how do i adjust the master/slave cylinders on my 2000 4runner 5speed?
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Rockdawg84
New member
look really closely at both the clutch master and the clutch slave I would bet that one is leaking fluid and needs to be changed. My personal practice is to change both of them at the same time. they are not that expensive and its peace of mind knowing both are good. and they are not that hard to change. Let us know what you find.
edit: Just reread your post. this is only happening in 3rd? are you getting any other whining from the transmission? Or other strange issues with the trans?
edit: Just reread your post. this is only happening in 3rd? are you getting any other whining from the transmission? Or other strange issues with the trans?
Last edited:
cordrayj1
New member
whining. yes. but very minimal. i did some research on ttora yest and found there is a shift lever ball seat busing thing that fixes any play i may have in the shifter. im pretty sure my synchro is bad for third. the reason i think this is because when i shift from 2nd to 3rd and just press clutch as normal and try to shift quickly it will grind. if i do the same but wait a few seconds it usually goes in no prob. if im steppin on the gas trying to move and shift fast and hard, well, expect grinding from 2nd to 3rd.
and lastly, if i shift as usual, but when i press clutch i tap gas while shifting to 3rd (to sync up tranny speed w engine speed), no grinding. . . hmmmmmm. seems like it HAS to be a synchro from all the research ive done so far. i looked in the FSM for the tacoma because theirs actually comes w the 5speed trans schematics.
it just all makes too much sense to me as far as a bad synchro goes. but im going to look into the master and slave. after all, this trans has 204,000 miles on it now and i cant say ive flushed more than once. but fluid looks pretty dang good. had new clutch at 165k i think?
and lastly, if i shift as usual, but when i press clutch i tap gas while shifting to 3rd (to sync up tranny speed w engine speed), no grinding. . . hmmmmmm. seems like it HAS to be a synchro from all the research ive done so far. i looked in the FSM for the tacoma because theirs actually comes w the 5speed trans schematics.
it just all makes too much sense to me as far as a bad synchro goes. but im going to look into the master and slave. after all, this trans has 204,000 miles on it now and i cant say ive flushed more than once. but fluid looks pretty dang good. had new clutch at 165k i think?
cordrayj1
New member
and ill say one last thing. and this is kinda directed at aussie lockers. . . i have noticed shifting and drivetrain differences since the locker. does is work? yes. perfect. just as it should. does it create a good bit of extra strain. OH YEAH.
and this is prob w only 20,000 on the locker.
and this is prob w only 20,000 on the locker.
Singtoe
New member
I am going to start up a hornets nest here but i think the Synthetic fluid is giving your you problem. Only if you Hydraulic system is in good shape and not leaking.
If it was me, Drain the tranny fluid. fill it up with a kerosene or diesel, start it up, Go through all the gears, (don't drive it) to wash out the syncro clutches, drain the kerosene, dry out and fill back up with some GL-5 gear oil.
My theory with synthetic fluid is that it is to slippery and it doesn't let the syncros clutch material grab the opposing cog.
Mobile 1 also has a lot of moly in it and the moly is what adheres to the clutch surfaces. Thus the reason to flush with kerosene.
cordrayj1
New member
FOUND SOME GOOD STUFF THAT BACKS YOU UP SINGTOE
found at: 4x4Wire - Overhauling the Toyota/Aisin R151F Transmission
(i know i have an R150f trans, but for educational purposes this was awesome info)
Stupid Synchro Tricks
Gently, lightly lap the synchro with its mating cone.
Marlin does not always replace the synchros, but does 'remanufacture' them (and the details of this process remain shrouded in the clouds of mystery � hey, he's gotta keep SOME things secret!). He has had people request new synchros, and almost always gets complaints when he puts them in, until they break in. Redline MT-90 GL4 synthetic transmission oil really helps with synchro engagement, and when you disassemble the tranny you will see why. The brass synchros grip the gear's cones, which are polished steel, spinning up the shift hubs to match speed as they engage. The inside of the synchros have ridges which displace oil and allow brass-to-steel contact. Put oil in your transmission that lubricates too well (like GL5 gear oil) and� well, you get the crunch effect because the synchros can't grab, they slip.
A mechanic in our local 4x4 club had a suggestion on synchros. Here's an old-school trick to help new synchros break in. Use a little bit of valve lapping compound and LIGHTLY turn the synchros against their mating cones to break any glaze and to remove ONLY the high points on the inside of the synchros. Don't overdo this or you will shorten the synchros lifespan � but doing it lightly truly works. You do NOT want to remove the interior ridges on the synchros; they are critical for operation. You also don't want to remove material as this will reduce the synchro clearance needed for long life. Be sure to wash off any valve lapping compound with solvent and a toothbrush; it will instantly eat your bearings if you don't remove it completely.
The old synchro, with the bright new one. Note the design change.
found at: 4x4Wire - Overhauling the Toyota/Aisin R151F Transmission
(i know i have an R150f trans, but for educational purposes this was awesome info)
Stupid Synchro Tricks
Gently, lightly lap the synchro with its mating cone.
Marlin does not always replace the synchros, but does 'remanufacture' them (and the details of this process remain shrouded in the clouds of mystery � hey, he's gotta keep SOME things secret!). He has had people request new synchros, and almost always gets complaints when he puts them in, until they break in. Redline MT-90 GL4 synthetic transmission oil really helps with synchro engagement, and when you disassemble the tranny you will see why. The brass synchros grip the gear's cones, which are polished steel, spinning up the shift hubs to match speed as they engage. The inside of the synchros have ridges which displace oil and allow brass-to-steel contact. Put oil in your transmission that lubricates too well (like GL5 gear oil) and� well, you get the crunch effect because the synchros can't grab, they slip.
A mechanic in our local 4x4 club had a suggestion on synchros. Here's an old-school trick to help new synchros break in. Use a little bit of valve lapping compound and LIGHTLY turn the synchros against their mating cones to break any glaze and to remove ONLY the high points on the inside of the synchros. Don't overdo this or you will shorten the synchros lifespan � but doing it lightly truly works. You do NOT want to remove the interior ridges on the synchros; they are critical for operation. You also don't want to remove material as this will reduce the synchro clearance needed for long life. Be sure to wash off any valve lapping compound with solvent and a toothbrush; it will instantly eat your bearings if you don't remove it completely.
The old synchro, with the bright new one. Note the design change.
YotaZach85
New member
I will agree that you probably need a master or slave cylinder, I also change them at the same time. The slave is something like $25 and the master is around $50. I would also suggest getting rid of that mobil1 and replacing it with Redline MT90, thats the only gear oil I'll run in a Toyota manual trans. You'll notice a huge difference in shifting with the Redline oil and you might be able to beat the 3rd syncro from going out for a little while but it sounds like it's gonna be going out on you prematurely.
Oh and there is an adjustment on the master cylinder but you really shouldn't mess with it, the rod that goes from the pedal to the master is adjustable but if you don't adjust it correctly you stand a chance of destroying your throw out bearing from not having the right amount of free play.
Oh and there is an adjustment on the master cylinder but you really shouldn't mess with it, the rod that goes from the pedal to the master is adjustable but if you don't adjust it correctly you stand a chance of destroying your throw out bearing from not having the right amount of free play.
Singtoe
New member
If the master or the slave is bad, the pedal will go down and not come back up. (I Think) .
You will feel it going out too. Every one is used to how there clutch pedal feels and when it craps out, the driver can usually tell a difference in the pedal.
I still think it is the synthetic oil giving you issues. Drain, flush and re-fill with good gear oil. I recommend Lucas Oil - You can get it at any parts store. This is my opinion but I always have great outcomes with Lucas.
You will feel it going out too. Every one is used to how there clutch pedal feels and when it craps out, the driver can usually tell a difference in the pedal.
I still think it is the synthetic oil giving you issues. Drain, flush and re-fill with good gear oil. I recommend Lucas Oil - You can get it at any parts store. This is my opinion but I always have great outcomes with Lucas.
Gerdo
New member
I will half agree. You should be using a GL-4 oil! GL-5 does cause issues with shifting because it is too slippery , ALSO GL-5 can attack the brass syncros because of the high sulfur content. I was having some "hard to get into gears" issues and switched to REDLINE MT-90 Red Line Synthetic Oil - Gear Oil for Manual Transmissions - MT-90 75W90 GL-4 Gear Oil After a few hundred miles, it shifts like new.
Singtoe
New member
The gl rating is the pressure rating of the oil. It is not the slipperiness of it. The redline websight says that Synthetic Gear oil in general is too slippery and that they add friction modifiers to make the syncros clutch well in manual trannys. Sounds like they added dirt into the formula to make it less slippier.
The FSM does not specify Gl-4 or GL-5. It says that both is acceptable.
Gl-4 is good for straight gears and GL-5 is good for sliding gears (ring and pinion).
I will be honest and offer that I have never dealt with redline oil. As it is harder to get and a lot more expensive. It might be great oil then again, it could be overly expensive plain oil. I can not offer in solid advice but only my opinion on the matter.
The FSM does not specify Gl-4 or GL-5. It says that both is acceptable.
Gl-4 is good for straight gears and GL-5 is good for sliding gears (ring and pinion).
I will be honest and offer that I have never dealt with redline oil. As it is harder to get and a lot more expensive. It might be great oil then again, it could be overly expensive plain oil. I can not offer in solid advice but only my opinion on the matter.
YotaZach85
New member
I tried just about every gear oil I could find in my Tacoma trans cause it was getting hard to shift on cold mornings, Redline is the only gear oil that would give me smooth shifts no matter what the weather was like. I do agree with you that the synthetic oil he is running is probably causing him trouble but Lucas will do the same thing that the Mobil1 is doing. Redline can be had online for about $10 a quart which is a little more than Lucas gear oil but it makes a world of difference and worth every penny.
cordrayj1
New member
just read the Redline website info on the MT90 stuff. DANG sounds like i screwed myself. we have brass synchros i think??????
and speaking of slave and master cyls . . . i did adjust the master a week ago cause the clutch wasnt engaging all the way. but the synchro issue was occurring before that.
now, my pedal was kind of "sticking" if you will, and i had to pull it back up w my foot every few pumps of the clutch. so what do yall think about that?
as far as flushing the trans. whats the best way? the diesel/kerosene method seems ok, but i just want to make sure that ALL of it is out before refilling w fluid. any suggestions on the flushing would be awesome. as well as the slave/,aster issue.
REMEMBER, this trans has 203k on it. never really had anything done but a new clutch and the flywheel was trued then. so other than that, i have no idea other than the fluid and a need for new slave or master cylinder.
and speaking of slave and master cyls . . . i did adjust the master a week ago cause the clutch wasnt engaging all the way. but the synchro issue was occurring before that.
now, my pedal was kind of "sticking" if you will, and i had to pull it back up w my foot every few pumps of the clutch. so what do yall think about that?
as far as flushing the trans. whats the best way? the diesel/kerosene method seems ok, but i just want to make sure that ALL of it is out before refilling w fluid. any suggestions on the flushing would be awesome. as well as the slave/,aster issue.
REMEMBER, this trans has 203k on it. never really had anything done but a new clutch and the flywheel was trued then. so other than that, i have no idea other than the fluid and a need for new slave or master cylinder.
YotaZach85
New member
They are brass sycro's. You need to get your master cylinder rod adjusted back to where it was and put a new master and slave in if the clutch wasn't engaging all the way, that means one of the components isn't doing it's job.
