Gear selection problem.

[joe75]

Hi,

I have a 87' Syncro that has lately been a pain to get into and out of gear. It has a 1.9 mTDI fitted. The box has been rebuilt using taller gears and new TDI clutch fitted. This was only done a few yrs ago and has done less than 10k miles, mainly on road.

The shift problem seems to come and go, sometimes its great then I stop at the lights and can't find any gears. I noticed worse with the engine running.

The gear linkage looks ok and when the gears are back it shifts fine and feels the same as normal. The linkage is a little sloppy but all the bushes and joints look ok and are well greased.

The clutch does not feel spongy but if I double the clutch and use the engine revs then gear selection comes back, most of the time ...

After lots of reading I have just replaced the master cylinder. As I was fitting the slave cylinder I noticed that I could move the arm the slave cylinder operates very easily. The lever moves up and down 10-15mm without any force or resistance.
This gets me thinking its a clutch problem? Should I be able to move this arm up and down that much without any resistance? Maybe this points to a clutch or thrust bearing problem?

Any ideas or thoughts before I drag the box out?

Thanks in advance.

[Aidan]

Joe there should be 10-15mm free play at the lever arm and 15mm movement at the tip of the lever arm when clutch pedal is depressed though it should take less than full travel to disengage the clutch
if it is fine with engine off then it's a clutch/spigot bearing issue - something causing drag on input shaft - have seen an issue with LUK clutches where the friction plate driver is too large a diameter and is bearing against the release bearing tube, though why that would become an issue over time rather than on the fresh installation I don't know

[joe75]

Thanks Aidan. You rebuilt the box for me via Syncrospares before we moved to NZ. Its so strange that one minute its all fine then the next i cant find any gears.

I am going to put the new slave & master cylinders on and bleed them, maybe one of them has a sale issue? If it still plays up then box out for a look at the clutch etc. Fingers crossed its I don't have to as parts here in NZ are non existent.

Good to know the 10 -15mm play is normal.

Again thanks.

[..lee..]

shot in the dark. dirt / dust in the bell housing not allowing clutch to slide on input shaft splines.

[joe75]

Managed to get the new slave cylinder on today. Those bolts are pain in the ... Especially with Syncro bash plates in the way.

The old slave cylinder felt very notchy and got stuck so maybe its my problem?

I only had ten minutes but could not get a drop of brake fluid out of the system. Whats the trick with bleeding the system?

Thanks again for help and ideas

[syncropaddy]

There is no trick as far as Im aware but you might now be looking at your problem.

[joe75]

The simple trick is to open the metal pipe on the master cylinder to bleed some of the air then the rest can be bled via the slave cylinder. So no air in the system but still poor shifting. It just feels very notchy ... WHY

I have just removed the front gear stick and cleaned up the 20yr grease and dirt etc. It all looks ok but have ordered a rebuild kit and new bushes as I am sure after 20 plus yrs they are worn! Pain in the butt as here in NZ T25 parts are nearly impossible to get, soits a UK or USA order. Long wait and lots of postage. Who's idea was it to bring a T25 Syncro to NZ

My next plan after greasing up the shift is to put a small spacer between the arm on the slave cylinder and gear box to give the lever more throw. Will see if this make any difference?

Wish me luck

[HarryMann]

1) .. can restrict (block) the movement of slave op-arm too, to force better bleeding of the slave.

2) Check the slave bracket and bracing bar for any movement (flex) when someone operating the clutch

3 Clutch and release bearing, arm (bushes) and forks (burrs) needs a good looking at

Wiki has stuff on this... https://club8090.co.uk/wiki/Ma ... x_specific

[xriss]

also joe might be worth having a sniff around your pedal assembly ..often ware on pins.. rods.. and ovaling deformations of the associated holes can occur...resulting in poor shifting and knackering of your synchro rings/box




i know a bloke thats recently imported a nice a rhd tristar in to kiwiville...ill dig out his email and pm you it,you may be able to help one another out..cant be too many in NZ

[HarryMann]

Yes good point Xriss, but I believe a pain to sort out by reaming and going up a dowel size. So new parts way to go?

[joe75]

Thanks guys.

I am in the process of replacing all the bushes in the gearshift. All of them where worn or seized, its amazing it shifted at all. I am sure most 25yr old Syncros are the same. Whether this is my problem only time will tell, but if nothing else I will have a supper smooth shift. I am still waiting for a few parts from the states to complete the job, worst part of being so far from anything.

I have also drained the gearbox oil. No bits of metal, but the oil was brown and dirty. Fresh 75w/90 GL4 going back in.

I have checked the pedal assembly area and it dosent seem to have to much wear and the slave cylinder bracket is okly

While under the van I noticed that where the engine bolts to the bell housing in places you can see the fly wheel where as in others there is a metal shield. Being a Syncro that gets used on the beach, dusty roads and through many fords i would have thought the bell housing should be sealed? Maybe I am missing some parts? If so i will have to make up something. Any one have any photos of diagrams of these parts?

next plan is once all the shift mechanism is back in and box filled with fresh gear oil I will try again. If no luck then its got to be box out Lets hope not as the Syncro is meant to be a daily driver ... and time is ticking.

Thanks for all you ideas and help. The wiki link is great...

[HarryMann]

Yes, there's certainly a thin steel plate twixt engine and bellhousing on the diesels, that has a big step (joggle) in it at the bottom to follow the contours; as usual these often get bent during removal or refitting, and should be carefully beaten straight with a heavy dolly behind it

There are two ports/large holes on the rhs of bellhousing, the lower a breather - should not be open to the elements if wading deeply. The upper one is for engine timing using flywheel markings (should have a screwed bung?)

It's also normal to seal the gearbox, plate and engine together with some sealer, for want of anything better, RTV silicon, which can cover a multitude of sins and peels off fairly readily when removing the box again.

Make sure the gearbox earth is very good, the engine earth even better and that the starter motor/bellhousing mating faces are nice and clean, the starter solenoid switch cable and connector a good tight fit on the spade, and the heavy starter cable direct fron the battery, very well fitted to the starter (insulate any excess bare areas of that cable )

Good luck! but keep the questions coming if you need too...

[joe75]

Yes, there's certainly a thin steel plate twixt engine and bellhousing on the diesels, that has a big step (joggle) in it at the bottom to follow the contours; as usual these often get bent during removal or refitting, and should be carefully beaten straight with a heavy dolly behind it

There are two ports/large holes on the rhs of bellhousing, the lower a breather - should not be open to the elements if wading deeply. The upper one is for engine timing using flywheel markings (should have a screwed bung?)

It's also normal to seal the gearbox, plate and engine together with some sealer, for want of anything better, RTV silicon, which can cover a multitude of sins and peels off fairly readily when removing the box again.

Make sure the gearbox earth is very good, the engine earth even better and that the starter motor/bellhousing mating faces are nice and clean, the starter solenoid switch cable and connector a good tight fit on the spade, and the heavy starter cable direct fron the battery, very well fitted to the starter (insulate any excess bare areas of that cable )

Good luck! but keep the questions coming if you need too...

I thought water and sand getting into the bell housing was not right. Why don,t people just put back the parts they remove.
Thanks for the info. I seem to have some of the metal plates but not all. Anyone have any photos or diagrams of these parts? I may either have to find some used parts or make something out of some sheet metal or aluminium. Any diagrams would be helpful.

I am still waiting on one last package from the states. It's the plastic ''ears' that are on the front shift rod. Mine where very worn.

[HarryMann]

It's the plastic ''ears' that are on the front shift rod. Mine where very worn.

Would be interested to see what they comprise of, and how they've effected a repair scheme. I thought Silverbullet (Holman Engineering) here was the only one doing any form of mod, as the originals are moulded in-situ

the plate would have to be steel, will see if we have a piccy ? Aidan may be able to help on that

[Aidan]

It's the plastic ''ears' that are on the front shift rod. Mine where very worn.

Would be interested to see what they comprise of, and how they've effected a repair scheme. I thought Silverbullet (Holman Engineering) here was the only one doing any form of mod, as the originals are moulded in-situ

the plate would have to be steel, will see if we have a piccy ? Aidan may be able to help on that

Holman Engineering supply the repair kits to a certain US Trade Outlet, Brickwerks is t'other outlet