Garngie
Well-Known Member
Looking for some answers, this just happened last night.
Just installed a new Centerforce dual friction clutch mated with an A833 four speed, no overdrive, which was freshly rebuilt about 400 miles ago. Using in a 68 Road Runner with a 440.
Took it out for a test drive last night for a few miles. For the most part, the clutch was grabbing well, but I did notice that it would slip after about ~4800 RPM, while fully engaged in gear.
During the test drive, I did a gradual pull in 4th gear and took it up to about 5000 RPM, and then pushed the clutch in and applied the brakes to slow down. After reducing speed, I rev matched and put it back into 4th gear, which is when I noticed the car seemed to suddenly lose speed and I heard a very loud grinding noise come from underneath the floor. I shut the car off and coasted to a stop. The grinding noise continued even after the car was off. It sounded like as if a bearing was eating itself apart.
I was able to start the car back up and limp it home. Shifting the transmission felt gummy and the grinding noise went on for about another minute down the road, regardless of whether or not I was in gear, had the clutch in or out, etc. My clutch + throw out bearing were working as expected, but the noise seemed to get worse when I would put it back into a gear.
After about a minute, the noise abruptly stopped and I was able to shift all four gears normally. However, I noticed that every time I shifted from 3rd to 2nd or from neutral to 1st, the gears would grind. Seems like the 1/2 synchro is damaged. I got it home and shut the car off.
I am using a mixture of about 80% ATF and 20% 80W90 gear oil, with a 3.55 spool in the rear. Motor should be making around 580hp and ~600ftlbs of torque.
Any thoughts?
Just installed a new Centerforce dual friction clutch mated with an A833 four speed, no overdrive, which was freshly rebuilt about 400 miles ago. Using in a 68 Road Runner with a 440.
Took it out for a test drive last night for a few miles. For the most part, the clutch was grabbing well, but I did notice that it would slip after about ~4800 RPM, while fully engaged in gear.
During the test drive, I did a gradual pull in 4th gear and took it up to about 5000 RPM, and then pushed the clutch in and applied the brakes to slow down. After reducing speed, I rev matched and put it back into 4th gear, which is when I noticed the car seemed to suddenly lose speed and I heard a very loud grinding noise come from underneath the floor. I shut the car off and coasted to a stop. The grinding noise continued even after the car was off. It sounded like as if a bearing was eating itself apart.
I was able to start the car back up and limp it home. Shifting the transmission felt gummy and the grinding noise went on for about another minute down the road, regardless of whether or not I was in gear, had the clutch in or out, etc. My clutch + throw out bearing were working as expected, but the noise seemed to get worse when I would put it back into a gear.
After about a minute, the noise abruptly stopped and I was able to shift all four gears normally. However, I noticed that every time I shifted from 3rd to 2nd or from neutral to 1st, the gears would grind. Seems like the 1/2 synchro is damaged. I got it home and shut the car off.
I am using a mixture of about 80% ATF and 20% 80W90 gear oil, with a 3.55 spool in the rear. Motor should be making around 580hp and ~600ftlbs of torque.
Any thoughts?
