65 replies to this topic

[HoneyBadger - BrianW]

I am finishing up the installation of a new transmission in my 99. I have the tranny back in, the PFF bolted back up and I was re-installing the drive shaft and noticed that I cannot rotate it by hand. At first I thought this was because the transmission was in gear, so I reinstalled the shifter and it is definitely in neutral. This does not seem right to me. I don't yet have the clutch slave installed so I can't just have someone put the clutch in to test it yet. I also installed a new clutch (ACT 4 puck unsprung), I used the alignment tool. I am fairly confident that I got the transmission aligned properly as it did not require much force to get it to mate up to the engine.

Maybe I am just over thinking this and as soon as I finish up everything will be fine. I just can't understand why I can't rotate the drive shaft with the tranny in neutral. Also, I cannot force the car into gear. Maybe it was just my old worn out tranny, but I could always get the car in gear without using the clutch.

[Cy Peake]

E-brake engaged?

[HoneyBadger - BrianW]

Unfortunately no it isn't. I can spin the rear wheels freely, they just don't move the drive shaft. I probably just need to get the clutch slave hooked back up and everything will be fine, it's just bugging me why it wont spin freely. That and I wanted to make sure I wasn't being stupid and there is some retaining pin that a new transmission ships with that I need to remove. Also, I was wondering whether it is possible to activate the clutch manually by pushing on the clutch fork.

[tony senese]

Unfortunately no it isn't. I can spin the rear wheels freely, they just don't move the drive shaft. I probably just need to get the clutch slave hooked back up and everything will be fine, it's just bugging me why it wont spin freely. That and I wanted to make sure I wasn't being stupid and there is some retaining pin that a new transmission ships with that I need to remove. Also, I was wondering whether it is possible to activate the clutch manually by pushing on the clutch fork.

yes the clutch will disengage if you just push the fork rearward.

[Sphinx]

Also, I was wondering whether it is possible to activate the clutch manually by pushing on the clutch fork.

In theory, yes, assuming that you've got enough strength and leverage. But it is hard as hell for my puny arms. Remember, to move that clutch fork, you are pushing on the fingers of the pressure plate. A stock one will move much easier than an ACT one, for example. But both will be hard to move (for me anyways).

If it isn't spinning freely (well, not totally free), then make sure you don't have a problem on the diff side. I'd disconnect one side of the shaft and turn it. Then try the other. That will isolate the issue at least preliminarily.

Can we start at the beginning, why did you drop the trans to begin with? Are you positive that you could freely spin the driveshaft before you dropped the trans?

[Qik Nip]

Brian:
If the transmission is in neutral, the cluch is not in play as far as rotating the drive shaft is conserned. If you have the drive shaft detached from the diff flange and you can't rotate it with the shifter in neutral, then the transmission has issues. Sorry to be the bearer of bad tidings.
Rick

[FTodaro]

If the transmission is in neutral the transmission should rotate freely. A dumb question I know but is the rear tires free and off the ground if they are and it does not rotate then you have a transmission issue.

What was the reason for taking it out, did you have it rebuilt? I just rebuilt mine and I bench tested it to make sure it spins free and shifted on the bench. Give us more information but its not sounding good.

[HoneyBadger - BrianW]

Can we start at the beginning, why did you drop the trans to begin with? Are you positive that you could freely spin the driveshaft before you dropped the trans?

I had a clutch that was slipping badly and needed replacing. I also had a nice grinding on 2-->3 shifts, so while I had the tranny out for the clutch I decided to replace it with a new OEM tranny. I replace the clutch and pressure plate with the ACT 4 puck, the flywheel and pilot bearing with new OEM and the throw out bearing with the ACT bearing. I know the diff was spinning freely with the old tranny as I had to rotate the drive shaft and diff to get to the bolts on the end of the drive shaft out.

Brian:
If the transmission is in neutral, the cluch is not in play as far as rotating the drive shaft is conserned. If you have the drive shaft detached from the diff flange and you can't rotate it with the shifter in neutral, then the transmission has issues. Sorry to be the bearer of bad tidings.
Rick

If this wasn't a brand new transmission I would be more suspect that there is something wrong with it. But I have to be honest, it is much more likely I screwed something up than my new transmission having issues. I was wondering if something could be slightly binding up in the bearing/pressure plate/clutch area after putting the tranny on and activating the clutch would straighten it out. At this point I am going to reattach the clutch slave, bleed it and see where that gets me. Then if things are spinning freely, I will pull the tranny again.

EDIT: I am pretty sure the tranny is in neutral... It certainly feels like it is, but I don't have any hydraulics on the clutch slave at the moment so I guess it is possibly I am wrong and just a dumb ass.

Edited by BrianW, 03-22-2011 08:41 AM.

[HoneyBadger - BrianW]

If the transmission is in neutral the transmission should rotate freely. A dumb question I know but is the rear tires free and off the ground if they are and it does not rotate then you have a transmission issue.

What was the reason for taking it out, did you have it rebuilt? I just rebuilt mine and I bench tested it to make sure it spins free and shifted on the bench. Give us more information but its not sounding good.

Yes, the rear tires are off the ground and they spin freely along with the plate that the drive shaft bolts up to. I first noticed this when I was trying to rotate the drive shaft to align the bolts that attach the shaft to the diff.

[dmathias]

Step one: replace and bleed slave cylinder. Verify trans is in neutral.

Possible problem - trans is stuck between gears - it happens. Someone showed me a trick once where they inserted a screwdriver into the speedo drive hole and move something to un-jam the trans. Don't know what though.

Anyone?

[FTodaro]

All I can tell you is that if the transmission is verified it is in neutral and the tail shaft will not rotate, its not something you did or did not do with the clutch. Think about what you do when its in Neutral you can roll the car around your shop with the clutch engaged. So if the input shaft is not rotating the tail shaft will rotate when its out of gear. So to me if you are 100% certain its out of gear, then its more likely the transmission and not an error in the clutch or transmission install. At this point if you are that far into it just try cranking over the motor with the starter out of gear and see what you get. Just disconnect the plug wires to see what it does or turn the crank by hand to see if you got a log jam in there.

The good news is if its the tranny and its new I assume you get a free be.

[Glenn]

All I can tell you is that if the transmission is verified it is in neutral and the tail shaft will not rotate, its not something you did or did not do with the clutch. Think about what you do when its in Neutral you can roll the car around your shop with the clutch engaged. So if the input shaft is not rotating the tail shaft will rotate when its out of gear. So to me if you are 100% certain its out of gear, then its more likely the transmission and not an error in the clutch or transmission install. At this point if you are that far into it just try cranking over the motor with the starter out of gear and see what you get. Just disconnect the plug wires to see what it does or turn the crank by hand to see if you got a log jam in there.

The good news is if its the tranny and its new I assume you get a free be.

+1

[HoneyBadger - BrianW]

Thanks, that is what I was thinking as well. I am going to finish installing the clutch slave and run through the gears just to make sure something isn't stuck or hung up because the transmission is brand new. If things are still not working I will yank the transmission back out.

[john mueller]

Possible problem - trans is stuck between gears - it happens. Someone showed me a trick once where they inserted a screwdriver into the speedo drive hole and move something to un-jam the trans. Don't know what though.

Anyone?

Weird things sometimes happen to transmissions when they get shipped... Really not uncommon for it to get stuck between gears.

I've never done the screwdriver trick but I've heard it works. But I though it was through the neutral safety stitch hole, or is it the back-up light switch... Maybe search the archive of the old site or search on miata(dot)net on how to do it.

[HoneyBadger - BrianW]

Weird things sometimes happen to transmissions when they get shipped... Really not uncommon for it to get stuck between gears.

I've never done the screwdriver trick but I've heard it works. But I though it was through the neutral safety stitch hole, or is it the back-up light switch... Maybe search the archive of the old site or search on miata(dot)net on how to do it.

The stuck in backup issue is fixed by putting a stubby screwdriver in the backup switch slot.

[Cy Peake]

You should be able to shift the transmission (motor off) without the slave cylinder attached. So it should be easy to find neutral.

[FTodaro]

After having thought about this for a bit. I think I would recommend getting the shifter partially installed so you know that you are in what gear, I would then put it in first gear and put a wrench on the front crank bolt and turn if a see if it will move the car forward. Then I would put it in reverse and do the same thing then put it in neutral and crank it a turn or two then go under the car and see if things are normal. If its stuck I would yell a real loud expletive and call a pro. at that point.

[HoneyBadger - BrianW]

I do have the shifter installed and am pretty sure at least the shifter thinks the car is in neutral. After talking with Ed Gilfus, he recommended sticking a pry bar in the U joint and giving it some gentle persuasion. He indicated that it is pretty easy for some of the internal 4th gear mechanism to get bound up and will most of the time come loose with a little force. I also cannot get the shifter to go into any of the gears. It will move left and right through the gates, just not into a gear.

[FTodaro]

I may have an idea of what happened but how to un jamb it is another story. When I was rebuilding my transmission, at the point that I had disassembled the transmission to the point that the shift rods and shift forks were removed, you can shift two of the hubs into gear so that it locks the main shaft and remove some of the nuts on the main shaft that hold on gears. In other words you have 3 shift hubs that share shifting between gears 1/2 3/4 and 5/R normally only one hub is engaged at a time were if the first gear hub is engaged the other two hubs are in neutral.

so if you wanted to lock the shaft you put two hubs in gear at the same time that would freeze the shaft. if some how two of the hubs engaged, that would lock up the tail shaft. If you can get them back into position all is good.

If your other suggestion does not work I would try shifting through the gears and see if you can hear the hubs going in and out of gear.

[HoneyBadger - BrianW]

Stuck in reverse!!!

It turns out that the reverse shift rod was stuck. You can fix it by removing the backup switch and manually moving the shift rod back. While this is possible with the transmission still attached to the car, I wasn't able to do it. I ended up removing the tranny, pulling the backup switch and once I could see what I was doing it was easy to push the reverse shift rod back into place. Knowing what I know now, it would be easy to do while on the car, but you would have to have done it once before to know exactly what you are supposed to do.

I now have the tranny back in the car with the drive shaft attached and spinning freely. It sucked to have to pull the tranny again, but I must say that I am getting pretty good at it now. LOL just under 2 hours to remove the drive shaft, loosen the PFF, remove the clutch slave and starter, drop the tranny, fix it and put it all back together.

I appreciate all the help and suggestions everyone provided. You guys(gals) make this a great place to come for help.