Clutch Failure???

[ricexr50]

Hi All! Had an issue with my EB resto mod. Has NP435 trans with 205 transfer case, & 351W. Was driving over the weekend and went to shift from 2nd to 3rd and wouldn't come out of gear (was at a higher RPM than just normal driving, but nothing crazy). I was able to pop it out of gear and then it wouldn't go back in any gear. Managed to start it in gear to get home and parked. Any idea of what might have broke before I pull the trans? Is it possible clutch fork came off throw out bearing? I tried re-adjsuting clutch a few different ways, but not helping. BTW...when engine is off, I can shift into all the gears. Any troubleshooting tips welcome! Thx!

 

[EPB72]

Possible the clutch fork pivot bolts broke ,,when you went to adjust clutch was there tons of free play?? any idea how old /milage there is on the current one,,

you can pull off the rubber boot at the fork and see if theres any thing obvious with a flash light...would suspect linkage,release bearing and/or pressure plate issue,,,

 

[Digger556]

Does the clutch pedal feel normal and return all the way when pressure is removed? If so, your pilot bearing may have seized.

If the clutch does not feel normal, have someone step on the clutch while you observe the linkage, fork and bearing. If it failed suddenly, odds are good the problem will be easy to spot.

 

[DirtDonk]

The most common failure points in a Bronco's clutch linkage are the pedal-to-frame rod (the one that runs through the floor) and the release fork pivot bracket (inside the bell housing).
But those are not the only possibilities as has been said. Any of the 8 or more parts in the linkage interface could have failed. A frame mount bracket for the "Z-bar" or the engine side bracket, or the z-bar itself, or the release bearing (throwout), fork pivot, or even the clutch cover itself. Lots of stuff there to go bad.

So to start with, physically check the linkage from top to bottom to see what's doing what and what isn't. Don't pull the transmission until you've at least checked that stuff.
Was the 351 out of a newer vehicle by any chance? If so it would not have come with the mounting hole for the engine-side bracket of the clutch linkage. The installer may have just bolted things up and left that un-retained, or used one of these style brackets: https://www.wildhorses4x4.com/product/EFI_Clutch_Equalizer_Conversion_Bracket/Early_Bronco_Clutch to make it work. That bracket might have come loose or broken.

Here are other affiliated parts: https://www.wildhorses4x4.com/category/Early_Bronco_Clutch including new beefier rods and bushings and cantilever/Z-bar parts and such.
Last on the page, part #8248 is the clutch fork pivot that often breaks. I've personally broken two of them, and replaced several more for others over the years. Also broke my stock clutch pedal rod and had to drive to work doing what you did. Start in gear, shift without a clutch, turn the key off at lights, use starter to get rolling. All fun stuff for a normal day at work in a Bronco!

Good luck. Hopefully it's the external linkage and not something inside.

Paul

 

[ricexr50]

Thanks for all the tips. Linkage seems fine from pedal all the way to clutch fork (Already broke and replaced the rod through the floor before!). Clutch fork doesn't seem to have any unusual free play and pedal feels normal and releases back like usual. Will get under tonight with flashlight to see if I can see anything further from clutch fork opening.

 

[Rustytruck]

I one had a broken clutch disc spring break off pieces and wedge between the clutch disc and the pressure plate. pushing the clutch did nothing to release the grab drove 5 miles working the lights and stop signs. could have gotten several tickets during the drive.

 

[phred]

Some of the clutch plates have bonded pucks on the p-plate side. I’ve had them break off and jam the disc against the p-plate.

 

[langester]

I had a diaphragm style clutch break off a finger of the diaphragm that wedged in and prevented it from working. Had to start it in gear and speed shift to get it home. I look forward to seeing what the issue is on yours, good luck with it!