Clutch Grind?

[GoCleanUrRoom]

Alright everyone. Been working on this issue for a while now and have finally hit a wall. Symptoms and info are as follows:

I have a JDM 1988 GVR4, I upgraded the clutch with an ACT2600 and lightweight flywheel.
Decelerating with the car in gear with clutch engaged makes a loud grinding noise that is extremely aggravating. The noise disappears when I push in the clutch pedal and when I accelerate. It will also disappear if I merely set my foot on the gas pedal and give it a tiny bit of fuel. My transmission bellhousing has grind marks on it from the pressure plate. I ground down the bellhousing a few millimeters where there was visible wear. Everything else on the car as been given a once over. Carrier bearings are replaced, rear diff is strong, no play in any axles, passenger (US driver) side axle carrier bearing is solid and flush with mounting point. Clutch is not dragging and has been adjusted per Jack's video and engages strong. Has anyone ever had this issue putting US market clutch into a JDM trans? And what are my best bets at resolution? I'm going to order stock JDM parts and put those in and see what happens. If you can help out at all, its very appreciated. Thanks for reading.

 

[slugsgomoo]

Do you have any measurements? I want to say that the FWD clutch is bigger than AWD, but it's been a lifetime since I read anything about it.

Also, small world, I spent a lot of my childhood out in Duvall, and there are several people on the boards in that general vicinity; I know @mitsuturbo is out in Monroe.

 

[yubh8tn]

Slugs, the disc and pressure plate(and everything that comes in a clutch kit) are the same for all 4g63t's. The differences are in the flywheels, awd ring gears are smaller than fwd. Sorry for derailing, just wanted to clear that up

 

[slugsgomoo]

Slugs, the disc and pressure plate(and everything that comes in a clutch kit) are the same for all 4g63t's. The differences are in the flywheels, awd ring gears are smaller than fwd. Sorry for derailing, just wanted to clear that up

fair enough, I haven't seen a clutch/flywheel for a FWD in probably 15 years 🤣 I just remembered something being bigger.

I don't understand how the clutch grinds on the trans housing

 

[GoCleanUrRoom]

Do you have any measurements? I want to say that the FWD clutch is bigger than AWD, but it's been a lifetime since I read anything about it.

Also, small world, I spent a lot of my childhood out in Duvall, and there are several people on the boards in that general vicinity; I know @mitsuturbo is out in Monroe.

No FWD parts have been put in, going from JDM flywheel / clutch to USDM flywheel / clutch. Once I get the trans back out I'll get some photos. I'm ordering JDM parts to go back to stock and see if that fixes the issues. And that's awesome, I just moved outta WA but miss the Monroe car scene a lot.

 

[GoCleanUrRoom]

Alright fellas: talked to the guys at Advanced Clutch, they say it could be gear rattle. I will be making a video of gauge cluster with microphone in engine bay, switching to really heavy trans fluid and doing the same to see if it quiets down at all. If that doesn't work I'm going to get a US market STOCK flywheel. If that doesnt work it's getting the JDM flywheel + clutch put back in. Will keep you all posted over the next few weeks / months.

 

[diambo4life]

Something is wrong with your clutch/flywheel combo. Time to take it apart and compare (measure) against the clutch that came with it. Make sure you are using an AWD flywheel etc.A gear rattle would not cause the clutch to make contact with the bellhousing.

 

[mitsuturbo]

There's not going to be any measurable difference between the USDM & JDM clutch/flywheel. Look up the parts in ASA vs online EPC (Japan) and I believe you'll see they're the same.
Do you happen to have solid (or upgraded poly) bushings in the rear subframe? Prothane engine mount bushings, perhaps?
Is the clutch sprung hub or solid?