Tranny / Clutch

I will try and best explain all scenarios. I just bought this car and will be taking tranny out to investigate, but requires some front rad support fix before I do. So place your bets.

2G: 6 Bolt Engine (20K). 7 Bolt Tranny. (Unknown Stage 2 puck clutch)

#1. Stopped. In 1st gear. Clutch in. Rev to 7500. (car does not move).

#2. Stopped. In 1st gear. Clutch in. Stalls

#3. Stopped. Neutral. Clutch Out. No Stall

#4. On an incline. Stopped. 1st Gear. Clutch in. Won't roll backwards.

#5. I have observed when up shifting from 3rd to 2nd, clutch in, once I hit second, RPM's come up and drop as if clutch were out.

#6. All shifts below 4K are painful to listen to.

#7. Locked out of all gears from a stop with engine on clutch in. Engine off. Mostly smooth getting into gears. (might be a little louder than usual?) I did notice that RPMS drop by 100 when attempting to get it into gear...



Thoughts? tranny? Clutch? Flywheel? Release fork requires shimming? Thanks in advance.

Chuck

P.S. Vent from top of tranny looks like it has been missing a long time. I changed fluids couple days ago (GM Syncromesh).. no change. (old stuff looked ok.. little dark, no shavings)

Are the numbers a progression of time? Or are you still able to rev to 7500 in first with the clutch in and the car not move?

If it is a progression of time, it sounds like clutch hydraulics to me. I would start by checking behind the boot on the master cylinder up by your clutch pedal, and checking the slave cylinder on the front of the tranny.

Well actually, I would start with a quick glance under the car for a small puddle of brake (clutch) fluid. Could tell you where to look next.

Edit: While unrelated to this issue, I would advise against synchromesh for these transmissions. The best stuff is Diaqueen, though lots of guys have had luck with MT90/MTL or a mix thereof for a cheaper solution.

Sorry. Not a progression of time.. if it were time...

#1. Car started stalling when cold with previous owner (I assume with clutch in and in first gear).

#2. Third was getting very notchy. When I test drove. It stalled once.

#3. Reverse became near impossible 2 days later. The 1st, 2nd then Reverse worked for a bit. But generally grinds. I just start the car with it in reverse already.

#4. Started getting lockout at stops. I was always taking off from second (easiest gear to get in) for awhile afraid of it not getting into any gear to take off.

#5. The RPM jump with clutch in and 2nd has happened a few times.

#6. Lock outs happening almost all the time now and gear changes either result in grind or VERY clunky. (There is a sweet spot between 3700 and 4200 that makes it bearable)

#7. I am almost certain pedal engagement is different between 1st and other gears. (been a week since driving it.. I forget).

The Clutch pedal rod to master cyclinder is adjusted as far out as it can go. The slave is pushing the release fork towards passenger side (gets past center).

There are no drips from slave (master and slave both replaced last year). I do have an unidentified light brown goo accumulating behind tranny.



As for tranny fluid, I have seen SOOOooo many arguments about which one to use.. I just grabbed what most people mentioned on DSMtuners. Honestly.. I just wanted to check condition of oil and look for shards. Refilled just to get me from Body Shop to Home to get that rad support fixed.

Definitely still sounds like clutch, but if you're not leaking fluid from anywhere, that would unfortunately mean the transmission will likely have to come off.

The brown goo looks like CV joint grease. I would check that boot right behind the crossmember there; I suspect you'll find it's torn.



I figured as much; I did the same at first. Unfortunately it's one of those large misconceptions due to the fact that shifting is generally improved immediately after putting it in. It's too slippery for our transmissions though, and you'll see accelerated synchro wear for sure.

Judging by its Viscosity, I would say dirty tranny fluid. Or diff fluid.

No, that's for sure CV grease, seen plenty of that in recent times.

Sorry; I'm theoretically supposed to be working right now and I must have skimmed past this the first time.

Can you push your slave cylinder back by hand? That is, grab your clutch fork and try to push the slave cylinder rod back into the cylinder. You should be able to push it in without much resistance.

I am theoretically supposed to be working too. DSM far more interesting



That's why I wanted to drain the tranny asap. But the fluid from tranny was the usual dark color. Not poo brown



It is very thick.. so you might be right about cv boot. I will take the wheel off tonight and see what is up.



Do I disconnect the rod from clutch first? Slave returns fully to driver side position when clutch is released. I only need to be taught once!

Nope, leave the hydraulics completely intact. You're testing to see if the auto-adjust valve in the master cylinder has been pinched off by overextending the rod. If it has, you won't be able to push the slave's rod back.

For the record, if it is pinched off, I unfortunately still don't expect that to be the main issue...just something you might as well fix while you're there.

Ugh. Tuner lug nuts with no key. No socket will grab them. Guess not tonight. Contacted seller. Thanks for help.

I watched jacks clutch adjustment video. Will try and check on things next week. Too damn hot in garage. Also, jacking from center member is scary with mid of front support rusted out as it is.

As mentioned, don't use syncromesh, not a good fluid for a DSM trans. Redline MTL or MT90 are much better options.

Definitely Mitsu CV grease, as mentioned, check the inner boot above the cross member.

Yup; CV Grease.

OEM Diaqueen, Redline MT90 or Motul Gear 300 are are best bets with these cars.

I've got Motul 75-90NS in my bros transmission and that thing shifts like extremely smooth. Its pricier than the Redline stuff, but you can feel the difference.

He isn't kidding about the Motul fluid. The bill will make you cry, but nothing takes away the sting quite like a buttery trans.

If you're going to fork out the extra cash, there's no reason to use anything other than Diaqueen. It is hands down the BEST thing you can put in a DSM transmission; its only downside is cost.

I managed to get Motul Gear 300 for $15 a quart in the US, so about the same as Redline, supposedly on par with Diaqueen as per Jon at TRE.

After reading through TRE's various oil recommendations, it turned me away from them quite permanently.

Motul is good stuff, and if you're getting it as cheap as Redline, it's a much better way to go. Diaqueen is specifically formulated for transmissions similar to ours with protection, longevity, and proper synchro engagement as the main focus. I don't believe for a second that Motul is just as good.

There's a lot of debate on oils, hell, Shep suggested a mix synchroshift.

I don't follow the word of one builder, I look at them all and voices of the racers and use what I think is the best price/performance ratio for my car and budget.

I've run the diaqueen, MT90 and now the Gear 300 in my Jacks built trans and they've all felt pretty much the same to be honest, I couldn't say any of them made it shift better or worse.

Tom from Tom's Turbo Garage recommends and uses Synchromesh.

At the end of the day I'd imagine the "best" oil is one that provides enough protection to extend the tranny's life, all the gears etc.

As to how that "feels", I'd guess it depends on the weight of the oil.

I remember going from whatever the hell was in my 1st DSM's tranny (was smooth), to Synchromesh, and tranny became notchy as hell, and started grinding.

My guess was that the Synchromesh was very light compared to whatever was in there.

As we've all probably read, the Synchromesh stuff isn't good for our specific tranny's syncros, as it reacts with the metals used in them.

I wonder if anyone has done a lab comparison of diaqueen vs the rest?

So small update: I adjusted clutch master rod back in a bit as I could not push release fork. Adjusted and now I can move by hand. Car will idle with clutch in and in gear. I still need to do a flush.

But before I do... I opened the dust cover for the release fork and a little friend fell out.



I poked and prodded inside with a rod and magnet. Other than fine dust, nothing else came out. So how does a flywheel / pressure plate pin end up falling out?

The other bad news.. center member to rad support bolts. The rad support (mostly right above the center member) is so rusted.. I can turn and wiggle both bolts by hand. Good new is .. the corners and about 12" in are in decent shape. So maybe only partial fix required?! Need to get that done before I can drop tranny. Does anyone know what all that wiring running through the front support is?

Anyway.. at least she is driveable. Once at operating temps, the shifting gets a little tougher, but bearable. Was nice to take her around for a few KM. She still doesn't roll back when in gear with clutch in. And I saw a rediculousy long 3rd gear with clutch in, rpms not dropping.

Hoping it's just a clutch or flywheel issue. May the tranny be spared. Fingers crossed.

Glad you unblocked the relief valve; that can become quite problematic.

Can't say I've ever seen a dowel pin fall out before, but given the shape it appears to be in, I'm willing to bet it got in the way at some point after falling out.

Still sounds like the clutch is dragging though. Do your synchros a favour: avoid any and all driving until this problem is resolved. I'm quite confident it is a clutch issue; the tranny CAN be spared, if you stop driving on it!

Consider it done. Next week I will grind away welds from center member, drop tranny and inspect. I'll post pictures.

I can deal with the center member / front cross member later.

I would still give the system a good bleed before dropping the trans, just in case. But the progressive nature of the symptoms, and the missing dowel pin, suggests to me this is more than just air in the lines.

There was a recent thread in the HELP ME! section that outlines the proper clutch bleeding procedure.

I appreciate all the help. I want to learn how to pull apart the front end anyway. So seeing I will have bumper and rad out.. Might as well look at the tranny.