Recent Resto - road noise from clutch

[Joe_68_F100]

I'm in the home stretch on a complete frame-off restoration of my 68 F100. I overhauled the 300 I6, and had the 3.03 manual rebuilt by a tranny shop while it was out of the truck. I bought a new clutch and had the flywheel resurfaced while everything was torn down. I also put in a new Mr. Gasket floor-mount shifter. I've got about 6 miles on the truck and am trying to get all the "bugs" worked out after tearing everything apart.

I'm getting a bad rattle noise from the clutch/front tranny area when I'm engine braking or coasting. It quits when I get back on the gas. It sounds like an old school bus, or a diesel dump truck. I also noticed that after I drive it a while, it will shudder when I'm easing into first (like slowly parking back in the garage) - nice and smooth when it's cold, or not driven very far. If I let the engine idle while it is parked in the driveway, it is smooth pulling back in. It will also occassionally not want to shift into first or reverse and grind a little trying to get there (seems worse after driving a while - never had it on first few shifts). Most of the time it shifts great. I will regularly get the school-bus noise though - especially if I up-shift a little early, or down shift a little late (low and high RPMs sound the worst). I also noticed a little bit of a burnt-brake smell after driving a couple miles. It also shakes pretty bad over about 45 mph. I don't know if the shake is related or not.

Any ideas?

[tac]

You said you replaced clutch and I assume you replaced pressure plate and throwout bearing also. Did you replace or verify that the pilot bearing was good?

[Joe_68_F100]

Yes - new pressure plate and throwout bearing. I also replaced the pilot bearing, pivot bearings, return springs, linkage rod, and pedal bushings.

I'm wondering if I've got the clutch linkage rod adjusted too far out - so the clutch is still depressed a little when the pedal is released. I could see that causing the clutch to slip and burn a little (also the shuddering). It would also explain why it acts different once it's warmed up since the flywheel is now hot and expanded - but I don't understand why that would cause the school bus rattle.

I've also noticed that I've got the tranny too full of oil. I did that by accident - it leaks out the weep hole on the top cover when driving. I don't know if that makes any difference - but it is making a mess!

[tac]

Clutch should be completely disengaged and there should be a little play in pedal before throwout makes contact with pressure plate. What kind of oil did you use and how did you overfill it? I would fix the things that you know are wrong before trying to diagnose it.

[sargentrs]

My 3.03 absolutely refused to go into reverse unless I was at a dead stop and if I was rolling any at all I had to hold in the clutch and e-a-s-e it into first. You may have to adjust your linkage to be right on the edge of going into first and not try reverse unless your at a complete stop.

[Joe_68_F100]

Tac - I filled it with 10W-30 motor oil before the cab was on - I just pulled the top cover and poured it in until the gear assembly was covered. I didn't notice until later that the fill port was lower than that. I just removed the fill plug and let the oil run out into a pan until it stopped - and then put the plug back in. That should have correct the level.

Sargentrs - I also noticed that it needs to be dead stopped to go into reverse - but reverse isn't synchronized on this tranny, right?

Thanks for the responses.

[tac]

Well, using correct gear oil around 90W will fix a lot of these symptoms. For sure this will stop it from throwing oil out of the vent, smoother shifting, and less noise. Start with changing the oil and see what is left.

[sargentrs]

Tac - I filled it with 10W-30 motor oil before the cab was on - I just pulled the top cover and poured it in until the gear assembly was covered. I didn't notice until later that the fill port was lower than that. I just removed the fill plug and let the oil run out into a pan until it stopped - and then put the plug back in. That should have correct the level.

Sargentrs - I also noticed that it needs to be dead stopped to go into reverse - but reverse isn't synchronized on this tranny, right?

Thanks for the responses.

That is correct. Reverse is not synched.

[Joe_68_F100]

I changed the trans oil this weekend, put 90W gear lube in, and filled it to the correct level. This did help make the truck run quieter - but I've still got the rattle. I sounds like the thowout bearing rattling in and out. It happens at low rpm's - like if I up shift a little too soon, or high rpms - like if I down shifted too soon or am flooring it up a hill. I isn't a high frequency rattle - like the throwout bearing is bad, but like it's bouncing between the pivot arm and the clutch.

The clutch kit came with an anti-rattle clip. I'm wondering if I don't have this installed correctly. I've never owned or driven one of these trucks in original working order either. Is this just the way they sound? I wouldn't think so.

Thanks

[sargentrs]

Will the rattle stop if you push the clutch pedal in a tiny bit? How's your free play?

[tac]

Yes, there is a clip that holds the throwout bearing to the clutch fork. That would probably make the noise if it is not clipped to the fork.

[Joe_68_F100]

Will the rattle stop if you push the clutch pedal in a tiny bit? How's your free play?

Thanks for the suggestion - I will try pushing the clutch in a little see if it stops.

Free play in the clutch seems good to me - but I don't have a good point of reference! I've never driven an older truck like this in decent shape. My closest comparison is an old junkyard dog on grandpa's farm - that clutch had what seemed like 500 ft of stroke and 1/8" of action! My truck is worlds better than that! The free play could be off, and I'd never know it.

I did put the anti-rattle clip in and it seemed to be snug at the time - but I had taken it apart a couple of years before - and I put it back together a couple of years ago now. This has been a long-term effort!

It's a thrill to finally get to drive it around though - even with the leaks and rattles!

[sargentrs]

If a tiny bit of pedal pressure makes it go away, you still have around 1-1 1/2" of free play, back off on your clutch adjusting rod a little and see if that does it. You don't want to back off too much so your clutch stays engaged all the time.

[Joe_68_F100]

I got it out again yesterday evening - and it got better if a pressed the clutch slightly.

Oddly enough - when I did it a few times to make sure I wasn't making it up - it got better all the time. I drove for another 15-20 minutes and didn't notice it at all. If it comes back, I'll adjust the clutch linkage!

Thanks