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R33 Jerk/hesitation At Low Speeds In Low Gears. Which Mounts?

StringyWeevil

By StringyWeevil,
in General Maintenance

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StringyWeevil Contributor

StringyWeevil

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Hi there. My r33 jerks when its in low gear and applying light throttle (around carparks and such) its not an engine problem Its more of a delay when I put my foot on the accelerator and let off and then jerks back and forth a bit if im not super smooth when pressing my foot down. I'm quite sure it's mounts however they all look fine and I was wondering if someone knew which mounts it might be? Engine, transmission or diff? It is a manual by the way, and no matter how smoothly you change gears, when you release the clutch it often clunks a bit, just feels very sloppy so im quite sure its a mounting bush that's stuffed somewhere. Have no Idea which one though. If anyone else has any info that would be great!

StringyWeevil Contributor

StringyWeevil

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I'm very used to clutch and its in good condition as far as I know. Not sure what diff backlash is but it's not a metallic sound, more of a thump or thud if that makes sense, when reversing out of the driveway slowly as I push the clutch in to disengage I can feel movement in the gear stick and there is a slight thud. Like I said I don't think it's an engine problem because revs don't change its just the feeling of the car. You know when you first learn manual and do a few kangaroo jumps? It's a similar feeling to that although it does it when it shouldnt. And under reasonably hard acceleration if I go over a little rut in the road the car jerks quite a bit and feels terrible when the rear wheels go over it.

DVS JEZ Grand Master

DVS JEZ

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Try to visually inspect engine and gearbox mounts.

Diff backlash is the freeplay between the gears in the diff. If there is too much freeplay (backlash) there will be clunking etc

AngryRB Grand Master

AngryRB

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what about a vacumn leak?

mines had a leak and i think thats what caused it to be jerky on low revs, when your driving and put the clutch in to change gear the revs will fall fast instead of steadily and that contributes to the next gear going in with a clunk

also a bit of clutch shudder can cause some symptoms when reversing slowing.

StringyWeevil Contributor

StringyWeevil

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I'll have a closer look at the mounts tonight, was just wondering if anyone else was experiencing the same problems who has fixed it before. I don't think it is backlash as like I said its not a harsh metal clunk. The jerking happens when in gear, clutch pedal fully released so it's not to do with the revs dropping but good idea anyway.

StringyWeevil Contributor

StringyWeevil

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Ok i have had a closer look and Im pretty sure you are right about backlash. All the bushes look mint, nothing wrong with them, but with the car jacked up and in nuetral there is a fair bit of play when i turn the driveshaft before the wheels engage. Does anyone know how to fix this? Will shimming the diff solve the problem or am I up for a new diff? Thanks guys

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