what clutch for cummins swap?

[GRU]

im getting ready to drop my 12v/nv4500 into my ford 92 crewcab dually. im figuring now would be the perfect time to put in a good clutch. i have no idea what shape or how many miles is on the one that came with it. ive read many places that dual disc is the cats ass. my mechanic friend say dual are crap and tear up transmissions. im probably going to tweak my p-pump (215 hp version) for some more juice but not much more than that. this is for a reliable family camper tow rig and gooseneck hauler. will tow 11- 15k at mot on a fairly regular basis. will a good quality HD single disc hold up to that? i want a good pedal feel and not be grabby/chattery either. thanks for the input.

 

[argve]

SBC - South Bend Clutch. I had some problems with mine but they DID stand behind it and I wasn't even the original purchaser of the clutch - can't ask for better service than that. Heck when I called them I wasn't asking for Peter to cover the clutch I was asking him since this one didn't hold then what should I run and he said that is the clutch and sent it to a shop for me to have installed. He wanted it professionally installed instead of me doing it and I can understand that.... so no complaint there it was just the shop that did the work was the problem... but I ran a CON OE and it wasn't grabby and I could slip the clutch to back the truck up with the camper attached. yes I could walk through the clutch early on but once it wore in a bit she held good but still I could walk through it if I was really pouring the coals to her in 5th but then again the Nanny goat was far from stock - don't know how she turned on the dyno because never had her on there but this is what she had...

#10 Fuel Plate
3k gov spring kit
AFC spring kit
Custom Injectors - larger than the 370 marine
Boost control elbow - tripped at 35psi
High flow exhaust and exhaust man
BHAF
Timing at 16.3 degrees

I also had the nv4500 the walking through the clutch didn't start until after I put in the locker - which sort of helped with the wheel spin issue at 50mph - sort of.....

 

[GRU]

wow. wheelspin at 50 mph??? what?? aside from the big injectors everything else you did is within my range of possibilities. hmmm... my mechanic friend had 2 different kind of trannies in his shop that were tore to hell. both had SB dual disc clutches. therefore he has deduced that all dual disc clutches are garbage and destroy transmissions. he is a transmission guru so i hesitate to argue but if they did that no one would sell DD clutches. but they sell a butt load, and LOTS of people recommend them, South Bend in particular. so im kinda at a loss...

 

[argve]

I tore my tranny apart a few times.... you can read about that saga here on this website but it boils down to the ole standard 5th gear failure and once.... once.... I welded it in place and well then a few thousand miles later it failed again but this time it broke the mainshaft in half.... oops.... I know on other sites that are primarily dodge cummins sites there are a ton of guys running around with dual disc and they haven't said anything bout tearing up the trannies so don't know what to tell you there. but if it were me I would do the DD and not look back. getting the power to the ground is what you are looking to do and from what I seen (me no expert at trannies) I would say the nv4500 is a good solid tranny and can take what you toss at her.

 

[argve]

yes on the wheel spin.... ask the guys that were at the IDI weekend following the purchase of the truck (that was dogcatchers first rally ) - I was giving rides left and right and leaving a ton of rubber out front of the campground. it's not some internet story... you can do that with the mods I listed / had. and she got 21-22 with a mix of city/highway driving - sole highway she would turn 24mpg. And I always never failed on any given day would have to roll black smoke and do launches from stop lights - it was in the owners manual that I had to and I always follow the rules.... <grin>

 

[GRU]

im going to check into them. something in the back of my mind says they cant be the root of the problem on those trannies that got destroyed. i got my 60# valve spring in the mail friday o as soon as i get them changed out and a clutch figured out and intalled the motor will be put in! im doing the valve springs in preparation for an exhaust brake and a potential 4k GSK if i feel its necessary. how much do you think i can get out of mine doing the mods you listed except the injectors? i dont know that i want to get that crazy with it... yet.

 

[argve]

haven't the slightest guess as to amount of power (numbers) but I always figured it didn't matter what the numbers were as long as it was enough power for me - if I needed more I would add something to get there and didn't care about the numbers. you should do pretty well with the stock sticks but you might need them but you might not. Just be aware that the 370 marine injectors have a rep of causing the engine to have a slight haze at all times out the exhaust pipe because of the spray pattern difference from the stock injectors as the pistons in a marine motor are different (swirl chamber is different). But there are injectors that are less hp than the marine 370's that will give you dang good power without the smoke - not quite as much as the 370's but by the sounds of it you aren't looking for the fire breathing dragon so....

you are correct to use the 60# springs when turning the higher rpms and especially with an exhaust brake. Remember you can plug one of the holes in the butterfly of the exhaust brake with a machine screw and lock nut to increase the back pressure so that it almost make the truck brakes useless and you can adjust how far the butterfly closes so really up the backpressure just be aware that when you do both of these mods that you will start blowing out the exhaust gasket between the turbo and exhaust manifold - I can't tell you how many I replaced in mine. without the hole plugged I sort of thought the exhaust brake wasn't worth the money spent on it, and after having it dialed in so that it worked so dang well (but I couldn't keep gaskets) I couldn't see going back to the stock setting on it, so I sold the exhaust brake. but had I never felt the tweaked settings then I would have been fine and happy but once I felt how it would almost skid the rear tires on dry pavement at high rpms when I engaged the EB I just couldn't bring myself to enjoy the stopping power of the stock setting...

does that make sense.... Basically I spoiled myself and said if i can't have it all the way then I don't want it (as I stomped my feet and held my breath).

 

[marblecrusher]

Either Southbend or Valair is the way to go, if your modding as well as towing more than 10,000 pounds regularly I would go DD. As far as a DD messing up a transmission eh i dont really buy it, especially the NV4500 Ive personally rebuilt a NV4500 in one of our bone stock 01 3500's rebuilt it once because of a 5th gear nut issue, and again at 130k because of a broken mainshaft. I know people running DD in there NV5600, NV 5600, and G56 trannys and thrashing on them pretty hard with little problems.

-Jordan-

 

[snicklas]

I can attest to the power and the clutch.

I had the Nanny Goat for a trip to Ky. I had my ~5500lb TT in tow, along with the topper on the Nanny Goat. The day we were headed out, I needed to run an errand, and the truck/trailer was blocking the drive, so I decided to just take the truck/trailer. I got about 2 miles down the road, a light was red, I pushed in the clutch to downshift, I did, and it would not go into 4th, or back into 5th, or any other gear for that matter. I had been holding in the clutch this entire time. I was down to about 25-30 and let out on the clutch and I could feel it lug along.... I was stuck in 5th gear...... I had the thought to go around the country block and limp back home. But before I got to the turn, a light had changed... I had to stop. I dove for the shoulder before I stopped.... I knew I did not want to stay there.... so I decided... what the heck, lets give it a try.... I was able to slip and then drive through the clutch until I got it rolling..... I was able to get it to a parking lot, and went an got my truck and picked up the trailer and had the truck drug in. So I had the power, and the clutch slip to get ~9,000 lbs moving. Plus, that was the same clutch that was in the Nanny Goat when it was sold..... I did not destroy it doing this.......

 

[GRU]

ive heard of the mainshaft on the 4500s to be a potential weak link. also most DD clutches require an upgraded main shaft correct? this is all leaning towards a $1000+ clutch and that completely out of my budget. hell putting a clutch in really wasnt in the budget at all quite frankly. from what ive been seeing companies do offer single disc models that are rated in the neighborhood of where i might get to "someday" powerwise. and can be had for $500 or less. valair, luk, and southbend all have clutches in this power rating. southbend being $950!! valair at $500 and luk at $400. so its between luk and valair. valair has been highly recommended, no one seems to mention the luk brand.

 

[GRU]

as far as mods go i really dont expect to ever be over 350hp at the crank.

 

[marblecrusher]

yes the mainshaft does need to be upgraded, your looking at $2000+ for the DD and the mainshaft upgrade. I would go with the kevlar/ceramic single disc from valair but i would get the kit that upgrades you to a 13" flywheel i believe that kit is around $700.

-Jordan-

 

[argve]

I do believe that SBC is a modified LUK - the fingers on the pressure plate have been modded to add additional clamping force... but don't quote me on that I just know that is what they do with the ones for the IDI's years ago... I assume it's still the same. Because Geo purchased one years ago for his truck and it came in a LUK box. And I know when I called LUK they told me that is what SBC was doing- but either way the CON OE I had in the Nanny Goat held up fairly good to the power I was tossing thru it.

 

[GRU]

i got the luk pro gold on recommendation from my mechanic friend. however the buddy that helped me put it in aid he turned the same clutch into shredded wheat just with fuel pump mods. so... only time will tell. i guess i cant go crazy with it for quite a while.

 

[chvycmnslvr68]

It dont matter what kind of clutch you put in ... if you pull extreme power and getting rough with it it can be torn out ... as far as the DD causing the tranny failure ... I dont believe it ... I believe that the reason they had the DD in the first place is cause they were to rough on things and the clutch was the weak point .. once upgraded the tranny was next ... simple deduction ... I am pulling around 300 HP and still running the original clutch from the 93 dodge with 400k on it ... I have never had a slippage problem and I can feel my rear tires slipping at around 55-60mph in 5th gear ... not breaking loose but slipping just a bit .. I am just running the GETRAG trans and that is the weak link in my Chevy .. but I am very careful not to pull too hard in 5th gear for long periods ... a short hill i willl just roll over it but a longer grade with a trailer I will drop to 4th early and save the tranny ... Its all just a matter of common sense .. You could always go with a 613 Fuller trans and then you willl have rear end problems .. when you start pumping up the horses you have to know how to drive them ... COMMON SENSE .. not so common really ...