Truck shaking in 1st gear

[Bass66C10]

My 66 shakes when I start off in first gear, second and third are smooth. I already replaced the (yoke) on the drive shaft.

[Chevy Fleetside]

You probably need to have the flywheel turned.

[PGSigns]

Yup sounds like some clutch work is in your future. Surface of the flywheel is no longer flat. Best fix is to have the flywheel surfaced if it is not to badly heat cracked and to put a fresh clutch in it. Here is a like to a thread here that shows a good picture of a toasted flywheel.http://67-72chevytrucks.com/vboard/s....php?p=5906610
Jimmy

[vince1]

If you have any drips coming from that area it could also be caused by oil on the clutch.

[Bass66C10]

I know my oil pan is leaking, I have the new gasket, just have not had the time to install it yet.

[1963c-10]

Hey Bass66C10.....welcome from Fayetteville NC and to the forum. Have you dropped the inspection plate and looked at the condition of the flywheel yet? I agree with the above though, sounds like a combo of an oil leak and flywheel needing machined or replaced.

[RKS0069]

Hi. My truck would shake a lot in second gear (don't use first) turned out the issue was that the front transmission mounts were a little soft, changed them out and all is good now. Very good chance you are just having clutch issues though. Hope you getter fixed soon.

[61K10]

mine shakes a little and clutch/f/w is all new, not rebuilt. everything is rebuilt trans tf/case to rear even the rear axle. I have leaf springs as well, which are org. which probably need a rebuild. Like RK said not only the clutch will cause this.

[padresag]

centre supports also will give that sensation if you have a 2 piece d/shaft. the rubber part will be collapsing. under throttle pressure esp in the lower gears where the torque multiplies you will feel it
ron

[Fla Grown]

I have the same issue. When I first got the truck 5 years ago it had the original 250 with a 3 speed trans and always shuttered in 1st. I pulled the engine to reseal the engine and replace the piston rings. Had the flywheel turned and put a new clutch in at that time. Still shuttered. Thanksgiving of last year I bought a built 250 from Tom Langdon and installed the same flywheel and clutch. Worked smooth for about a week and then the shuttering came back. I drive it every day 70 miles round trip. If I park it for a few days and drive my H3 it wont shutter for a day but it always comes back. Sounds like I need a new flywheel and clutch as well!

I have replaced the carrier bearing and universal joints as well.

[Bass66C10]

Thanks, I am going to try and look at the flywheel this evening and see what it looks like

[c20 diesel]

Had same problem years back. new clutch turned flywheel still shake AKA clutch chatter. first & reverse. problem was motor mount & mount on bell housing bolts loose one bolt had fallen out. fix mounts problem went away.

[Mackie]

A good test for motor mount problems is to have someone rev the motor while you watch for the motor to lift or twist.
If you trust them have them try to drive ahead slightly with the e brake set while you watch.

[61K10]

I have some urethane ones sitting, might put them in and see if any difference. you have to remember my eng has a horse-shoe ft mount not side mounts. I had a 62 V8 lfb years ago and it was butter smooth while taking off. My clutch is a cheap 11" zoom, maybe if i bought a $$$ center force clutch??

[1976gmc20]

Originally Posted by Mackie

A good test for motor mount problems is to have someone rev the motor while you watch for the motor to lift or twist.
If you trust them have them try to drive ahead slightly with the e brake set while you watch.

No need for a second person. The floor gear shift will tell you

I've been alerted to motor mount problems twice now by the floor shift moving sideways in low or reverse under a heavy load.

[luvbowties]

...seen 'em do it when bell housing-to-block bolts were loose...
Sam