Gear selection problem.

[silverbullet]

Have you fitted a new clutch master cylinder? This still sounds like the recuperation valve inside has failed, I've had it happen on other cars. Sometimes they "pump up" the slave, other times they go intermittent (valve not closing all the time, think there's a little light spring inside that can break or rust through) or they just leak, but the latter is pretty obvious!
It's barely an hour's work all done and the cylinder is only around £40...

[HarryMann]

Yes, says new cylinder... they are very often at fault and one of the first things to change if it isn't new anyway I agree...

[joe75]

Hey Guys,

Latest update.

I managed to get a few days on a ramp which makes working much easier. After spending an evening reading on various forums I had some more ideas to try.

I worked out that I could select the gears easy at the gear box with the linkage off, with the engine running and with the engine off. I did notice that sometimes it would just pop in and other times it would take a more effort to select the gears but i could find all the gears.

I then went onto the linkage. I think my new rear gear selector bush was getting stuck on the gear linkage bend near the gear box.(photo below of the bend in the rod) So I put back on my old bush, gear box ball and cup.

I then adjusted the linkage as per the Bentley to give me a base line position. I could get all the gears but 1st was hard and needed to push down to find it. Next I loosened the center gear shift rod joint and with a pair of vice grips on each rod I slowly turned the rod clockwise. It only took a little amount of turning but lots of time to find the perfect selection of all gears. With engine off and on.

I next looked at the new slave to see if it was throwing the arm on the cross shaft far enough. With a spacer between the slave rod and cross shaft arm i noticed the the cross arm moved and extra 5mm making my clutch bite higher off the floor. I think I will have to make up and adjustable rod so I can fine tune this as the clutch bite is closer to the floor and it would be nicer to have it higher.

With the above done I drove the van in all gears on the ramp and all was fine

I next looked into the reverse shudder. On the ramp reverse worked ok but with the van on the floor the shudder was so bad that even with the clutch fully depressed the van would not roll in reverse. This in turn caused severe kangaroo bounce when trying to reverse. I have a de-coupler fitted so wondered if I had put the vacuum pipes (and wires) on the correct way? (anyone no the correct pipe and wring)
I pulled the de-coupler and rear dif lock knobs and pushed them back in and it seemed better? Someone said my VC could cause wind up in reverse?

One thing i noted while under van is the new pooh plate still leaves the bell housing open to crap entering. (photos below) Are other Syncros like this? I feel with sand and water getting in there it won't do the clutch much good?


Today was the first day i got to drive the van. Set off, all gears good, would even say smooth . Engine on or off. Still get some reverse judder but not so much, but rolls freely in reverse, clutch in and in gear. After about 10km, gears start playing up, notchy selection, hard to find gears. Then I come to use reverse, lots of judder and generally not happy about going backwards.
With the engine off in the car park I select the gears, a little notchy but more or less ok.

Off we go again and it dosent want to release from 2nd, like its stuck in gear. Then all fine again...ahhhhh Next I am at a busy bit of rd and I can't find any gears, i end up bending the gear stick to find 2nd ... Then the gears are back but notchy.

The van is now dumped on the drive way ....

So what the XXXX is wrong?

Is it an intermittent selection problem in the box that comes and goes ... That is my latest theory.

I am sure you guys are bored of this post by now, but ideas please.

[jebiga41]

Just an idea but might be worth looking at the front selector arm to see if it is bent where the front forks are just where it attaches to the bottom of the gear stick also the distance on the splines where it meets the UJ is correct ?

[Aidan]

what oil are you running in the box ?

intermittent problems in the box are pretty dam rare, the only thing I can think that could cause that is a failed selector shaft, which can be changed insitu, I'll test one on the bench and send it over if you send me your address, or you can take one back after the hols - I'll be here if you want to come see me whilst you are over

if the problem was restricted to 1st and 2nd it would be the relay lever's broken, for that to affect all the gears the guide bolt would normally have had to have come out - if you feel on the top of the box inboard of the reverse switch you should find the 13mm head of an M8 bolt on the top of the case - you would have seen a hole if it was missing when you took the box out, near the yellow paint marks on the top of the box

[joe75]

Thanks Aidan. Your help and knowledge is gratefully accepted

I only think it is the box as I can notwork out what else it could be? With the problem being intermittent it is so dam frustrating.

The new gear oil that went in the box was 4 liters of Valvoline Dura Gear, Synthetic Blend, SAE75W-85 GL4. I checked the level the other day while on the ramp and it was about 2cm below the fill plug.

I just looked at the photo of the box below and I think the M8 bolt is present? To the right of the yellow in the photo. Would I need to remove this bolt to pull out the shifter shaft?

[Aidan]

should be 4 1/2 litres and if you overfill, ie till it flows out not really a problem better too much than too little, personally I don't like fully synthetic, some of them are known to not offer enough protection to our box which is old technology, though the semi-synthetic 75W/90 Carlube and Fuchs Titan I've been using and recommending over here seem to be fine. The yanks use to swear by Redline MT90 but there has been loads of evidence of wear on crown and pinion etc.. with that and it is no longer recommended, they've now gone for a Swepco product as used by the Porsche possee, I've stuck with my recommendation £22 oil changed regularly as I know if peeps put in £50+ stuff they won't change it.

yes that's the bolt head in the piccie and no it doesn't have to come out to remove the selector shaft and with the reverse switch housing it is usually possible to check the relay lever is working correctly too, I say it can come out insitu but I've only ever done it on a petrol and even then I didn't actually remove it fully so this is a little bit new territory, may require box lowering a little, sorry I just don't have time to put one on the ramp and try it this week and don't have a diesel syncro to hand at the moment, though will have one in next week so might try it before we pull the box.