littleball_s4

Need a little help here. I've used the search but can't find a similar case.

Problem is I can't select 1st if the car is at a complete halt. It's not grinding, it simply doesn't want to engage. Tuesday evening was ok, yesterday morning was impossible. I left the car at a car wash in the middle.

It happened very seldom before (all I had to do was to put the stick in neutral, cycle the clutch and after that was smooth like silk) but now it's 90% of the time. I can select any other gear and, if I dont cicle the clutch, 1st would engage with no problem.

And the most strange thing is that if the car is moving slightly I can downshift to 1st if I want. No grinding, no effort.

Do I blame directly the car-wash? Temps dropped 5º in these days, could it be also related to it?

And the most important question:

Where do I start? Oil change? Rebuild? Links?

Thanks a lot!

whitefox

I work at a car wash and I have to drive every manual car because no one else knows what they are doing. I doubt 5 degrees would change anything, they probably screwed it up.

hinchcliffe

Mine sometimes does this, I throw it in reverse to line everything up first then it slips into 1st nice.

Ever change the diff. fliud? Sometimes that'll help.

littleball_s4

I never fcked a gbox and I can't imagine how this is done, no matter how green you are. Anyway, everybody is used to manual cars here in Spain. Can't see how "people" can do that to a nice car. It makes me want to... ah, well.

hinchcliffe: Exactly what you say, it "upshifts" from reverse nicely. And no, never changed the oil. But being so nice in the rest of the gears and so bad in 1st...

Thanks anyway. I'll Keep you posted.

Vilhuer

Could have something to do with those springs and pistons which are meant to stop from selecting two gears simultaneously. Either that or reverse gear lock in transmission cover is my bet.

littleball_s4

Thanks, Vilhuer, but I'm afraid I know nothing about gearboxes.

I understand the basics (axles, gears, syncros, selectors) but never had time to look deeply into one, so I must confess it's the first time I hear about the reverse lock and those springs and pistons.

Do you mind to elaborate a little more or perhaps point me into the right research direction? I know I'll not attempt a tranny rebuild mysef, but perhaps aligning, or swapping something simple outside it is feasible.

Is it the case?

Sorry to steal your time.

Mike Frye

Littleball,

You mentioned the temperature.

Is this your first winter with the car?

Does it do after it's warm or just when you get in it after it's been sitting cold.

Now that the weather is cold, mine is tough to get into first the first time after it's been sitting. When I first start, I put it into 2nd (without going anywhere), then through 3-5th just sitting there once and it will go into first after that.

Once I'm on the road the fluid warms enough to shift into and out of all gears.

littleball_s4

NJsharkfan, thanks for your comments.

Nop, it's the second winter. I don't remember having problems when I bought the car. And I definitively didn't had problems with it on tuesday. It's my daily driver, you know, I'm pretty sure about it. And for the shake of clarity: it's not tougher to get in to first, it's impossible until you somewhat manage to align something. It's not a matter of effort, it's a matter of nº of "neutral+cicle clutch" attempts.

I don't feel vibration or friction. I just hit a dead stop or not.

Temps dropped from 5ºC outside (10º in the garage) to 0ºC or -5ºC. That was my main suspect when I picked her yestarday evening from the car-wash and felt the problem for the first time. But she rested in her place in the garage tonight after a 30km run. This morning the problem was still there. It improves slightly after warmed up (30km more). But not much. Cold 10% success at 1st attempt, warm perhaps 30%. It was 95% before. (wich mean that I needed 2 attemps max, now it takes 6 or 7, so going via 2nd is the best choice).

I greatly appreciate your help.

John V

Vilhuer,

I could be wrong but if he can select reverse, I think that rules out the lock out pins and their springs (since the lockout pin and shaft detent are common to 1st/reverse selector shaft). I'm not familiar with the newer 5 speeds but wasn't there a flat sping metal clip that was known to break off and up in the bottom of the gearbox? Is that what you called the reverse lock-out?

Vilhuer

928 gearbox is quite normal in a way that generic explanation how manual gearbox works does apply in our case also:
http://auto.howstuffworks.com/transmission.htm

If you look explanation how three selector rods work in bottom part of the above page most important thing to pick from it is that only one of three should be moved out from center position at any given time. If more than one moves it will mean two gears are on simultaneously. This will lock up entire gearbox because two gear pairs have different rotation ratios yet they share both incoming and outgoing shafts. To prevent several gears from being on at same time three selector rods try to keep each other from moving away from center by means of several small springs and pistons. These are designed in a way that only one of three shafts can move from center position at any given time. As it moves it also moves these small pistons to different position and they in turn will prevent other two shafts from moving away from center. If parts are worn, oil is wrong kind or too old these parts might not function properly and can prevent shifter from moving. These small pistons and springs are build inside front end of gearbox casing. Its possible to get abroximately half of the small stuff out for inspection without taking gearbox down. There are few small covers which screw out from casing and hide springs and pistons. WSM and PET should help in locating these. Your problem could be that reverse/1st selector cannot easily move to 1st gear side when gearbox is cold.

Since '82 MY 928 manual box has had small locking mechanism inside gearbox cover which purpose is to guide selector from 1st to 2nd gear when lever is pushed straight out of 1st and towards reverse. This is suppose to allow fast 1-2 shift during spirited driving. This system has only three parts, its mount which is bolted to gearbox cover, small hook plate which does actual selector forcing and flat spring which purpose is to push down the hook so that hook is always ready to catch selector and sidetrack it to 2nd gear. Hook is sort of just hanging from mount and being pushed down by the spring. It might be possible that if hook is stuck to mount it could stop selector from going into 1st gear. System would have to be pretty badly shot to be able to do that though.

Vilhuer

1st and reverse do share same pin (piston in my previous message) but selector shaft moves different directions over its head. If that part of selector shaft is worn it could be more worn from 1st gear side. This would make selecting 1st more difficult than reverse gear. There is also other pin between reverse/1st selector shaft and other shaft next to it which have to move out of the way for R/1st to be able to move away from center position. Other end of this other pin goes to small dedent in other selector rod. If other rod is not exacly in center position its possible pins head will not find the hole. When oil is cold selectors do not move so easily. If going through reverse first helps it could mean that one of the pins or selector rods isn't in exacly right position and is preventing selection until its moved a little. Usual sign of worn parts. Changing fresh oil in could take symptoms away for a long time. Its possible to do some adjustments on what position selector fork is in relation to selector rod in those cases where fork is held in position by bolt. Early boxes use clocking pins and thus don't really have any adjustment available.

Small about 1" long metal piece in oil drain magnet is piece of that spring from reverse lock. Once it breaks of it will fall down to bottom and end up in magnet. In most cases nothing else happens other than from 1st to 2nd forcing action might not always work when on the move. Usually it works when stationary as gravity is keeping hook down. If one is really unlucky entire gearbox is destroyed when that spring piece gets between gears. There are cases where entire box casting has cracked because of this.

littleball_s4

I've just had a conversation with a very good mechanic, and he says ****ing a syncro in one day is feasible. Even in one shift, if the driver is idiot and strong enough (traaeeeaeeaaack). In that case, both dog teeth and sleeve are not triangular anymore, but rather square, so they hit each other instead of sliding to engage. Only if you're lucky enough to have them perfectly aligned the attempt would be a success.

That would explain why I can engage it as soon as the car is moving.

But then, the most puzzling (and probably key) thing to me is that it's 100% ok from 2nd or reverse. I see the syncro sleeves are parallel, but not the gear teeth dogs (at least not always, because both gears spin at a different speed. So if you engage 2nd, why is it much easier then to engage 1st? (I've seen it also in other cars with faulty 1st gear, but never bother thinking about it).

Ed Hughes

Must be a Spanish word, I've not seen it on this forum before.

Mike Frye

Dude, you can't say that, there are ladies present.

John V

his mechanics fetish aside, this doesn't sound like a synchro problem... perhaps a dog tooth problem or as Vilhuer pointed out, a combination cold, fluid, wear or hanging issue.