Clutch slipping issue.

So I’ve put about 100mi on the 1uz swap. Things have been fine driving so far, but I took it out tonight and immediately noticed the clutch slipping. I wasn’t even getting on it hard. Just mild throttle input to accelerate uphill and it began acting like a CVT transmission. 

Im running a RAM hydro TOB (78100), a landcruiser 1” master, and then a 5sfe mr2 flywheel and these:

http://www.specclutches.com/605892/spec-stage2-pressure-plate-mr-2-stc732-525249

https://www.lceperformance.com/Pro-Clutch-Disc-20R-22R-RE-8-7-8-p/1053009.htm

Both the pressure plate and disc are rated for more than the engine outputs. (300hp rating, engine makes about 260tq when new)

https://www.lceperformance.com/Pro-Clutch-Kit-22R-RE-81-88-8-7-8-p/1053042.htm

I am noticing a drip from the clutch bleed line along the frame rail, so maybe the hydro TOB isn’t able engage fully? I wouldn’t think that would be the result, I would think it would just be hard to shift. It hasn’t ran the master dry ever. As far as abuse, I’ve only done two light burnouts and a couple 0-60 pulls to redline. (I know, I know... it’s hard to resist the power) 

Is it possible there's a leak inside (or getting inside) the bellhousing which could be lubing the flywheel/clutch surfaces?

I had that in a Samurai, oil ran down the timing mark hole onto the clutch.  44Dwarf suggested hot water & Dawn dish detergent down the hole; worked GREAT !!  Sorry that doesn't fix the leak, but will save a clutch replacement.

Good luck.

Good to know guys, thanks!

914Driver said:

I had that in a Samurai, oil ran down the timing mark hole onto the clutch.  44Dwarf suggested hot water & Dawn dish detergent down the hole; worked GREAT !!  Sorry that doesn't fix the leak, but will save a clutch replacement.

Good luck.

Wish I'd tried this when it happened to mine...a mechanic suggested I pour Coke into it (was an in-the-field quick fix), which worked for a little while, but I ended up changing the clutch.

In reply to GameboyRMH :

Rumor has it that a rally team with a slipping clutch once repurposed their windshield washer system into a clutch Coke injection system mid rally and successfully finished an event that way.

¯\_(ツ)_/¯ said:

In reply to GameboyRMH :

Rumor has it that a rally team with a slipping clutch once repurposed their windshield washer system into a clutch Coke injection system mid rally and successfully finished an event that way.

Reminds me of the story I heard of a guy who had the mechanical fuel pump on an old carbureted car die. He siphoned gas out of the tank and filled the washer fluid bottle with gas, then aimed the washer nozzles down the carburetor's throat and limped it home spritzing fuel down the carburetor every couple seconds with the washer pump 

Alternatively, are you certain that the TOB is fully disengaging from the clutch?

There you go.   Free play when the clutch is engaged.

Master cylinder pushrod is adjusted wrong, or the throw out bearing is too tall.

There is only one way to adjust a master cylinder pushrod.  With the pedal all the way up to the stop, the pin between the clevis and the pedal should be loose.  You should be able to install the pin without moving anything.

I have read too many stories on this board about adjusting pushrods incorrectly to not write this.  I'm sorry if I'm being pedantic.

Streetwiseguy said:

Master cylinder pushrod is adjusted wrong, or the throw out bearing is too tall.

There is only one way to adjust a master cylinder pushrod.  With the pedal all the way up to the stop, the pin between the clevis and the pedal should be loose.  You should be able to install the pin without moving anything.

I have read too many stories on this board about adjusting pushrods incorrectly to not write this.  I'm sorry if I'm being pedantic.

Can you dumb this down slightly for me? Im about to adapt a camaro clutch hydraulic system to a miata and would much rather have it right the first time. 

 The Hydro throw out bearing is set up from Xcessive to Manufacturing for this particular transmission to engine combination. I’m not saying that it is correct, I’m just saying that it was set up ahead of time for me. I did as ram says and measured the throw out extended length, The depth of the clutch cover to flywheel surface, and the free play in between. 

 If the throw out system didn’t have enough fluid in it I would think that it would be very difficult to shift gears, right? Whereas, currently, it is very easy and smooth shift between gears. When I get home tonight I will check the clutch pedal rod free play. 

 One question I had is do you guys think by doing those burnouts and hard acceleration that I could have damaged the clutch disk already? considering I drove it gingerly the first 25 miles, then gave it some hell, and then went back to driving it gingerly. I have read that you need to do the break-in procedure, but I have also read that you don’t need to really do that and that you can just drive the crap out of it right out of the box 

Dusterbd13 said:

Streetwiseguy said:

Master cylinder pushrod is adjusted wrong, or the throw out bearing is too tall.

There is only one way to adjust a master cylinder pushrod.  With the pedal all the way up to the stop, the pin between the clevis and the pedal should be loose.  You should be able to install the pin without moving anything.

I have read too many stories on this board about adjusting pushrods incorrectly to not write this.  I'm sorry if I'm being pedantic.

Can you dumb this down slightly for me? Im about to adapt a camaro clutch hydraulic system to a miata and would much rather have it right the first time. 

Oh man.  Are you using the stock htob?  If so, call me when you are near the car.  This took me a good amount of time to get right...  having done almost exactly what you are about to do....  I can help.

Do you have a drill press and calipers?

In reply to wvumtnbkr :

Yes and will do!

Gotta bit of fab and welding before clutch setup, but im doing my best to soak it all in prior to the day i need it.

Trackmouse said:

 

 One question I had is do you guys think by doing those burnouts and hard acceleration that I could have damaged the clutch disk already? considering I drove it gingerly the first 25 miles, then gave it some hell, and then went back to driving it gingerly. I have read that you need to do the break-in procedure, but I have also read that you don’t need to really do that and that you can just drive the crap out of it right out of the box 

Nope.  It might chatter or something if you treated it really badly, but no way it should slip, no matter how badly you might have abused it.

Dusterbd13 said:

Streetwiseguy said:

Master cylinder pushrod is adjusted wrong, or the throw out bearing is too tall.

There is only one way to adjust a master cylinder pushrod.  With the pedal all the way up to the stop, the pin between the clevis and the pedal should be loose.  You should be able to install the pin without moving anything.

I have read too many stories on this board about adjusting pushrods incorrectly to not write this.  I'm sorry if I'm being pedantic.

Can you dumb this down slightly for me? Im about to adapt a camaro clutch hydraulic system to a miata and would much rather have it right the first time. 

Pretty straightforward.  With the pedal at the top of its travel, sitting against the upper stop, the pushrod to pedal pin should slide in without having to move the pedal down, and no way on earth should you have to push the master cylinder piston down at all to make it slide through the pedal.  The pushrod should be slack with the pedal up.  Watching closely, you should be able to see the slack get taken up in the pivot pin by pushing down on the pedal a quarter/half inch or so, and the piston should then start to move.  .

Driven5 said:

Alternatively, are you certain that the TOB is fully disengaging from the clutch?

I cannot be certain, since it is hidden from eyes currently. 

In reply to Streetwiseguy :

Thanks!

Streetwiseguy said:

Dusterbd13 said:

Streetwiseguy said:

Master cylinder pushrod is adjusted wrong, or the throw out bearing is too tall.

There is only one way to adjust a master cylinder pushrod.  With the pedal all the way up to the stop, the pin between the clevis and the pedal should be loose.  You should be able to install the pin without moving anything.

I have read too many stories on this board about adjusting pushrods incorrectly to not write this.  I'm sorry if I'm being pedantic.

Can you dumb this down slightly for me? Im about to adapt a camaro clutch hydraulic system to a miata and would much rather have it right the first time. 

Pretty straightforward.  With the pedal at the top of its travel, sitting against the upper stop, the pushrod to pedal pin should slide in without having to move the pedal down, and no way on earth should you have to push the master cylinder piston down at all to make it slide through the pedal.  The pushrod should be slack with the pedal up.  Watching closely, you should be able to see the slack get taken up in the pivot pin by pushing down on the pedal a quarter/half inch or so, and the piston should then start to move.  .

Thank you for posting that! Just got done looking at the push rod of the master, it’s all the way against the back of the clevis and pedal arm. And the lock nut was loose... so I’m thinking when I installed it I forgot to adjust it. But, it’s looking like the push rod’s threaded end is too long. So I’m thinking I’ll remove the master, cut some threads off, and then have adjustability. 

The other option would be to create a master cylinder spacer, but I have absolutely no way of making that. My fabrication buddy is leaving at the end of the month and he is tied up till then. 

Can the push rod be removed from the master cylinder without removing the whole master? I’d like to not have to disconnect lines and getting the master in there was a PITA. For reference: 1986 landcruiser clutch master 

Unless you can come up with a way to cut it while it's still under the dash, it needs to come out.

Edit: You might be able to pull the boot off and snapring out of the master to get the pushrod out, but you run the risk of losing the guts of the master on the floor.  I'm 6'2", 260, and I don't fit under dashboards well... I'd rather pull it out the front.

Ok, thanks. I’ll remove it, too much ish under the dash to get a grinder in. 

So what if I back the mounting bolts out, replace them with longer bolts, and then use washers to shim the clutch master out about 1/4”? That way the push rod is also backed out 1/4”. Any reason the entire master cylinder body would need to sit completely flat on the firewall? Would it be ok resting against just the washers on the firewall?

I wouldn't call it ideal, but it should work.  I'd be worried about odd stress on the firewall in the long term.

Dusterbd13 said:

In reply to wvumtnbkr :

Yes and will do!

Gotta bit of fab and welding before clutch setup, but im doing my best to soak it all in prior to the day i need it.

I'm pretty sure you are going to need to order tick performance htob spacers.  I had to in this arrangement.