Jumps out of 1st gear

[Dan398]

Good morning, I just bought a 1988 Bronco II 4x4 2.9l 5speed manual transmission Truck. The door sticker says the transmission code is "D" I think it is an FM146. I bought it not running, It is now running but it jumps out of 1st gear. I have to hold the shifter to get it to stay in gear. I took it on a short test drive and all other gears are OK. I can not find any information on this transmission. I thought it was an M5R1? so I thought I would pull up the carpet, remove the cover and inspect the 1-2 fork. It appears to be an FM146. I was an ASE Tech back in the 80's but had to leave because of back problems. I'm pretty good with anything except manual transmissions. I really don't have any experience with repairing them. I'm looking for any information that could help me decide the repair path or even if I should attempt it. Any help would be greatly appreciated. Thanks Dan

 

[ekrampitzjr]

How many miles on the truck? Usually you run into this problem when a vehicle (or its transmission) has a lot of miles on it, I mean 300,000+ (500,000+ km). Had a Ford Festiva years back with a 5–speed manual that eventually, at nearly 400,000 miles, had to have the shifter held to stay in 5th gear. I believe it's the synchros that wear to cause this.

 

[Uncle Gump]

You know... the shifters in that transmission get pretty sloppy. I know mine is.

Unfortunately... I've never found a repair kit for one. NOS pieces are unobtainium too.

Core Shifters makes a nice shifter... but spendy. Too spendy for a shot in the dark I'd guess.

 

[SenorNoob]

Yeah, at the price of a core shifter, I'd swap in an M5OD. Then if you still want a better shifter, they offer one for it.

 

[Dan398]

I don't think I relayed the problem correctly. I need to get to the shift forks and syncro rings. The shifter is fine.