I have a 92 SR5 V6-3VZE 4x4 manual 5-spd with the R150F transmission and VF1A transfer case. The truck has 169,000 miles. I just replaced the clutch last week due to really bad disc slipping along with Marlin Crawler shifter bushings (both main and 4x4). Unfortunately the previous issue of some hard shifting has remained and in fact now seems worse than before the clutch replacement. I was really hoping the clutch would maybe resolve it but...nope. It grabs like a new clutch should but it shifts hard into 1st, 1st to 2nd, and into reverse where the gear is spinning /grinding. So much so in fact that I just turn off the truck, put it in reverse, then start the truck again and let out the clutch. Sometimes reverse is ok though and shifting through gears 3-4-5 always seem fine. If I double or triple pump the clutch it seems to help a little but not wondrously. I also made sure the pedal height (5.9"), pedal play (~3/4") and clutch master rod are all in spec as per the FSM which I own. I will re-bleed master/slave (...again...) but wonder if my tranny needs a rebuild and or if I should replace master / slave. I had to replace the master/slave 5 years ago as the master leaked inside the truck so it was fully replaced but with a crap Chinese eBay unit which summarily leaked and failed within 2 years (this after 20+ years and 150k miles of OEM quality!!!) so upon that failure I just just wound up rebuilding the original OEM AISIN body I had held onto and rebuilt it with a rebuild kit. I also purchased a new AISIN slave. So I've only got maybe 3 or 4 years on the rebuilt master and new slave but who knows how good rebuild kits are or even if when you buy AISIN of eBay or Amazon if it's the real deal or fakes. Who knows! -- Regardless, the fluid still looks brand new and is full and has stayed full since the last repair and bleed out several years ago. I don't see any leaks anywhere and my engine bay is very very clean so I'm sure I'd notice it. The pedal feels strong now (a lot more than before the clutch change and I assume because of the new pressure plate) and is not spongy. So ..it works, but maybe not as well as it should? Or is my tranny just going belly up? Do I need new gearbox fluid? Or is the original OEM master body possibly worn some internally and just needs replacement even though it has no leaks? I just don't know what to do or where to start.

Secondly, I don't like the fact that you really have to press the clutch pedal almost all the way to the floor to get it to disengage. Is there any good mods for the clutch master that are bolt on? I remember reading somewhere that people use a larger master cylinder from Supra or Celica or something like that which shares the same exact bolt pattern but holds more fluid and gives more fluid push. For a V6 I really think the small dinky master looks wimpy and feels wimpy. Thoughts? Solutions?

Lastly, I want to upgrade to Redline MT 75w-90 GL-4 in the next few weeks as I don't know if the gearbox / x-fer case and diff fluids have ever been changed. (and will use the GL-5 in diffs) -- However I've also read that if you are having tranny issues it could make things worse but if the tranny is ok, it will help make it shift smoother. So.. I feel like I should just try it because if my synchros are shot anyway (as the truck has 169k) then I might as well find out and fix it all now. I'm pretty sick of the guesswork. Please help guys!

 

I never installed a New clutch Kit without a New Master and Slave.

Did you compare all the New Clutch parts with the old

The wrong release bearing can be real frustrating .

Look to see the firewall or clutch bracket is not broken.

Maybe with a helper see if your getting the full range of movement on the slave cylinder

Drain the Transmission Fluid see how much metal is in it and if it is really burnt

If things are self destructing in the trans it only takes one small piece to stop things completely

 

I did check the clutch pedal mounting bracket very carefully with a flashlight and small mirror to look at the far left / back side and upper left corner against the firewall where it seems that everyone commonly has the fatigue cracks and lucky (or unlucky) for me I have no visible cracks at all, just a little minor spotting of rust here and there on the entire bracket. I also have some squeaking issues when I fully depress and then release the pedal which at first I assumed was the clutch spring or the clutch master cylinder (cmc) but upon careful investigation was able to fully determine that it is on the ~7 o'clock position of the rear end of the cmc pushrod where the large diameter portion of the pushrod (like 3/4" or 1" wide) is rubbing against a very small protruding portion of the clutch bracket. I can see the wear mark. So at least that little headache can be quickly resolved with a nail file and some grease. I wonder how many people have had this same issue and thought it was the spring.

As for the cmc / slave I think you are right in that I should probably go ahead and replace them first in not knowing which exact one I had rebuilt. I will check receipts tonight to try and determine that but at the end of the day it's probably a lot better to just start fresh since the clutch is brand new. What's another $100 at this point. I already saved at least $1,000 in doing the clutch myself.

As for the gearbox I am ordering all the fluids today. I wanted to also know if there is any way to flush the gear box much like you do with a quart of engine flush that is used 10 minutes before an oil change. Like pour it in, drive around your local neighborhood for 5 minutes, change all gears, then drain the fluid. If so I'd really like to do that.

Another fear I have in all this is if the flywheel was machined too much. As said before though I definitely think this was the original clutch and original flywheel as all the transmission, pressure plate, and flywheel bolts looked untouched. Both the clutch disc and pressure plate I removed are AISIN and the flywheel had somewhat of a light gold tint to it and the flywheel face had very small, evenly spaced micro grooves sort of like a vinyl record which I assume is from the OEM lathing. So in seeing this I assumed it was a factory finish and felt safe to have it machine polished as it did not look like any secondary machining had ever been done. It certainly did not look like what you see from secondary machine polishing which is very very smooth with swirl type marks on the face and outer edge. So that said, I am assuming I did the right thing by paying $50 to have it machined vs buying a new one and do hope the very reputable local shop I took it to would have informed me if their polishing would put it beyond spec. I guess I'll find out soon enough, uggh.

Lastly, given that people get their OEM flywheels polished a few times coupled with the fact that the clutch fork likely sustains a little wear over time on its 3 contact points (of the slave cylinder divot, the center pivot point divot, and the two small fork contacts which push on the release bearing), I wonder if this combined wear is enough to also be a contributing factor for bad disengagement as across those three areas could amount to several millimeters of wear (maybe 2mm to 5mm) that the stock slave's push-rod extension length is just not able to make up for. Combine this wear with the flywheel machining and it could be a full 5mm or more.

As a test I'm thinking of back-filling the slave rod divot with some silicone first to see what happens as that will give maybe 1/4" (~5mm) of added push on the pressure plate. My final thoughts on this though are what are, if any, available upgrades for the master and slave, particular those which are able to give a longer extension of the slave cylinder. With people regularly getting their flywheels machined at least twice as well the fork wear I discussed, as well people often using heavier duty clutches, I think it only makes sense to use better components and one huge added benefit to a slave with more rod extension is the fact that the clutch would be able to disengage more at the top of the pedal (something I would greatly appreciate) instead of having to always push it to the floor. By having a longer slave rod and more fluid push from the cmc I think you could then much better adjust the pushrod to taste for where the disengagement is..ie, high, medium, or low. As is, I carefully set everything to spec as per the FSM and it is disengaging close to the floor, maybe 1" to 1.5" away...and well...that sucks lol. It is however exactly what and where the FSM specifies. It really should be at least 1" to 1.5" higher in my opinion. I hate feeling like I'm foot cranking an old motorcycle each time I push in the pedal.

I read somewhere a few years ago that people were using cmc/slaves from a Supra or Celica or something like that which are direct bolt on with the same patterns. I searched all my saved links and of course I couldn't find the info. I'd really like to know because if I'm going to buy these new again, I'd really like something a little better with more ooomph. I also say this because in the next year or two I really want to do the 5VZE swap and put in an HD clutch. So if I can upgrade the cmc/slave for the R150F tranny...now is definitely the right time. If anyone knows about this for the 3VZE / 5VZE please answer..p-l-e-a-s-e !!!

 

If there is any advantage of The Clutch Master from a Celica or Supra I don`t know My Supra is Gone but a few Celica Parts around yet

 

Anecdotally, I have read that an aging soft line (from master down to slave) can expand under pressure, reducing the slave travel. I changed my soft line when I recently did my clutch and did not really notice a difference, but hey it's only a couple of bucks. You could at least maybe visually inspect yours to look for bulges or anything.

 

Was just reading about rubber hose life. Article said 6 yrs as they start breaking down from inside and out. Mentioned signs, of course bulging but also a deterioration of fluid as water will get through hose with time. I found it interesting.

 

Wow, only 6 years huh? Marlin Crawler sells a braided steel line for $35, one of the claims is that it gives your clutch a "linear" feel...I wonder if anyone on YT has tried it, I'd be interested in one if I was sure it made a difference.

 

 

Cool muddpigg, I'd love to hear some firsthand thoughts on it.

 

mines just starting to go through this at the moment. what usualy happens is the clutch master starts leaking back up into the reservoir through the check valve. and its not until the piston passes it that it can start activating the hydraulic pressure on the slave.
this happens due to the acidic nature of old clutch/break fluid.
the seond problem, is that the first oring on the master piston gets tired and needs pumping to push back and seal, which is why u get improvement by pumping a few times.
neither of these two issues create an external leak.

 

Thanks for the input! The clutch is definitely not fully disengaging as much as it should. The new clutch itself is working great, grabs great, etc, but I just have to press my tip-toe really hard to floor (and my carpet is out btw) and then it works as normal and the shifts are smooth. So its a CMC/SC issue for sure and or SC rod length issue. The pedal pressure seems good too but because the dot fluid is a little darker than I would like to see I will go ahead and buy the Marlin Crawler stainless hose and perform a rebleed. If that does not work with the stock SC rod I'll have to move to plan B with a new CMC/SC all...over...again and will also lengthen the SC rod a little. I'm kind of befuddled with all this because the original two cylinders lasted 150k before I ever even messed with them so why would they crap out again after only 10,000 miles.

After really analyzing how everything works together --pedal play, pushrod travel, slave extension, etc,-- what I think is another big culprit is the design and length of the slave cylinder rod itself which I feel does not account for wear over time nor slight discrepancies in aftermarket parts. There is obviously no adjustment, save for a little at the Master pushrod. In case anyone wants to know, the slave pushrod for the 3VZE / R150F is .031 diameter x 65mm (so ~5/16" x 2-9/16"). I own the two FSMs and in the drawings for the clutch installation and pedal adjustments, and with proper pedal height and adjustments the clutch still engages / disengages really close to the floor (as was apparently designed). So my thoughts are that with wear over time on all components, and even with adjusting the cmc push-rod back toward you the driver to gain more displacement via a forward push stroke, (and assuming your fluid is totally ok) it is just still not quite enough if other links in the chain are worn (such as the clutch fork, pressure plate, flywheel, etc). As I originally said these wear factors on the clutch fork pocket, central pivot ball, fork points, as well a machined flywheel could all add up to a 5mm stroke loss, possibly even more. Maybe the new throw bearing is also slightly smaller too (I never even thought to carefully compare my original to the replacement). The clutch kit I got is from NAPA auto, a LUK brand kit # 1116059 which is a stock replacement. The pressure plate says made in South Africa but the replacement disc is AISIN which is good.

Regardless, the only way to account for such wear and slop is a CMC/SC combo that can A; provide a longer stroke of the SC rod through more adjustment length (which it can't or is just not fully functional at the moment) or B; simply replace the SC rod with a longer one or an adjustable one of same diameter. I mean even at best, with an absolutely perfect CMC/SC, new fork, new flywheel, etc you are still left with a clutch that is designed to operate very close to the floor which I assume is a pisser for a lot of people. Add in these wear issues and the release point is now guaranteed to be somewhere at least 1/4" deeper into the floorboard.. NOT GOOD!

 

ur posts are too long haha, i have to stop u at the second paragraph and correct u. a hydraulic clutch system doesnt need adjusting. it self adjusts over time. it should always settle to the same amount of travel in the master cylinder regardless of wear.

 

X2 on too wordy.

THere is an adjustment on the hydro clutch. At pedal side of push rod. Funny don't think anyone mentioned the easiest stuff first we all flexed our understanding.

I don't think a spacer will help. THis is extending the travel distance of pedal stroke has to travel to fully stroke piston in master cylinder.. Maybe lengthening the push rid. Only if it is an pedal adjustment issue

 

Sorry for the novel guys, just trying to fully explain the issue and what I think are remedies. And I understand of course that you can adjust the CMC rod in or out but that adjustment allowance is pretty minor in a cylinder that is maybe all of 2.5" long inside. I know that extended slave rods are sold for other vehicles with hydraulic clutches for this same issue so if other people use them I can't be crazy to think it would help to make the disengagement closer to the top of the pedal stroke, given of course that the CMC/SC are in proper working order to begin with.

Just to experiment I have some 1/4" steel rod on hand that I will first cut to 3" (thus adding 7/16") and see how it feels as I'd definitely like the clutch to disengage a lot closer to the top of the pedal. If that works I can buy an extended pre-made rod (DSM for $14.99 which is .031" x 3.75" made for 1990-1999 Turbo Eclipse, Talon and Laser which have a stock 3.5" rod). If my pick-n-pull was a little closer I'd go hunting for one as 3.75" or 3.5" would likely be way too long but could be cut down. I'll try my DIY rod first with the added 7/16" and see how it feels and then re-tailor as needed.

If anyone sees a big problem with this or thinks it won't work or that by raising the engagement point via a longer rod and pushing too hard could F-up the pressure plate or disc, please let me know your thoughts. Again, my main thoughts are engineers most often design things to an exact specification to last maybe 100,000 miles. They don't think of multiple wear factors beyond that and how best to compensate for them!

 

quote
"given of course that the CMC/SC are in proper working order to begin with"
but u dont know that.
i think u had two issues to begin with. CMC not working causing the hard shifting.... and a worn clutch.
and please dont take offence to my comment on long post. i do it too, u want others to be on the same page.
however consider you may be on the wrong page, and want aomeone on the right page to recognise it and bring u over there. best way to do it is keep open minded.
im trying to do that and thats where i come to the conclusion something must actually be amoss in your CMC.
cmcs are often interchangeable and work fine with other setups. the issues ur describing indicate more than an adjustment issue.
The adjustable slave rods would be for completely missmatched fork and slave setups. its possible u have a completely different pressure plate now yes, which could alter the max clutch depress travel. but usually the aystem has so much extra travel that its irrelevant.
id say ur master is leaking in the early stages of depressing, and not building enough pressure to fully seal the check valves from the reservoir untill the pedal is in half way, leading to a lack of total teavel.

 

Sure, I definitely don't disagree with that assessment which is why I had also said I'll buy the hose first and do a bleed, then move on to replacing the CMC/SC again if that doesn't help. So as stated "providing all things all working" and the clutch still disengages close to the floor (as is designed and illustrated in the FSM) is there any other way to get the release a lot closer to the top of the pedal? Aside from just fixing the main issue at hand, I would really not like to have to fully depress the pedal each time once it is working right. It wasn't so noticeable before but with this new pressure plate there is definitely lot of pressure necessary and seems like a workout. It's not so much of a major issue for me, but my wife drives our truck too sometimes and I already know she's gonna bitch about my mechanic skills and ask why its so hard. lol.

 

Might be the tranny itself. I’m thinking syncros.

I made it a bit further through your 1st post