Toughest clutch?

[thegoat4]

I bought my truck used with a mauled clutch, made it limp along for 20k, now I've gotta replace it.

I do a lot of towing and regularly have to push trailers up a steep hill in reverse, which is kind of hard on the clutch, so I want what can take that kind of abuse best.

The plan for now is OEM, but I'm open to suggestions.

The truck is stock, 3.0, '98.

 

[MAKG]

Load is irrelevant to the clutch.

The clutch needs to take your engine's peak torque, whether loaded or unloaded. Heavy loads do not change this.

Because of that, OEM will be fine even if you're dragging trailers full of dirt. Your driveshaft may not like it much, but your clutch isn't going to slip due to the load.

 

[rusty ol ranger]

Actually, makg, yes the clutch is relevent.

Its going to need alot more clamping force to stay togther with 4000lbs behind the truck then if your hauling around an empty ranger.....see what I mean?

You can take a brand new clutch, overload it, slip the hell out of it, and tear it up.

later,
Dustin

 

[MAKG]

Umm, Dustin, your engine puts out a certain peak torque. Floor the throttle near the torque peak and you'll see it even with a completely empty truck. Just how does a 4000 lb trailer make your engine more torquey?

Sure you can burn out any clutch by being stupid with the slipping. But it's only going to slip if YOU tell it to, so that's driver error.

 

[michowski]

Zoom clutch ftw. Its made of kevlar material, comes in a kit with everything you need, even an alignment tool. So far this one hasnt slipped once wether its hauling something in the back or just a 3 grand clutch dump. Lots of clamping force. Ive had it submerged underwater (trail said stock trucks, they lied lol) and it still didnt have any slip. So far I couldnt be any happier.

 

[thegoat4]

Let me clarify a little. I do not have a problem with the clutch slipping while engaged. My problem is that due to having high loads on the truck, and not having really low gearing, plus doing a lot of backing and starting on an incline, my clutch gets more than normal wear and tear.

Low engine torque + fast gearing + heavy load = fast clutch wear. Common knowledge.

So what cluch can take more heat / slipping?

I know that there are things I can do to avoid the problem: regear the truck, move the loading dock, bigger truck, automatic, etc. But for now none of that will happen and I need a clutch, so I may as well beef up this area while I'm in there.

 

[michowski]

I like zoom and would recommend them. I know a lot of people with 500+hp drag cars that run zoom clutches and they all recommended it to me. They take abuse, built for towing, hp. This kit comes with everything you need.... http://store.summitracing.com/partd...924677+4294839534+4294865886+115&autoview=sku

 

[AllanD]

Umm, Dustin, your engine puts out a certain peak torque. Floor the throttle near the torque peak and you'll see it even with a completely empty truck. Just how does a 4000 lb trailer make your engine more torquey?

Sure you can burn out any clutch by being stupid with the slipping. But it's only going to slip if YOU tell it to, so that's driver error.

Mike, I grew weary of telling you this but I'll try one more time
You are wrong, sadly you don't know how wrong you are, but I'll keep trying....

the factory clutches for all but the 4.0 engine suck sweaty balls.
It is INADEQUATE out of the factory, Re-man clutches aren't any improvement, and some of the aftermarket ones are just as crappy.

The reason the clutch SLIPS is because NORMALLY there isn't sufficient resistance against the thrust to allow it to slip

Look at another item that slips... Why do tires slip?
When the force exceeds the grip slippage occours
while you say the engine doesn't produce enough torque to make the clutch slips and use indiuctive reasoning to imply that the engine is making more torque to make it slip you are plain and simply wrong, you are looking at the wrong end of the equasion... there isn't enough RESISTANCE against the force available to make the clutch slip, but when you add resistance it does slip...

when the resistance against the force increases slippage WILL occour unless the clutch has sufficient grip to prevent it.

Without the 4000lb trailer there is insufficient resistance to prevent the truck from accelerating, with tongue weight the tires are less likely to break loose. something has to give and to use an old saw, the weakest link in the chain lets go, in this case the clutch...

I say again for clarity the stock clutches suck hairy balls.

It's partly because in most trucks the axle gearing is
simply too damned tall and the fairly tall reverse and first gears
only aggrevates the situation further.

This is why I have been advocating the 4.0 flywheel and clutch for the 2.9 for six or seven YEARS, failing that (the the 2.3 and the 3.0) I really liked the Centerforce2 clutch (NOT the dual friction with which I have NO experience) that I used on my 2.9 before I discovered that the 4.0 clutch was a bolt on (With the 4.0 starter)

EITHER extra engine power/torque OR more vehicle mass completely changes the entire part survival equasion.
If you are an engineer I shouldn't need to explain it to you.
I do know that if you designed aircraft I would now refuse to
knowingly fly in one you designed....

I know that I tried several stock-type clutches on the 2.9 (and that includes TWO ford replacement clutches In FORD boxes) and liked none of them but I didn't have to hate them long because none of them lived longer than about 20K miles, then I tried the CF-2 that clutch lasted 115,000 miles and it was working when I replaced it, and I only replaced it when I did because I was installing a younger engine and a rebuilt transmission prepping for a trip to Oklahoma and didn't want pull the trans again to replace the clutch three months later it was at that time I put the 4.0 clutch in behind my 2.9 and I never looked back... (Now I have a 4.0 in front of a 4.0 clutch)

Extra grip isn't going to hurt a damned thing
Extra temperature resistance in the clutch isn't going to hurt anything either.

Infact improving the clutch at the very least isn't going to hurt anyone's truck so WHY IN THE NAME OF GOD do you keep recommending against upgrading clutches?

Mike, I'll make you an offer, I'll assemble a truck just for you
Put a stock clutch in it. Hitch it to my 1880lb dovetail trailer then have you back it into it's parking place.
Or you can use the NON-4.0 RBV with a stock clutch of your choice... BTW, no cheating by using low-range!
after that you can appologize to every person you've called incompetent over the years on this issue.



AD

 

[4x4RangerGuy]

Mike, I grew weary of telling you this but I'll try one
the factory clutches for all but the 4.0 engine suck sweaty balls.
It is INADEQUATE out of the factory, Re-man clutches aren't any improvement, and some of the aftermarket ones are just as crappy.

Allan, I didn't realize how small the 3.0 clutch was. When I first took it out of the box I didn't think it was the right one at first and they just mixed it up. I ended up measuring it according to spec and it was right on. What is the point of it being so small?

 

[MAKG]

Allan, I'd take you up on that if it weren't for the 3000 mile distance. I'm not likely to get out to the East Coast any time soon.

But I'd like to hear how you think "resistance" affects static friction. As would, presumably, a number of earthquake researchers (the best model uses very similar physics). Especially since you seem to think low range is "cheating." The engine torque is HIGHER if the RPM is more appropriate. You see full engine torque at any load, at WOT at the proper RPM. What "gives" is that the vehicle accelerates. Acceleration will of course be much slower with a lot of weight behind the truck. Proper clutch use will not break the tires free. The 3.0L isn't THAT torquey. Now, if you're "dumping" the clutch, that's another story entirely, but that's not an appropriate towing technique. I am assuming the driver doesn't want to fishtail out of a dead stop, loaded or otherwise.

The only variable I see is excessive heat due to a lot of slipping. So, please explain what physics you think I'm missing here.

Now, if the clutch DOES slip under full throttle when unloaded, I certainly agree that it will when loaded as well.

 

[Zer0PSI]

Allan, I'd take you up on that if it weren't for the 3000 mile distance. I'm not likely to get out to the East Coast any time soon.

But I'd like to hear how you think "resistance" affects static friction. As would, presumably, a number of earthquake researchers (the best model uses very similar physics). Especially since you seem to think low range is "cheating." The engine torque is HIGHER if the RPM is more appropriate. You see full engine torque at any load, at WOT at the proper RPM. What "gives" is that the vehicle accelerates. Acceleration will of course be much slower with a lot of weight behind the truck. Proper clutch use will not break the tires free. The 3.0L isn't THAT torquey. Now, if you're "dumping" the clutch, that's another story entirely, but that's not an appropriate towing technique. I am assuming the driver doesn't want to fishtail out of a dead stop, loaded or otherwise.

The only variable I see is excessive heat due to a lot of slipping. So, please explain what physics you think I'm missing here.

Now, if the clutch DOES slip under full throttle when unloaded, I certainly agree that it will when loaded as well.

It's common sense! If you are towing an extremely heavy trailer and you clutch doesn't have enough clamping force the engines torque will overide the clutch and it will slip.

 

[MAKG]

It's common sense! If you are towing an extremely heavy trailer and you clutch doesn't have enough clamping force the engines torque will overide the clutch and it will slip.

Then I guess I don't have common sense because your engine has the SAME torque on the clutch at WOT with it unloaded, at a given RPM. Just like it has the same torque in any gear or even removed from the vehicle on a dynamometer (though the vehicle will certainly accelerate differently -- such is the difference between torque and acceleration). Now, please explain the physics or let Allan do it.

So, in what sense is torque not torque?

 

[Zer0PSI]

OK a clutch has a certain clamping force, and when a load is placed on that clutch that exceeds it's clamping force it slips. So imagine you have a truck and are hauling a 2,5000 lb. trailer. The added weight of the trailer places stress on the entire drivetrain, so when the flywheel spins the clutch will slip because of the added force required to turn the driveshaft, where as with no trailer the drivetrain will not be under stress and the driveshaft can turn without resistance.

 

[MAKG]

But the LOAD on the clutch comes from the ENGINE TORQUE. What one means by that is how much torque the engine places on the flywheel. It's what you measure on a dynamometer. There is no 4000 lb load on that.

How are you going to make that go up with any load?

It's VERY hard to get around this bit of physics unless one goes into dynamic (shock) loads or somehow changes the coefficient of friction.

 

[rusty ol ranger]

Ok MAKG....

So....your saying, if you tkae a 87 Ranger, with a 2.9L making 170ftlbs of torque, and hook 4000lbs behind it, and then take off, its going to take the same amount of twist on everything to get it going as if it was empty?

Um....no.

Yes, the engine may be making the same amount of torque regardless, but if the resitance on the wheels of the truck (whihc then adds it to the axle, driveshaft, so on) increses, then something is going to slip if its overloaded, if you have a good clutch, then the wheels will turn and you'll take off, if you have a shitty clutch, then the flywheel will turn, but instead of bogging the motor, the motor will simply overpower the clutch, and start glazing things, while the input shaft on the tranny moves slower then the flywheel.

Think about it.

later,
Dustin