M5R2 issues...

 I'm hoping someone here has run into similar issues, or has some ideas. In short I bought a rebuilt transmission for my 90 f150. After installing it, the transmission doesn't seem to want to shift properly. I also replaced everything else, clutch, flywheel, pilot bearing, slave cylinder, master cylinder & line. I've even pulled the pedal assembly and checked the bushings. Anyway it doesn't want to go into gears intermittently. It gets easier to shift if you do things like go to 3rd first, then reverse. It also seems that first to second gets easier if you really get on it and shift very quickly. I can also shut it off and shift through the gears. And when i jump back in its stiff to shift again. I've also taken it to a really good mechanic locally to double check everything and he couldnt find anything wrong, he also re-bled the clutch. I'm wondering if it could be a pilot bearing issue, or possibly a weak slave cylinder that works just well enough. Grasping at straws lol. Anyway if anyone has any advice it would greatly appreciated. And i'll probably post up some pictures later of the truck. She's lowered and sechhh

I had this problem with my swapped 3400 into an rx7.  It was because the clutch wasn't fully releasing.

I could turn the driveshaft by hand with somebody pushing the clutch, so I thought it was good.  Nope.

You basically need to be able to fit a ziptie between the clutch disc and the flywheel surface to ensure it is releasing properly.   I did this by drilling a hole in the bell housing and sticking about .040" of feeler gauges in there.

My issue was that it was not bled enough.

That certainly sounds like you're not getting full clutch disengagement.

Make sure the firewall isn't flexing or cracked around the clutch master. Fairly common problem for these trucks, there's a reinforcement kit available for this area.

The last time I installed clutch hydraulics in one of these, the bleeding procedure was some sort of self-bleed involving pumping the pedal rapidly for a long time, rather than bleeding with a bleeder screw. It's been a while though.

 Thanks for the info. I did check the firewall, and on my truck there's a little metal plate on the inside of the cab that the clutch MC bolts to. That and the firewall itself looked good. Just in case i painted the bracket lol. I will be pulling the trans out again when I get the fortitude, and double checking everything. Perhaps even replacing the SC as much as I hate to just throw parts at it. I almost wonder if the pressure plate bolts aren't tight enough. This is most likely happening because I didn't enjoy a winter transmission replacement in the gravel enough the first time. Anyway i'll let you guys know what i figure out...Or at least a cool picture of a truck on fire.

I wouldn't tear it apart yet.  Try a vacuum or reverse or pressure bleed first.

If you pp bolts were loose, it would still disengage.  Also, it would probably make an unholy racket.

Did you struggle getting the trans in?  It's pretty easy to bend the center of the disc if you let the weight of the trans hang on the clutch before you bolt the trans down.

Using only one finger, how far can you push the clutch pedal down?  More than an inch, and you have something adjusted wrong, or there is still air in it.  

 It was a pain to get getting the transmission to go the last couple inches, even after double checking that the alignment tool went in easily. As far as clutch travel goes there isn't much, probably an inch or less. Thanks again for all the replies

Has anyone ever bled a concentric slave cylinder by hooking up the line and pushing the SC before installing the transmission? Seems like it would be more effective than opening and closing the bleeder, pumping the pedal etc. 

Been there, done that.  I have an M5R1 and they use pretty much the same hydraulics.

Common problems:  clutch bleeding.  I don't care if you bled it 20 times, there is probably a wee bit of air in there.  They are impossible to bleed properly... so difficult that the aftermarket has an entire segment of powered reverse-bleeding machines to combat the problem and even that doesn't always do the trick.

backwards friction disc.  If the disc is installed backwards, the hub rubs the flywheel and keeps it spinning.

machined flywheel.  If someone cut the flywheel, the slave cylinder is now farther away from the diaphragm and won't disengage fully.

Munched pilot bushing

bent/broken finger on the diaphragm.

rear main seal leak making the disc gummy.

Bottom line; find someone with a reverse bleeder.  If that doesn't do it, rig up a clear bleeder hose from the slave down into the reservoir and pump the pedal for a day or so.  I did that and got a few bubbles AFTER it was reverse bled, but my problem is still exactly the same.  I just took delivery of an entirely new set of everything between the block and the transmission; rear main seal, new flywheel, clutch kit, pre-bled master and slave, throwout bearing, pilot bushing.  I'm replacing a nearly new clutch because it won't disengage fully.  It might not need all those parts, but if I'm going through the trouble of tearing out a transfer case, transmission, and getting greasy, I'm not going to hope I find something obvious.  If I'm going to the trouble, it's getting parts thrown at it.

 So I did remove it all, replaced the slave cylinder again. This time I prefilled the slave and hooked up the line.  Then I pushed on the sc while someone watched the reservoir for bubbles. At first the clutch pedal was soft, but it pumped up quickly. Took it for a drive and it's a lot better going into first. If...or when I have to deal with a concentric slave cylinder again this is what I would do. Bench bleed the clutch master cylinder, fill the SC and bench bleed, hook it all up without installing the MC, have someone hold the mc high up beer bong style while you push on the slave slowly until there are no bubbles. I don't think I would even mess with the bleeder valve. I hope this helps someone. This really was a PITA, thanks for the help from everyone that replied btw. 

Thanks for following up for those of us playing along at home! 

Glad to hear you got it sorted out!

I've seen a few of the ranger guys bolt the whole setup to the wall to bleed it all out.

 Does anyone know what drives the gear on the vehicle speed sensor? I finally bought the gear for the sensor after a coworker threw my whole sensor away. Anywayy.. it's not reading at all. And looking/feeling in the hole I don't feel another gear or anything that would actually drive the gear. Any info would be appreciated, thanks