Experts Please Help Diagnose

[Evaporate]

Experts Please Help Diagnose, the mechanic and clutch manufacturer are stumped as well.
I don't know if this belongs in tech or drivetrain, plus it's an LT1, but here goes:

--Summer 2003 I had the t56 tranny rebuilt with a Mcleod Street Twin and steel fw installed. Everything seemed fine no problems with driving or noises.

--Fall 2003 after about 3k miles on new setup, I moved to Socal (drive ~400mi) no problems. I do however, have an annoying oil leak, which appears to be an oil pan gasket leak.

--November 2003 I drive back up to Sac (~400mi) and lose a lot of oil from the leak. I replace the oil, but plan to fix the leak at a later date.

On the drive back to Irvine (again, ~400mi) I get a horrible grinding as I drive and try to shift. I made it all the way home but the noise was just horrendous. I really had to work to get the shifts in and had to bear with the loud grinding noise.

--January 2004 I take my car to the mechanic, thinking that I had a rear main seal leak. The mech drops the tranny and says it is not leaking. The clutch disks are just fine, but the center hub of the plates is messed up. He said the disk plate hub had play over the input shaft. Basically, the hub was machined wrong by Mcleod's hub maker and it also tore up my input shaft. I had both replaced with a good hub.

There is still a slight grind as I take the car home, the mech tells me the plates are probably just wearing in and it will probably get better.

--February 2004 The horrible grind is back. I decide to adjust my adjustable master cylinder. By adjusting the pedal to ~3" off the floor the noise was much more avoidable, and the car's idle felt crisp and lower. But still present every so often, plus I don't feel comfortable with the pedal being unnaturally low.

-- March 2004 I start to get a bad lurching/jerking of the car in low rpm in reverse or 1st gear. Checked connection of plugs and wires and for arching, nothing major. Now I really believe it's clutch related. A board member advises me to check the clutch fork for grinding on the PP.

--Today, March 20, 2004 I separate the tranny and bellhousing and look at the fork. I don't see any signs of grinding nor is the fork's bolt loose.

What do I do now??

I know this is long and I thank everyone for reading it. Please give me any ideas or similar experiences.

Daniel

[Evaporate]

TTT please.

[jmd]

Originally posted by Evaporate
rebuilt with a Mcleod Street Twin

I get a horrible grinding as I drive and try to shift. I really had to work to get the shifts in and had to bear with the loud grinding noise.

The clutch disks are just fine, but the center hub of the plates is messed up. He said the disk plate hub had play over the input shaft. Basically, the hub was machined wrong by Mcleod's hub maker and it also tore up my input shaft. I had both replaced with a good hub.

There is still a slight grind as I take the car home, the mech tells me the plates are probably just wearing in and it will probably get better.

If it grinds when you're trying to move the stick into the next gear, my firxt thought is clutch not releasing fully. If the disc hubs were binding on the input, they could cause a poor release & lead to the grind. This all ties into the lurching in 1st/rev.

I have seen a site with another guy who had disc / input issues with the McLeod twin (LT1 also) but I don't have the link at present.

I'd pop the trans. out & see how the splines are working together. I have a feeling it's Deja Vu with Red and his twins. :(

-Matthew

[Evaporate]

jmd- The incorrectly-machined hub was the first thought for a source of the grinding problem. So the shop replaced both the hub and imput shaft and told me they could use the same discs since they were still in really good shape. But now, with a hub that is "correct", why would I still get grinding?

On cz28.com, a couple members are telling me there that it might be my oil pan leak problem finding its way to the clutch. This was my initial thought because when the leak became major after a long drive, that's when the clutch probs began. But why didn't the auto shop report any problems of oil on the clutch? They also said there wasn't a rear main seal leak.

So the problems occur with the pedal being fully depressed. I remember that every now and then, I could avoid the noise by half-stepping the clutch (like a partial push, hoping it would fall into gear).

I adjusted the master cyl. to where the pedal was set 3" from the floor, only at this point or lower did the noise go away. But it wasn't completely gone because every so often, if I turn the car on in gear, it would grind. Plus, now the shaking in low rpm that led me to go on and pull the car apart. I'm stumped:confused: