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Hi All 993 folks
Has anyone ever had gear selective shutdown!
(1995 manual G50 6 speed box)
I was driving in 6th for 3 hours all good, Stopped at a toll gate and pulled off in first went to select 2nd- no joy- I can now only engage 3rd and 4th no other gears (incl Reverse).
Not temp related
Tried selecting with engine off
Clutch seems fine (in 3rd & 4 th!)
Even parked up and gave the old girl an hours 'rest' no change.
Anyone got any ideas before I start to dismantle the beast.
Thanks
Mark
I lost the ability to get into 1/2/R, turned out to be a broken shift spindle inside the gearbox. Replaced with an upgraded part from Guard and all is well.
To check this disconnect the shift linkage from the gearbox and thread a bolt into the gearbox shift shaft. If you can get all the gears acting directly on the gearbox, then it has to be linkage related and likely a simple fix.
If you still have the same problem its internal and I would look at the spindle as the first culprit.
Will the shifter move left/right? The linkage could be binding in some manner as to not allow the shift rod to rotate, which would lock out all gears but 3/4.
You will need to get the car up on jackstands, remove the belly pan and check the linkage. It should all move freely, but with little slop. As Top-Gun stated the next step is to disconnect the linkage from the output shaft and try to manually move the shaft through it's paces. Hopefully you find something simple and external!
Thanks for all the info. I will be get under and start digging.
In response to CEMOTO - the gearshift will move both left and right and past the reverse gate but seems physically blocked from travelling up or down into 1&2 5&6 and reverse gears. Makes no difference if the engine is running or not.
Question for TOP GUN are 5&6 and 1&2&R selected using the same shift spindle - if they are selected using different spindles I assume it would be unlikely to have two break at the same time.
MANY thanks its great to have some ideas before I start.
I'll try to explain how it works, unfortunately I don't have a picture handy. Inside the gearbox are 4 shift rods, one for each plane of gears (R, 1-2, 3-4, and 5-6). These are horizontal and parallel to each other and they each have "lugs" that all align when in neutral. The shift spindle is perpendicular to the individual shift rods and has a lever on it that slides up and down and rotates about the spindle. This lever has a mating lug and is what moves the individual shift rods. The lever is connected via ball/socket to the main shift rod which is what connects to your shifter.
When you rotate the main shift rod (like when you move side to side in neutral) it moves this lever up and down the spindle to align with whatever gear plane you want (i.e. 1-2, 3-4, 5-6). When you move the main shift rod forward and back it rotates the lever about the spindle which pushes the shift rod engaging each gear.
The spindle has a weak point in that the diameter is necked down on the ends and they like to shear where this diameter is reduced. When this breaks the lever flops around preventing it from smoothly sliding up and down between the shift rods, preventing you from getting certain planes. Its entirely possible you'd still align with 3-4 but not align with anything else.
Post 3 - update (thanks Top-Gun for the box details I now understand the shift spindle)
Mystery continues
I dropped the pan underneath - shift linkages all looked okay - I disconnected selector shaft rubber rubber doughnut link. I was able to select all gears very easily by hand and with the shaft disconnected the shifter moved in all directions no problems.
I reconnected the rubber connector and NOW I CAN SELECT ALL GEARS!!!
But - there has to be a reason for the problem - the rubber link looks to be in good condition.
I will wait for advice before I drop it off the axle stands and try and drive it!
Would the shift spindle be effected by load when driving?
Post 4 Thanks Chaoscreature as you have gathered I am pretty intimidated by the gearbox so all information (pics) helps me to figure out what could cause this malfunction. in answer to your question.
Yes the shifter moved left and right with ease and past the reverse gate but was physically blocked from engaging up and down into R 1&2 5&6 -All the linkages look like new and I have a full range of motion.
One Idea I had - could it be a mounting that is worn -moving under load and effecting the alignment of the selector shaft?
Here is a picture looking at the shift selection mechanism from the other side. The rod with the little ball-joint and all the detents is the shift rod, the part that you can grab and shift the gears with.
Inside the transmission the shift rod is supported by a series of linear bearings allowing it to move in/out and rotate. The ball joint in the new pictures is connected directly to the vertical actuator in the first group of pictures (with springs at top/bottom).
In the first group of pictures there is a pointer just below a ball detent on the vertical actuator. This is your "shift gate" and is what keeps the shifter from moving all ***** nilly all over the place. A small piece of debris or a slight misalignment in this whole mechanism stack could cause your symptoms, but it sounds like everything is now freed up.
I would recommend draining and replacing your fluid if you haven't done so recently. Filter it a bit to see if there are any fragments of "stuff" in it. I lost all my downward gears a while back due to a little metal chip in the linear bearings (hence the rebuild pics!).
Also, the shift linkage is terribly sensitive... I still don't understand that. While the car is in the air you should lubricate and clean all the shift linkage just for drill.
Hope this helps! Please post what you find as it may help others
Post 5 Not Good news - Transmission oil full of metal bits - so that was the cause of the selection problems!!
I am now going to remove the transmission - following NSULLY https://rennlist.com/forums/993-foru...p-and-lwf.html
What a great post -
I have a couple of questions - if anyone can help
There is a clutch Hydraulic Line across the transmission crossmember - does this need to me split where I am pointing?
and just above the clutch slave I have noticed what looks to be a flywheel timing sensor for the electronic ignition - this appears to be mounted on the transmission. Does this have to be removed and if so how.
Many thanks - I will post updates on Nsully's great work - he's and expert I am a newbee and there are losts of things that I just could not have done without him but there were a couple of things that were obvious to him that I need explaining.
Thanks All
Post 6
Nsully just put me straight - re the sensor.
He wrote:
The sensor bolts to the engine case so you can leave it in place. Remember to re-adjust to specs on install regardless of whether you remove/replace the flywheel.
Re Hydraulic Pipe: Still dont know if I can drop the Tranny without splitting the Clutch Hydraulic pipe - if anyone has done it please advise.
10-31-2014, 08:51 PM
Gear Selection
