1993 240sx manual transmission problem, rough or won't shift sometimes

[zer0c123]

Didn't want to thread hijack the other on threads on transmission shifting problems.

Symptoms

-sometimes won't shift into 1st gear or reverse. Feels like the gear gets stuck half way. Doesnt happen too often, but i usually just force it in when this happens.

-shifting into 2nd, there is a clunk sound and sometimes rough. ( this happens mostly all the time)Sometimes from 1st to 2nd, it won't shift into 2nd. I have to apply more force. When this happens the shifter feels like it rubbing metal on metal. (this happens like once or twice each day i drive.)

-whenever i clutch in and shift into reverse the whole car suddenly shakes real quick with a clunk sound ( the quick shaking feels like an automatic transmission when you shift from N to R. The clunk sound seems to occur whenever i clutch in and immediately shift into reverse fast. If i clutch in and immedialely put the shifter to the right and slowly pull the shifter down to reverse, the shifter tends to vibrate/ grind on something.I have to clutch in and slowly and just casually or slowly get the shifter into reverse to avoid any of the above. After reading other posts i thought maybe the problem was the shifter bushing, so i took the shifter out and the bushing was still intact.

I saw this question in another post "When the trans is failing to shift smoothly turn the car off and shift through all the gears. Is there any problem getting it to slide into gear then? How is the pedal feel when you have the problem? Does it change when the problem occurs?"

-there have been a few times when after the car is off and leaving the car in gear like 1st and reverse, I have to force it into gear.

-pedal feel doesn't seem any different except for a clicking noise that i have been ignoring for the last 2 years. Not sure if it matters, but usually when i'm holding the clutch down with my usual force, if i apply some more force i go down another 1 to 1/2 inches.

I changed the transmission fluid to redline gl-4 stuff and inspected the white bushing under the shifter. Would a failing slave cylinder or air in the hydralics cause this? Seems these are most of the responses to these problems, but others usually just cant shift into gear at all. Car has 120k miles with original clutch and dampener. This has been on since the end of last summer.

Modified by zer0c123 at 5:41 AM 4/27/2006
Modified by zer0c123 at 5:55 AM 4/27/2006

[zer0c123]

Here is the pic of the transmission drain plug. There wasn't alot of shavings compared the one shown in the articles section.

[NISTECH]

The key here is your having to force it into other gears with the car off. The transmission has no rotation so it should be relatively easy to shift through all the gears when off. Is it any particular gear its hard to shift into. Keep in mind if you are on a slight incline and it is hard to get OUT of gear that would be normal as there is a binding on the gears. However it shouldnt be difficult to get into the others gears once you reach neutral. If this is the case I would be guessing possibly a bent shift rod or worn rod bushing as the sorce of the binding movement.

The drain plug doesnt look abnormal as far as build up.

[zer0c123]

Is it any particular gear its hard to shift into

Car off:

The trouble with 1st and reverse is just random.

Today after i got home, first and reverse was ok. But i tried cycling though the gears 1-5. 2nd and fourth needed slightly more force. They would go halfway smoothly, but would need extra force to "pop" into place. When i mean pop, i can hear a small pop sound when it goes in. Somes they would all be ok, but then 4th would needed extra force to "pop" into place.

Car on:This something new that I realized today. if i'm coasting down a street and try to cycle through the gears, it would be rough to move the shifter through the gears. 3 to 4 had a weird clunk sound and i could feel that it was clashing against something when i was shifting 3 to 4 back and forth. Going into 2nd felt like it rubbing against something.

Also i forgot to mention that sometimes i have trouble downshifting from 4th to 3rd. The shifter just wont go into 3rd sometimes, but doesn't happen too often.