My 95 Prizm has 110,000 miles, and is in great shape all things considered. The one problem is with the manny tranny. When cold it shifts just fine, but when hot, like after sitting at lights for long periods of time, the clutch won't disengage totally. I have to ease it into R slowly to stop the tranny down, and then put it in first. I've replaced both the master and slave cylinders, with slight improvement, but the problem persists. Any suggestions?

Ok: It sounds like you said that the clutch is not fully disengaging. Reverse in the vehicles I know is not synchronized and would be the easiest to get that gear crunch/zip when selecting that. In all cars if you go too fast from neutral to reverse they give you a time with that.

The syncros have more leverage to stop the gears in the trans in the higher gears if the clutch is dragging they would be easier to shift into. This should not happen or be necessary and the problem is either that this hydraulic linkage can't travel as far as needed or is out of adjustment. I don't deal with tons of standards and the pedal height adjustment may be preset on this car as long as the components are correct and air bled out. Sounds like you have taken care of that and if not bleed the air out again.

There should be a "free-play" spot at the top of the clutch pedal where it really doesn't do anything. It must have some but not too much there. I don't have a spec for it but about an inch would be close. If this is more than that it isn't allowed engough travel to disengage the clutch fully for shifting. If too little the problem shows up as the clutch "riding" itself when a load is on the engine and would cause early clutch wear out but that isn't this problem.

Adjust to close to that if it's bled out should solve this. If not it could be a warped disc or I've seen rusted ones that don't fully disengage.

Sorry if I just confused you. I'm getting tired as I've been at this for too many hours right now. Give me a slap if you want

T
Tom Greenleaf - MetroWest Boston - USA
_________________________________________

http://www.autoacsystems.com/tomgreenleaf/

THX for the reply Tom, yes it’s definitely the clutch failing to fully disengage at times. There are some things in your reply I hadn’t considered, like the linkage needing adjustment. I adjusted the clutch pedal when I replaced the MC. The system is bled right, but I have to wonder if air is getting in somewhere I can’t find. What has me confused is that it’s so intermittent, only acting up when very warm like when going from light to light for several minutes. The reason I brought up putting it in R is because that’s how I’ve been stopping the tranny from spinning so it goes into 1st easily. I seem to be able to ease it in slowly better in R. Also, if I rev up the engine, that seems to help it go into 1st when it’s acting up. If you have any other ideas I’m all ears. THX again.

I'm a little confused as to why "R" is NOT giving you a hard time with this, why this is temp sensitive, and why reving up helps for 1st?? I guess if air was still trapped somewhere it could make disengaging more trouble when warmer as the bubble would be bigger to compress.

Just perhaps there is something funky going on with the synchro and just maybe changing the gear oil would help with this. Not being there I do suggest giving that a try and bleeding out the hydraulic linkage again checing adjustment again too??

Tom
Tom Greenleaf - MetroWest Boston - USA
_________________________________________

http://www.autoacsystems.com/tomgreenleaf/

I’m more than a little confused too Tom. J Particularly over the temperature sensitivity. The same thought occurred to me about the air bubble expanding as it heats up, but I’ve bleed it so often, that air must be getting in some where if that’s it, and for the life of me I don’t know where or how it could be. I changed the gear oil first thing, looked like the first time it had been changed. As to reverse, it does give me a problem, it’s just that I use that gear to stop the tranny down when it’s acting up, cause it’s easier to do slowly and keep grinding to a minimum. I called in to Bobby Licus on Sun, and he suggested it might be an internal bearing starting to seize up. Oh well, if it is something internal (or infernal) like that I’ll just drive it till it quits and then swap trannys. THX again Tom.