Gearbox oil change

[Bren]

I want to change the gearbox oil on the passat.

Car has done 141 k (low for one of these) however sometimes there is a slight crunch going into 3rd. Passat boxes are'nt the best - my dad got rid of his as his six speeder died. Despite the fact it was tatty and the back doors would'nt unlock somebody bought it and put it back on the road. Car is still going.

I hav'nt topped up a manual gearbox for years - 1990 in fact - my first SD1 - it had a terrible gear change.

It will cost £40 ish - £30 for the oil and £10 for the tool to remove the bung. Not hopeful it will save the box but if I don't try I will never know. Not looking forward to a dirty, awkward job.

[cort1977]

Have you got one of those utility pump things with the S shaped metal tube?  Makes it much easier (or even possible in some cases).

Will watch with interest as I should do my passat now it looks like I'm keeping it.

[jonny69]

I would definitely change that oil. You simply can't leave gearboxes that long on their original oil - NO oil can take that!

I don't know if it will solve your crunch though, I think the damage has already been done. It's probably a worn synchromesh ring or something.

[Bren]

8 minutes ago, jonny69 said:

I would definitely change that oil. You simply can't leave gearboxes that long on their original oil - NO oil can take that!

I don't know if it will solve your crunch though, I think the damage has already been done. It's probably a worn synchromesh ring or something.

My fear as well. Some passat experts said catch it early enough and you can save it. When my dads went the car was undrivable - we managed to limp onto the back of a low loader.

[Bren]

Had a look at everything - Haynes BOL states fill plug is 17mm hex.

On ours it is same as the drain plug - 12 spline tamperproof plug. I have ordered the removal tool which is hopefully coming tomorrow - no point in buying the oil unless I can crack the filler and drain plugs.

[Bren]

This is what you need to undo the drain plug. And in my case, the filler plug. It cost a tenner.

I took the precaution of cracking both open before ordering the oil. £ 23 for 4 litres of 75w90 synthetic.

[paulplom]

That sounds like far too much common sense for here imo. Normal procedure would be to drop the oil out before finding out the filler plug has chemically welded itself to the box.

[beko1987]

I really want to do the gearbox fluid in the ZX, it's awfully vibratey... I did the fluid in the XM and it transformed it, the changes became so smooth. Was an easy job too

[skattrd]

A bit late, but I used to use Redline MTL in VW gearboxes, it cured the second gear crunch I had on a couple of cars.
It probably was more to do with oil change than the new brand of oil used, but I've always stuck to that in VWs.

[leafsprung]

Modern oils in old gearboxes can have a rejuvenating effect in my experience. Not familiar with VW boxes but I can vouch for the fact that after many years of Defender spannering, bang up to date manual transmission oils (Fuchs Sintofluid in this instance) had really genuinely transformative effects for graunchy old LT77 and R380 main gearboxes. The LT77 was designed to run on ATF which was then retrospectively up-specced to LR's own MTF94 when the R380 was developed; the '94' being the year of introduction I believe. A technically better oil than ATF but still superseded by modern offerings. 

Regardless of this many people even now still swear that their 40+ year old designed LT77 was designed to run with cheap as chips Dexron 3 so that's what they'll stick to thanks very much and just accept doing bi-monthly fluid changes (because that's what you're expected to do as a LR purist), ignoring the fact that in 40 plus years oil technology hasn't exactly stood still.