924Board.org

Gatornapper · Joined: 23 Oct 2021 Posts: 294 Location: VA

Seems to be a definite absence of any information on how to remove the slop in the shift linkage on the G31 tranny.

Only thing I see in front is 4 small nylon (?) bushings, Part #99992400240 called "Plain bearing" here:

http://www.autoatlanta.com/porsche-parts/hardparts.php?dir=924-80-85&section=701-05

I've ordered them from Pelican, cheap - so I hope they help.

Looks like that's about all one can do. Two ends of Guiding Rod #9 don't look like they would wear, and there is nothing to replace on the Gear Shift Rod #8.

Any help/advice is greatly appreciated.

GN
_________________
'87 944 S, looks & runs like new - sold my sweet 931; '76 914 2.0 mostly restored; 2011 Porsche Cayman S in Meteor Grey, 3.4L, Softronics ECU tune 355+hp , PDK w/Sport Chrono. Got this thing for Porsche's.......

Gatornapper · Joined: 23 Oct 2021 Posts: 294 Location: VA

On this forum, there is this:

"The bushings back at the transmission, accessible only from underneath the car (reaching around to the top side of the transmission are harder to change. The are part # 911 424 223 03. They are also used on the 914, and can be purchased from more common sources like Performance Products as such (914 shift linkage bushings). In this case, the cross pin holding the joint together (it's designed like a u-joint) must be driven out to one side. Then the joint is separated. A 13mm bolt is removed and the aluminum joint casting can then be removed from the car. The plastic bushings can be replaced by hand at this point."

I have successfully rebuilt the shift linkage in my 914 which now shifts like new, and am familiar with this bushing - but I do not see where/how it fits in the G31 tranny. Can anyone show me a detail with these bushings?

Can you access them with the car on a lift, or does tranny have to be dropped?

As always, thanks for the help.

GN
_________________
'87 944 S, looks & runs like new - sold my sweet 931; '76 914 2.0 mostly restored; 2011 Porsche Cayman S in Meteor Grey, 3.4L, Softronics ECU tune 355+hp , PDK w/Sport Chrono. Got this thing for Porsche's.......

Cedric · Joined: 27 Aug 2004 Posts: 2762 Location: Sweden

Accessible, but awful to reach. The gearbox have to be lowered to maximum, the reinforcement in front of the rear suspension have to be remove.

The g31 linkage should be great. The plastic cup bushing is most likely shot and the black ones in the joint.
_________________
1980 924 Turbo
www.instagram.com/garagecedric/

Gatornapper · Joined: 23 Oct 2021 Posts: 294 Location: VA

Can't be worse that getting the WUR off and back on.......

Or can it?

GN

Cedric · Joined: 27 Aug 2004 Posts: 2762 Location: Sweden

Carrera RSR · Joined: 08 Jan 2010 Posts: 2312 Location: Somerset, UK

2 reasons for sloppy linkage.....

95% likely to be broken nylon in the cup
5% possibility that the bolt on the UJ has come loose

I've replaced 3x cups in 12 yrs
I've had one case of loose UJ bolt in 12yrs.
_________________
1980 931 - forged pistons, Piper cam, K27/26 3257 6.10 hybrid turbo, 951 FMIC, custom intake, Mittelmotor dizzy & cam pulley, H&S exhaust, GAZ Gold, Fuch'ed, Quaife
Now www.924board.org/viewtopic.php?t=34690
Then www.924board.org/viewtopic.php?t=31252

924-76 · Joined: 05 Jun 2006 Posts: 1489 Location: Ontario, Canada

Both were shot on my car when I bought it.

If you have more work to do in the area, like flushing and cleaning rust out of the full tank, you should consider removing the tranny out.

Good luck
_________________
1976 924 N/A ROW SOLD
1980 931S
1981 931 Part car RIP

MOTANUL · Joined: 19 Nov 2018 Posts: 216 Location: ROMANIA BUCHAREST

3 reasons for sloppy linkage.....

10 - Angular joint / 477711176A. most likely (very difficult to change)
13 - / nylon - Plain bearing / 99992400240 (I changed them working in the car)
5 - / Bearing bracket / 477 711 237 A - out of 3 G31 Shift mechanism only one had this piece worn out. (occurs less frequently - probably in cars with many km)

Ref. to nylon - Plain bearing / 99992400240
A friend modified the piece a bit and put small needle roller bearings.
It's more work - but I think it's the best solution if you have the parts taken off the car.

I have a different modification: I completely gave up 99992400240.
The car shifts gears exactly (without play), but transmits vibrations to Gearshift knob.

I think the best compromise is with small needle roller bearings (involves small modifications to existing parts).

_________________
1980 Porsche 924 Turbo (931) diamond silver metallic/helios blue metallic
sold Porsche 924 NA 1979

Mike9311 · Joined: 14 Dec 2004 Posts: 1797 Location: Chicago-ish

Funny little addition here. I have been upgrading the CS with a stock appearing shift knob on the Ideola short shift kit. Figured while I was there I would try and reduce some of the play I was feeling. I added washers at the two pivots with the clips and then I tried something more with the bushing up front.

Bushing "5" in the drawing above: I took it out and inserted two o-rings into the backside cavity of the rubber bushing to reduce flex and remove slop. They fit perfectly and tightened up movement. Not sure if I like the feeling just yet once installed though. Going to 4th seems to require more force. Going back the next day felt improved as if I had already forgotten the original feeling. I will update
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

jacobroufa · Joined: 18 Nov 2016 Posts: 531 Location: Belvidere, IL

Gatornapper · Joined: 23 Oct 2021 Posts: 294 Location: VA

My responses in RED......

Gatornapper · Joined: 23 Oct 2021 Posts: 294 Location: VA

Mike -

Great idea on the O rings on part #5. I'll try the same.

GN

Gatornapper · Joined: 23 Oct 2021 Posts: 294 Location: VA

Thanks. Flushing & cleaning tank was the very first thing I did when I got the car. Actually little rust, some rust debris in trash collector in bottom but not bad.

I have lift, but it stays busy and I do not want to drop tranny if at all possible.

Someone said it could be lowered enough to get rear U-joint off. But even that is last resort.

Thanks.

GN

Gatornapper · Joined: 23 Oct 2021 Posts: 294 Location: VA

Mike -

Would appreciate more info on putting O-rings on backside of backside of cavity. Does bushing 5 come out easily? Doesn't look like it to me.

Please explain with more detail where you put O-rings - size? tight around shift rod?

Thanks,

GN

Gatornapper · Joined: 23 Oct 2021 Posts: 294 Location: VA

Today I received my 4 new #13 - / nylon - Plain bearing / 99992400240 and installed them with new lithium grease.

They did improve the tightness of the linkage for sure, maybe 30-40% at most though, but about what I expected as existing bushings didn't look too bad.

Still plenty of room for improvement.

GN
_________________
'87 944 S, looks & runs like new - sold my sweet 931; '76 914 2.0 mostly restored; 2011 Porsche Cayman S in Meteor Grey, 3.4L, Softronics ECU tune 355+hp , PDK w/Sport Chrono. Got this thing for Porsche's.......