Car bucks violently back and forth

[rjpbboi]

Hello,
My car has been bucking violently back and forth after I let off the gas. The car only bucks when I am only lightly on the gas or off it completely and it does not do it in all gears, although I forget which it does it in. The problem also goes away when I get back on the gas, but I believe this may be do to the force generated by the drivetrain outweighing the force exhibited by the problem itself and may not be a true remedy for the problem; although it would indicated that the problem does not exponentiate at increasing engine speeds. It is not a lugging problem as the car is at sufficient rpm for the gear (around 1800 in 3rd while slowing down). I've also ruled out any motor problem as the problem disappears when I put the clutch down or otherwise shift into neutral. I replaced the u joints about a year ago, but I don't suspect the driveshaft has anything to do with this as the problem does not get worse as I increase engine speed. My original guess is the transmission mount, and I have yet to check this. I'm just wondering if anyone else has any ideas as to what it might be so I can check a few things while I have the car in the air. Thanks again.

 

[foxbodymike87]

In my car if you get low in first gear it bucks to the point the tires screech.

 

[RangerJoe]

I was chasing a similar problem a few months ago. It started at the first sign of really cold weather. I was running 15-16 degrees of timing and someone recommended that I lower it down. I lowered it to 12 degrees and it seems to have taken care of the problem. Something to consider maybe. Good luck with it.

Joe

 

[rjpbboi]

Yeah, that timing issue might be it. I didn't think of that. I'm not positive what my current timing is, but I know I move it all over the place. I'll let you know. Thanks again.