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914World.com _ 914World Garage _ Trouble with fourth gear
Posted by: Darksude May 8 2018, 08:34 PM
I own an old 1975 Porsche 914 and we recently got the car up and running. One issue we are having trouble getting it into fourth gear. We don’t know if it may be the linkage or if it’s something more complex.
Posted by: jcd914 May 9 2018, 12:09 AM
Look at your linkage first.
Check the tapered set screws at the coupling just past the firewall and at the trans shift console.
And check all the plastic bushing in the linkage.
The set screws work loose and the plastic bushings deteriorate.
Jim
Posted by: Dave_Darling May 9 2018, 12:37 AM
Always check the linkage first; it's easy and can cause issues. Also look into the center tunnel (carpet off) to see if any of the cables in the center tunnel shift from side to side when you push the clutch. The tube that the clutch cable goes through in the center tunnel can break loose, and that can sometimes interfere with the shifter in the 4/5 plane.
Unfortunately, it is often the case that problems with one single gear is in the transmission itself, and some disassembly will be required to fix.
--DD
Posted by: Darksude May 9 2018, 06:11 PM
I don’t know if this changes any of the answers but it’d hitting something physical. We can’t really tell what it’s hitting though. We also don’t know if that spring block is the case 
Posted by: jcd914 May 9 2018, 06:43 PM
I don’t know if this changes any of the answers but it’d hitting something physical. We can’t really tell what it’s hitting though. We also don’t know if that spring block is the case
There is almost no chance this issue you have is in the tunnel or at the shift lever.
It is possible the clamp you see in your picture has come loose and the rod is not moving directly with the shift lever.
There is a bushing between the shift lever and shift rod but it almost never (in my experience) fails.
You can unbolt the shifter housing from the tunnel and lift it a little and look in case there is something loose in the tunnel that is blocking the shifter but it is not likely.
The for and aft movement of the shifter is limited by the shift lever on the transmission. When it reaches the end of it's range of motion it stops the shift rod which in turn stops the shift lever.
If bushings in the shift linkage have failed then the shifter and shift rod and transmission shift lever do not move in sync.
You need to be looking at the linkage under the car from the firewall back.
Jim
Posted by: Gint May 9 2018, 06:48 PM
Trashed shift coupler bushings will do exactly that, make it tough (impossible) to find 4th gear. In my expereince anyway... As others have said, check all the linkage and associated bushings. There is as good a chance as any that you'll find the issue right away.
Posted by: Darksude May 9 2018, 06:53 PM
I don’t know if this changes any of the answers but it’d hitting something physical. We can’t really tell what it’s hitting though. We also don’t know if that spring block is the case
There is almost no chance this issue you have is in the tunnel or at the shift lever.
It is possible the clamp you see in your picture has come loose and the rod is not moving directly with the shift lever.
There is a bushing between the shift lever and shift rod but it almost never (in my experience) fails.
You can unbolt the shifter housing from the tunnel and lift it a little and look in case there is something loose in the tunnel that is blocking the shifter but it is not likely.
The for and aft movement of the shifter is limited by the shift lever on the transmission. When it reaches the end of it's range of motion it stops the shift rod which in turn stops the shift lever.
If bushings in the shift linkage have failed then the shifter and shift rod and transmission shift lever do not move in sync.
You need to be looking at the linkage under the car from the firewall back.
Jim
Thank you! I will look at that immediately and see if something is blocking it or loose.
Posted by: Darksude May 9 2018, 06:54 PM
Look at your linkage first.
Check the tapered set screws at the coupling just past the firewall and at the trans shift console.
And check all the plastic bushing in the linkage.
The set screws work loose and the plastic bushings deteriorate.
Jim
Thanks!
Posted by: Darksude May 9 2018, 06:54 PM
Always check the linkage first; it's easy and can cause issues. Also look into the center tunnel (carpet off) to see if any of the cables in the center tunnel shift from side to side when you push the clutch. The tube that the clutch cable goes through in the center tunnel can break loose, and that can sometimes interfere with the shifter in the 4/5 plane.
Unfortunately, it is often the case that problems with one single gear is in the transmission itself, and some disassembly will be required to fix.
--DD
Thanks! I’ll look at it see what I find
Posted by: Darksude May 10 2018, 09:17 AM
Trashed shift coupler bushings will do exactly that, make it tough (impossible) to find 4th gear. In my expereince anyway... As others have said, check all the linkage and associated bushings. There is as good a chance as any that you'll find the issue right away.
Thanks for the advice! I’m lifting the car today and we’re gonna get a look under it and see what’s the issue
Posted by: Dr Evil May 10 2018, 12:16 PM
Click my link in my sig below for my notes. It will help you diagnose your issue and also see about helping prevent others. I 100% agree with the above, tho.
Posted by: dr914@autoatlanta.com May 10 2018, 01:05 PM
could be hitting a broken clutch tube, as the bracket that holds it against the left side of the tunnel breaks, moves the clutch tube over and then when shifting into fourth and fifth, the bottom of the shifter hits the tube.
Hold the shifter toward fourth fifth, and then push in and let out the pedal and see if you feel that action through the shifter
Posted by: porschetub May 10 2018, 05:31 PM
[quote name='Dave_Darling'
Unfortunately, it is often the case that problems with one single gear is in the transmission itself, and some disassembly will be required to fix.
--DD
[/quote]
my experience (somewhat bitter) is that if one or more gears aren't working its generally adjustment or bushes,when this is right only one gear not going in or staying in its inside the box....my issue 
.
Mine ever so gently pops of of forth,no fuss no noise,everthing has been checked,checked again and updated where it can be,all other gears are fine.
Posted by: Darksude May 10 2018, 05:47 PM
We weren’t able to lift it today but we figured out it needs to be adjusted.
Posted by: barefoot Aug 5 2018, 12:54 PM
could be hitting a broken clutch tube, as the bracket that holds it against the left side of the tunnel breaks, moves the clutch tube over and then when shifting into fourth and fifth, the bottom of the shifter hits the tube.
Hold the shifter toward fourth fifth, and then push in and let out the pedal and see if you feel that action through the shifter
Like this ?? Mine was off to the wrong side of the shift linkage !!
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