Hello,
Looking for clutch suggestions. Recently I performed these mods to my 1999.5 F250:
EBPV delete (with riffraff pedestal and outlet)
4" diamond eye turbo back straight pipe
Riffraff billet turbo wheel
hydra with php boxed tunes

in any tune except stock, my clutch slips around 1800-2000RPM in 4th and 5th (6-10lbs boost according to Forscan)
I have really only driven around with the 40hp dd tune as its PLENTY of power for me, even too much. I wish there was a 20hp tune lol.

I noticed getting onto the freeway, when warmed up, the clutch slips about 100-200RPM and then settles. Felt like an auto locking up in OD. If it was a 4r100 like my old truck, it would be a nice feel. But....its not.

I really like how smooth the clutch engages on this truck, but i also would like to have the confidence i can run this thing in at least the 40hdd and 40hp tow tunes with confidence when i go to use my 9,000 lb camper this summer.

Been looking at the South Bend 1944-6OK , or a LUK clutch (a brand i'm familiar with and have had nothing but good experiences in stock configurations)

Any one here running either one with beginner mods like me with good luck and smooth engagement?

I have stock turbo (except riffraff wheel)
stock injectors
35" tires
3.73 gears

Thanks in advance

-HP

 

I believe that's the SB I use, but I have more mods and tow a 13k# 5th wheel. Held fine with 60+hp tunes long before going to single shots and T4

 

I run the SB 1939OHD which is the same clutch Wes444 has and the same as you are looking at, but the kit uses the OEM flywheel after it has been resurfaced.

The clutch has been performing great for many years towing a 5th wheel cross country.

They are pricey, but sometimes you get what you pay for.

I run PHP 65 HP tune with a Borg Warner turbo 100% of the time.

 

Thanks for the info,
How's the engagement vs stock? Is it pretty drivable when unloaded?

thanks,

-HP

 

Very much so. As long as the transmission and clutch engagement are as designed. Clutch pedal should be full up position before applying the accelerator pedal. 90% of the time my truck is on the road, the 5th wheel is attached to it and the clutch engagement is smooth and confidence inspiring each time.

If you are going back in, you may want to consider some other things to change out or upgrade and save yourself the trip in the near future.

- Updated shift fork - https://www.riffraffdiesel.com/updat...f6-99-03-7-3l/
- Throw out bearing - Not sure on a source, but maybe @Wes444 is able to help based on this post.
- Pilot bearing/bushing - https://www.ford-trucks.com/forums/market/1754885

 

I've been reading about the bushings on the clutches here and there.
I would think that there is a good reason South Bend goes with the kevlar?
Has there been issues with the bearings supplied in the SBC kits?
Last time did a clutch was on a small block chevy 350 in a '75 blazer. This project is worrying me a little bit!

 

Nice, thanks to Sous' post I don't need to link my clutch thread

Like Jeff said we have the same "clutch", but different kits/part numbers. The friction disks and pressure plates are the same, but the 44 comes with their flywheel so if a resurface of the original is something you don't have time or access to get the 44 and you can bolt it up and go.

Their flywheel came with their totally junk "kevlar" (aka white plasticy splooge from a troll) bushing pressed into the flywheel so I went with the Fitzall bearing since the oilite bushings were a custom thing that no one was making when I needed mine done

PEdal engagement required a touch more effort. Their TO bearing is all metal vs the stock composite one

 

Double post

 

Regarding the SB Kevlar bushing, see the notes from our friend Wesley below. The only thing I might add is that gummy bears or frozen Jell-O would serve as a better bushing than the SB kevlar. They make great clutches though.

 

Today I was driving home, and it started slipping a little easier than yesterday. I feel like I better start ordering parts.

My beautiful wife reminded me that when i replaced my turbo pedestal(on the 1st attempt), the o-rings didn't seat properly and i spilled about 2 qts of oil down the back of the motor, and that might be why its slipping.
Have you guys heard of that happening due to oil spills?
In that case is this thing totally toasted or is there hope the oil might burn away and the clutch will start grabbing better again?

not super hopeful about that possibility...

Thanks for all your input and invaluable experiences!

-HP

 

Definitely a possibility for the ZF6 if you haven't done the drain tube mod yet

 

you think spraying some simple green down there would do anything?

 

Nope. If you really did get oil on the clutch its permanently hooped. The fibers of the friction disc are permanently impregnated with slippy goo. That could be the problem but my guess is your clutch is just worn/glazed such that it barely worked and then once you added some ponies it wasn't enough. If you did get oil on it I think you would have noticed a long time ago.
I should add, once the clutch starts slipping once, it will slip more often and more easily every time since the heat will glaze the clutch more and more each time until it's useless.

 

Fatal flaw in the valley drain design in a manual transmission truck. See links below...

• https://cimg5.ibsrv.net/gimg/www.for...c320884b35.jpg
• https://www.ford-trucks.com/forums/1...ml#post9720173

 

Well I bit the bullet and bought a South bend 1944-6OK Clutch Kit with a new flywheel.
I was looking at my up-pipes, they are not bellowed, but also not leaking. I'm really on the fence about replacing them. (did it on my last truck and lost a bit of skin off my knuckles even with the transmission out)
Definitely going to do some version of the drain-tube mod while I'm in there though.

I did a rear main seal on my last truck also, so I'm ready for that if it calls for it. local shop down the road has the motorcraft seals in stock.

Its going to be a fun weekend!