Clutch Slipping in High Gears

REY 427 · #1 (**permalink**) 03-27-2017, 06:55 AM

I'm experiencing what I believe is my clutch slipping. I was cruising down the interstate and went to pass slower traffic. I didn't down shift and kept it in 5th gear. I floored it maybe 75% down and the RPMs immediately jumped up as if I was spinning the tires. I started to slowly let off and the speed finally caught up to the RPMs. I immediately knew something was up. I tried it again a short while later but this time in 4th gear and it did the same thing. Am I correct to assume that the clutch is slipping? I don't experience the other effects of the clutch slipping on lower gears. It's not rough coming out of 1st gear, the fluid is full, no burning smell. Is it common for this to fail with with such low mileage? The car has 4,000 miles. I'm running a Roush 427R with a T56 6 speed. Thanks for your help!

cbreez · #2 (**permalink**) 03-27-2017, 07:10 AM

A clutch will start slipping in higher gears first. Needs replacement but you could probably nurse it a while longer by staying out of high gears...They can fail anytime depending on who's driving, oil leaks, etc.

REY 427 · #3 (**permalink**) 03-27-2017, 07:25 AM

Quote:

Originally Posted by cbreez

A clutch will start slipping in higher gears first. Needs replacement but you could probably nurse it a while longer by staying out of high gears...They can fail anytime depending on who's driving, oil leaks, etc.

So if that's the case, any recommendations on what clutch I should replace it with? Not sure where to start. Anything in particular that I should keep in mind since I'm running a T56? I know there are variations of this transmission. I used to run 6 puck ACT clutches on my previous single turbo RX-7s and they held up pretty damn good.

REY 427 · #4 (**permalink**) 03-27-2017, 08:06 AM

Just spoke with Frank @ BDR and he thinks that the pin on the slave cylinder might need adjustment or needs to be shortened. Anyone have experience with this? I'm going to look into this and see if that helps.

Steve Gallegos · #5 (**permalink**) 03-27-2017, 02:40 PM

Happened to me about 3 yrs ago. took it to my trany guy, pulled the trans, bad clutch. Went with a race/street clutch from Summit, about $250.00. Also needed a new fly wheel. I think it was around $200.00. worked great ever since. If it was the slave, you would be able to get it in gear, but not out. That happened to me also. Leaking slave seal. New slave everything fine.

REY 427 · #6 (**permalink**) 03-27-2017, 03:34 PM

Quote:

Originally Posted by Steve Gallegos

Happened to me about 3 yrs ago. took it to my trany guy, pulled the trans, bad clutch. Went with a race/street clutch from Summit, about $250.00. Also needed a new fly wheel. I think it was around $200.00. worked great ever since. If it was the slave, you would be able to get it in gear, but not out. That happened to me also. Leaking slave seal. New slave everything fine.

How many miles did you have on it when you replaced the clutch?

Cashburn · #7 (**permalink**) 03-27-2017, 03:42 PM

Quote:

Originally Posted by REY 427

Just spoke with Frank @ BDR and he thinks that the pin on the slave cylinder might need adjustment or needs to be shortened. Anyone have experience with this? I'm going to look into this and see if that helps.

That would not exhibit what you are seeing. It would be difficult to get into gear, it would not cause it to free spin.

Your clutch is NG.

REY 427 · #8 (**permalink**) 03-27-2017, 03:54 PM

Quote:

Originally Posted by Cashburn

That would not exhibit what you are seeing. It would be difficult to get into gear, it would not cause it to free spin.

Your clutch is NG.

That's what I figured. What clutch setup would you recommend? This is a street car that sees no track time. Thanks.

RET_COP · #9 (**permalink**) 03-27-2017, 05:04 PM

I went with a complete McLeod super street pro setup with flywheel, TOB and fork. Performs flawlessly. My other choice would be a RAM powergrip HD. I'm not saying you need the dual friction material as I have, you could possibly get chatter for a split second depending on gearing and how smooth you are. I don't. the organic material might be good in your application or a McLeod twin Disc setup which many have.
I have a 351 with 410 RWHP/390 RWTQ 2600lbs curb wt.

REY 427 · #10 (**permalink**) 03-27-2017, 05:36 PM

Quote:

Originally Posted by RET_COP

I went with a complete McLeod super street pro setup with flywheel, TOB and fork. Performs flawlessly. My other choice would be a RAM powergrip HD. I'm not saying you need the dual friction material as I have, you could possibly get chatter for a split second depending on gearing and how smooth you are. I don't. the organic material might be good in your application or a McLeod twin Disc setup which many have.
I have a 351 with 410 RWHP/390 RWTQ 2600lbs curb wt.

I'm looking at McLeod's website and they have several clutches for a 26 spline input shaft. Do you happen to know what part number is the one you bought?

RET_COP · #11 (**permalink**) 03-27-2017, 05:53 PM

I separated everything
11"Diaphragm Pressure plate Long pattern #360850
11 dual friction disc GM 26 spline reverse hub #260571R
Steel Billet Flywheel #463200 11” 28 Lbs. 0 bal with a 28oz weight bolted on.
PP Bolts 3/8 Gr. 8 Shouldered #1500
Adjustable Pivot ball #16909
Fork Extended length #16922
good customer service
go through Summit it's cheaper but let McLeod answer ALL your questions.

Dimis · #12 (**permalink**) 03-27-2017, 06:06 PM

+1 vote for the McLeods RST Twin Disc street clutch.
And while you're at it upgrade to a Steeda tri-ax

REY 427 · #13 (**permalink**) 03-27-2017, 06:14 PM

I noticed that McLeod clutch is rated up to 500 HP. Is there one rated higher since I'm running a 550 HP Roush 427?

jhv48 · #14 (**permalink**) 03-27-2017, 06:29 PM

Before you fork out all the $$$$ for a new clutch, make sure that's what is really the cause of your slipping.
A clutch slave rod that doesn't completely release the clutch can cause your clutch to slip. Easy to check. Crawl underneath and have the clutch pedal depressed. Then watch when the clutch is released. If the clutch fork doesn't travel all the way back, then all you'll need to do is shorten the slave rod.
I had it happen to me. Easy fix.

RET_COP · #15 (**permalink**) 03-27-2017, 06:29 PM

The steeda tri ax is nice I have one. . Those numbers are rated at a much heavier car There's a lot more to it. Talk to the tech dept they'll explain it in detail. The twin will hold mega power

Dimis · #16 (**permalink**) 03-27-2017, 07:08 PM

Quote:

Originally Posted by REY 427

I noticed that McLeod clutch is rated up to 500 HP. Is there one rated higher since I'm running a 550 HP Roush 427?

She'll hold... no problems!
I pushing more HP & TQ than that without any problems.

ha_pe_1968 · #17 (**permalink**) 03-28-2017, 04:03 AM

Hi!
Same motor (Roush 427R - 550HP, 450RWHP) same problem with the clutch.
Have replaced it with a RAM powergrip which is rated for 550hp.
Works great till now without problems.
Brent Blykins helped me a lot to decide - he is a great guy :-)

Peter

Cashburn · #18 (**permalink**) 03-28-2017, 07:33 AM

We'd put a Centerforce on that setup as would Roush if you buy it together.

Tim7139 · #19 (**permalink**) 03-28-2017, 07:54 AM

Not for nothing but at 4000 miles there is no way you should need a clutch unless it was a world class parts mismatch, you beat the crap out of it or it was mis adjusted right from the get go. At that pace of wear, I suspect you'd be constantly smelling burnt clutch before now.
I would absolutely find out if a readjustment is in order before thinking about replacement.

REY 427 · #20 (**permalink**) 03-28-2017, 10:20 AM

Quote:

Originally Posted by Cashburn

We'd put a Centerforce on that setup as would Roush if you buy it together.

What part #?