out of a plastic POS. The previous poster said he put a new slave in when he installed the transmission. Some people refer to hydraulic throw out bearings as slave cylinders. So I said my experience with slaves is they are hit and miss. Sometimes they just go bad prematurely. Plus he also said his master cylinder connection is tight and not leaking any fluid.
 

2010GlassGT

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So, correct me if I'm wrong here. But, I thought by clutch master cylinder that you meant the brake master cylinder. I was under the impression that it was a shared system. Is there something I'm not checking on the inside of the car?
 

Juice

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So, correct me if I'm wrong here. But, I thought by clutch master cylinder that you meant the brake master cylinder. I was under the impression that it was a shared system. Is there something I'm not checking on the inside of the car?

They share the reservoir/fluid ONLY. The Clutch master is under the dash as it has been said before. You can see a hose from the master cylinder reservoir go through the firewall, that is the clutch master cyl feed.

Is the brake fluid level good in the reservoir? This is definitely a clutch issue. I would not drive the car like that, this issue is beating the crap out of your syncronizers/blockers.
 

2010GlassGT

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They share the reservoir/fluid ONLY. The Clutch master is under the dash as it has been said before. You can see a hose from the master cylinder reservoir go through the firewall, that is the clutch master cyl feed.

Is the brake fluid level good in the reservoir? This is definitely a clutch issue. I would not drive the car like that, this issue is beating the crap out of your syncronizers/blockers.

Thanks for the info. I should be checking for leaks, cracks, etc. right? Brake fluid is good in the reservoir, checked that. It really sucks because it's intermittent and great most of the time. I don't know what would cause it to be erratic and not all the time. I don't drive the car daily as I have another vehicle, so it can sit until I figure this out.
 

Juice

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Thanks for the info. I should be checking for leaks, cracks, etc. right? Brake fluid is good in the reservoir, checked that. It really sucks because it's intermittent and great most of the time. I don't know what would cause it to be erratic and not all the time. I don't drive the car daily as I have another vehicle, so it can sit until I figure this out.

I didn't realize it was intermittent (or I would have said air in the clutch line) Still, doing the clutch bleed procedure maybe worth a shot. I don't think you have a leak, or the fluid level would be low.

To bleed the clutch, Ford says put around 20" vacuum on the master cylinder reservoir and pump the clutch pedal. That said, I never put any vacuum on mine after installing a NEW slave/throwout when I put my tranny in. Just pumped the pedal, and it worked. Sorry to say, but I see a trans pull in your future.
 

2010GlassGT

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I didn't realize it was intermittent (or I would have said air in the clutch line) Still, doing the clutch bleed procedure maybe worth a shot. I don't think you have a leak, or the fluid level would be low.

To bleed the clutch, Ford says put around 20" vacuum on the master cylinder reservoir and pump the clutch pedal. That said, I never put any vacuum on mine after installing a NEW slave/throwout when I put my tranny in. Just pumped the pedal, and it worked. Sorry to say, but I see a trans pull in your future.

My install was similar to yours. Installed the transmission, pumped the pedal and it was good to go. I don't have a Mighty vac or anything, I can try to pick one up. Even though I'm thinking if there was any air in the line, it would've risen to the top as the system is self bleeding. It might be worth noting that my issue is either at low RPM (idle in 1st or 2nd and it gets stuck) or on downshifts, never on upshifts.
 

rocky61201

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It might be worth noting that my issue is either at low RPM (idle in 1st or 2nd and it gets stuck) or on downshifts, never on upshifts.

I hope it doesn't happen to you because it sucks being broke down on the side of the road with busted throw out bearing. It sounds like yours is getting ready to fail because as you described above when you hold the pedal in for longer than a second (at idle and downshifting) it is slowly losing pressure and disengaging the clutch. At speed when upshifting you are using the throw out bearing maybe for a quick second or less (not enough time to lose pressure). Now based on that you could also surmise that the clutch master cylinder under the dash has a bad seal and is slowly losing pressure as well. It's possible but I've been on this forum since 2009 and never read about a clutch master cylinder failing in that manner. When they break it is always the plastic clevis that attaches to the clutch pedal.

There may be air in the system but I doubt it because as you said in your first post everything was fine for the first 5k miles. You also said this has been going on for the past 1k miles. Consider yourself lucky you made it this far on a failing throw out bearing.

Do the vacuum bleeding 1st, doesn't cost anything. Then if you do wind up pulling the transmission, you might as well replace the throw out bearing anyway. Even if you think it's ok, its sort of standard practice to replace it whenever dropping the trans.

Your clutch system is a hydraulic system, like any other hydraulic system. Just the same as brakes or even a 3 ton hydraulic jack. If there is air in the system it will be hard to pump up to full pressure. If there is no air in the system but a slow leak somewhere (or a bad internal seal), then you can still pump it up to full pressure but it will slowly lose it via the leak. Ever bought a cheap Chinese floor jack??? Then jack your car up with no problem, but then watch your car slowly drop to the ground.
 
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Juice

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I was thinking of this as I was driving last night. As it is intermittent, there is a possibility that the MASTER cylinder is bypassing fluid internally. I had a brake master cyl do that. Had good brakes sometimes, and sometimes the pedal sank to the floor gradually.

So, the choice is:
1 Try replacing the master
OR
2 Pull trans and inspect clutch/slave.

That is the bottom line IMO.

How does the clutch pedal feel compared to BEFORE this issue started? Did the feel of the pedal change?
 
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DiMora

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I wanted to post an update on my investigation into the noise I get from when in 3rd or 4th gear, under load, and from 1,500 to 2,000 rpm. I have the T56 Magnum XL with a RST dual disc clutch. Let me say that the transmission and the clutch operate well, with no problems at all. It's just the noise that drives me crazy.



So far I've confirmed that the driveline angles are within 2 degrees, rebuilt the rear end, greased and adjusted all the torque arm, watts link, lower control arms. I removed the transmission and sent it back to Plymouth, MI. It came back last week, freshly went through by the factory (at no charge) and they found nothing that would cause the noise I described. They did some adjustments and replaced the 5th and 6th synchros.



I reinstalled the transmission last week and I think it shifts a little easier. None of this was done by the "scientific method", it's just me and the seat of my pants. Anyway, the noise remains as it was, completely unchanged. All that's left is the clutch. And I know that my RST was overkill, it just came in the kit I purchased.



So I bought an Exedy stage 2 single disc clutch with a steel flywheel. The part number is 07953FW. It may end up being a little stiffer, we'll see. I just hope the noise is gone. It's going to be a couple weeks until I have a full day in garage by myself, but once it's done I'll post the result.



Thanks for listening...



The noise you are hearing is the twin disc clutch / floater plate assembly rattling...it's perfectly normal with a McLeod RST or RXT and there is nothing you can do about it other than:

1) Don't load up the car at such a low RPM.
2) Install a single disc or different brand clutch if you can't live with it
 

2010GlassGT

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I was thinking of this as I was driving last night. As it is intermittent, there is a possibility that the MASTER cylinder is bypassing fluid internally. I had a brake master cyl do that. Had good brakes sometimes, and sometimes the pedal sank to the floor gradually.

So, the choice is:
1 Try replacing the master
OR
2 Pull trans and inspect clutch/slave.

That is the bottom line IMO.

How does the clutch pedal feel compared to BEFORE this issue started? Did the feel of the pedal change?

The clutch definitely feels weird when it's not working (locked in gear). It's pulled me along and held me on a hill. I'm thinking more and more that the slave is defective. If I remember right, this was a Ford OEM part. Hope the transmission is OK. I could always send it back to Tremec for a inspection.
 

rocky61201

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The clutch definitely feels weird when it's not working (locked in gear). It's pulled me along and held me on a hill. I'm thinking more and more that the slave is defective. If I remember right, this was a Ford OEM part. Hope the transmission is OK. I could always send it back to Tremec for a inspection.

it's the slave/throw out bearing. You know how when you are parked with the car running in neutral and you cannot force it into gear? That's because torque is still being applied to the input shaft, counter shaft, and main shaft of the trans. That torque keeps you locked out of shifting it into gear until you engage the clutch.

Well that same principle keeps you from shifting out of gear if the clutch isn't fully engaged and torque is still being applied to the input shaft, counter shaft, and main shaft. (Unless you yank on the shifter really hard)

The reason your clutch is failing to engage is because the throw out bearing isn't engaging the clutch and preventing torque from being applied to the trans.

Even if you had a brand new car with 10 miles on it and you are cruising along in 1st or 2nd, then try to get it out of gear without engaging the clutch the same things happens right? You can't get it out unless you force it.

If you ever get the chance to rebuild a tremec manual transmission you will get to understand real quick how everything inside works. There is another thread "TR3650 Rebuild". It is fairly detailed with lots of pics. The internals of the 3650 probably ain't much different than a T56.

Also - It is rare, but if for some reason the combination of the flywheel, clutch, and bellhousing you have might require you to shim the throwout bearing. Some flywheels are thinner than others and you have to shim the throw out bearing. And not every bellhousing is cast with the exact same dimensions. You may have to measure everything with a special dial caliper. Same principle as setting up a rear differential because no two rear axles are cast identical either. The difference might only be .010 but that might require a shim. There is a procedure/manual for it but I've never had to do it first hand.
 
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2010GlassGT

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I just wanted to post an update to my problem. I pulled the clutch and noticed that the floater straps did not have equal spacing and that there was actually wear on the edge of the clutch disc. Somehow the clutch was contacting the straps when hot and not allowing movement, causing my issue.

I sent it back to McLeod and they rebuilt the entire assembly. They also informed me that there was an updated adapter ring design and included that in the rebuild. The new adapter plate is not flat in design and there is more space between the straps/clutch disc. Hopefully this helps someone in the future. I do not know exactly how old my clutch was or when they introduced the newer design. Reinstalled the rebuilt clutch with a new pilot bearing to be safe, the used slave, and the car shifts and runs like a champ at all temperatures. No issues.
 

2010GlassGT

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Well, here I am, a year later. I've put about 7K miles on the rebuilt clutch and have the same issue once again. I am fed up with McLeod and am pulling out their clutch and replacing with a single disc. Once I am able to see the components, I will post an update on what the problem is this time. I have the same symptoms, so I'm leaning towards the same issue (floater straps/clutch disc contact).
 

Norm Peterson

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Subscribing . . . I'm considering a Magnum XL with different (2.66/1.78/1.30/1.00/0.80/0.63) ratios for road course stuff. No drag racing. Stockish power, so 6000 rpm and nothing special planned for the clutch. Lightweight steel flywheel, possibly.

There's way too much in this thread to read right now, what with gift wrapping still ahead of me.


Norm
 

1950StangJump$

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I literally just picked mine an hours ago up from JPC Racing. I got the 2.97 ratio and combined it with 4.10 rear gears. RSt clutch with 450 RWHP.

Definitely noisy and mechanical in feel. As I drove it, I could feel it break in, though shift effort is not really easy no matter what giving the nature of the trans. Looking forward to spring to run that paces ...
 

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