I printed out the manual from the FAQ section which covers the trial reassembly of the first and second motion shafts. I completely stripped the the shafts to check the syncros, needle roller bearins and change the gearing on the second motion shaft. To set up the shafts seems to need a torque wrench or similar in n/cm that looks as though it's a special tool from VW. I have made sure where all the spacers/shims came from where everything was pulled apart so I know where they all go. My question is that; does someone have a good method to get this right? I think this procedure is to get the right preload on the bearings.

Regards

Phil

Torque wrenches are normally calibrated in Newton metres and pounds feet (foot pounds if you like).

A newton meter means that it will just turn the load (nut, bolt or whatever) when the force of one Newton is acting on a radius (spanner, if you like) of one meter (length)

Pounds/ Feet (lbs/ft) is similar, but in this case, it is the a force of one pound (lb) acting on a radius of one foot (ft)

What you are looking at for the bearing preloading of your gearbox, is Newton centimetres (force of one Newton acting on a radius of one centimetre.

These units can be interchanged as long as they add up to the same thing, for example 10 Newton metres can be a force of 10 Newtons acting on the radius of one metre or a radius of 10 metres with a force of one Newton acting on it.

If you can find part of your shaft with a diameter of two centimetres (that means that the radius would be one centimetre) Wrap some soft string round it, attach a spring balance with      Newton calibrations on it to the string, keep up a steady pull on the spring balance and when the shaft is turning, read the spring balance - that will tell you how many Newton centimetres it takes to turn the shaft.

If you can't find a spring balance with Newton calibrations, consider using inch/pounds - the same principle, but measuring the diameter of the shaft in inches (don't forget to half it in order get the radius) and a spring balance calibrated in pounds (lbs)

If the bearings on the shaft are new, you should be working for the top end of the tolerance (to allow for bedding in) - if the old bearings have gone back in, they won't bed in any more, so keep it to the bottom end of the tolerance.

 

Regards

Only thing I had to source is the dial test indicator, this is used to measure the movement side to side (play) of the shaft between the 2 bearings.

If it's between whatever tolerance it says in the guide then it's okay, if it's out you will need to add or remove shims. These are behind the bearing races. This is very important as the gearbox will fail very quickly if there is too much play. 

I have onty ever had to change these shims a few times and that was when I fit a different differential and swapped the actual shafts (not gears), if your keeping the same internals then chances are new bearings will not add/remove enough to warrant changing shims. 

 

The only other thing I can see needing a torque wrench is for the end gears (whatever they are called) inside the black cover that has a big torx bolt. I have seen these sheer off after rebuilds and have been advised by several gearbox rebuilders to always replace this bolt as it takes a lot of stress and heat so only torque it down to the specs in the guide for a new bolt. 

Edd China done a good demonstration of how to improvise a setup to achieve a preload on a LSD on the MKI (iirc) Ford Escort episode of wheeler Dealers if you can track that episode down,

 

paul m.

Thanks for all this advice. They are all new bearings I'm using. My son has a quarter drive torque wrench down to about 5 nm so I will look into using that. I have DTI so I can measure the end play. Thanks for the tip on the fifth gear torx (star) bolt. VW  had used thread lock and it was a real pain to get out. I used an air powered impact driver in the end to loosen it. I will see if I can use a more conventional allen head bolt instead including the bolts that hold the driveshaft flanges in. I checked the manual and it uses torque wrenches calibrated in ncm so I will see if I can convert readings from my son's wrench from nm to ncm. One thing I didn't ask was about the availability of the shims (020 311 391 A-Q)(085 311 391 A-M)(084 409 383 AE-BH) Do VW supply them or does anyone else have them? I will use the spring balance method if necessary. Other posts in the past have mentioned the difficulty of getting the outer race of output shaft  bearing at the clutch end of the gearbox removed. I put put two short welds on to the race which was enough to shrink it when it cooled and then levered it out. My last resort was going to be be drilling two small holes opposite each other into the back of the bearing from the clutch side of the gearbox castings and then using a small pin punch to drive out the bearings. Then when the bearing is removed drill and tap the holes for small grub screws that will seal the oil with the use of a thread lock. There are a couple of You Tube videos on fifth gear 085 adjustment. Are these helpful or are there tips somewhere on the forums because I've already had a 085 that pops out of fifth hear after about half an hour of use and I don't want that again?

Regards

Phil 

My problem with using a torque wrench in this situation, is that far more force is required to get the shaft turning than is required to keep it turning, so in that respect, a torque wrench does not give an accurate indication.

The shims are readily available. They are literally a few pence each and come in aboutn10 different sizes. 

There is a thread somewhere about fitting an LSD to the 085 that details all this and has part numbers etc. 

 

As as for the bearing races what I do every time is heat up the aluminium case around the bearing then tip it upside down and give it a tap and it should just fall out. I would strongly advise against drilling the casing anywhere near the bearings as this is surely going to lead to early destruction. 

 

Fifth th gear is nice and easy to adjust. Op the black end cap off and you will see a fork that links to a ring around a gear. When 5th is selected the fork moves the ring over the gear. The aim is the have the ring sit exactly on r not higher or lower. 

The adjustment is simple, there is an Allen head on the pivot of the fork and a 13mm hex nut under it. Slacken the nut, select 5th and turn the Allen bolt until the ring sits properly over the gear. Tighten and check job done :) 

Dixy thanks. I googled shims and there appears to be a lot that is not VW on line. Thanks for the fifth gear adjustment advice.My aim is to install the engine and gearbox together with no leaks and no faults. So the selector ring has got to sit right on the bronze syncro to be in the right place? After so long the gearbox is the last thing I have to finish so I don't want anything to be wrong.

Regards

Phil

Well I spent most of the day setting up all three shafts in the gearbox and it's not something I want to repeat in a hurry because it's so time consuming temporarily fitting the shafts and testing the end float of each one. The output shaft was the hardest because I put the spacer in behind the blind bearing in the clutch housing (and I don't have the special puller to get it out) and this has made the shaft too tight at the other end so to get round it I am getting the spacer washer that is against first gear ground down so it is thinner and gives the correct preload to the bearings. The only worry is that if the spacer washer is case hardened will it then be bent after grinding. If the washer is case hardened the ground side will go towards the bearing. I needed a shim washer for the input shaft which was available from TPS in Portslade and will be delivered overnight. While there I checked if other shims are available and they are but have changed part numbers. With the new diff I have only needed a shim at one end to get some preload on those bearings.

I wouldn't grind anything down as that will just move something where it's not supposed to go. 

To get the bearing race out of the bell housing just heat the bell housing up all round the bearing and then when it's hot enough it will just fall out. 

I'm sorry, I didn't see your post and I have already had the spacer washer ground down and all the gearbox assembled except for fifth gear. All gears from first to forth and reverse appear to select as they should. I will remember the heating trick for next time though. The bit that worries me now is the clip that goes over the fifth gear selector shaft because it got broken and I welded it up. So I am hoping it will hold once everything goes back together. 

If you surface grind the spacer that is behind the bearing it is doing the same as putting a spacer in behind in the bearing outer race and the shaft position ought not to change.

When I stripped the gearbox originally I broke the clip the holds the fifth gear selector fork on to the selector shaft.I welded it up in the hope it would be all right. Yesterday I found they were still available so I have one coming from Germany. During this rebuild I have been surprised by parts that are still available.Some examples are: 1: All bearings and seals. 2: 1st-4th gear syncro rings. 3: fifth gears in one ratio. 4: 3.84 output shaft that allows Quaife LSD. 5: fifth gear cover gasket. TPS say they are never told when parts become unavailable so get your parts while they are still available.

Yep pretty much all the parts are still available for these it's just cost effectiveness as some of the parts are dearer then a complete used box. 

Wish I had rad this earlier as I have a few spares you could of had :) 

yes grinding the shims down is effectively the same as using a smaller sized shim but if your not able to do that properly I would always advise to get a new one in the right size. 

 

I was was changing bearings in an 085 yesterday and remembered another usueful tip. Put the new bearing races into the freezer at least a day before. This shrinks the metal making it quite a lot smaller. Heat the casing to remove the old ones then get the new ones out the freezer and they literally just drop in. 

For the bearings themselves I usually smash the cage around it and take all the pins out so I'm left with the inner race then use the puller tool on that. When I am ready to fit the new one I heat it up really good either with a blow torch or on the gas hod in the kitchen, again it just drops on to the shaft with no hassle. 

 

Glad you got it sorted buddy, there is no feeling better then knowing you did it yourself

I have another 8P 085 that didn't sound good after a clutch cable failed so I will be rebuilding that at some stage. I got a 10 ton press in the end which makes the job so much easier so if you fancy a trip to West Sussex to dis/assemble a gearbox, I am happy to help. Bexhill Gearboxes were very helpful in the process so I would recommend them. So I'm just waiting for the clip for the fifth gear selector rod and the adjustment for that. Then it will be all finished. Yes doing it yourself is satisfying and a lot different from rebuilding a 084. Is there a good way of testing the box before it goes in the car? I think I'm getting all the gears because all the selector rods are doing what they should do. I have made a short shifter so I am hoping that will work as well.

guys any sources for syncro rings?  my bearings sound ok but its a bit ropey going into 2nd and 3rd 

I have seen some on gearbox websites and I think Ebay but according to the manual there are wear limits that can be checked so that may be worth looking at.(I think only the 1st-4th syncros are available) Also after looking a few now they can get out of round for some reason.For instance my fifth gear one does not seem to fit the gear very well and rocks slightly on the tapered section. On the inside of the syncro ring is a serrated surface. If they are full of dirty oil I think they can't disperse the oil well during a gear change causing the syncro to slip too much. The exact oil must be used as recommended by VW because of the reasons mentioned before and that a mineral oil is likely to "burn" on to the inside of the syncro.This was proven when I cleaned my syncros there was burnt on residue that could only removed by light sanding or scraping. I have only been fussy about the syncros because of the mods to the gearbox and that I am going to use a short shifter. Check your clutch. It may not not be disengaging completely but I guess you have covered this. 

When it becomes difficult to select gears 2 AND 3 it's not likely to be the easy adjustment of the selector position as that is only really when it's difficult to select gears that are in groups for instance 1-3-5 or 2-4 and reverse etc. Which is a shame as that really easy.

This sounds like the most common bearing which is the second motion shaft (I think that's what it's called?) It has the bigger bearing in the bell housing. This bearing is the first to go and gives the shaft play and means selecting certain gears is hard and with use only gets harder. 

The main reason for this failing is low oil level mainly caused by a bad selector seal. 

Its not always obvious this bearing has worn until it's very bad, so if you are planing on working on it I would recommend doing it sooner rather then later as it will only wear more and mean you will need to source more parts.

does it point to anything that its almost perfect on a hot day after a run and at its worst on a cold winter day cold start ?...gearbox has fresh synth oil of the correct grade 

 

ive got a spare box to put in, if thats decent i may try and repair the other 

The biggest pain in the whole 085 rebuild is refilling it with oil. I have always filled them by the filling plug and it's always messy so I thought there has to be a better way and then realised that if you remove the speedo drive making sure that the plastic speedo shaft is not dropped into the gearbox. Then put a funnel that is a tight fit into the speedo drive hole and pour the oil in. The level/filling plug can always be left out to make sure the correct amount of oil is in the gearbox. (3.1 litres) I'm sure this has been done before but there is no mess. This was done with the gearbox out of the car to make sure it doesn't leak before it goes in the car but it can't be that more difficult in the car.

On 7/8/2016 at 17:53, caretakerplus said:

Torque wrenches are normally calibrated in Newton metres and pounds feet (foot pounds if you like).

A newton meter means that it will just turn the load (nut, bolt or whatever) when the force of one Newton is acting on a radius (spanner, if you like) of one meter (length)

Pounds/ Feet (lbs/ft) is similar, but in this case, it is the a force of one pound (lb) acting on a radius of one foot (ft)

What you are looking at for the bearing preloading of your gearbox, is Newton centimetres (force of one Newton acting on a radius of one centimetre.

These units can be interchanged as long as they add up to the same thing, for example 10 Newton metres can be a force of 10 Newtons acting on the radius of one metre or a radius of 10 metres with a force of one Newton acting on it.

If you can find part of your shaft with a diameter of two centimetres (that means that the radius would be one centimetre) Wrap some soft string round it, attach a spring balance with      Newton calibrations on it to the string, keep up a steady pull on the spring balance and when the shaft is turning, read the spring balance - that will tell you how many Newton centimetres it takes to turn the shaft.

If you can't find a spring balance with Newton calibrations, consider using inch/pounds - the same principle, but measuring the diameter of the shaft in inches (don't forget to half it in order get the radius) and a spring balance calibrated in pounds (lbs)

If the bearings on the shaft are new, you should be working for the top end of the tolerance (to allow for bedding in) - if the old bearings have gone back in, they won't bed in any more, so keep it to the bottom end of the tolerance.

 

Regards

That is exactly how i do it it works a treat, thumbs up couldn't of explained it better :) 

On 7/29/2016 at 19:05, steveo3002 said:

guys any sources for syncro rings?  my bearings sound ok but its a bit ropey going into 2nd and 3rd 

where abouts in cambridge are you ,as im 5 miles from downham market and could pop over if your stuck 

 

linton area mate....would be good to meet up sometime

 

im up to my ears in an engine swap at the mo , will get into the gearbox after ive recovered from that