cooked clutch

[BJMarshall]

The clutch finally gave up this weekend. I was towing at almost 20k combined weight. It pulled great, and the egt's were controllable. I could maintain 70-75 no problem. I only had to let out of it a couple of times. I could make it get hot (over 1250) if I wanted to. I watched the boost and pyro pretty close. On the hills, if I held the throttle where the boost was around 25, the egt's would stay between 1100 and 1200, but if I gave it a little more, the egt's would come up. Boost would easily go to 35, but it would get hot in a hurry.

I've got a couple of questions. When I was loaded heavy, and I got on the throttle hard, the truck would get so loud I could hardly stand it. It was a loud roaring sound. It felt like there were solid motor mounts on it and the body was mounted directly to the frame with no cushion anywhere. Is this just a by product of making so much torque, or should I look for a problem somewhere?

My other question is what do you guys recommend for a new clutch? Toward the end of my trip(I had been driving for about 7 hours) I was getting on the interstate and I let the rpms get a little low. I needed to merge and something was coming. I just mashed it down. It pulled hard, but as soon as boost came up, the clutch started slipping. Form that point on, I had to be careful with it or it would slip.

Sorry for writing a book

 

[DTroy]

The noise and vibration was probably resonance. (makes my eardrums rattle)



As for the clutch, South Bend is a big seller. Quality products, great service.

I bought mine from Dan at Quad 4x4. He's a stand-up guy.



You blew the clutch away with that low end torque. I did the same thing on a hill. Mashed the throttle and smelled the clutch frying. That was right after

installing the fueling box.

 

[ARhine]

the noise could be a bad motor mounts or transmission mounts not handling the torque.

 

[DTroy]

Good point. Possibly deteriorated motor mounts or transmission mount. Loose bolts for the mounts. Loose crossmember.

 

[DTroy]

I'd almost forgotten about this. When I first got my Dodge, one of the bolts for the motor mounts was loose. Not the ones that bolt to the engine, but the one that goes through the frame. I could see where the paint had worn off from the movement. Just a thought.

 

[DTroy]

One more. . the exhaust may be touching where it shouldn't be when the engine is under load.

I had a Furd Turd that had a transmission mount go bad. (happened gradually) A clunk and some vibration had started when I got on the throttle. It was fine when I was cruising. Turned out to be the exhaust hitting.

On that same truck, I had ALL of the bolts fall out of one of the motor mounts. The mount ended up getting wedged in between the block and the frame. The engine was rotated a tad.

Good luck.

 

[JLuechauer]

My gentrag and clutch recently died on me. I am using quad 4by4 for my conversion kit to the NV4500 and I am putting 450hp south bend clutch in also.

hopefully it will arrive this week.

I hate the smell of a clutch burning.



Before my gentrag gave up it rattled like crazy in 1st 2nd 3rd gear. I don't know what your sound is exactly. But hopefully it doesn't end up like mine.

 

[bgilbert]

You should hear the load roaring sound when you have two 5" stacks right behind your ears. . I get the same 'load roaring sound' when I mash the throttle, only I'm always empty. Like the mighty Cummins comes to life, says finally I get to work. I think that 'load roaring sound' is just the big ole Cummins yawning... . Like c'mon light duty pickup lets go, lets do some real work hehe. .

As far as clutch goes, I think we both know, that mashing it when in a big gear at low rpm's is a clutch killer. You know, you can use the shoulder if theres no room to get on the interstate, run it for miles if need be. Just from what I've read on here, stay away from the Luk clutches. I'd call SBC and tell them what you do with the truck, and what power level you are at and where you intend to be at. . I'm in the same boat as you, as I need a clutch, I plan on getting at least a 450hp, 1000ftlb clutch in at the minimum.

 

[BJMarshall]

I know it was my mistake. It was late and I was tired.

I'm having a little trouble stomaching $1100 for a clutch.

 

[Greenleaf]

I don't know about the clutch personally, however I'd be giving PDR a phone call. Them guys always seem to know just what we need.



I called around looking for a flex plate. All the "other" guys had was this 800 HP $400-$500 buck unit. I talked to Piers and he knew just what I had to have.



Prices are nothing to gripe about. Just do it.



-S

 

[JLEONARD]

I'd call SBC

From what I have read on all these forums I have to agree with Bill... . this is where I will call when I get to be facing a clutch job.

Oh yes... I get the roaring/vibration/yawning sound too... . was not there prior to the Bully Dogs :-laf ... . but lately it's mixed in with a slightly detectable leak via the exhaust manifold gasket on #1. So that's another item on the todo list.

Jay

 

[BJMarshall]

Glad to hear I'm not the only one. Mine didn't really sound like this until the PODS.

 

[RDBuck]

Southbend vs Luk clutch

I just bought a clutch from Southbend and if you look close you will see Luk printed right on the face of the metal plate part of the clutch. It is my understanding that they start with a Luk and modify it for different applications.

 

[DTroy]

I believe that's true. It's South Bend's design modification, and LUK does the actual manufacturing.

 

[BJMarshall]

I got it apart, and I need a little help. I need a new clutch fork and ball. Where?? The clutch plate itself wasn't worn, but the flywheel and pressure plat had some serious hot spots. Obviously not wear, but just overpowered.

The pilot bearing was very loose in the flywheel too. I know that can't be right. Should I have the flywheel machined to accept the roller type pilot, or just get a new bushing?

Last question. Where can get parts for the Getrag? I am leaking a little oil out the front. Bearings are very tight and there is little to no wear on the gears. No scuffs anywhere. I think I just need to get a new seal for the front, and I also need the small boot that goes on the shifter.

Barry

 

[DTroy]

I would definitely get the flywheel machined for a roller bearing. Better yet, get the heavy duty ball bearing that South Bend Clutch and Quad 4x4 sell. It is well worth the insurance. If you have a sloppy pilot bushing, it will cause you problems.

To get a better idea of what's out there, check out the Quad 4x4 site. Lots of pictures and some really good info.

 

[PHellen]

Go with the 450 south bend clutch. I DID and I LOVE IT. Don't cut corners when i comes to good drive train products.