1975 914 1st gear jumping out issue Options

[ndfrigi]

Hi 914's owner! I have 75' 2.0 914 and I'm having a problem with my 1st gear. It jump out upon releasing the clutch. I already replaced all the shift bushings but when I push down to 1st gear and while releasing my clutch, there you go it jump out or grinding from the gear happens. Any suggestions on how to fix it? thank you and God Bless!

[Richard Casto]

In short there is a recess that is machined within the syncro hub (that is mounted to the gear) and the associated slider (that moves when you shift gears). That positive feel of engagement you get when you shift into gear is when the hub and slider are becoming 100% engaged. The two recesses are now merged into one single recess and the synchro ring was compressed during the shifting motion has now popped into the merged recess. The force of the syncro ring living in that recess is what keeps the slider and hub engaged (car in gear). To shift out of that gear you get another positive feel of disengagement as you compress the ring to get it out of the recess and then the slider disengages from the hub and you are back into neutral.

So what causes it to pop out of gear? Ultimately there is not enough force keeping the slider and hub engaged. Typical causes would be...

1. Worn hub, slider and/or synchro (items associated with the ring in the recess are worn out an no longer provide the required force to keep engaged).
2. Incorrect adjustment on the shift fork (not able to fully engage 1st so it pops out before it is 100% engaged).
3. Incorrect adjustment on the shift linkage (not able to fully engage 1st so it pops out before it is 100% engaged).

Any are possible. As you say you have problems only with 1st, I tend to think it is most likely #1 and not #2 or #3. If you said you had a problem with 1st, 3rd and 5th, then it would be more likely to be a shift lever adjustment problem.

Depending upon how mechanically inclined you are, you can (as Jim suggested above) shift into first via your lever. Then detach the shift linkage and then double check directly at the linkage on the transmission that it is in first gear and fully engaged. This should remove any questions as to linkage issues. Then see if it pops out of 1st gear when you apply power (drive the car).

If you have narrowed it down to being inside the transmission then I would not use 1st gear until you can get it fixed. The first/reverse slider is a particular costly item and any 1st gear "grinding" is an indication that you are damaging the slider and synchro hub. They may already be worn beyond reuse at this point.

Lastly you mention that reverse work fine. If you had said you also grinding when shifting into reverse, I would say that your clutch is not fully disengaging. But that does not sound like the case.

Sorry about your problems. Let me know if there is anything else I can do to help.

Richard

[ndfrigi]

In short there is a recess that is machined within the syncro hub (that is mounted to the gear) and the associated slider (that moves when you shift gears). That positive feel of engagement you get when you shift into gear is when the hub and slider are becoming 100% engaged. The two recesses are now merged into one single recess and the synchro ring was compressed during the shifting motion has now popped into the merged recess. The force of the syncro ring living in that recess is what keeps the slider and hub engaged (car in gear). To shift out of that gear you get another positive feel of disengagement as you compress the ring to get it out of the recess and then the slider disengages from the hub and you are back into neutral.

So what causes it to pop out of gear? Ultimately there is not enough force keeping the slider and hub engaged. Typical causes would be...

1. Worn hub, slider and/or synchro (items associated with the ring in the recess are worn out an no longer provide the required force to keep engaged).
2. Incorrect adjustment on the shift fork (not able to fully engage 1st so it pops out before it is 100% engaged).
3. Incorrect adjustment on the shift linkage (not able to fully engage 1st so it pops out before it is 100% engaged).

Any are possible. As you say you have problems only with 1st, I tend to think it is most likely #1 and not #2 or #3. If you said you had a problem with 1st, 3rd and 5th, then it would be more likely to be a shift lever adjustment problem.

Depending upon how mechanically inclined you are, you can (as Jim suggested above) shift into first via your lever. Then detach the shift linkage and then double check directly at the linkage on the transmission that it is in first gear and fully engaged. This should remove any questions as to linkage issues. Then see if it pops out of 1st gear when you apply power (drive the car).

If you have narrowed it down to being inside the transmission then I would not use 1st gear until you can get it fixed. The first/reverse slider is a particular costly item and any 1st gear "grinding" is an indication that you are damaging the slider and synchro hub. They may already be worn beyond reuse at this point.

Lastly you mention that reverse work fine. If you had said you also grinding when shifting into reverse, I would say that your clutch is not fully disengaging. But that does not sound like the case.

Sorry about your problems. Let me know if there is anything else I can do to help.

Richard

Wow Thanks Richard! Now I have more idea what to look at. Keep you posted. God Bless!