Release bearing riding pressure plate (1 Viewer)

[farpolemiddle]

Backstory - 1969 fj55 with a 90s SBC and a older AA adapter to older style H55f. Conversion done in the 80s and motors replaced as they wore out. 305 to 327 to 350. The clutch died in a weird way. The springs in the clutch plate wore through their keeps until one was proud enough to wedge between the flywheel and the pressure plate. Clutch that worked fine to perma neutral out of nowhere. I pulled the tranny and since it was a leaky mess took it to get rebuilt. The clutch was old school 3 prong deal. H55f had a turned down bearing retainer to use a chevy release bearing and cast arm.

Turns out most of the gears in tranny was toast so I bought a new H55f from toyota. Apparently the H55f bearing retainer changed to my delight so I took the new front bearing retainer to a machine shop and had a sleeve inserted to gain strength since the ID was different than the old one and then had it turned down to use chevy release bearing. I bought a low profile 11" LUK clutch and it went together fine.

Now for the life of me I can not get the clutch adjusted so that the release bearing stays off the pressure plate. Thought it was the slave so I bought a new slave, master and traded hose combo from JT outfitters. That went in fine and I still get it adjusted. I back off the adjusters on the slave until it doesn't drag drive it round the block and crawl under idling and it is spinning. back it off some more and same thing until it is so loose I don't have enough to disengage the clutch. Drives fine when it is working. Tried adjusting the peddle all over the place as well. What am I doing wrong? It has a decent strength spring on the slave.

 

[farpolemiddle]

So looking at it again I have the AA mount that has the slave upside down. I bench bled it and bled it on the truck but I am going to pull it off and turn it the right side up and bleed it again. I am also going to try a stiffer return spring at the slave.

 

[scrapdaddy]

Something I had forgotten to do...grease the transmission input shaft where the throw out bearing rides, slides a lot better.

 

[Downey]

Ok, Mud guys will be getting very tired of seeing me print this same old story, BUT you are the exact reason I do. Toyota hydraulics does NOT have enough travel to disengage a Chevy clutch. The guys who will say I am wrong because they are using a Chevy clutch with no shifting problems, actually do have shifting problems and evidently don't recognize it. With a standard Chevy clutch your adjustment would have to be:
(a) Where the T.O. bearing is always riding on the pressure plate fingers in order to get full disengagement- - -this will just burn out the bearing in a hurry.
(b) Where the T.O. bearing is backed off the pressure plate fingers- - -this will not allow full disengagement, so guys simply drag through the gears and evidently don't think something is wrong.
For this reason both AA and Downey build special "Chevota" clutches that are machined to require less travel to disengage the clutch. I don't know what AA sells their Chevota clutch for, but my Downey clutch (pressure plate & disc) sells for $252 plus the ride.

 

[B y r o n]

So am I wrong to assume that because it is a hydraulic clutch, that self adjusts as the clutch wears, will always have some contact with the pressure plate fingers (3 or multiple) just like disc brake pads will always have slight rotor contact?

 

[73FJ40]

So am I wrong to assume that because it is a hydraulic clutch, that self adjusts as the clutch wears, will always have some contact with the pressure plate fingers (3 or multiple) just like disc brake pads will always have slight rotor contact?

Yes.

It is not a hydraulic clutch. It is a hydraulically actuated clutch release mechanism. It's no different than a mechanically-linked system, other than the hydraulic system has the versatility to be mounted for both LHD and RHD vehicles by changing the length of some steel tubing and flex hose.

 

[bikersmurf]

Ok, Mud guys will be getting very tired of seeing me print this same old story, BUT you are the exact reason I do. Toyota hydraulics does NOT have enough travel to disengage a Chevy clutch. The guys who will say I am wrong because they are using a Chevy clutch with no shifting problems, actually do have shifting problems and evidently don't recognize it. With a standard Chevy clutch your adjustment would have to be:
(a) Where the T.O. bearing is always riding on the pressure plate fingers in order to get full disengagement- - -this will just burn out the bearing in a hurry.
(b) Where the T.O. bearing is backed off the pressure plate fingers- - -this will not allow full disengagement, so guys simply drag through the gears and evidently don't think something is wrong.
For this reason both AA and Downey build special "Chevota" clutches that are machined to require less travel to disengage the clutch. I don't know what AA sells their Chevota clutch for, but my Downey clutch (pressure plate & disc) sells for $252 plus the ride.

Where I get most tired of it is I followed the DOWNEY INSTRUCTIONS using, "a standard 11" low diaphragm type clutch", and have had none of the problems you describe in 21 years. 21 years later still running the same clutch, and the transmission shop that rebuilt the 200k mile trans saw no problem with it. (The transmission got new bearings even though they weren't needed, but it had 200k miles so why not.) Now you come along and tell me it can't be working and I was a fool to follow DOWNEY's INSTRUCTIONS... say weren't they the ones that came with the kit you sold me? Also you, apparently, can diagnose a problem over the internet that no local expert who has driven the truck can see. Thankfully you have the magical cure for only $252 usd plus the ride and labour... what would I do without you?







Oh wait, till 20 years later you tell me I used the wrong parts again.

My July 74 works 100% with the stock clutch master, slave, and braided steel line. Jim if you're ever in the area, you're welcome to drop by and show me how I'm wrong... and how a starter that bolts to the DOWNEY bel housing will actually have the correct clearance to work with my 168 tooth flywheel and how my cast iron 4 speed nose cone bolted to the block isn't necessary.

 

[bikersmurf]

The throw out bearing will be ruined if it rides on the fingers of the pressure plate. There should always be clearance. Can you look inside or do you also have a 360 degree bel housing?

 

[pb4ugo]

IDK, if this will help or not. A friend had a similar problem with the T/B catching the PP and spinning it periodically. He was running a SBC, AA bellhousing and a stk 4speed. The PP wasn't a fancy one, it was just a stk chev low profile PP. He looked up into the bottom of the bellhousing and noticed the wire/springs that retain the fork to the pivot ball were loose and allowed the fork to sag slightly off the ball. His fix w/o removing the tranny was to use a zip strip around the fork and wire/springs to snug it up. It worked like a charm.

 

[farpolemiddle]

Ok, Mud guys will be getting very tired of seeing me print this same old story, BUT you are the exact reason I do. Toyota hydraulics does NOT have enough travel to disengage a Chevy clutch. The guys who will say I am wrong because they are using a Chevy clutch with no shifting problems, actually do have shifting problems and evidently don't recognize it. With a standard Chevy clutch your adjustment would have to be:
(a) Where the T.O. bearing is always riding on the pressure plate fingers in order to get full disengagement- - -this will just burn out the bearing in a hurry.
(b) Where the T.O. bearing is backed off the pressure plate fingers- - -this will not allow full disengagement, so guys simply drag through the gears and evidently don't think something is wrong.
For this reason both AA and Downey build special "Chevota" clutches that are machined to require less travel to disengage the clutch. I don't know what AA sells their Chevota clutch for, but my Downey clutch (pressure plate & disc) sells for $252 plus the ride.

It had a chevy clutch for 25 years. It was the 3 prong style that was slightly less low profile but a shorter throw out was used. The current throw out and pressure plate are about the same thickness so I don't know what to say about this. Part number in the clutch I should have put in? Edit. I'm not seeing a hybrid like this on AA website.

 

[farpolemiddle]

IDK, if this will help or not. A friend had a similar problem with the T/B catching the PP and spinning it periodically. He was running a SBC, AA bellhousing and a stk 4speed. The PP wasn't a fancy one, it was just a stk chev low profile PP. He looked up into the bottom of the bellhousing and noticed the wire/springs that retain the fork to the pivot ball were loose and allowed the fork to sag slightly off the ball. His fix w/o removing the tranny was to use a zip strip around the fork and wire/springs to snug it up. It worked like a charm.

I suspect this could be part of my issue since then all is a little worn. The fingers on the cast arm that actually hold the bearing have a little play as well. Can't be helping.

 

[farpolemiddle]

The throw out bearing will be ruined if it rides on the fingers of the pressure plate. There should always be clearance. Can you look inside or do you also have a 360 degree bel housing?

I have the older open bottom bell housing. I can see and get too most everything in there.

 

[bikersmurf]

There should be a visible gap between the fingers an the throw out bearing. If not, what is preventing the bearing from moving back? The slave rod may need to be cut down.

 

[farpolemiddle]

I seriously can not find this Toyota chevy hybrid clutch on Downey's website and I am pretty sure AA advocates using a Different set up and no longer sells a hybrid clutch. I'm like $3,500 into this. I will drop another $250 on a Downey clutch if need be. I'll just drive it as is until it murders my current tob.

 

[Downey]

Bikersmurf, I'm thrilled you have gotten 21+ years use out of the same clutch. I used a stock Chevy 11" low cone diaphragm clutch in my first Chevota, it worked if I did a very touchy/borderline adjustment, but then had to be re-adjusted all the time. Downey then started having special Chevota clutches built primarily because "it could be done", and this resulted in no more touchy clutch adjustments.

At this point know one will have to read my clutch opinion anymore, ya all run what ever you want!!!!!!!!!

 

[farpolemiddle]

Bikersmurf, I'm thrilled you have gotten 21+ years use out of the same clutch. I used a stock Chevy 11" low cone diaphragm clutch in my first Chevota, it worked if I did a very touchy/borderline adjustment, but then had to be re-adjusted all the time. Downey then started having special Chevota clutches built primarily because "it could be done", and this resulted in no more touchy clutch adjustments.

At this point know one will have to read my clutch opinion anymore, ya all run what ever you want!!!!!!!!!

I am listening. What is the part number. I can not find it.

 

[65swb45]

I am listening. What is the part number. I can not find it.

The Downey website is not owned or controlled by @Downey . He sells his stuff through eBay.

If you do a thread search, I believe you will find more info on the low profile pressure plate. They do exist, and they are really the way to go. IIRC, it's a modified LUK. I used to stock them, but sales have been slow, so I dont think I have one on the shelf at the moment. Of course I'm typing from home now, so there's no way for me to check.

Best

Mark

www.marksoffroad.net

 

[farpolemiddle]

Well if you have one I will give you my moneys. I am tired of messing with this and I am just going to drive it to reduce my hate. I am not pulling that transmission in my driveway again any time soon. Looking at it underneath I really think it is a combination of there being waaayy too much slop in the pivot point. I reduced it by running a spring hooked to the pivot point in the other direction towards the TC. The other issue is the nubs on my cast fork that hold the release bearing are worn as well which also eats some of the tolerance when releasing the TO bearing before it actually pushes it away. The only way to fix it right is to pull the trans. It does drive fine though I do not like the feel of it. It is almost too soft compared to my old clutch.

 

[bikersmurf]

I guess I just got lucky. I don't remember ever adjusting mine. I'm glad there is an option for those who are having issues. If I was doing the conversion today I'd likely not mess around with an unknown variable. I'd buy a clutch from Jim.

That said... knowing how well the Luk clutch has worked for the last 21+ years, I'd not hesitate to buy another Luk clutch. Also, knowing 1.5F Clutch Master bore works with the Slave bore to give plenty of throw to have enough free play and still disengage fully before it's 2/3 of the way down... and not have a heavy pedal... I'd also recommend this setup.

I don't know if the braided stainless steel line is a factor or not... it has been there for 25 years since the OEM rubber line blew when it hit the exhaust. I put a new one beside it and after 25 years it still looked new.

Karma must've been working in my favour... the SBC I could find when I needed one just happened to have Ram's Horn manifolds on it. The donor car also had a 4 bolt Saginaw steering box... it ended up in a 71 Nova I had instead of the 40. Before the box the Nova was terrible to drive and needed an alignment... afterwards it was a pleasure to drive and the alignment was correct.

 

[Downey]

farpolemiddle, I sent you a PM. BTW, I was raised in Portland, hope you are "Keeping Oregon Green" for me.