Ok I've got this MK1 GTI that jumps out of fifth gear. Took it down to my local Gearbox repair place that said, oh you can repair that yourself, very generous considering I was offering them some work, anyway he said Just remove the end housing and you can see all the components there, the selector rod is on a thread and you can rotate it one turn in order to pull the fifth gear in a bit more. So I took the end off and sure enough when I select Fifth it looks like the fork has worn a bit as the little synchro teeth don't seem to be pulled in enough so they are flush with one another. Here's the problem, how the hell do I get the selector fork off to rotate it one turn on it's thread. I've been looking at it now for about an hour and I'm still sratching my head ! It seems like the whole selector shaft needs to come out of the gearbox but that would mean a full gearbox dismantle which he led me to believe was unnecessary. Please help me !
I think what he means it to lift the locking plate(find your haynes!!) and screw the selector shaft through the selector fork( the optimal position according to haynes is 5mm) If you read the book of lies, preferably the green maintenance and repair issue, and not the newer, pants service manual you should have a good idea what I'm on about.
Unforunately at the moment I only have the 'Pants' Blue service manual which just says 'leave the gearbox to a professional'. I've seen the locking plate on the diagrams but can't seem to see one on my fork, is it supposed to be on the end that I can see i.e. on the end of the threaded shaft and the tabs fit into those two slots on the end of the thread, because if so I don't have one which could explain a lot. Actually by sticking a pair of pliers into the two slots on the end of the threaded shaft I've managed to turn it about one turn but then it stopped, I think because now the spacer sleeve is being compressed, so it won't go any further. Unfortunately the synchro teeth still aren't engaged flush so this probably won't help much.
The plate will be under the thread, inbetween the selctor fork(the 2 forks legs and hole at the top) and the hole at the bottom.It should be tight against the bottom plate of the fork assembly. The edges of the plate are riased slightly so you can lever it up out of the way.
No there is definitely no locking plate fitted. The selector fork has obviously worked it's way loose without it and that's why it jumps out of gear. I'll go and order one and try and fit it, although by your description Hotgolf I'm still not quite sure where it should be fitted. I'll probably draw a diagram then post it up so someone can tell me where to shove it !
The jumping out of 5th is usually caused by low tranny fluid level, leaving 5th gear unlubricated, since it sits higher than the reat of the gears. This destroys the bearing.
Good point, but if there is no locking plate on the 5th gear selector then theres a good chance that it has worked it's way into a different position causing it to jump out of fifth. On the oil point though, see if there is any excess movement in the synchro hub of 5th gear. If there is and it doesn't feel smooth any more then there is a chance that the needle bearing, or even worse the deep groove ball bearing holding the output shaft is shafted.
There doesn't appear to be any excess movement in the hub but I've ordered a new bearing anyway, may as well do it while it's all in bits. Also had to order a 12 point spline tool in order to get that nut off the synchro hub :-(
Ah, One more thing, where do I adjust the selector fork position to when I eventually put things back together ? I mean too far out and it won't hold it in gear, too far in and it could cause excessive wear on the fork/hub. Is it a case of take up the slack then another half turn or prehaps there's some distance to measure ? Cheers everyone for the help so far !
I have this problem on my Rover, I tried to top up the oil but found it was already at the max. Doesn't appear to have been checked before either. Mine doesnt just slip out of gear it is forced out of gear. If you hold the gear stick in fifth you can feel a fairly hefty amount of pressure pushing it. It doesn't just slip back in either it has to run in another gear for a little while first. The less I use it the more it will stay in gear when I do need it.
Here are some pics of the locking plate. You screw the selector tube until the distance "x" in the second picture is 5mm. Its the distance from the flat part on the fork and the top of the tube. BTW the tube is a left hand thread. As you already know, you have to remove the larger fifth gear cog and syncro to get a new locking plate on. The central 12 point bolt is very tight!. I'm assuming the box is in the car, so all you need to do is put the box in gear and have someone hold the brakes. If the box is out of the car, then you need to lock the box in 5th and reverse at the same time (let me know if you need to know how to do this). To turn the selector tube you are supposed to use a VW special tool, but a macpherson strut tool works just as well. I tend to just get some pipe grips on the side of the tube, rather than trying to turn it from the top. You have to then take the box out of gear to get the cog and syncro off as it twists slightly as it comes off the shaft. When you get the bits off and refit with a new locking plate, fit it loosely as in the pic. The tube is a slight taper and the closer you move the plate in the direction of the gearbox, the tighter it gets. Whe the adjustment is correct, tap the plate down and ya done. BTW, when retightening the fifth gear bolt, you need to add some thread locking compound. And as I always say, do not pull the selector rod out of the box, as the all the forks will fall off it inside the box and you'll be looking at a complete stripdown!! Hope that helps.
Harry that's brilliant, everything has suddenly come into focus ! Many thanks, I'm sure I can deal with this now.
