No 5th gear

[frankg]

Hi all,

I just got my sons truck on the road after a complete rebuild of the engine and transmission. You all helped out with a ground problem, so hopefully one of you can assist with a transmission issue. I rebuilt an M5R1 with all new bearings and syncros and it shifts perfectly until 5th gear. It goes in smoothly, but the second you release the clutch, it grinds and throws the shifter out of gear. Anyone have any ideas or run into this themselves? Theres no noises, whines or anything while driving, until 5th.

 

[scotts90ranger]

sounds like it's not fully engaging 5th gear, did you get the right synchro's for that? does it go in reverse fine? before '92 they had a higher tooth count on the 5/R synchro's, if you got the wrong kit or got the wrong synchro's on that gear that could cause this

 

[frankg]

I think we did, compared everything as we replaced. Reverse works, no problem.

 

[tomw]

In general, transmissions pop out of gear when the respective shafts are not parallel. The teeth get a lateral (vs radial) thrust on them if they are not parallel, and will shove one gear away from the other. The detents on the collars are not really holding the gears in place, they just give a bit of resistance to moving the collar and unlocking the collar/gear mesh.
If the shaft bearings are worn, the cluster gear, for example, can get cocked relative to the driven gears.
Was anything worn on the shift linkage? Fork fingers on the sides, or the inner ring of the collar? Not having worked on one of these, is it possible the shift fork was installed 180 out? Some have a bias towards one gear or the other, some are exactly centered.
tom

 

[frankg]

From the perspective of what your saying, The only thing I can think of is the slider for 5th/Reverse my be flip/flopped. The length of travel would be shortened and not allowing 5th to engage fully. Everything else, from bearings to forks was replaced. We ran the gears thru their paces, as much as we could sans clutch. I'm going to pull the tail and verify the slider.