Gearbox/Clutch grinding noise initiated at half clutch release.

[Haywes]

I've done a lot of searching and can't seem to find anything definitive, just a few maybe's, so I was hoping someone on here might have experienced something similar or know the solution so I can get it sorted in one shot when I open it all back up again!

Recently swapped out my old CA for a new CA - fairly straight forward, nothing special, but after putting the gearbox/clutch etc all back together I now occasionally get a grinding/slipping noise. I can feel it through the pedal and gearbox. Sounds pretty grim! The car didn't do this at all before.

Only thing that makes me slightly unsure on what might be causing this noise is that it's only really initiated when lifting the clutch to engage a gear. So when the pedal reaches halfway it'll start making this grinding/slipping noise (not as heavy or metallic as grinding gears, but still fairly harsh), and will stop after a few seconds, usually quicker if I depress the clutch again. But the car still selects the gear and the clutch engages properly, and the car seems to drive fine? The grinding doesn't affect the car getting into gear at all from what I can tell, so it's not just me, or that it's out of fluid etc and that I'm grinding the gears

Things worth noting: Flywheel bolts were torques up correctly with some threadlock applied, clutch lined up properly and all went together as it should. Did check the release bearing but as my clutch kit was in great shape I didn't test it super thoroughly, so I'm aware this could be the culprit, but wanted to check if anyone had any further info/ideas so that I can replace stuff when I lug it all off of the car again. Reused my clutch, flywheel, pressure plate etc from the old engine as it all seemed in good shape.

Is this likely to be cured by replacing the release bearing and possibly the pilot bushing? I know people usually say replace the clutch while you're in there but mine's pretty new so there's no need!

Any help is much appreciated

[Haywes]

Bump - any input? Been out for a drive a few times, as said it only really seems to initiate when I put the pedal down past half way now and again, but gears still select, fairly certain it goes away once the cars in gear.

[Dastardly]

I would fit a new release bearing, they aren't expensive. You want a Nissan one really there are a few bad ones out there. It's worth fitting a new clutch fork pivot thing too as they are cheap and are known to break. You said you torqued the flywheel bolts, this might sound weird but what Nissan recommends I personally think is too tight as I've tried torquing them before and mine were going to snap before the torque wrench clicked off. Just check they haven't stretched when you've got everything apart although it sounds like they'll be alright. Did you re-use your own gearbox or is it one that came with the engine? Also did you remember to fit the plate between the engine and the gearbox?

[pointz]

I would suggest the release bearing but can't see how you would feel a worn bearing through the pedal.

Does the clutch slip at all? And what clutch do you have fitted? Did you fit the friction plate around the correct way as you have transmission side and flywheel side i believe. Correct me if im wrong!

Other than that without feeling it it's hard to say.

[skyshack]

Check you have a gearbox input shaft bush in the back of the crank.

If the "new" engine came from an auto it wouldn't have had one.

http://www.sxoc.com/vbb/showthread.p...pigot-bushing/

[Haywes]

I would fit a new release bearing, they aren't expensive. You want a Nissan one really there are a few bad ones out there. It's worth fitting a new clutch fork pivot thing too as they are cheap and are known to break. You said you torqued the flywheel bolts, this might sound weird but what Nissan recommends I personally think is too tight as I've tried torquing them before and mine were going to snap before the torque wrench clicked off. Just check they haven't stretched when you've got everything apart although it sounds like they'll be alright. Did you re-use your own gearbox or is it one that came with the engine? Also did you remember to fit the plate between the engine and the gearbox?

Bought a release bearing as soon as I knew I was going to have the box off again. I'll look into a fork too. When I torqued the bolts they didn't seem too tight, but they certainly were a pain in the ass to initially get off! Will check them too.

I reused my old gearbox, bought the engine without one, and the plate between engine and box was refitted. Cheers!

I would suggest the release bearing but can't see how you would feel a worn bearing through the pedal.

Does the clutch slip at all? And what clutch do you have fitted? Did you fit the friction plate around the correct way as you have transmission side and flywheel side i believe. Correct me if im wrong!

Other than that without feeling it it's hard to say.

Clutch doesn't slip as far as I can tell, and the friction plate apparently only fits one way around, but yes, I made sure it was the right way around either way.

When I said I can feel it through the pedal, it's more just the roughness rather than a direct feel through the pedal.

Check you have a gearbox input shaft bush in the back of the crank.

If the "new" engine came from an auto it wouldn't have had one.

http://www.sxoc.com/vbb/showthread.p...pigot-bushing/

I did check to make sure it had one, however I didn't replace it. Engine came off of a manual. Again, as soon as I knew that I'm gonna be taking the box off again I bought a new one right away. Thanks for the advice bud!

Thanks for the advice guys

[Dastardly]

It's not the fork that goes but the pivot ball. It just screws into the gearbox. If I remember correctly driftworks sell them.