I just replaced the 5spd transmission in my 97 with an 01 tranny that has 54K miles. I bought the tranny from an org member. I replaced the lower rubber clutch lines with a braided line and also installed a new slave cylinder. My dad helped me bleed the clutch line using several clutch pedal pump and bleed sequences. The clutch pedal still feels somewhat weak but he said that nothing was coming out of the bleeder valves except fluid. The problem I am having is that 2nd gear grinds only when the rpm's are high (around 3k or more). It grinds when shifting from 1st to 2nd and also when downshifting from 3rd to 2nd. Whenever the rpm's are low, it shifts into 2nd without any issues.

If some air is still in the lines, could it cause 2nd gear only to grind?

My clutch master cylinder is original with 291k miles. Could a worn out master cylinder cause only 2nd gear to grind?

Should I forget about air in the line or a worn out master cylinder as the cause and focus on the synchros as the main culprit?

 

The clutch hoses are a pita to bleed. Did you get the one piece line that goes from MC straight to SS?

 

I just got the shorter line that goes from the slave cylinder to the hard line.

 

Probably still have air trapped in the line. Could also be a bad synceo on #2

 

Air in the clutch line will not only effect one gear, it will effect all shifting.

It sounds more like 2nd gear syncro is worn out.

 

I was afraid of that. I was told that the tranny only had 54k miles on it. Never would have thought the synchros would be bad this soon.

 

It will be more noticeable on the most worn, but otherwise OK syncro. It could be a combo if the two.

 

What type of oil did you put in the trans?

 

Amsoil from Talkinghorse

 

If air is still trapped in the system, can it cause only one gear to grind?

If the master cylinder was bad, can it cause only one gear to grind?

I'm thinking about taking it to the dealer to let them bleed it. As stated, my dad and I bled the clutch lines by slowly pumping the clutch, holding the pedal down, and then opening the valve. We did this sequence for about 12 or so cycles, with the last 4 or so times getting all fluid out of the lower and upper valves. When initially bleeding, the clutch pedal was dead and would not return by itself, so I had to manually return it. It was this this way for about 4 or 5 sequences of bleeding. The clutch finally began to return on its own. I am assuming that it is normal to have to manually return the clutch initially when bleeding?