Shudder taking off from a stop

[MacVette86]

I have an 86 with the 4+3 tranny. Sometimes when I take off fronm a stop in first gear the car will shudder a bit. If I rev it up a bit and slip the clutch a little it will take off smoothly. I have no problems shifting gears, it goes into reverse butter smooth and the clutch isn't slipping.

Is this common for this year vette? Or is my technique off?

 

[Hib Halverson]

Does this shudder occur as you are releasing the clutch or does it happen after the clutch is locked-up?

 

[MacVette86]

It occurs as I'm releasing the clutch.

 

[nyernga]

It could be either your technique or a slipping clutch. I can make mine shudder if I don't give it enough even throttle. Find a flat level area and with no throttle, slowly let the clutch up. The clutch should engage smoothly. If it does, then I'd say it's your foot...


Len

 

[Patrick]

MacVette,
Because you're inquiring about an '86, I'm going to move this thread to the C4 Technical and Performance forum.


-Patrick

 

[MacVette86]

So you're saying the car should take off in first gear with no throttle being applied? I know these cars are light and have a lot of torque, but that doesn't seem realisitc?

 

[G Winter]

My 90 with the 6 speed will take of nicely at an idle.

 

[nyernga]

So you're saying the car should take off in first gear with no throttle being applied? I know these cars are light and have a lot of torque, but that doesn't seem realisitc?

C-4's are full of suprises and yes.....it WILL go forward. You just have to let up very slowly on the clutch

 

[Ken]

Hey Len, I can't make mine shudder - ever. It'll either stall or go like hell! :L

One of the reasons that the car moves so easily has to do with the computer and emissions equipment. Ever notice how if you depress the clutch while you're moving, at any speed, and the rpms don't drop? The revs will stay increased until the sensors detect slowing and a complete stop.

That's also a reason there's a irksome quality some automatic transmissions have; you know, when you almost come to a stop at a red light and it changes before you stop completely, and when you hit the gas again the revs and the speed doesn't always synch with low gear, and it seems as though you've put your foot in it like you're trying to beat other traffic. :L

 

[nyernga]

Hey Len, I can't make mine shudder - ever. It'll either stall or go like hell! :L

Well we ARE talking stock here Ken. And your vette is anything but stock.

Len

 

[MacVette86]

As usual, everyone is correct I tries to take off on a flat area without applying any gas and sure enough, it took off effortlessly. This thing is a torque monster!! Anyway, I guess that means the clutch is good and I need to work on my technique):

 

[G Winter]

3000 RPM , pull your left foot back quickly then allow the right foot to find the floor.

 

[MacVette86]

Yes, I mistakenly tried the 3000 RPM launch. After getting sideways and leaving a lot of smoke and noise, I was off and running The neighbours were not impressed. I drove the car quite a bit today and I'm getting much better at launching it. Thing is, I learned on a standard, have driven trucks, cars, three in the tree, four speed, five speed, etc, etc. I had a standard 2000 Mustang GT for three years until I bought my RAM Quad Cab Hemi last year. The thing is, this Corvette is the trickiest standard I've driven to date. Doesn't seem to like finese, it just wants clutch and lost of gas

 

[Achilles]

Mac, I had the same problem with my 86 and was told the throw out bearing was going bad preventing the clutch disk from meeting the flywheel evenly.

I was also told that because the car hadn't been driven in awhile before I bought it, that there was rust or crud build up on the flywheel.:confused

I had a new clutch and preasure plate installed and flywheel resurfaced. Works great now. They didn't bleed the slave correctly and I had to do it myself. But that's another story and another thread.

 

[wwood]

I agree with the reply above. In my experience the problem is most probably with either the pressure plate and/or the throw out bearing.

 

[MacVette86]

I got my Helm's maual on CD and performed all the diagnostics/tests that were listed for the tranny/clutch. All passed with flying colors! Yet, ever once in a whi9le I still get the shudder. So I just finished dropping it off at a reputable drive train shop and asked them to inspect everything. We'll just have to wait and see.