FM146 Won't Engage

[ArizonaRanger]

I've got a 91 Ranger: 2.9 with the FM146 Transmission.
I was driving down the freeway in 5th, when something went wrong. I'm not exactly sure what, but it felt like the truck kicked itself out of gear and into neutral. I pressed on the clutch, and it went straight to the floor with no resistance. I pulled the shifter out of the 5th gear slot, and coasted to the shoulder to call a tow. After a while of waiting, I tried the clutch again, and it seemed to have pressure now, giving a normal amount of resistance, but the shifter won't go into any gears, even with the clutch all the way down.
My first thought was a problem with the hydraulics. I checked the fluid a couple of weeks ago and it looked fine, but I'm going out to check again.
Has anyone had a similar problem, or perhaps knows what it might be. I'm willing to do my own work on it, as long as I know what I'm trying to achieve.
Thanks

 

[adsm08]

Sounds like the slave popped. What you described is pretty much what happens when they go.

I'd plan to do all the hydraulics (buy a pre-bled kit and thank me later) and a clutch while you are there.

If you have a few extra dollars to spend on the job the 4.0 clutch upgrade is nice.

 

[RonD]

So trans won't shift even with engine off?

 

[ArizonaRanger]

I just tried it, and with the engine off, it went into 1st and Reverse, and I could wiggle it into 2nd. I started it up in 1st, and let out the clutch and nothing. I could still get those three gears and only those three, but it wouldn't catch in any of them.

 

[adsm08]

Ok, maybe not the slave.

It's still time to take the trans out.

 

[ArizonaRanger]

Thank you for the advice. Just to update, it's running again. I took it to a shop I trust (since I myself don't have a lift) and they pulled the tranny. Apparently I had developed a leak, and all the fluids drained out of the transmission. It overheated, and sheared the input shaft completely off, as well as wrecking the gears. So new tranny, and new clutch, slave, etc. while it was out. Runs like a charm now.
What kills me is that I do complete checks every three months, and it blew up a week before the next check I was going to do, when I would have spotted the lack of fluid.

 

[adsm08]

Maybe you should step up your schedule.