On/off gas surge/jerking feel

[Cubieman]

I have noticed this more and more lately and it's getting annoying. When I get on the gas (especially 3rd, 4.10 gears) or when I let off the gas the car jerks/bucks. It doesn't make any kind of noise or clunk, simply a jerky feel when on/off pedal.

This feeling not exclusive to me getting on the gas hard and letting off, this also happens during regular city style driving. The faster I go and more quickly I let on/off pedal simply makes the feeling more pronounced.

When vehicle is neutral (6MT) I can rotate the driveshaft by hand maybe 1/10th-1/12th of a full rotation. When vehicle is in gear I can barely move the driveshaft, maybe 1/4" back/forth max.

The CV joint at the end of the driveshaft is solid and doesn't move independently of the driveshaft and CSB is in good order.

When vehicle is in neutral with rear wheels off the ground I can move each wheel about 3/4" in either direction before before driveshaft begins to turn. I understand the diff. must have some lash but this may be excessive.

The diff. was rebuilt by the PO at MNC Performance with 4.10 gearing, this was about 15K back.

I wonder if the diff. has to much play and IF that is indeed the case if that would warrant a full diff. rebuild. I can't imagine that would be a DIY deal, at least for me at this point.

All bushes are OEM. I understand there is a number of reasons for the clunk etc. and many have been covered but my main concern is diff. slop as that could be a pricy endeavor that is not a DIY.

I very recently changed the rear diff. mounts and guibo, both of which were in need of changing. This took care of some of the "Clunk" I have always had but made this "driveline surge" more pronounced.

[Good]

You didn’t replace the front diff bushing? Only the rear?

[Cubieman]

You didn’t replace the front diff bushing? Only the rear?

Correct, plan on dropping subframe this fall for new bushings and front diff. bushing. The rears are low hanging fruit, easy, the front not so much.

[Cubieman]

I read a while back that someone on here supposedly had their front diff. bushing replaced with the diff. installed, I do not see how that is possible at all.

I plan on changing the front diff. bushing when I drop the entire rear end for a topside reinforcement but if somehow just maybe it could be done in situ I would be all over it. Just seems as though that would be impossible.

[ATB88]

The front can be done with the subframe still in the car, diff dropped. It's a giant PITFA though.. getting the old one out took me through the 7 stages of grief, and getting the new one in wasn't much better. As with any job, the exact right tool might have made it dramatically easier but I didn't have it, nor do I know exactly what it is.

[sapote]

I have noticed this more and more lately and it's getting annoying. When I get on the gas (especially 3rd, 4.10 gears) or when I let off the gas the car jerks/bucks. It doesn't make any kind of noise or clunk, simply a jerky feel when on/off pedal.
ed.[/B]

Hard to tell from your description it’s due to backlash or due to engine surging/dropping too fast.

[Epsilon]

I had major jerking with an original diff (100K miles) that had so much backlash. It felt like it took a second to wind up before engaging. It's since been replaced with a slightly lesser mileage diff and new bushings. This dramatically improved the drivability but there's still a bit of jerk that is more pronounced with the sport button enabled. I don't think there's anything else to do in the backend for me but to look at the driveshaft. From research and online feedback, I'm thinking CV joint.

[sapote]

I had major jerking with an original diff (100K miles) that had so much backlash. It felt like it took a second to wind up before engaging. It's since been replaced with a slightly lesser mileage diff and new bushings. This dramatically improved the drivability but there's still a bit of jerk that is more pronounced with the sport button enabled. I don't think there's anything else to do in the backend for me but to look at the driveshaft. From research and online feedback, I'm thinking CV joint.

I wonder if this is due to r/p excessive plays or the worn LSD clutch metal teeth.