MX-5 Miata Forum > NA/NB (1990-2005) Miata > NA (1990-1997) General Discussion > '96 5 speed. Let's talk shift forks.
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Kymmie420
2nd July 2015, 08:58
Ok so I'm pretty bummed. My '96 5 spd that I bought in April is a nice lawn ornament at this point. I was driving on Father's Day evening, coming up on a red light, engaged the clutch and felt something give in it. Tried shifting into first and couldn't. Pumped the clutch a few times, no dice. Couldn't shift into ANY gear. Replaced clutch master cylinder and clutch line when I bought the car. We replaced the slave last week on the off chance it failed, but from under the car, you can see the new slave working when someone is pressing the clutch. So my bf says my shift fork probably broke or bent, which he said is a common miata issue. This is my third miata and I haven't had this issue before :-/
I can't find one to buy a replacement.
What's the chance that this is the issue?
Also, I have three other parts miatas right now, can I pull the shift fork from one of my other trannys? Generally I would just do it but the other miatas are 1.6L and this one is the 1.8L.
What are yall's opinions on this?
What's the easiest way to replace a shift fork? Should we pull the tranny to do it? Or I have a friend with a rack I could put the car on and raise it to get to everything from underneath, would that be the easiest method?
FYI, I did remove the console to ensure that there wasn't just something that got stuck in the shifter, keeping it from shifting gears, nothing was in the way.
Tim A
2nd July 2015, 11:40
FWIW...I've never heard of a clutch fork breaking on a Miata. Not saying it can't happen, just that it would be news to me.
That said, all NA Miata use the same tranny. So you should be okay with any or all related parts from one of your donor vehicles. AFAIK, you will need to pull the tranny to service.
redbone3
2nd July 2015, 13:12
Can you shift the transmission when the engine is not running? If you can then it could be the shift fork or the pressure plate or some other clutch related problem. If you can't shift it with the engine turned off you have a transmission problem.
gtxhawaii
2nd July 2015, 13:33
As Tim says, most clutch or transmission work means the trans has to come out. If actual parts damage, often cheaper to swap the trans or clutch from a parts car. Hydraulics the most common issues, shift lever bushings next, then clutch mechanical failures, actual internal trans failures are most rare.
Be Sure the clutch fork is moving close to an inch. Pulling a trans in order to find out you have clutch hydraulic issues gets irritating.
Kymmie420
2nd July 2015, 14:12
I can shift with the car turned off which is why I don't think it's the tranny itself.
I have ordered a new clutch to replace the oem clutch on the car just to be on the safe side. I just don't know. Lol. I'm pretty good with engine work and other things but when it comes to trannys and whatnot that's not something I know much about
no rotors
2nd July 2015, 14:37
Does the clutch pedal have a different feel to it now, since the problem popped up for the first time?
If so, how is it different?
Does the gear shifter feel any different? If so, how?
Kymmie420
2nd July 2015, 14:49
Does the clutch pedal have a different feel to it now, since the problem popped up for the first time?
If so, how is it different?
Does the gear shifter feel any different? If so, how?
Yes, I noticed immediately after I felt the "give" that the clutch pedal became very stiff and harder to press than before.
pacomutt
2nd July 2015, 14:59
Hi again Kymmie, It's highly likely you only have a hydraulic problem as opposed to a mechanical transmission problem. A little tip: next time you're at a red light, and can't shift into first, just shut the engine off and then shift into first. When the light turns green, and you can safely go, start the engine and accelerate normally. You'll probably even be able to upshift with little struggle. Hey, it beats sitting in traffic in an intersection, and will let you get to a place where you can safely pull over.
If you still have the old metal clutch line, they are very difficult to bleed the air out without a power bleeder. I prefer these lines over the flexible lines, however. Since you recently worked on the slave cylinder, you need to go back to the basic hydraulic problems that these systems have.
no rotors
2nd July 2015, 17:21
+1 - As GTX said, see if there is about an inch of movement at the clutch release arm.
Don't go pulling out the trans until every other possible external cause has been proven to be ruled out. Don't guess, don't assume. Prove every component in the entire clutch system from the pedal to the clutch fork works as it should:
The adjustable push rod at the top of the pedal, the master cylinder, the flex line, the slave cylinder, and its push rod.
Check and double-check to verify the correct operation of all of them.
Kymmie420
3rd July 2015, 02:24
Hi again Kymmie, It's highly likely you only have a hydraulic problem as opposed to a mechanical transmission problem. A little tip: next time you're at a red light, and can't shift into first, just shut the engine off and then shift into first. When the light turns green, and you can safely go, start the engine and accelerate normally. You'll probably even be able to upshift with little struggle. Hey, it beats sitting in traffic in an intersection, and will let you get to a place where you can safely pull over.
If you still have the old metal clutch line, they are very difficult to bleed the air out without a power bleeder. I prefer these lines over the flexible lines, however. Since you recently worked on the slave cylinder, you need to go back to the basic hydraulic problems that these systems have.
I know I could have shifted into first with the car off and drove it, but my bf did not want me to do that and said if I did that he wouldn't help me fix it.
I replaced the clutch line with a stainless steel clutch line and it was bled, it's worked fine for the past two months until this :-/
Kymmie420
3rd July 2015, 02:26
The adjustable push rod at the top of the pedal, the master cylinder, the flex line, the slave cylinder, and its push rod.
The line, slave, and master are all good, we've checked them. I'll see about checking the other externals this weekend and see if it might be something more simple before pulling the tranny, we don't want to have to do that. We've already pulled two trannys from miatas since February.
Kymmie420
3rd July 2015, 02:27
Does the gear shifter feel any different? If so, how?
No the gear shifter doesn't feel any different other than being unable to shift into any gear with the engine running
Meierznutz
3rd July 2015, 03:22
Kymmie, since you replaced the master and slave I vote for re-bleeding the system to see if there is improvement. If you can not get the pedal back then change the trans. Since you have two, use the one with lowest miles as they all fit the same. I would drop a new clutch in it while the trans is out. 1.6 and 1.8 are also interchangeable as long as you use the proper flywheel to match. Best of luck!
1990MX5
3rd July 2015, 09:57
My clutch fork broke so it is in fact a possibility. I had over 300k miles on the car when it happened so YMMV. Also might be a good idea to replace the clutch fork pivot if you do need to replace the fork.
owm
3rd July 2015, 09:58
Something like this happened to me 2 months back. Was driving halfway when I suddenly was unable to change gears. Pumping the clutch pedal multiple times I could shift but was not a sure-thing.
I could shift into all gears when the engine was off but once it was fired up, I was unable to shift into any gear. There was heavy resistance and you could hear the internals grinding if you tried to force it in.
Turns out my pressure plate had a single broken finger:
https://scontent-kul1-1.xx.fbcdn.net/hphotos-xpa1/v/t1.0-9/11224274_495026873981820_230913106927501913_n.jpg? oh=c6b3a2b47f34b57f7f6628613217a839&oe=560EFEF5
Replacing it cured the issue. So if you are sure your master and slave clutch cylinders are in good nick, no air bubbles in the system and you are able to shift easily when the engine is off, it could be that :/
gtxhawaii
3rd July 2015, 19:14
Yes, stuff breaks. My last clutch job was a medium mileage '95 that shifted funny at times, then jammed up totally. A clutch hub spring had busted and one of the pieces finally stuck sideways and wouldn't let the clutch disengage. But I looked for everything outside the bellhousing before I pulled the transmission.
MillBasin
20th September 2015, 21:42
Hi,My 95 M with 64K would not shift while running. Shifted when not running .Clutch is soft. Could i drive it in 2nd gear to get it to repair shop? No engine noise. No fluid leaks. Thanks
pixel wrangler
20th September 2015, 21:53
Release fork possibly broken? Any gurus here know how to check short of pulling the trans?
http://dave.oc7.org/gallery/29234-1/DSC_8812.jpg
Ron
Black
20th September 2015, 22:22
Release fork possibly broken? Any gurus here know how to check short of pulling the trans?
http://dave.oc7.org/gallery/29234-1/DSC_8812.jpg
Ron
It's real simple:
IF the dang slave-cylinder rod is moving back and forth when someone pumps the clutch pedal and you are still having clutch/tranmission issues then it's time to open up the tranny. period.
most common cause is worn clutch parts, but could be tranny parts... you will know once you get insise and look...
damaged clutch, busted pilot bearing, shamrocked release bearing, cracked release bearing fork
IF the car won't shift when its OFF then the gearbox itself is buggered...
again this will be obvious once you get inside...
broken shift forks, busted bearings, worn syncros, etc...
vkeith
21st September 2015, 00:23
Hi,My 95 M with 64K would not shift while running. Shifted when not running .Clutch is soft. Could i drive it in 2nd gear to get it to repair shop? No engine noise. No fluid leaks. Thanks
Yes, you can drive it in any gear that you can get it to move with. If the pedal feels soft and there is no fluid loss, your master is probably leaking internally. If you can pump the pedal several times and get the pedal back momentarily, it's the master.
They are very easy to change out, and a master is only $20 at most auto parts stores. IIRC, you only need a 12mm socket, a 10mm flare nut wrench, and a small wrench for the bleeder (6mm, I think).
You may also want to check the flex line for bulges. Have someone repeatedly press and release the clutch pedal while you feel the flex line for bulging. Flex lines aren't a common failure part like masters and slaves, but they do occasionally fail.
1990MX5
21st September 2015, 07:50
The shift fork cracked on my 90 and made it extremely hard to shift. Symptoms of bad hydraulics. Changed the master and slave but it was the fork all along.
toolinalong
21st September 2015, 18:31
Re #18 , un bolt the slave , remove the rubber bellows from the release fork and have a look as best you can .
gtxhawaii
21st September 2015, 18:54
Re #18 , un bolt the slave , remove the rubber bellows from the release fork and have a look as best you can .
The busted shift forks I know about were at the pivot pin. Or the pin snapped. This shows with the boot removed. If the push rod and fork movement are right, you probably have to pull the transmission to inspect deeper.
Jaeger
21st September 2015, 20:31
If the push rod and fork movement are right, you probably have to pull the transmission to inspect deeper.
I've never been able to find a spec for how much movement the slave and fork should have. Mine has maybe 13mm of movement but I don't know if that is within spec or not. Does anyone know what the spec is?
Black
21st September 2015, 20:45
I thank it moves about a 1/2" to 3/4" of an inch...
if the thing is moving then the clutch hydraulics are OK...
again, if the slave is moving enough to push the release bearing fork, then its NOT the hydraulics, and its time to drop the transmission..
.
toolinalong
22nd September 2015, 18:43
Bill the fella ask for a way to look before he pulls the trans . Have you tried this method ?
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