nilknarf007 Posted May 10, 2020 Share Posted May 10, 2020 I hope you guys can save me again. I recently changed the clutch in my 85 f150 with 4.9 and NP435 tranny. Replaced the clutch, flywheel, pilot bearing, throw out bearing, fork, pressure plate, and even replaced the rear main seal. The rear main seal was leaking before, and I figured my clutch chatter was either due to misuse by the PO or oil getting on the clutch. Also had a broken motor and tranny mount, so I replaced both motor mounts and the tranny mount. I took special care not to get oil on anything during re-assembly, and made sure everything was torqued to spec. No more oil leak, but still have the chatter. It only chatters in 2nd gear taking off from a dead stop. Doesn't chatter in granny or reverse. The only way to take off smoothly is to really rev the the engine and ease the clutch out way too slowly. And yes, I've been driving a clutch vehicle for 40 years. Any ideas or suggestions? Link to comment Share on other sites More sharing options...
old55pete Posted May 10, 2020 Share Posted May 10, 2020 Did you have the flywheel resurfaced? If not that will cause a chatter and make the clutch grab and slip as well. Did you check the trans input shaft and bearing for wear as well? These will also cause a chatter. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 10, 2020 Share Posted May 10, 2020 Welcome back Rob! Maybe it's just the torque springs in the pressure plate? I know it's new, but if the clutch transmits enough torque to get the truck moving then the springs will rebound. If you're just easing into it like that, it happens over and over. Link to comment Share on other sites More sharing options...
nilknarf007 Posted May 10, 2020 Author Share Posted May 10, 2020 Did you have the flywheel resurfaced? If not that will cause a chatter and make the clutch grab and slip as well. Did you check the trans input shaft and bearing for wear as well? These will also cause a chatter. I put a new flywheel in. I had about 3-4 thousandths of play in the input shaft, but I've seen worse without any ill effect. I really don't want to take out that transmission again unless I'm going to have it rebuilt. That was a pain! I replaced the clutch in by brother's E-150, same engine, same trans, about 35 years ago. I did that without a transmission jack without any trouble. Then again, I was 18. Link to comment Share on other sites More sharing options...
nilknarf007 Posted May 10, 2020 Author Share Posted May 10, 2020 Welcome back Rob! Maybe it's just the torque springs in the pressure plate? I know it's new, but if the clutch transmits enough torque to get the truck moving then the springs will rebound. If you're just easing into it like that, it happens over and over. Jim, is there a way to solve this? Will it work itself out over time? Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 10, 2020 Share Posted May 10, 2020 Jim, is there a way to solve this? Will it work itself out over time? Oh so many memories! Thinking "if I don't get this off my chest I'm taking my last breath under here" Clutches can be grabby until the friction beds in to the new flywheel and pressure plate. How many miles do you have on it now? Link to comment Share on other sites More sharing options...
nilknarf007 Posted May 10, 2020 Author Share Posted May 10, 2020 Oh so many memories! Thinking "if I don't get this off my chest I'm taking my last breath under here" Clutches can be grabby until the friction beds in to the new flywheel and pressure plate. How many miles do you have on it now? About 600 miles on the new clutch, but 500 of that was interstate. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 10, 2020 Share Posted May 10, 2020 About 600 miles on the new clutch, but 500 of that was interstate. I'd say keep driving it. I find it might take a few days for a clutch to settle in (in my truck, the way I drive) But I think within 300 miles of stop and go it is going to be as good as it gets. Oh, and try not to let it chatter too much. You'll end up spotting the plate and flywheel. Link to comment Share on other sites More sharing options...
Gearhead Posted May 12, 2020 Share Posted May 12, 2020 Newbie here. I have 35 years as a Ford tech. I've seen engine performace issues mimic clutch chatter. Don't know what your running so here's a couple highlights. Worn cam, sounds strange but saw it with my own eyes. Bad air induction tube between mass air and tb, wire shorts, bad tfi module. In my experience I've never seen a clutch chatter only in one gear. I've have seen other problems mimic it and be gear sensitive. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 12, 2020 Share Posted May 12, 2020 Newbie here. I have 35 years as a Ford tech. I've seen engine performace issues mimic clutch chatter. Don't know what your running so here's a couple highlights. Worn cam, sounds strange but saw it with my own eyes. Bad air induction tube between mass air and tb, wire shorts, bad tfi module. In my experience I've never seen a clutch chatter only in one gear. I've have seen other problems mimic it and be gear sensitive. That's a real interesting idea. I don't often consider that posters aren't able to articulate what they're actually experiencing. I took it to mean he never used the granny gear in his NP-435 under normal conditions. With many of these gearboxes you could literally sidestep the clutch at idle in first and the truck would lurch to a walking pace. Not much chance for the clutch to shudder with deep ratios like that. Link to comment Share on other sites More sharing options...
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