My friend has a 2WD 1990 Toyota pickup. I did a clutch job for her about 2 months ago. then last week her transmission was acting up. popping out of 3rd and 4th. grinding going into 3rd and 4th. with 3rd being worse then 4th. I diagnosed this as bad syncros and suggested we swap out the transmission. The transmission was only a 4speed, and I suggested swapping it for a 5 speed. This last weekend I swapped out the 4 speed for a 5 speed sourced from a junkyard (with a 100 day warranty). I then took it for a test drive and its popping out of 3rd and 4th. grinding going into 3rd and 4th. with 4th being worse then 3rd. 1, 2, and 5 work fine.

Yesterday my friends neighbor heard about the problems with the new transmission and took a look... he says the slave cylinder is bad because some times it extends fully and some times it does not extend fully.

I would love to change out the slave cylinder and have it solve this problem, but I have been thinking about this all morning and I've got a few questions that makes me think his diagnosis seem fishy. I need a second opinion from some mechanically oriented minds.

If it were the slave cylinder wouldn't their be problems in all gears not just 3 & 4?

he visually saw this slave cylinder not fully extending. that being said, wouldn't the slave cylinder be leaking if it were bad? The peddle feels the same so that fluid has to be going somewhere... and if its not pushing out the rod then its got to be leaking..... OR is it a master cylinder problem and the fluid is leaking back into the reservoir?

I'm thinking this sounds like a master cylinder problem? any other thoughts?

you can get a slave cylinder for the truck for less then $15 and the master cylinder is around $40

I'm inclined to change out both master and slave cylinders and solve the problem of the rod not coming out all the way, then drive it and if the transmission is still acting up, get a new one under the warranty.

__________________

For the master cylinder get in the cab and look under the dash. When the master cylinder fails the rear seal goes and they leak backwards into the cabin. Have you verified that the system is well bled? I like to gravity bleed clutch hydraulics.

Yeah, I'm going to bleed it. the fluid is goose.

I'd like to plug the line coming from the master cylinder and feel the peddle not move.

__________________

Ehhh?

No. You can have a bad master cylinder or slave cylinder even without losing fluid.

This happens when the piston seal is bad and the fluid simply goes around the piston. No fluid is lost. There is good pedal 'feel' but not much work is happening because the brake fluid simply moves around.

I suggest replacing both the master and slave together. If you only do one, the new one will make the old one bad. Replace them both.

I think this will solve your problem. Doing this is easy enough for a toyota truck.

__________________
Ben
1987 190d 2.5Turbo

lol should read gross don't ask me how that type-o came out... maybe it was all that beer i consumed yesterday at my friends wedding... yeah, i'm gonna blame it on that.

__________________

I agree that they should both be changed at the same time. I think thats going to be tonights work.

__________________

And for a fraction of the cost, you can buy the rebuild kits and do them yourself with little effort, in no time at all. Why buy the whole thing, when it's the seals that go bad?

- Shelby

__________________
1980 300D - Veggie Burner !

I would vote for a worn out pilot bearing. The hydraulic operation of the clutch has no bearing on whether the transmission stays in gear. It may make shifting difficult, but once in gear, it should stay in gear. Popping out of gear is usually caused by bearing play where there shouldn't be any.

This and the fact that 1,2 & 5 have no problems at all is what makes me question if the hydraulics are only cause to this problem... maybe we're dealing with 2 problems here.

__________________

I second the person who wrote that a bad clutch is not going to cause it to pop out of gear. Never heard of a bad pilot bearing causing that but I've definitely heard of internal transmission wear causing that problem.
Can you upshift/downshift without the clutch or double clutching without it grinding? If you can't get it to shift without grinding at all by upshifting slowly or double clutch downshifting, then I'd say the problem is internal to the transmission.

__________________
1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

This is still my gut feeling! yes double clutching does make 3rd more usable. (I can get in in 3rd 4 outta 5 times if i double clutch it) I want it to be external, because I don't want to spend another 6hrs swapping out another transmission... and maybe the hydraulics are on the way out. but popping out of gear, only 2 gears being effected, being able to double clutch 3rd, all that screams syncros to me.

If it were just 4th maybe the input bearing being out of wack... but you would think there would be bearing noise.

I'm not exactly new to manual transmissions... especially Toyotas! I've only owned a Toyota with a manual since... well before I could drive I helped my dad rebuild a Toyota transmission in his car, that became my car, and I still own that beast!

A side note the neighbor guy who is pointing to the hydraulics is not exactly my best friend, hes one of those guys who loves to poke his nose into things, and knows car, and acts like no one knows as much as him. so, while I'm 100% open to his suggestions I tend to come to my own conclusions because he just rubs me the wrong way.

My friend, is a very pretty girl... not exactly the type to crawl under the truck and rip the transmission out. So the news I have about the hydraulics is from her and the nosey neighbor. I really want to look at it for myself.

I'll get to look at the truck soon, maybe not tonight she just informed me. but I have a feeling that while the hydraulics may be causing some of the problem, I just can't believe they are to blame for all of this.

__________________

New parts (master and slave cylinders) are cheap enough to purchase. Kits will only work if the cylinder walls are not pitted or too damaged.

When you change the clutch, in addition to the disk, you have to change the throwout bearing.

__________________
Ben
1987 190d 2.5Turbo

Ahem...time for a picture perhaps?

__________________
Ben
1987 190d 2.5Turbo

You fixin the car for pussy, dawg?

__________________
1985 CA 300D Turbo , 213K mi