hey guys, I am looking for some help trouble shooting an issue. having an issue with what I am guessing is heat in my transmission. Around town transmission shifts fine, but it would seem that as the transmission gets alot of power put through it, it feels like it refuses to go into gear like its syncros are not working at all. it wont shift into any gear, until i double clutch it and it goes back into gear and then all 6 gears and syncros work fine. the problem seems to be progressing worse. originally just happened when i was tuning for 15-16 psi through my 6258 after a lot of runs, i figured i just overheated the transmission because i was having problems going from 3rd to 4th. also felt like if i missed the shift by hitting in between the forks it would lock all gears out until double clutched. unable to tell if that issue is related. But I backed off and used high boost less. i installed some thermal shields on the down pipe between the exhaust and transmission to save it from direct heat. seemed to maybe help. but driving around today on wastegate psi of 10, after a number of consecutive shifts under boost it would seem to get harder to shift with each gear leading to being unable to shift into any gear without double clutching. pulled over and it felt like the clutch was unable to disengage and I could not shift it into any gear at a stop. I tried adjusting the clutch linkage, no change, tried pumping the clutch to see if i was losing pressure and couldn't get it into a gear. until i rolled it backwards with my foot out the door then pushed in the clutch and it went into gear. and then shifted into every gear fine. got going again. got to another straight to trouble shoot and gave it some boost and noticed it seemed the shifter started tightening up. at that point i called it and drove home without going full throttle and it shifted fine the whole way home. my current plan is to do a fluid swap, maybe i toasted the fluid or its just not holding up. if anything to see what it looks like. do you guys have any thoughts?

clutch is a flyin miata organic disk with a lvl 2 pressure plate.
transmission is from a 2000 that had about 121000 miles. filed with the ford motorcraft stuff and has a miataroadster shift kit installed.
currently has about 1300 miles at new power level

 

well I think i fount the problem. got it up on jacks and drained the fluid. looked fin. not to much glitter magnetic plug looked fine. refilling with mt90 and 1/4 lightweight shock proof. Upon going to refill i found that all the bolts holding the miata roadster shift kit in had loosened alot and one had backed most of the way out. must not have torqued the nordic washers enough. refilled and re torqued the shifter and took it on a test and gave it some pulls and shifted fine. might update if it comes back

edit: the problem came back

 

update. replaced master cylinder, slave cylinder and fluid. still same problem. looking into new transmission. might tear old one apart if i get a new one

 

Ditch that POS flyin Miata clutch and get a Supermiata/949 clutch. Or an ACT. Or almost anything besides the FM unit. They’re nothing but problematic for anyone I’ve encountered who’s run one, they’ve all experienced similar issues to you of the clutch working when cold or hot, but not both.

 

If all the gears have the same behavior likely could but hydraulic/clutch related. Not likely all the synchro's start dying together. Make sure your length for the master cylinder rod if also flush on the MC.

 

replaced everything on the hydraulics side and had no difference. Going for everything and got a new 6 speed from a msm and a 949 clutch disk on the way that I will install with the fm stage 2 pressure plate.

 

10 years and 30k miles of absolute abuse at 300+hp on mine...


Also, regarding the short shifter, are you sure you got the proper one? They changed shifters from NB1 to NB2 and you may have some weird mid model year since it's "a 2000 trans". Since it's super easy to do, can you put the stock shifter back in? Or really confirm with 100% certainty that it's the right short shifter?

 

I mean as certain as possible, no part number on the bushing that i can remember seeing. Email shows right one was ordered. Ordered a new bushing for the new trans. Only thing I am thinking now is I used the less than a year old normal throw out bearing with the fm stage 2 pressure plate. I have Seen some reports of it not engaging all the springs on the heavier pressure plate so I have also ordered a fm heavy duty throw out bearing. The car is up on stands and about ready to have everything taken out but I'm gone for a couple weeks. I will update the thread when I get everything out and look around. If it all looks fine I'm going to put the new trans in anyways and maybe take apart the old one and see if I can find anything apparently wrong.

 

I mean, as you probably know the 6sp can have issues shifting when they get really hot, the aluminum shift forks grow too much with heat and act up. I know the 949 guys had issues on a race car and I think added a cooler to solve the issue. I’m not sure what power level that happens at but from your description it doesn’t sound like it’s enough power/time/hot enough ambient temps to really be the culprit. But I guess before you tear the entire thing apart it could be worth trying a thermocouple in the drain plug to see what the fluid temps are getting up to.

 

I have heard of this and I thought that's what it was originally. But I thought that problem would just lock out a set of gears. Also the motocraft stuff I changed out didn't look or smell burnt. I think I saw 949 mention the az6 runs hot but I'm driving around in ambient temps no higher then 65. And I can reliably replicate the issue to be on hard acceleration. The more boost the faster the lock out. On 10 wastegate psi it's in 4 gear changes to redline. At 16psi by the time I'm going to 4th I'm locked out. City driving it will go all day through every gear just fine

 

Ah yeah, even from your initial description it didn’t really sound like the gearbox itself was overtemping.

So just to clarify, when you say “going to 4th I’m locked out,” you can shift out of 3rd but not into 4th? And it then wont go into any other gears?

Does it feel weird pulling it out of third? —I.E.excessive effort at the shifter and/or big clunk like it’s still having torque applied?

Lastly, any clutch slippage you can detect? I wonder if under full power the clutch is slipping, maybe not enough to really feel but still putting a huge amount of heat into the flywheel and pressure plate, and causing enough expansion to not fully disengage. Does that theory make any sense?

For that level 2 clutch FM claims a rating of ~350ftlbs at the crank so, what’s that, about 300ish at the tire? I’m not at all versed in turbo numbers/specs to know if that’s a figure you may be eclipsing. But also in 1-2-3 I’d wager tires would spin before slipping the clutch

 

yep will pull out of gear fine. Doesnt feel like its kicked out of gear or anything. I generally shift with fingers hooked to give the syncros a cushion, but when it lockes out it pulls out of the last gear it was in wether that's 2nd or 3rd or 4th and won't go into any other gear until about 15 sec of coasting followed by a double clutch Rev mach into any gear. Usually 3 or 4. But sometimes 2nd depending on how much speed I have lost due to coasting. Have had it lock out to a stop and had to push the car back with my foot while in neutral then it will go into any gear.


Your expansion theory makes sense but I'm not quite feeling any clutch slip. Never actually felt that in a car though. Power delivery is smooth though. Power shouldn't be that high, Similar builds should put me around 270? 280? Probably less. I Was waiting to get it dialed in before going to a dyno for the last bit of power. My ebc is also tuned in open loop with around 25 duty cycle till about 5k then ramping up to about 34 to redline boost cut is at 217kpa or 220kpa....the laptop is back on land so I can't quite give specifics on the tune for about 4 days

 

I come bearing (its a pun) news...and a question got it out and apart. besides smoking and breaking the CAS while taking it out. I think I found the problem. got the engine and trans out and it looks like the pressure plate ate the throw out bearing. yum. Upon re-reading some instructions FM says to use their heavy duty throw out bearing and I now see why. it has a much larger surface area for the fingers


sweet heat discoloration

the throw out bearing looked....not great, i dont remember putting that much grease on when i threw it in there



now regarding these spots, I imagine they are hot spots. or would they be something else? they don't feel to different from the material surrounding them. Am I overthinking them? I have a 949 organic disc ready for when I get the new pressure plate. but I have already had this flywheel resurfaced once. maybe 3k miles ago? maybe 5k? should I look into doing it again? order a new flywheel? I would be going from the FM organic clutch to the 949 organic clutch. or hit it with some emery cloth and send it? (partially joking)



current plan, wait for new pressure plate, figure out whether to get a new flywheel or not and slam it all back together with the lower mileage MSM transmission, heavy duty throw out bearing...and get a new CAS. maybe other minor clean ups and upgrades while the engine is out again

 

Your FM pressure plate and flywheel looks similar to the one I pulled from my MSM. Mine was probably never adjusted perfectly by the first two onwers, the Goldilocks zone was extremely small. I could barely get my stage one kit to fully release, FM recommended shaving or removing the rubber bumper pad to maximize pedal stroke as I already had the pushrod length about as long as I could get it without blocking the pressure bleed hole.

I put up with it while I saved to build another MSM engine and I considered an FM stage two clutch kit but I'm glad I purchased a Supermiata / 949Racing pressure plate and 4-puck sprung friction disc. It's been holding 18 psi for a few thousand miles (GT2560R, new higher flowing FM manifold/outlet pipe, 2.5" Magnaflow exhaust). The only negative issue has been squealing noise taking off in 1st gear, often shifting into 2nd, and getting started in reverse. The well designed pressure plate allows it to be slipped fairly easily despite being very grabby. It really wants to lock up and heats up quickly if you slip it, then it starts chattering but that only happens getting up my sloped driveway. First slipping to get up over the curb without grinding the nose or muffler tip, then again backing up to the garage, and a third time slipping to get moving once the door is fully opened. Otherwise, it's been great! I didn't want to drastically increase pedal pressure with the FM level two or ACT pressure plates, Ed suggested the 4-puck since I am at or just passing the limits of the organic friction disc with their PP.

Yep, I just went out to my scrap pile and confirmed, the FM PP fingers on mine look similar but the grooves aren't as deep. My flywheel looked worse than yours, I the ~10.3# flywheel (FM stage one clutch kit) resurfaced. A machine shop was able to resurface it, said the towers weren't all the same height from the surface so maybe my kit had multiple issues to begin with. The instruction state to make sure you can still push the slave piston back in by hand, if you adjust too far you can block an internal pressure bleed hole. It took me multiple attemps to get it just right so it fully released without adjusting the master pushrod too tight/long. I highly recommend the supermiata pressure plate, had to wait about three months for mine because they were backordered. Call and ask local shops about resurfacing the flywheel, it shouldn't cost much more than $125 on the higher end (here). I think I paid about $90-$95 because they had to cut deeper than they expected, my friction surface looked like a picture of a galaxy.

Lastly, beware of shops that might take your flywheel without telling you they are outsourcing the job. I first took mine to a local "clutch and u-joint" shop. They said they could resurface it but didn't tell me they were sending up north to another shop. The next day they called to tell me it wasn't possible, that the dowel pins couldn't be removed. When I realized it would cost $400 or more to replace it I drove back to get it before they scrapped it, only they didn't have it. They wasted three days of my time and lost any future business. I took the 3.63 ring/pinion gears to a different shop to install in my MSM differential.

 

Which of these throw out bearings did you use?

Hd left oem right


The sheer surface area looks like it would keep the problem from happening again. It almost looked like the pp was slipping off of the bearing and getting wedged on the inner face. Whats been ordered so far is

- another stage 2 pp for the higher clamping force. I dont find the extra weight really that bad and I have the right bearing this time. If it really is as important as it seems, FM should really include it with the pressure plate and raise the price.

-A 949 organic clutch. It's on hand, I'm hoping the extra clamping force will raise the held torque a little and im hopping if it does slip will be the weak point in the build "hopefully" saving the transmission from to much applied torque. I'm not looking to break any records, just hit the 300hp club and not have it grenade itself when I look at it wrong.

- An ACT streetlite 13.5# flywheel. Just a little shaved weight. Cause the speed this thing revs is quite terrible. BUT I still want it to not be miserable to drive around town and from what I have seen fly wheel weight will act as a damper to the transmission helping save it.

- a not broken cas.....
- and a new heating pad for the engine oil pan, one of casualties of this engine pull

I'm hoping these combination of things will make a working project

 

Either way you need to replace the pressure plate and throw out bearing, but I'd wager your pressure plate was loose, which side loaded the bearing a little and destroyed it. I've seen that from torquing a pressure plate once. I always go around a couple of times, and ideally, while very cost/time prohibitive, you go back and re-torque after some mileage.

 

The **** show continues. New pressure plate bearing and clutch are in and broken in. Trans shifts fine and clutch works. All good right? WRONG. Thought the clutch felt lighter. Bought a bore scope and it turns out FM sent me a level 1 pressure plate, they are just about impossible to tell apart unless you know what to look for. Just throw a new one in you say? Well I didn't think I would get the wrong part and I have already made an appointment for tuning and dyno runs on the 1st of July and I'm about to be gone for 2 weeks. I'm quite miffed by FM sending the wrong part. Current plan is now just send it for the tuning and pray I get near power goals

 

I guess a final update. The lvl 1 pressure plate, 949 clutch and 14# flywheel ended up holding 300 wheel torque. 291 whp. Tuned at ar motorsports. Decently happy with that. Limiting factor was the injectors which were ff640 and a bp05 head. They said with the bp4w I could have got another 20 hp with small changes

 

Oh damn, hi! I tuned this. Besides a few things I fixed in the beginning, your **** held up great. Clutch never gave me problems. Would have loved to do more, but more boost just wasn't making more power. You can kind of see it in the graph, it's pretty flat from 5500 to redline. I tried removing the filter, no change. Maybe an exhaust restriction? Seemed unlikely, hence I blame the head.

Also, ignore our wideband, it needs a new sensor and some cleaning, I tuned off your wideband, so ignore that graph. Shame on that graph, half of it is our shitty wideband. I logged all the dyno runs, I can post one of those if you want.

With your radium FPR at 60psi, the FF640s were no issue, I think you maxed out around 70%DC, so easily capable of 300+, but not too much more. You'll need E85 to make more than that anyways, and at that point you'd probably want ID1050x. Head just didn't seem to want to cooperate this go around.

I did compare yours to my 6758 (yours is 6258, yes?), and you definitely spooled better, but after 5000, my setup continued to climb to 330hp.

 

hello! people like you are a legend to me! I was telling martin when he was letting me ask questions I could be there forever! it is a 6258 indeed. Id take the extra spool for my street car over the head room of the 6758. My goal was to try and break the 300hp but this will definitely do until I want to do something again. It's been about a 2 year process and with being gone for about 7 or 8 months last year I just want to enjoy it. And the machine shop took 9 months to get my engine back to me

Sorry about the things you got with the inspection. Im not working with to much in terms of time and tools, and all the work has been solo... and I haven't really learned how to do big boy wiring, and I underestimated how much I was going to wire when the project started. Martin described the head issues i know i should have got a bp4w head but got caught up with other parts of the project. Also I live on the coast with no e85. And I dont know where the job will move me in less than a year.