Clutch problem?
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Clutch problem?
Hey guys this is my first post so bare with me. I have a 1974 F250, FE engine, np435, np205 t-case and Dana axles. My problem is that I have replaced the clutch to spec and manual guide but when I am driving the truck it seems to "slip" but when I tested the clutch for slippage the truck passed the tests. Did the chock test to see if the engine died or kept going, downshift test and so forth and they all seemed to pass. So what I am trying to figure out is if the clutch doesn't seem to actually slip then what would be my problem for rpm to increase but speed to not? Any help would be awesome. Thanks guys.
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From: Taxachusetts
Where's the clutch grabbing at - off the floor or at high pedal? Adjustment could be off a bit. I think 1.5" - 2.0" of pedal free play is standard.
Where it grabs is up to individual taste but the standard is as stated.
Where it grabs is up to individual taste but the standard is as stated.
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The clutch starts to grab pretty close to the floor and as far as free play it fell into the range like you said. I took the inspection plate off the bottom to just make sure the throwout bearing wasn't contacting the fingers with the clutch out and it wasn't riding it at all.
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From: Taxachusetts
Ok..grabbing close to the floor is where I prefer....but that's just me. I adjust the clutch by feeling pressure on the throw out arm, and fine tune from there.
When you get a chance, take her in first (well, second as it were) to about 2200 RPMs then back off the go fast pedal...let her wind down for a bit, then punch it - not too much - don't want to disturb citizens, hehe.
Take note of what happens...not so much the RPMs but the ***** to the wall test. Peek at the RPM gauge and make a mental note of what she sounds like at that RPM. Shift as normal after that. Try it again in second (3rd) this time....same thing as before...note what happens and get back to us with your test results, yes?
When you get a chance, take her in first (well, second as it were) to about 2200 RPMs then back off the go fast pedal...let her wind down for a bit, then punch it - not too much - don't want to disturb citizens, hehe.
Take note of what happens...not so much the RPMs but the ***** to the wall test. Peek at the RPM gauge and make a mental note of what she sounds like at that RPM. Shift as normal after that. Try it again in second (3rd) this time....same thing as before...note what happens and get back to us with your test results, yes?
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From: Taxachusetts
Fair enough.
What's yer gear ratio in the differentials? If you have 4.56s, humongous 48" sneakers and a 12" lift, she won't get out her own way. These vehicles are work trucks un-modified, and don't have the poop as a Pinto with a 289 in her, y'know.....
What's yer gear ratio in the differentials? If you have 4.56s, humongous 48" sneakers and a 12" lift, she won't get out her own way. These vehicles are work trucks un-modified, and don't have the poop as a Pinto with a 289 in her, y'know.....
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The truck has 4.10s, 36 inch boots but no lift. Factory ride height and I checked out the gear ratio to make sure too and marked the tire and driveshaft and spun it and it checked out. The truck is mostly a work truck for me anyway pulling trailers or hauling some wood or what not so I'm not expecting it to scoot around like a go kart. The only thing is doing say 35 in 4th it was churning 2100 rpm or so
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Postmaster
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From: Taxachusetts
Yeuup, that 's off....at that speed and your setup you should be turning ~ 1340 RPMs.
Generally, ~ 2500 RPMs equates to 65 MPH.
So she feels like she's slipping....when you put her back together did you grease the pilot berrin? Not too much, yes? Mebbe there's some residual grease on the clutch surface...? Can you smell anything when clutch is engaged and you're on it for a bit?
Mebbe try adjusting the clutch again such that there's less free play.....?
Generally, ~ 2500 RPMs equates to 65 MPH.
So she feels like she's slipping....when you put her back together did you grease the pilot berrin? Not too much, yes? Mebbe there's some residual grease on the clutch surface...? Can you smell anything when clutch is engaged and you're on it for a bit?
Mebbe try adjusting the clutch again such that there's less free play.....?
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Replaced the bearing, bushing, and greased it with a finger dap or two. I don't smell any burning or anything at all even brought in a few other noses and they didn't even smell anything. As far as adjusting it would that make that big of a difference if when the pedal is up the pilot bearing isn't even touching the clutch fingers? And it's not grinding or anything going into gear so that's why I thought the adjustment was where it needed to be.
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Sorry I meant throwout bearing
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Did you replace the clutch with quality parts? I ran into the same issue with a jeep xj. Everything looked correct , went together fine but did not perform as expected. Lesson learned took it apart the second time and replaced with better parts and all ok
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From: Taxachusetts
At what point on the pedal travel do you feel some resistance to clutch engagement...as in when do you feel some pressure? Half way down, an inch or two off the floor, at the top, etc...?