Engine/Transmission (1998.5 - 2002) South bend 13" HD clutch experiences

[KY Diesel]

Hello TDR, I have searched and read many threads but cannot find what I'm looking for. I believe it's time for a new clutch for my 2001 NV4500 CTD. My stock clutch is starting to slip horribly in 4th and 5th with my edge drag comp set on anything greater than 3x5.

My truck is my daily driver and never tows or pulls anything, but I do drive it very spiritedly when I'm on the highway at times. I would really like the freedom to hammer down in 4th and 5th without worrying about clutch slip.

Ive called and briefly talked with Peter at SBC who suggested the 13" OK-HD (rated at 425hp) for my needs. For those of you who have ran this clutch, did you experience any slipping with moderate power adding mods? Would it be wise to consider the OFE instead?

Current performance mods:
Edge drag comp
Adjustable wastegate elbow
Vulcan big line kit
GDP fuel boss
1st gen style intake with AFE BHAF (relocated battery)
4" dp back to a stock 3" tailpipe (no muffler or res)

Future plans:
RV275s
60mm compressor upgrade on the hx35

Thanks for any input!

 

[Joseph Donnelly]

The OK HD will be somewhat smoother and should hold if you break it in gradually--don't roast it and glaze the partial surfaces that are worn in and gripping the pressure plate and flywheel. The OFe is an excellent clutch for higher power levels, but with a heavier feramic plate it isn't intended for speed shifting--too much weight for the synchros to act in a flash. For that matter, the HD organic facing is a bit heavier than the standard organic facing (it is wider) so keep in mind the NV4500 is a truck transmission, not a Muncie crash box. Every clutch is a compromise and both of these are top quality units.

 

[HHhuntitall]

IT's been my experience, South Bend clutches tend to hold up very well. Looking at your mods, I'd think the OK would be a good clutch for you. I've run it in several of the trucks I've owned, installed a few for customers, and only had one give up, and that was my fault, after putting about 48-50psi boost into the engine, the clutch couldn't hold it. But I knew that and kept ahead, so that's not the clutch's fault. I've been using South Bend for 15 years, and only had one problem with a disk out of the box, but that was overnighted and fixed ASAP. I really only like using South Bend clutches, as I know I can trust their product and they'll support me however they can. Great company to deal with. (hmmmmm, sounds like an infomercial, but I really like their product!) If you're going to be adding any more power, you might consider the OFE. I'd also suggest the OFE-K, with flywheel, as their support bearing design is far superior to the factory needle bearing setup they come with.

 

[KY Diesel]

Thanks for the input gentlemen. I plan on placing my order tomorrow, and installation will be during my vacation in a few weeks.

 

[Regcabguy]

Great clutch! Mine holds Smarty #7 with 285's and a 2000# camper on my back without slippage in 5th.

 

[NIsaacs]

We installed an OKHD in my brothers '96 F-450 Rollback truck with a modified 7.3, it did fine until he went all out and added 50 hp. injectors, bigger turbo and tossed the small chip in favor of some custom tuner and when he hit the propane it smoked it. Not the clutch's fault at all. So we installed an SBC twin disk, so far so good.

Nick

 

[KATOOM]

I have this clutch and it holds my EZ and RV275's fine while towing a 14-15k 5th wheel. Very nice engagement too.