Spin driveshaft by hand to test clutch disengaging

[ddavisart]

Hey guys, instead of lifting the rearend up/spinning the rear tires in the air to check that a clutch is disengaging when the clutch pedal is pressed in......Is it possible to do the same with just turning the driveshaft by hand? Would a twin disc have too much friction you think to turn a driveshaft by hand to tell if it is disengaging? I was thinking it should, but I cannot spin the driveshaft by hand and get it to turn in 1st with the clutch pressed in.

[andrewb70]

Hey guys, instead of lifting the rearend up/spinning the rear tires in the air to check that a clutch is disengaging when the clutch pedal is pressed in......Is it possible to do the same with just turning the driveshaft by hand? Would a twin disc have too much friction you think to turn a driveshaft by hand to tell if it is disengaging? I was thinking it should, but I cannot spin the driveshaft by hand and get it to turn in 1st with the clutch pressed in.

This is good way to test if the clutch is disengaging, but it should be done in 4th gear (direct drive). Repeat this test again in 4th gear and have someone else press down on the clutch slowly. You want to find the point where you can turn the driveshaft by hand and still have a couple of inches before the pedal bottoms out.

Andrew

[ddavisart]

Thanks Andrew, It wouldn't spin in 4th, but i could get it to spin in 6th by hand in its highest gear which is promising. It is a t56 magnum

[andrewb70]

Thanks Andrew, It wouldn't spin in 4th, but i could get it to spin in 6th by hand in its highest gear which is promising. It is a t56 magnum

Was the clutch pedal fully on the floor when you could spin it!

[ddavisart]

It still had a good ways to go before it went that far. I still need to make a pedal stop and it has a tilton hydraulic tob that i didnt want the piston to push the seal out on, so was being careful. I had the wife pushing it slowly in the car with me underneath checking the driveshaft.

[andrewb70]

What's odd is that you were not able to spin it by hand in 4th hear. This tends to be the easiest gear because the input and output shaft are locked together and nothing is going through the gearset.

[ddavisart]

Hmm...possibly my wife didn't press it down as far in 4th as she did in 6th. I was telling her to try to use to the same strength, but 2 person job so i couldn't really verify. Once it started to spin i had her ease up a little and it would stop. Seemed like it was grabbing and releasing in 6th as expected. Will have to maybe test 4th again tomorrow. Do you always set your pedal stop in 4th? I was able to verify the clutch fingers moving when the pedal is being pressed through the hole in the side of the trans that the fluid line runs out of.

[andrewb70]

Hmm...possibly my wife didn't press it down as far in 4th as she did in 6th. I was telling her to try to use to the same strength, but 2 person job so i couldn't really verify. Once it started to spin i had her ease up a little and it would stop. Seemed like it was grabbing and releasing in 6th as expected. Will have to maybe test 4th again tomorrow. Do you always set your pedal stop in 4th? I was able to verify the clutch fingers moving when the pedal is being pressed through the hole in the side of the trans that the fluid line runs out of.

Forth gear is generally used because it is the easiest to spin. I am actually about to install the Tilton 6000 series bearing in my GTO, but I am have a Richmond 6 speed. When you install the pedal stop, just make sure there is enough adjustment there so you can fine tune it when the car is running. The general rule of thumb with organic friction disks is that you want .090 clearance between the flywheel and disk. I am not sure if this would be different for a dual disk clutch. You obviously have no way of measuring this. The way I have done it in the past is by sound. When the driveshaft first starts to turn, you will hear the disk and flywheel dragging against each other. As you press the pedal more, you dragging sound should disappear, and that's your approximate point where you have a clean release.

Andrew

[ddavisart]

I like the dedicated bleed line on the tilton unlike some of the oem ones. Looks like it should hold up and nice quality. Thanks for the tips

[andrewb70]

You're welcome. The Tilton bearing will be an improvement to the one I am using now.