Trouble with 1st gear, Won’t shift into first Options

[Jackkboyes]

Just bought a 72 914. Had been sitting for a long while, just got it started about a week ago. Tried to do a test drive today and it won’t shift into 1st. All the other gears are working great. Any ideas what it might be? Originally I had thought I might just need to bleed the clutch, but realized there is no grinding sounds of the gear attempting to engage. Am I going to have to do a trans rebuild or swap? Let me know if you have had similar problems or any ideas of what I can try. [quote]

Here is a pic of the car

[porschetub]

No clutch to bleed as its a cable operated system,make sure the cable is adjusted properly with correct pedal freeplay and all the bushes are good on the shift rod,firewall and gearbox points.
When the bushes are replaced and clutch adjusted properly you have removed two main causes so that's a good start before you go further,I would think if its not grinding this will most likely sort it for you.
Good luck.

[PanelBilly]

Search for the procedure to adjust the shifter.

[xperu]

No clutch to bleed as its a cable operated system,make sure the cable is adjusted properly with correct pedal freeplay and all the bushes are good on the shift rod,firewall and gearbox points.
When the bushes are replaced and clutch adjusted properly you have removed two main causes so that's a good start before you go further,I would think if its not grinding this will most likely sort it for you.
Good luck.

As stated check your cable adjustment, also check all your bushings at your shifter, at the firewall and the trans shifter. New bushings make a great improvement.

[rhodyguy]

Sounds like you need to purchase a Haynes manual. Seriously. It will make asking questions easier...at a minimum.

ALL of the bushings are prob shot. Source a complete package and do every one of them.

[worn]

Sounds like you need to purchase a Haynes manual. Seriously. It will make asking questions easier...at a minimum.

ALL of the bushings are prob shot. Source a complete package and do every one of them.

How is shifting into reverse?

[Larmo63]

This is the car that you and Tanner bought, huh?

I saw the video he posted of him operating the throttle when you were driving it?

(This is Lawrence, Carson's dad)

[Jackkboyes]

Sounds like you need to purchase a Haynes manual. Seriously. It will make asking questions easier...at a minimum.

ALL of the bushings are prob shot. Source a complete package and do every one of them.

How is shifting into reverse?

Shifts into reverse great. As well as all of the other gears, I can get it rolling in second, I just don’t want to burn my clutch out.

I’ll have to purchase of that book.

[914Mike]

[/quote]

Shifts into reverse great. As well as all of the other gears, I can get it rolling in second, I just don’t want to burn my clutch out.

I’ll have to purchase of that book.
[/quote]

It's possible that someone locked out first for some reason, or the syncro ring is shot.
More likely the syncro ring AND dog teeth are toast.

My first gear would always go in if the car was rolling, but never when it was stopped.
A new syncro ring and better dog teeth and it is now possible to get it in gear by playing with the clutch pedal, but the habit of slipping it into first just before the car stops rolling is much cheaper than a new first gear slider...

[Dr Evil]

Probably a broken block in the gear. It will force the synchro band to not collapse so you cant get the slider over it. If it is not grinding, I bet this is the issue as if the band does not collapse, then the teeth cant meet the slider and no grinding will happen. Not too bad to fix. Parts arent too much. Hit me up if I can help.

[tejon007]

[quote name='914Mike' date='May 4 2019, 11:25 PM' post='2711142']
[/quote]

the habit of slipping it into first just before the car stops rolling is much cheaper than a new first gear slider...
[/quote]

Maybe works for a temporary "fix" and you probably already know this...but, long term it will wear the TO bearing and thrust bearings ( i.e. sitting at a traffic light while holding clutch pedal down). Even more so with a heavy pressure plate.

Maybe think about putting the correct fix on your "to do" list. Best Wishes

[jcd914]

Often first gear can be fixed with the trans in the car still but you don't get to see the wear of any other gears.
And without a lift it would not be a fun repair.

Jim

[tejon007]

..with or without lift...fixing thrust bearing damage not my idea of fun either. TO bearings arent cheap either.... (IMG:style_emoticons/default/smile.gif)

[Jackkboyes]

I’m going to try some of the quicker fixes first (adjusting the linkage and checking the bushings). Thanks for all the replies. I am starting with the bushings in the shifter, I’m not sure what the bushings is called, but it’s cracked (I’ll attach a picture). It’s the bushing at the end of the shifter that slides into the main linkage.

You think it could be as simple as replacing that bushing?

[Jackkboyes]

Let me know what you all think

[Dr Evil]

Well, it’s worn and cracked so can’t hurt to fix. Won’t fix your issue.

[Dr Evil]

I was asked if I could elaborate on what I think is wrong with 1st in this situation.

Here is a pic of a stock 1st gear from 73-76. I can tell that its likely from those years (if not messed with) because the bottom block (red arrow) is wider. The early ones are smaller, but still fail in similar ways, but usually wont hold into gear or wont let you get into gear. This is also first because it has two notches for blocks, has a hooked upper block (Yellow) and a single energizer band (Tan). You only need one band in 1st because you do not upshift into first. (Oddly, you dont down shift into 5th, either, but it has two bands.)

So, lets begin with the basics of operation:

Shifting into 1st gear means that you move the slider towards the gear, which is always enmeshed with its partner gear. You are not grinding gears when you hear that noise, you are beating the slider against the synchro hub (dog teeth).

If all is working well, the slider is not really spinning at the same speed as the gear so it needs to be sped up/slowed down. You will be close in speed if you are shifting correctly, so this is a minor change. The speed is matched by the slider pressing against the synchro band (Green).

The synchro band is spring steal, and covered in molybdenum "parkerized" which is a sacrificial friction surface. It acts like a spring loaded tire tread. So, slider pushes against this metal tire which matches the speed of the slider/shaft and the gear and its shaft.

The slider then "clicks" into place. That clicking you hear is the synchro band (Green) being compressed against the beveled recess inside of the slider. This compression is accomplished by the bands and blocks inside of the synchro band (red, tan, yellow).

As the slider is moving onto the synchro band, the synchro band is allowed to rotate. It rotate, presses against the top block (yellow), which presses against the energizer band (tan) which presses against the bottom block (red). The compression of the energizer band pushes it against the synchro band (green) and keeps the synchro band expanded inside of the slider to keep the slider locked onto the gear.

The slider has teeth that enmesh with the dog teeth on the gear and that is where power is transferred.

Disengaging the clutch pulls torque/pressure off of the energizer bands and blocks and allows for the slider to be disengaged from the gear and the synchro band to relax allowing for this.


So, what is going wrong, likely, with this OP transmission? Three major clues:
1- Not grinding while trying to get it into 1st gear.
2- Not going into 1st gear.
3- Goes into reverse no problem.

Based on your new understanding of how this synchronization mechanism works, you possibly have figured that for there to be no grinding (so no slider teeth hitting dog teeth) the slider must be blocked from hitting the dog teeth. This typically happens when the bottom block (red) has a piece break off causing the synchro band (green) to be unable to compress. The dia of the synchro band remains too large for the slider to push past so the teeth of the slider quietly wear down the synchro band and themselves. This will be obvious when you look at the parts as all the parkerizing will be gone.

Another common failure mode is that there will be grinding, or not, but the gear will pop out under load. That indicates a failure of one or more of the synchro package: band too worn to keep engaged, broken or bend energizer bands or blocks.

I assume that the center tunnel rod, and all external shift bits have been checked for obstruction. If all clear, and you can move into R, then the above is the likely issue. Revers has no synchro parts. The gears are straight cut and slide right into each other when no load is applied to the set (clutch disengaged).

Hope this helps. If I ever get time, I may make some short instructional videos regarding some of these things. It is all covered in my rebuild DVD as well.