So I bought this truck a few months ago. The seller told me that the transmission had been removed to "get new bearings installed" and the clutch was also replaced at that time. He said it was a new South Bend clutch. Seemed to drive ok. I've made several 600+ mile round-trip trips since I've owned it without issue. I never did like the way the clutch felt, but I'm also used to driving a much older truck with mechanical linkage. Feels like the clutch releases closer to the end of the pedal travel, and grabs pretty quick when letting up on the pedal. Fluid level is good. But never had any trouble getting into any gears, upshifting or downshifting. Anyways, this past weekend, I hooked up my 16-ft box trailer and loaded it up with household stuff. The load was heavy, I don't know how heavy, but it certainly wasn't anything more than what I've pulled with other similar trucks. Going uphill, it would slip and I would have to drop down to 5th real quick to finish the hill. Then on the long hill, slipped in 6th, dropped down to 5th, then ended up having to go all the way down to 3rd because of the loss of momentum. Embarrassing. My guess is that it's got a cheap and/or light duty clutch where I should have a heavy duty clutch. Am I missing something? Anything else I should check before committing to a new clutch? Who makes a good clutch? 99 F-250 4X4 SD / 7.3 / ZF-6. (I sure do miss my 72 F-350 with the 390 and NP-435 granny low 4-spd. She would've pulled it - no problem!)

 

Is it definitely the clutch slipping? Did you smell burning clutch?

 

No, I didn't smell burning clutch. I hit the pedal and downshifted as soon as I felt it. What else could it be?

 

The engine RPM's would suddenly increase while the truck did nothing while going up the hill. Like I said, as soon as it happened, I downshifted. Drove the truck to town today, unloaded. Seems to work just fine. I even slammed the accelerator down while going up a hill in 6th to see if it would shutter or slip. Nothing.