First Gear

[aj81spider]

The car is running, but as I drive it lots of problems are coming to the fore. The most serious/irritating right now is first gear. I have a newly (OK not that new - it was rebuilt 18 months ago - then sat on my garage floor till now) rebuilt transmission. All the gears work fine except for first. When I put it in first and hold it there I can start moving and it will stay in first after the engine engages. However if I come to a stop, put it in first and don't hold it in it slides right out. The transmission clicks into the other gears and stays in gear. First does not have that click and it doesn't seem to go as far in.

Any likely causes for this?

Will it hurt the transmission in a serious way if I ignore it for the summer and address it in the fall/winter?

I know you're going to say bring it back to the guy that rebuilt it - however he is a 2 hour drive away, and at the speed he works I will not have a car this summer while he works on it.

[wizard124]

I'm no expert but since I recently rebuilt mine, I think I have a fairly good understanding. This is my take......

1 and 2 are on a shared shift rod. There is also a shared shift fork attached to that rod. The fork rides in a groove of the shift cone. The cone moves back and forth engaging the syncro/1st and syncro/2nd gears. also on that rod are little cups . As the shift lever is moved, a small spring loaded ball is pushed into that cup which holds the rod and keeps it from backing out.

Whew! Your second appears to snap into place and holds. This suggests that there is a ball and spring working on that rod. I do know these detent balls are actually pointed cylinders of 2 different lengths. if these are interchanged? this could be your problem. I don't know.

Were the shift forks replaced during the re-build? The 1/2 and the 3/4 forks are identical. If these were interchanged and had worn differently or one was slightly bent, this could prevent 1st from being moved fully to proper engagement. I am not one to force any thing, but.... Do the length of the shift throws seem to be the same? If 2 is short then maybe that fork is bent?

My last hypothesis is. If the 1st syncro spring is installed too tight,it will prevent the syncro from sliding fully into the 1st gear. This would probably prevent the cone from fully engaging the gear, leading to your problem.

Unfortunately, I don't see a fix other than tearing into the tranny.

Hopefully, someone will post with an easier fix.

[vandor]

I wonder if he replaced any of the components pertaining to first gear? Normally the cause of this problem can be a worn shift fork, the gear, the slider, or the combination of the three.
Yes, it is possible that the spring was put on wrong and that is preventing first from being engaged all the way. As long as you are not grinding gears it should not do any damage.

[aj81spider]

Thanks for the replies (and Wizard - the detailed explanation of how it works). Sounds like there is no simple fix so I'll drive it for now and tear into it in the fall.