Clutch causing transmission to grind gears

[jt15833]

I am on the first few driving days after swapping a used KA24DE and a used transmission into my car. While letting the clutch out and while shifting gears while moving, with the clutch in, the transmission would grind pretty roughly, a rough clanking/grinding noise from in there.

I was convinced it was the transmission because it was second hand and I didn't think a clutch could cause this. However after driving the car more today, I learned how I could let the clutch out and avoid the grind completely. If I pay close attention and don't get back on the gas until the clutch is about 75% let out, I won't ever hear the grind. It still grinds a little while switching gears, but it's far less severe than the clutch-out grind. The last piece of evidence that makes me think it's the clutch is if I am stopped at a light, in 1st gear with the clutch in, and rev it up, I will start to hear the grind.

Maybe it doesn't have anything to do w/ the transmission at all? Is there something that could happen inside the bellhousing to cause this?

Last piece of info, I had a CA in the car before this and I adjusted the clutch with the rod near the pedal to try and make it fit me more. Perhaps this could cause something? I have bled the slave cylinder and actually measured the clutch fork travel, at the end of the fork near where the slave cylinder pushrod makes contact, and it moved just under 0.75 inches. Not sure if anyone knows if this is ok of the top of their head, but if someone could measure theres that would be some good info to have.

Thanks guys

[srpowered240sx]

sounds like t/o brg, pressure plate, pilot brg, or engine issues. get it on a lift and have someone listen from under car.

[jt15833]

agreed, a lift will be hard to find though unless I want to pay.

I will drop the transmission out this weekend if adjusting the clutch rod doesn't help. What should I look for in there to be out of place/malfunctioning?

[biggie]

First check clutch pedal, line, bleed, adjust pedal.

Then would be looking at the clutch pressure plate. I had a brand new one that was bad and causing it.

[jt15833]

what should I look for at the pressure plate? I'm gonna check out the TOB and the pilot bushing, didn't check those too good before the install.

anyone ever messed with the clutch pushrod at the pedal? I adjusted it a while ago and want to mess with it again to see if it's the problem, but I am trying to think about if it needs to thread into the pedal more or out of it. I'm talking about the 'Push Rod' at the top left of this pic

[biggie]

I don't know how to look at the pessure plate to see if its ok. Mine looked fine, but didn't work. Replaced it with an OEM one and all was fine.

Just get someone to push you clutch pedal and see if the 'ram' on the slave cylinder is moving. It should more 1/2" to 3/4". If that's the case then you clutch pedal, line, MC, SC are all ok.

[jt15833]

i adjusted the pushrod pretty much from all the way in to all the way out with no luck, all it did was change the engage point of the clutch w/ respect to the clutch pedal. I guess something under there is messed up I will take a look at.

[Didderson]

bleed the clutch slave cylinder.

Your clutch fork isn't depressing the pressure plate enough.

[jt15833]

I bled it a few times in the beginning and I think I bled it enough. I played with the pushrod, threading it into the clutch pedal to make the clutch engage sooner in the pedal travel vs threading it out and having the engage point further in the pedal travel. Today when driving on the highway I experienced what seems like a worn clutch, I'd be in 4th and at 2.5k rpm then try to give it gas and the revs would climb but the speed wouldn't, it was obvious the clutch wasn't properly transferring power. Do you still think I need to bleed the clutch? I will try again - is it essential to use a plastic tube coming out of the bleed nipple?

[jt15833]

To anyone who finds this - the problem was an automatic trans pilot bushing was installed where I needed a manual trans one. Check this before installing things together/in the car!