'96 Polo 1.4 16v

[majic79]

Hi guys, I've just bought a Polo 1.4 16v for a rally car project, but I'm struggling to find some extra info.

I have a haynes manual for the 6n polos, but it doesn't cover the 16v. This is fine for the majority of the work I'm doing, but the car needs a new cambelt and I need some reference material. Is the engine covered in another manual?

Also I want to find out some more information about the gearbox as it's futched, is it used in another model? What ratios is it running? does it have a limited slip diff? (I found some hypoid gear oil in the boot, and that's usually the stuff to use in a LSD) also if anyone with some experience of these, could they tell me what part is it that fails on these gearboxes and can the gearbox be strengthened to prevent this sort of failure?

Thanks in advance

[Crasher]

No this engine is not covered in that manual but it is covered a little better in the Golf 4 manual. All 6N and 6N2 085 gearboxes are utter crap, it is THE Achilles heel of the car, you should try a Polo 6N2 GTI, they are a sick joke where gearboxes are concerned. No it does not have an LSD, all modern gearboxes use hypoid oil. No the box cannot be strengthened, it was designed as a 4 speed for 50PS max, asking it to handle 100PS+ was a stupid idea that was bound to go wrong.

[majic79]

Can you give me some more information about where it fails? I've read about 5th failing (not meshing) and some other problems, has anyone actually cracked one open and had a look?

[Crasher]

Diff bearings and input/output shaft bearings.

[majic79]

Races or bearings? I've seen rebuild kits for £90 (I have the tools and an appropriate workspace to do the job) just wondering if it'll be a case of repair the fault and then wait 60k miles for them to go bad again

[Crasher]

Races and bearings are matching parts and so the same thing. A £90 rebuild kit is not going to have all the parts required in my experience and rebuilding an 085 box is quite difficult compared to the 020/02K and especially the really easy to rebuild 02A/02J.

[majic79]

I'll re-phrase my reply, what, specifically, on the gearbox fails? You said input/output shaft bearings, my follow up is, is it the Bearing (the bit that spins in the races) or the Race faces that fail? Could it be a thrust washer/bearing that's causing the issues? I'd really like to know the ratios for the box as well, but google's not showing me much there. I'm not new to cars, but I'm new to VW's, so I don't know where all the identifying plates are, what all the pitfalls are nor the names of any reputable companies.

I'm going to be using the car for rallying, so I need to be sure that the 'box will take some abuse, and won't detonate on me when I give it some stick. If it was teeth falling off, then I'd see there being a problem. If the diff crown wheels fell off, or the diff exploded (like metros do), again, I'd see the problems.

What I'd really like is a cheap solution to the problem, and if the only issue is wear and tear on the bearings, then possibly someone has addressed this and it can be easily rectified. How many £90 rebuild kits have you bought and how many gearboxes have you rebuilt?

I've rebuilt enough engines and gearboxes over the years to qualify as "handy with a spanner" and I have no issues with tearing down and rebuilding this 'box. I'd just like to make my life a bit easier and call to the gods of VAG to point me in the direction of the fault and how to fix it and/or improve on the design.

[Crasher]

Bump this later so I see it from home.

[majic79]

bump for more info

[Crasher]

The output shaft taper roller bearing 311 405 625 F (actually a very common inner rear wheel bearing) at £15 and the main taper rollers for both shafts 085 311 123 D (085 box specific parts) of which there are three at £18 each, tend to be the most troublesome, especially the two on the end of the shafts.

The needle roller bearings 085 311 115 of which there are four at £3 each and 085 311 431 C of which there is one at £6 (these are the gear on shaft needle rollers) tend to be OK but still should be replaced as should all syncro cones which are about £210, seals and gaskets which are about £35 including some blanking plugs.

If you want the box ratios. I need the box code and the main code is on the data sticker in the boot or in the service book and stamped on top of the clutch housing to block flange under the distributor.

Cheap and rallying are not good companions, I only but genuine VW gearbox bearings as they are such a paint to do I only want to do it once, where you buy your parts is up to you.

The 085 is one of the worst boxes to rebuild that VW have ever used.

With those part numbers I am sure you can amuse yourself for hours on Google.

[majic79]

If I had the choice, I'd rebuild with a different gearbox. Unfortunately the regs for the area of motorsport I'm entering into requires that original equipment be fitted (as supplied out of the factory) - so using an alternative gearbox isn't an option.

It's a shame that original VW gearbox parts are such a problem, or I'd buy them as well.

If I had a bigger budget, I'd have bought a newer car, not a £200 nail. But as I have a mortgage and limited funds, I'll have fun rebuilding my car, getting intimate with all it's moving (and non-moving) parts and be able to address all it's myriad problems when things go wrong.

[majic79]

Some details of what I'm doing are here:

http://www.clubpolo.co.uk/forum/index.php?showtopic=150753

[Crasher]

What is the problem with the original VW parts? Why are they “such a problem”?

[majic79]

Oh, I don't know, maybe they wear out after 60k miles, necessitating a rebuild?

I suppose to anyone in the business, repeat business is good, so they go ahead, blindly rebuilding gearboxes with (substandard) OE parts and telling their customers that "VW Stuff is amazingly reliable" and expect them to overlook one simple fact: the gearbox that's failed came from that same "amazingly reliable" source in the first place