The Stovebolt Site Forums The Shop Area Driveline double clutch question

I have a 216 with a floor shift 3 speed Trans in my late 1947 Chevy truck and since having it in the truck whenever I shift from 1st to 2nd it grinds. I get going up to speed when leaving the stop and push in the clutch the engine is at idle with the clutch in before I attempt to go into 2nd and instantly grinds. I tried adjusting the clutch but no good results. Tonight a guy told me to double clutch when going from first to second. It seems to be helping a lot. My question is why does this work and is there any type of adjustment I overlooked that I can go back and do to resolve having to double clutch all the time? Going into 3rd is no problem.

Had this problem on a 3 speed saginaw. My "syncro" for second gear went bad on a hard 1st to 2nd shift. Would act as yours does. The double clutching makes the problem go away, as that is how you shift big rigs which don't have any "syncros". Yours trans prolly needs a rebuild.

It was a used transmission I picked up off of here so I dont doubt that it could use rebuilt. I am just attempting to hang on to it as long as needed before the rebild.

Nothing wrong with double clutching. Figure out how to do it well and keep driving.
The operators manual for a Roadranger transmission explains it pretty good, its required (every time) to shift one of them.

It boils down to you matching speeds of input and output for the gear you want so it'll slip into place. Its a little more than just pushing the clutch in twice.

Grigg

Roadrangers have been driven millions of miles with no clutch action at all. The only time we used the clutch on the 10 and 13 speeds we drove was for starting and stopping. If he's having to double-clutch that 3-speed on an upshift, there's something really wrong with the 2-3 synchronizer.
Jerry

What is being done is matching RPM to the gear you are into. First to second the RPM has to drop, third to second RPM needs to go up. No clutch should be all should be necessary, but may help. As said previously the synchro is bad, no adjustment to be done, it needs to be replaced. Rebuilding a 3 speed is not that difficult.

Larry

I agree that a rebuild is in order because the entire transmission is probably well worn. However, if he has mastered double clutching, he really isn't hurting anything by driving it and he should be ok driving it until he gets around to rebuilding it.

5/8 Ton,

Once you get good with double clutching, you will be ready for the next step, which is shifting without using the clutch at all.

It is all about experience with your tranny and listing to the sound of the engine so you can match the gears. To shift up you might have to give the gas a little bump to get it out of gear, and to shift down you will want to rev the engine up once you are in neutral so as to match the speed to the lower gear.

I used to do it all time when I had a 3 speed transmission in my '51 1/2T. I had to remove the synchros because they were worn to the point where they would lock the tranny up in gear. So I got very practised at double clutching and shifting without using the clutch.

Kurt

Pull your transmission and repair it or replace it. Putting it off by double clutching or not clutching is just putting off a repair that needs done.