91 Pickup SR5 4WD

Ive been having this problem for the past 6 months and I'm getting desperate! My truck pops out of 1st gear and 1st gear only. It ONLY happens when I'm at a stop and trying to pull out. When i do get it into first gear i can drive around in 1st without it popping out. If i am on an incline it will drop out no matter what. If I'm going downhill then i roll in neutral a couple yards then (with the clutch in) shift to 2nd then to 1st for a smoother transition. If I'm rolling it seems to go into 1st easier although it has happened before even when I'm rolling slowly. Ive searched online and asked friends and I've gotten a lot of feedback but nothing seems to work. Also my clutch pedal grabs at different points all the time. Sometimes its very close to the floor and sometimes its normal around half way to the floor. It gets bad and gets better all the time so hard to pin point but I bleed the slave and there were no air bubbles and it temporarily fixed that low grab/spongey/no pressure feeling. It seems that when my clutch pedal is grabbing low to the floor the dropping out is worse.

Heres what i did already to try and fix this problem:

1) Replaced clutch master cylinder
2) Replaced clutch slave cylinder
3) Replaced clutch

4) Replaced gear shifter seat/bushings (after replacing my gears felt a lot tighter and not loose in terms of when i put it into any gear i could barely move the shifter around. felt nice. thought that was a fix but dropped out after a while)

5) Dropped transmission and replaced synchronizing gears (these were worn pretty bad so i thought i found the fix but after replacing and after driving around maybe 50 miles or so it dropped out again)

Everything was replaced with brand new parts. Still dropping out of first and I am out of clues to what is going on. If anyone can help I would really appreciate it!


I have an instagram for my truck at @zkc_91yota if you want to follow!

 

I have a similar situation in my 1992 4WD 3VZE. It has been present since I bought the truck with 10K on the odometer way back when. At startup from a dead stop it will now and then drop out of gear with a bit of a bang, pretty startling if you have not heard it before.

What I think is happening is that it does not fully engage into first gear. I have discovered that if I hold the shifter in position at startup it will not drop out. I suspect as I start to move it fully engages into first gear.

So I just hold the shifter lever in place, and live with it. Not too bad since I have to grab the shifter anyway to shift up as I accelerate.

 

How's the ball on the end of the shifter? Is there a lot of play in your shifting lever?

 

I went through all the same routine, still pops out of first if my hand isn't on it. It's strange because I can barely hold it at all when accelerating and it wont ever pop out, the second I take my hand off it though, boom!

I just deal with it, or I could go get another used 150f and swap it but it's not that big a deal for me really..

 

I forgot to mention.. If i try and hold it in first while I'm pulling out then it will grind gears. So i would say its not fully engaging when i put it into first position. Basically its coming out of gear no matter what

 

I don't see a lift on your truck and it is possible that it does not have the same transmission in it that it came with but I have seen floor boards not let the shifter go as far as it needs too. Basically I am wondering if something somehow is keeping it from being able to go as far as it needs too. I experienced the same problem with a lifted truck one time.

 

I would hope you put new bearings in when you had the transmission apart.

If not I think Terry may have nailed the problem

could be the floor it might be the shifter boot if it is not correct for the vehicle

I have a problem my transfer case shifter pops out of 4 high Because of a new boot.
I just have been to lazy to fix it.

 

Was this ever solved! I have the EXACT same symptoms now. I can’t figure it out. I have done the same fixes as you with no results! Please help!!!!

 

Im having the same issue now. Please tell me how you fixed it! Thank you!!