915 shifter nut torque...How tight?

[70S Targa Guy]

I am finally getting around to replacing my shifter bushings in my 915 trans...the two bushings up front on the shifter and bracket and the two bushings on the shift coupler in the rear tunnel between the seats. I am taking pics and will post a simple tutorial when done. BTW, the passenger side bushing on the shift coupler was totally gone and in pieces in the tunnel! No wonder I had no 5th gear anymore.

Anyway, when I took the shifter out I noticed on the front part of the shifter there is a 22mm nut that holds the shifter linkage including the new bushing that is pressed into the bottom round part of the shifter. When I removed the shifter from the car I noticed that 22mm nut was loose as I could tighten it with my fingers. I tightened it with a socket wrench to snug it up tight, not gorilla tight but much tighter than it was before. However, when I turned the shifter assembly upside down, even after tightening that 22 bolt there is still about 2mm of play fore and aft when I slide the bottom of the shifter assembly by hand. I think that is normal looking at the physical construction of the shifter but I just want to make sure. I don't have a Bentley with torque values. I have Waynes 101 projects......
Could someone tell me how tight that 22mm nut should be torqued to?
Also, is there any maintenance that can be done to the actual shifter itself (besides the 2 usual bushings that I am replacing?) Here is a picture of the nut on the shifter located towards the front of the car. Thanks.

[jnewman]

Don't know what year your car is? For my '84 Bentley says:
Shift Housing removal and installation (1984-1986)
"Tightening Torques
Shift rod bushing bracket to housing.....10 Nm (89 in-lb)
Shift housing to tunnel..........................25 Nm (18 ft-lb)"

Others who know more can chime in. Looking forward to your description of how this goes for you so I can learn from your mistakes! I am ordering the bushing kit from our host - my first DIY project on the pcar!

[911pcars]

Snug. It isn't going anywhere, but before you do, rotate the set screw with an M6 hex wrench to remove that 2mm of fore/aft play that actually adjusts how easily the lever moves left and right. YMMV. The size of the lock nut is a result of the set screw needed as a pivot pin. Thus, you don't have to tighten it as though your life counted on it.

As for maintenance, make sure all friction surfaces are clean and lubed. I prefer water-proof synthetic grease.

Sherwood

[revmax]

Check out Pete Zimmerman's 915 Red Line Technik WIKI rebuild tutorial. It's a great ready for the 915 gearbox minded. I went through my box a while ago and this was a great help. In a nutshell, the master tells you everything on what it takes to make it right. Good luck.

Porsche Wiki

[euro911sc]

I gave myself .015 clearance on that fore/aft adjustment. So far so nice

[70S Targa Guy]

Originally Posted by jnewman

Don't know what year your car is? For my '84 Bentley says:
Shift Housing removal and installation (1984-1986)
"Tightening Torques
Shift rod bushing bracket to housing.....10 Nm (89 in-lb)
Shift housing to tunnel..........................25 Nm (18 ft-lb)"

Others who know more can chime in. Looking forward to your description of how this goes for you so I can learn from your mistakes! I am ordering the bushing kit from our host - my first DIY project on the pcar!

Thanks, but those torque values are not for the bolt/nut I needed. Those torques listed above are for bolts 18 and 20 in the diagram below denoted by the blue arrows. I have the 3 volume Bentley for my UrS6 cars and the diagrams in my Bentleys always have the bolts numbered with corresponding torque values listed on the right side of the page. Just curious, could you check your Bentley and see if they list the torque for nut/bolt #5B in the diagram denoted by red arrow. Thanks. BTW, the bushings I am replacing are #22, #23 and two bushings in the shift coupler #27 denoted by the green arrows. If you need to make the diagram larger to see it better just hit "Ctrl" and the "+ =" keys on your keyboard.
If you tackle this job soon it really is a very easy process with the exception of removing the pin from the shift coupler to replace those 2 bushings. I was using the vice and socket method as described in this forum but I guess I have an old vice that does not open wide enough to fit the coupler and the two sockets. I am going to take the coupler to my buddy who has an air hammer to remove pin which will take 10 seconds to remove. It took him 5 seconds to remove the dreaded threaded pin on the bottom of my front struts when I replaced both ball joints.

Originally Posted by 911pcars

Snug. It isn't going anywhere, but before you do, rotate the set screw with an M6 hex wrench to remove that 2mm of fore/aft play that actually adjusts how easily the lever moves left and right. YMMV. The size of the lock nut is a result of the set screw needed as a pivot pin. Thus, you don't have to tighten it as though your life counted on it.

As for maintenance, make sure all friction surfaces are clean and lubed. I prefer water-proof synthetic grease.

Sherwood

Thanks Sherwood,
Which set screw are you talking about? Are you talking about 5A in my diagram?

Originally Posted by revmax

Check out Pete Zimmerman's 915 Red Line Technik WIKI rebuild tutorial. It's a great ready for the 915 gearbox minded. I went through my box a while ago and this was a great help. In a nutshell, the master tells you everything on what it takes to make it right. Good luck.

Porsche Wiki

Thanks Revmax...I already have Zimmerman's write up in my archives and I read his tutorial before I started this job. However, his writeup has no torque values for shifter bolts or any info regarding the shifter. His tutorial is mainly for transmission rebuilds.

[70S Targa Guy]

Thanks Sherwood,
Which set screw are you talking about? Are you talking about 5A in my diagram?

Nevermind Sherwood...I was having a senior moment...I don't know what the heck I was thinking and so concerned about the torque of that 22mm nut for. I didn't even see that set screw. I just went out to the garage & tightened i.e. turned that set screw in, tightened the 22mm nut and all the fore/aft slop and movement is now all gone. I am wondering if the shifting will be more crisp and precise if I remove all the fore and aft movement or I take euro911sc's advice and adjust so that there is a bit of play, .015" fore/aft to be exact. What do you think...tighten it so there is absolutely no play fore and aft or adjust as per euro911sc's specs? Thanks.

[911pcars]

Originally Posted by 70S Targa Guy

Thanks Sherwood,
Which set screw are you talking about? Are you talking about 5A in my diagram?

Part 5A looks pretty small in the illustration. It's this one I'm referring to:


Hope this helps,
Sherwood
SeineSystems.com

PS: Just saw your response. Tighten the set screw until you're happy with the correct amount of play. I prefer as little as possible w/o binding. BTW, increasing the clearance also reduces the fore/aft transfer of motion of the shift shaft to the gearbox by an equal amount. Depending on the adjustment of the shift coupler, this may or may not create gear engagement issues.

[70S Targa Guy]

Got it! Will do. Thanks for your helpful & concise reply.

[euro911sc]

BTW, that 0.015" was a spec I got from the Pull'ooMA reference manual...

[70S Targa Guy]

Originally Posted by euro911sc

BTW, that 0.015" was a spec I got from the Pull'ooMA reference manual...

Thanks Euro...I don't want to sound like an idiot but what the heck is the Pull'ooMA reference manual?

[euro911sc]

LOL It is an anachronym for a highly technicaly based reference source I used to use a lot when I was an engineer. Stands for: Pulled out of my ass You should try it some time... but please... use your own reference

[Walt Fricke]

While you are at this, one thing you can do to really tighten up your shift linkage is to remove the built-in slop in the shift coupler bushings.

Did you install new stock bushings? They will be better than no bushing, no question. But the low buck way of removing the ovality which is built-in is to find a bushing which fits closely (but not tight) around the cross pin. Enlarge the plastic bushings so suitable short lengths of your new bushing will press in. Put the coupler back together without these bushings, then press eash of them in around the cross pin.

Voila - much less slack in the system.

For an encore, consider the Seine Shifter. That plus round, not oval, coupler bushings, will make you think you are driving a whole new car.

[DRACO A5OG]

+1 on Sherwood's Seine Gate Shift Kit.

I just installed it and it is FANTASTIC, while I was there I took out all slop at that nut, Stick is Snug as a Bug.

It shift very naturally now.

[70S Targa Guy]

Originally Posted by euro911sc

LOL It is an anachronym for a highly technicaly based reference source I used to use a lot when I was an engineer. Stands for: Pulled out of my ass You should try it some time... but please... use your own reference

I figured it was something like that

[70S Targa Guy]

Originally Posted by Walt Fricke

While you are at this, one thing you can do to really tighten up your shift linkage is to remove the built-in slop in the shift coupler bushings.

Did you install new stock bushings? They will be better than no bushing, no question. But the low buck way of removing the ovality which is built-in is to find a bushing which fits closely (but not tight) around the cross pin. Enlarge the plastic bushings so suitable short lengths of your new bushing will press in. Put the coupler back together without these bushings, then press eash of them in around the cross pin.

Voila - much less slack in the system.

For an encore, consider the Seine Shifter. That plus round, not oval, coupler bushings, will make you think you are driving a whole new car.

No, I am installing with the round replacement bushings Pelican Parts - Product Information: 99-1758-424-M230 purchased from our host.

I definitely have the Seine Shifter on my to do list as soon as I can find a good used one. Thanks.

[Concestor0]

Originally Posted by 911pcars

Part 5A looks pretty small in the illustration. It's this one I'm referring to:


Hope this helps,
Sherwood
SeineSystems.com

PS: Just saw your response. Tighten the set screw until you're happy with the correct amount of play. I prefer as little as possible w/o binding. BTW, increasing the clearance also reduces the fore/aft transfer of motion of the shift shaft to the gearbox by an equal amount. Depending on the adjustment of the shift coupler, this may or may not create gear engagement issues.

Tightening this set screw to remove play in the shifter along with replacement of bushings and proper shifter adjustment has made a world of difference. I was certain that I would be overhauling my 915 transmission this winter but now I'm not sure it is necessary. I still have to pause a little longer going into 2nd (or double clutch) but everything else is smooth sailing.

I have had the car for a year now and have never known (until now) how smooth and precise the shifting should be, plus, no annoying rattles. I read many posts on changing bushings and setting up the shifter but very little is mentioned about this "set screw" (part 5A/5B?). Mine was quite loose and tightening it has made at least as much difference as changing the bushings.