View Full Version : 6 speed rear seal

Joe Morreale
07-03-2011, 11:13 AM
I recently replaced the rear seal on my 6 speed trans as it was slightly weeping fluid. One month later it is weeping again. My friend at a trans shop said that it might need a tail shaft bushing. Is anybody familiar enough with the six speed to know if there is such a bushing and what sort of labor involved in replacing. The leak is hardly anything but I hate to see me $25. a quart trans fluid land on the driveway.

07-04-2011, 08:46 AM
I know on the 6-speed, there is a bushing, a plug and then the rear seal at the end of the shaft. Normally, all that's needed is the rear seal. Did you put it in yourself or did you make sure it is seated properly? If it's still leaking, I doubt it's a bushing. As for the plug, the only way to get that out is to pound it out from within the case using a hammer and long rod so you can imagine what that'll cost to disassemble the tranny enough to get to that point.

Joe Morreale
07-12-2011, 05:04 PM
I didn't install the seal. A transmission man did. This is the second new seal he's put in. I'm sure they have been installed properly. To get to the plug and bushing I'm assuming the tailshaft must be removed. Can this be done while the transmission is still in the car? I'm probably going to have to tolerate this leak for a long time as it sounds expensive to fix but I hate leaks.

07-15-2011, 08:23 PM
Sorry for the delay. No, tranny has to be out.

Joe Morreale
07-16-2011, 09:42 PM
Definitely going to have to wait. I'll just keep an eye on my fluid level. It's hardly leaking, leaving one or two drops in the driveway overnight but i don't know how much tranny fluid I'm losing when driving. Is is pulling the plug then filling until it overflows the only way to check the fluid? It's such a P.I.T.A., especially without proper jacks.

07-17-2011, 01:42 PM
Afraid so. I'm just wondering if a sensor can be used instead of the fill bolt. Perhaps also, you could drill and tap a hole in the tranny's top plate so you can get to it quickly and pour a little fluid in every few months (6-speed only).

I haven't seen a Miata yet that doesn't drip something somewhere, except mine of course. ;) j/k Most of the time, fluid leaks from a rotten or torn lower shift boot and then down the tranny. It may look like a rear seal at first but can be traced back up to the boot. I know in your case, it's a relatively new boot since I'm the one who installed it. No way it's worn out in a few months.

Joe Morreale
07-18-2011, 10:55 AM
If you were to try and top off your trans by removing the shifter could you see how much fluid you need? Or is it back to that fill bolt again.

07-18-2011, 04:45 PM
I haven't seen a Miata yet that doesn't drip something somewhere, except mine of course. ;) j/k
Ad mine to that list. Although that evaluation is not quite fare since you drive yours so infrequently. I did spend a fortune fixing the leaks and things have stayed dry to date. It's a beautiful thing.

Joe Morreale
07-30-2011, 09:27 AM
Rear seal seems to be leaking worse. I'm going to have to check to fluid. I'll probably top it off with regular dino fluid even though I have fifty bucks worth of Motorcraft in it. My friend the transmission guy thinks I need to replace the yoke, bushing and seal to guarantee it won't leak again. I wish I could pull the trans myself, it would save me a bunch of money. I don't have the equipment. This has been an issue since I got the car with 25k on it.

07-30-2011, 10:21 AM
If you're going to go that far, you might as well do the clutch but I know it's easier to say it than pay for it. Just the fact that you recently had the rear seal done makes me wonder if it's not installed correctly. I mean, it shouldn't be leaking at all.

Joe Morreale
07-30-2011, 10:48 AM
This trans hasn't had the rear seal not leak for more than 3 months at any time since i owned it. It starts off as barely weeping then gets worse. I think maybe when the dealer installed the clutch they cocked the drive shaft or something at some point. Maybe damaging the bushing or the joint at the yoke. I don't know. It has had 3 rear seals in it in 65k. Your right about not being able to afford a clutch as it would be the wise thing to do it that point, but I can't. I am sacrificing my bodywork funds for this transmission work.

07-30-2011, 11:12 AM
That's a 6-speed, isn't it? Perhaps consider trading it for a low mileage 5-speed?

Joe Morreale
08-08-2011, 04:55 PM
What I thought was transmission fluid on the driveway turned out to be motor oil. The oil line on top of the valve cover was leaking down the bellhousing to the back of the trans. I put it up on a lift to check to trans fluid when i discovered my oops. 3/8 of a turn tighter and I hope it got rid of the leak. The trans was down less than a couple ounces, so I'm not that concerned about it at this time

08-09-2011, 08:00 AM
How many miles do you have on it?

Mine is starting to sweat oil as well... so I've already ordered the required parts so I can change them while I change the water pump & timing belt.

Joe Morreale
08-09-2011, 09:54 AM
About 85k. The seal that was leaking was the pipe joint at the back of the valve cover. The one with the copper washers.

08-09-2011, 12:03 PM
ohhh... ok! though it was the Cam Cover Gasket... I guess is normal to start having some leaking with this amount of miles.