1st Gear problems

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BobP
Posts: 67
Joined: Sun Jan 13, 2002 12:01 am

1st Gear problems

Post by BobP »

I have a '75 914 1.8 and have been having a strange problem with 1st gear grinding.

Basically the problem seems to be heat related, 1st gear almost always works fine when the car is cold. I can engage 1st either stopped or by matching revs when slowing down.

Once I drive for a while and everything warms up it becomes almost impossible to engage 1st gear, even with double clutching and matching revs as best I can or while stopped.

The car had a new clutch intalled and the shift linkage bushings replaced when I bought it 2 years ago. My mechaninc and I did a bunch of tweaking on the linkage to get it working this well, originally it was very sloppy.

What else should I look at? Am I going to have to rebuild the tranny to sort this out?
stevestromberg
Posts: 434
Joined: Tue Mar 13, 2001 12:01 am

1st Gear problems

Post by stevestromberg »

Check the adjustment at the shifter, also the set screws as they will loosen up and give strange shifting problems. Steve
kevin powers
Posts: 216
Joined: Mon Dec 24, 2001 12:01 am

1st Gear problems

Post by kevin powers »

how much of a free play difference is there when the trans is in 1st as opposed to rev at the shifter? if one is tighter than the other try and make it a little more equal. a little bit of adjustment can sometimes make a big diff.does the car feel like it wants to move when you put it in 1st at idle?
BobP
Posts: 67
Joined: Sun Jan 13, 2002 12:01 am

1st Gear problems

Post by BobP »

There is not much free play at all in first, when I first got the car it would sometimes pop out of first and we readjusted until we solved that problem.

As far as wanting to move in 1st gear, do you mean with the clutch disengaged? If so, no the clutch disengages fine, the throwout bearing was bad when I got the car, I had the clutch, pressure plate, throwout bearing and clutch cable all replaced. If you mean with the clutch engaged, yeah it will move at idle, but it really needs more gas than that to move without stalling.
BobP
Posts: 67
Joined: Sun Jan 13, 2002 12:01 am

1st Gear problems

Post by BobP »

I had heard/read that elsewhere about being able to do first gear without removing the tranny/engine. Is it real tough? I am not a great mechanic, I used to do my own brakes and tuneups and things, but have not had the time over the last few years to work on our daily drivers myself. At least the Porsche is a toy and if it takes me a while to get it back together I can still get to work, I didn't have that luxury in the old days.

I still wonder whether replacing the synchros will gain me anything, as it shifts pretty good cold. I test drove another guys car two years ago, he said it had no 1st gear synchro and you couldn't get first anytime except at a complete stop, mine actually shifts easier at a slow roll than when stopped once it starts acting up.

I am thinking when sports car driving season returns around here, I will try tweaking the linkage and shifter adjustments again and if all alse fails I may go for the synchro kit.

Thanks for the info
Racer Chris
Posts: 665
Joined: Sun Jan 13, 2002 12:01 am

1st Gear problems

Post by Racer Chris »

I have had a problem where first gear pops out as soon as the clutch is let out. Since this was in my race car I went without first until I was ready to remove the engine/tranny (something I do frequently). I stand the gearbox on end to retain the fluid and remove the end cover. I remove the shifting gear for 1st & reverse and file the smeared teeth which won't engage, with a small flat diamond file until it fits together again. This is really only a temporary fix but costs nothing. Someday soon I hope to do a thorough rebuild when I will replace such worn components. I have always been good at disassembling mechanical stuff but only recently have the confidence to reassemble these things myself.

Chris Foley
Chris_914
Posts: 250
Joined: Fri Mar 16, 2001 12:01 am

1st Gear problems

Post by Chris_914 »

The first gear syncro Only can be changed with the tranny still in the car. The problem being heat related is most likely due to the viscosity of the oil. The syncro rings are cheap but the first gear slider goes for about $110+ if worn. Easy job, remove the exhaust and tranny end cover and your there. I did use a special tool to remove/install the dog teeth on the syncro hub but I am sure if care is taken alternate methods could be improvised.

Pelicanparts.com
syncro ring c-302-301-06 $20.00
1st gear hub c-302-241-06 $104.30
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Chris
75 914 2.0L
72 1302s Super Beetle
71 Squareback
97 K2 Golf

[This message has been edited by Chris_914 (edited 01-14-2002).]

[This message has been edited by Chris_914 (edited 01-14-2002).]
Chris_914
Posts: 250
Joined: Fri Mar 16, 2001 12:01 am

1st Gear problems

Post by Chris_914 »

Pick up a copy of a Haynes repair manual for the 914/4. It goes into great depth on the transmission. Though this is not related to first gear, ignore the part about removing the speedo drive gear with a bent nail, completely impossible, it requires a deep socket. First is the most used gear and requires more from the syncro than any other gear. It is possible to be an adjustment problem, but if the throw for 1-R gate is off so would 2-3 and 4-5 gates. I was surprised to find how easy this tranny is to work on. The first time I opened it up I expected the inner workings of a clock and parts to go flying every where, it is actually a pretty simple device. The first and reverse hub is completely seperate from the rest of the gear cluster. No degrees in mechanical engineering are required Image

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Chris
75 914 2.0L
72 1302s Super Beetle
71 Squareback
97 K2 Golf
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Bleyseng
Posts: 994
Joined: Fri Apr 21, 2000 12:01 am

1st Gear problems

Post by Bleyseng »

I have replaced the 1st gear syncro and as Chris said it's pretty easy. Replace the dog teeth is harder but still should be done at the same time. It did make it easier to shift into 1st afterwards.
If you are opening up the transmission with it out of the car you might as well check the rest of the transmission, or take it in for service to freshen it up.
Leave the transmission in the car if you are going to just fix the 1st gear syncro.
Geoff

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76 914 2.0L
ray greenwood
Posts: 1941
Joined: Thu Jul 19, 2001 12:01 am

1st Gear problems

Post by ray greenwood »

The problem will most probably be the first gear synchro,but not totally due to wear. As the gear oil heats up...and gets thinner. The synchro sets deeper onto its cone. Though this allows more friction and makes it "grabbier"..usually to grabby to line up with the sliding collar effectively, what the real culpret is ...is a combination of decreased gap between the synchro ring and hub (wear) COUPLED with excessive slack in the entire stack of gears on the shaft. Its not serious and is usually just a shim. If changing the synchro ring only improves it marginally, the correct thing is to dismantle and check the play between all gears on the shaft..and the endplay of thewhole stack. Ray
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Dave_Darling
Posts: 2534
Joined: Thu Apr 27, 2000 12:01 am

1st Gear problems

Post by Dave_Darling »

A tech article on replacing the 1st gear synchro without removing the transmission from the car:
http://www.pelicanparts.com/techarticle ... repair.htm

--DD

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1974 VW-Porsche 914 2.0 (Type IV powered!)
http://www.pelicanparts.com
BobP
Posts: 67
Joined: Sun Jan 13, 2002 12:01 am

1st Gear problems

Post by BobP »

WOW, Thanks everybody. I have a Lash maintenance manual, it is not real impressive. I will pickup the Haynes and also take a look at the article at Pelican.
dehaan914

1st Gear problems

Post by dehaan914 »

Hey,
I've also replaced the synchro on 1st gear and also replaced the dog theeth gear for firts, here are links to some pics of the proces taken from my site,

a picture of the parts that come out when you disasamble first gear (and reverse) http://home-4.tiscali.nl/~t213230/maint/knutsel7.html

a picture of my worn out dogteath gear http://home-4.tiscali.nl/~t213230/maint/knutsel6.html

if the links don't work go to http://drive.to/porsche914 and click on 914 driver, followed by maintenance

greets form overseas,
Jacco de Haan
Delft, the netherlands
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