Lost 1st and 5th gear

[daiberl]

Hello,
I need some help, I can't my 1983 911SC into 1st and 5th gear, all other gears work fine. Just uninstalled the shifter and checked, everything is fine, re-installed and again no 1st and 5th gear. Checked coupler, also looks good, nothing blocking. What else can I check?
- Juergen

[Bill Jennings]

daiberl,
When you say it won't go into those two gears do you mean the gear lever goes to the normal position for those gears but the gear does not engage or is there something blocking the lever from going to the normal position for each gear?
Has this just suddenly happened , done any related work on the car recently such as adjusted the coupler or clutch?

Cheers
Bill

[daiberl]

It happened suddenly and there is a blocking which doesn't allow the shifter to go into 1st and 5th, all other gears are not blocked.

[Reiver]

How does your clutch cable look....is it properly adjusted for full release?

[theiceman]

stupid question , everything was fine till you installed the shifter right ? engine wasrunning when trying to get into gear ?
sorry i just had to ask.
if yes its a coupler adjustment required

[unclebilly]

Sounds like your coupler is not allowing the shift rod to go back far enough. Loosen it, pull it forward 1mm and try again.

[daiberl]

Clarification: Everything was fine but then I lost 1st and 5th gear. After losing the gears I go the shifter console out and re-installed it.
Also checked the coupler, I can get in 3rd gear so it has enough play. The clutch works perfect with all the other gears, it really feels like it is blocked when you try to get in 1st and 5th, all other gears work and the car drives great.

[HelmetHead]

Just went through a similar issue with a 915 gearbox where the first gear brake band jammed against the syncro ring causing the syncro to expanded and the shift sleeve couldn't go against the syncro to make the shift. This was apparently caused by a forceful downshift into first gear while the car was moving at speed.

[daiberl]

Originally Posted by HelmetHead

Just went through a similar issue with a 915 gearbox where the first gear brake band jammed against the syncro ring causing the syncro to expanded and the shift sleeve couldn't go against the syncro to make the shift. This was apparently caused by a forceful downshift into first gear while the car was moving at speed.

Did you lose only 1st gear or also others? I think 1st and 5th are on different "parts" (sorry, not sure about the correct term) of the transmission, or?

[HelmetHead]

It was just first gear for us.

[jpnovak]

Using the coupler in the tunnel can you select all 6 gears? (5 forward, one reverse?)

This will help isolate the shift linkage from internal problems with the shift selector.

There have been issues with the shift guide fork on the bottom of the transmission. You can look inside to see if more than one gear is selected or blocked on the shift forks. These are visible once you remove the guide fork from the bottom of the transmission. yes, you have to drain and replace the gasket to take a look.

If you can select all 6 gears using the shift coupler then look for worn or missing bushings. YOu said the coupler was good. a little play due to worn bushings for an improperly adjusted coupler can cause problems. The same for the shift rod bushing and lower ball cup bushing. First and fifth locations of the shifter are the farthest away in shifter position.

first would be couterclockwise and push in on the transmission coupler. (when facing the transmission)
Fifth would be clockwise and push in on the transmission coupler (when facing the transmission)

[daiberl]

Originally Posted by jpnovak

Using the coupler in the tunnel can you select all 6 gears? (5 forward, one reverse?)

This will help isolate the shift linkage from internal problems with the shift selector.

There have been issues with the shift guide fork on the bottom of the transmission. You can look inside to see if more than one gear is selected or blocked on the shift forks. These are visible once you remove the guide fork from the bottom of the transmission. yes, you have to drain and replace the gasket to take a look.

If you can select all 6 gears using the shift coupler then look for worn or missing bushings. YOu said the coupler was good. a little play due to worn bushings for an improperly adjusted coupler can cause problems. The same for the shift rod bushing and lower ball cup bushing. First and fifth locations of the shifter are the farthest away in shifter position.

first would be couterclockwise and push in on the transmission coupler. (when facing the transmission)
Fifth would be clockwise and push in on the transmission coupler (when facing the transmission)

Followed your guidance, looks like I can not select 1st and 5th when using the selector. I think next step is dropping engine and transmission, nice winter project but not what I was planning over the next months.

[Walt Fricke]

Before you drop, why not drain the transmission and remove the four nuts holding the cover plate on the bottom. The shift guide fork is attached to it with two nuts on studs. If the fork came loose, it can cause otherwise improbably problems.

I can see why you are baffled if you can get 3d, but not 1st and 5th. But 3d is on a different shift fork rail inside the tranny, and conceivably it was adjusted just a bit differently than the other two, and isn't affected.

And yes, a long shot - if the fork is loose, why wouldn't that make getting any of the gears 1-4 difficult. And moreover, it isn't apt to have much effect on 5th, which does not use it. The only thing in common with the two affected gears is the main internal shift rod, and it is hard to see how something like this could happen outside of some sort of simultaneous failure of two unrelated parts.

I know you tried moving just the selector, but it is not easy to hold and manipulate down there in that hole in the tunnel. Did you try Uncle Billy's suggestion to move the coupler 1mm or so back? This will create more throw in to gear positions 1, 3, and 5. Just in case.

[daiberl]

Originally Posted by Walt Fricke

Before you drop, why not drain the transmission and remove the four nuts holding the cover plate on the bottom. The shift guide fork is attached to it with two nuts on studs. If the fork came loose, it can cause otherwise improbably problems.

I can see why you are baffled if you can get 3d, but not 1st and 5th. But 3d is on a different shift fork rail inside the tranny, and conceivably it was adjusted just a bit differently than the other two, and isn't affected.

And yes, a long shot - if the fork is loose, why wouldn't that make getting any of the gears 1-4 difficult. And moreover, it isn't apt to have much effect on 5th, which does not use it. The only thing in common with the two affected gears is the main internal shift rod, and it is hard to see how something like this could happen outside of some sort of simultaneous failure of two unrelated parts.

I know you tried moving just the selector, but it is not easy to hold and manipulate down there in that hole in the tunnel. Did you try Uncle Billy's suggestion to move the coupler 1mm or so back? This will create more throw in to gear positions 1, 3, and 5. Just in case.

I tried to move the coupler back but it didn't help. I will drain the oil this week and take a loo to the shift guide fork, maybe I can see something, but I have to drop the engine and transmission either way for doing a few other things so it might be a good opportunity to do it now.