924 Snail shell transmission issues
 

Hello, I have a 1979 924 with the 5 speed snail shell transmission. The transmission has been getting harder and harder to shift into first, to the point it won't shift at all. Its as if the shift lever will not move to the left enough to engage the gear.

The very difficult to replace back shift bushings were replaced about 15,000 miles ago. The bushings under the stick show now wear. There is no slop in the shift lever, so I do not think it's a shift linkage issue.

Any ideas? Do I need a transmission rebuild?

Thank you,
Ernst

I seem to recall there may be some alignment/adjustment points for the linkage? Or perhaps those have slipped since you did the bushings?

Hopefully you've also replaced the fluid with an appropriate type recently? Word is those snailshells tend to be very picky about the fluid used...

do you know how to doubleclutch into first gear or do you rely on the synchromesh to get the gears going the same speed during your shift?

if you can;t doubleclutch maybe try shifting just as you are rolling slowly, just before your stop because when the gears are turnign they are able to drop in easier. If you stop and then force it into first this is more rough.

If you doubleclutch properly , and it does take practice to shift into any gear by this method , it will help wear the synchromesh "fit" in. If you do rough shifts and rely lots upon the mechanical function of the synchromesh to align the gears even when they are not going the same sped as one another , the opposite will happen.

when you downshift, try using the clutch to release the trans into neutral, and then put the clutch in and give the gas a little "bump" then slip the clutch into the lower gear, done correctly you are matching the spin speed of the gears while they mesh and thus taking a load off the synchromesh, the synchromesh helps the gears align when they are not going the same speed as one another.
I thinkit is easier to learn by doing htis shifting down from 4th to third or third from second. in first gear you are able to put a lot more torque on things so if the technique and feel is at first, all wrong, also easier to do damage.



one way to learn is to drive a car with a good manual tranny and attempt to learn to shift without the clutch at all, it does take practice before such becomes a fluid motion. many harley owners are quite good at doubleclutching when downshifting. if you take note you will often hear them as they approach a light and shift down and when disenguaged give the throttle a controlled little bump. the sound of that is noteworthy.

the timing of this the amount of throttle given and the speed of the vehicle are all combined, its almost easier to be shown by an experienced driver or rider. on a bike when he stops he wants the bike in first rrady to go. he doesnt; want to be fighting or forcing it it into first when the light changes. the technique is the same exept a bike has different controls.

some cars like for example , most manual transmission japanese cars have becoime quite good at making gearboxes easy to shift, with some older and worn cars it can be harder, there was a point in time before synchromesh was invented, and then it would be more important to match gear speeds for a smooth shift.

If you buy a car from someone who isnt; good at shifting the trans at the correct speeds and giving it a pause as they go through neutral then you can be buying a car with worn synchromesh and it will be harder to shift as they have done a little damage.

when I upshift I tend to pause in neutral, Im not racing id rather feel the gears slip in nicely, if you go from one gear to another quickly it is depending more upon the mechanics of the syncromesh and you may feel some roughness.

as you shoift gears you can feel them enguage through the shifter if you get the shifts right the feel wil be silky smooth.

try when you move the shifter to use two fingers and not your whole hand this will make you more sensitive to the "bump" you feel, and try to minimize the feel so it feels smooth as silk then you are doing it right. if it wont go into a gear dont force it just put the clutch in fully, and go to a higehr gear. then let the clutch out and then try again. If you are rough thats causing damage. if you grind gears you diodn something not right. it will take practice.

done correctly you can easily gear down and in a fluid motion change the engine speed to match the loiwer gear removing the shock from the drivetrain. you cna then get a burst of speed by gearing down and incresing revs in a fluid motion whout shock to the drivetrain. once revs are up and you are in a lower gear you are set to stomp the throttle and now since engine revs are up the engin is in a higher power range , closer to the redline than if you had allowed the revs to drop during the shift. its less shock on the drivetrain and smooth driving wins in performance and fuel economy as well as transmision lifespan.

a racer could describe that better , perhaps. truckers may also be experts.

a while back on this forum a more experienced person person recommended I believe it was a "redline" lubricant, the jest of it was to change the fluid and then press the gearshift gently towards different gears without trying to engage them, his theory (as I understood it) was that this could improve syncromesh performance. i guess it was perhaps distributing fresh clean oil in the area of the synchro rings.

maybe the post could be uncovered by searchign for "redline" I believe that was the recomended name brand of lube.