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Auto gearbox help.

Posted: 02 Dec 2016, 19:56
by offtherailz1
Hi,
Just trying to learn a little about my first ever T25. I had to buy an auto so that's what I've got , sorry I understand they're not popular but hey thats what i needed. Anywway, looks like its leaking around various gasket, any pointers as to where I could get these, or if at some point I need to, get it second? it drives well, changes well, no noise etc Where the filler tube joins the box is weeping also.
Any recommendations on oil?
Also, I'm trying to get my head around the accelerator cable/linkage. I've got myself a new accelerator cable, but the pedal is doesn't spring back all the time. It's on my list of jobs to do.

Any, any advise would be great. Phil

Re: Auto gearbox help.

Posted: 02 Dec 2016, 22:55
by 123-jn
Full gasket set from vw heritage
https://ie.vwheritage.com/shop/01039800 ... ed-models/" onclick="window.open(this.href);return false;

Use ATF Dexron 2 or 3 in the auto box. If it has not been changed and is not a nice red colour drain the box by undoing the filler tube nut around the base of the filler. Take off the sump and change the autobox oil strainer (just a single screw) Replace the sump with a new rubber seal after cleaning any sludge out. Now fill with fresh ATF. This will only have changed about half the ATF as the pump and torque converter will still be full of old stuff. So after a few miles drain the oil again and refill with fresh. After the third drain down its pretty good. Level is checked to between the max and min marks on the level with the engine running. The main failure is the seals between the autobox and the final drive which are also available from heritage.

By the way there is nothing wrong with the Auto box, they are lovely and relaxing to drive and will easily do the max speed limit of 70mph and faster. Only downside is hill climbing which they are a bit slower at and towing.

If you still have the old water/oil cooler fitted to the front of the gearbox near the mounting think about fitting an air/oil cooler instead as they are much better at cooling the oil. I fitted a 15 row cooler to mine (no more hot smelling trans oil after a run).

Re: Auto gearbox help.

Posted: 03 Dec 2016, 07:59
by Sir Brixalot
I've got the same. Nice to have one in heavy or stop start traffic but a real PITA if anything goes wrong. How much is leaking and are there any problems ie gears sticking or big jolts changing gear.

Just changing the fluid a few times can make a big difference. The van has to be driven for six miles or more to get up to the atf level correct for topping up and the fluid changed with the engine running. Do not overfill if you do though Amazon has siphon kits for about £15, easier than draining from underneath and being soaked in atf. :mrgreen:

The first thing to do is get a jet wash and blast of any crud on the gearbox so you can see exactly where the leaks are coming from . It is possible that changing the pan gasket is all you need(do the strainer at the same time)

It's common to see fluid coming from the 2nd gear brake band piston cover (aka servo cover). On some sites it says the gasket can be changed in situ as there's loads of space by removing the hefty spring clip and changing the seals behind the cover. A clamp is needed to put the cover back on. There is a good possibility though that the brake band will slip down meaning the pan and valve have to be dropped anyway to push it back up.

On the top of there are two breathers with a small spring loaded cap make sure they're clear of debris.

On the US sites where autoboxes are more common its recommended that an external atf cooler is fitted as the stock VW atf cooler isn't the best and are known to fail.


For rebuilding the gear box section only I've had quotes starting from £900 but often lot higher and for doing only the servo cover seal £200 plus. Finding a decent mechanic has been difficult though.

Mine is in for work on Monday for the servo cover and another leak where the gearbox joins the transaxle so I can let you know more after. I'll probably do all the seals because they were all fitted at the same time so they're all be stiff now.

They are fantastic boxes when they're working properly!

Re: Auto gearbox help.

Posted: 03 Dec 2016, 08:29
by offtherailz1
Two great replies there so thanks for taking the time to do that.

No great jolts or noises that I noticed. I got it ebay without seeing it, the price was right and I took a punt. It was 100 miles away in Bath, an old couple had owned it and it was last taxed and mot'd in 13. I got the guy selling it to MOT at a garage of my choice to see what it would fail on and it passed with two minor advisories. So I went to pick it up, drove it around Bath for an hour without issue, got about 40 miles from home and it overheated on the motorway. Luckily I think I stopped quickly enough and just caught it! Whoever done the maintenance for the old couple need flogging. The pipe that goes from the thermostat to the distribution pipe by the RHS cylinder had cut it and put a section of what look like scaffold pipe in! I got trailered home, and when I took the thermostat and that pipe off it was full of corroded metal!

I have flushed it out, changed the water pump, new Gen thermostat and housing, every pipe now with new rubber or stainless and done the RHS cylinder gaskets. The rubber gasket was split, I couldn't find any trace of the green one and there was no metal one in the head! Monday its the left hand side. I took the risk, and in a strange way I'm happy it let me down, because I know where I am starting from, and really enjoying it, it was got for the longterm and although it needs respraying it is pretty solid, so a good starting point. The 60 miles I did do were great. :D

Back to the gearbox, my two modern cars are auto's but my 1303 Bug is manual. I wanted a more sedate ride with the auto so its important to nurse it. The gasket set is ordered, I'' get the other head off, new gaskets and back together Monday, then its a jet wash on the gearbox to leak detect, plus the first lot of new gear oil. mine is pitch black!
Phil

Re: Auto gearbox help.

Posted: 03 Dec 2016, 09:23
by Sir Brixalot
I think a separate area for Autoboxes on here, much like the alternative engine area, would be handy to hold the autobox knowledge all in one place. Great for advice, parts and who fixes them properly...Rob?

Re: Auto gearbox help.

Posted: 03 Dec 2016, 23:16
by R0B
To be honest mate,there are not enough auto owners out there to justify a separate section.I think the mechanical section is enough to cover the few auto box questions we get.

Re: Auto gearbox help.

Posted: 04 Dec 2016, 14:24
by Smiffo
Afternoon SirBrixalot et al.

Interesting read here on the site in `club stuff` and `downloads.`
I found it the other day while nosing about....

http://www.club80-90.co.uk/pages/downlo ... %20Ass.pdf" onclick="window.open(this.href);return false;

http://www.club80-90.co.uk/pages/downlo ... ernals.pdf" onclick="window.open(this.href);return false;

Not sure if you have that or seen it etc. First link might have something on that plate you were asking about recently SirBrixalot?

Re: Auto gearbox help.

Posted: 04 Dec 2016, 19:23
by Sir Brixalot
Cheers mate I have got those. Don't fancy having a go. If I had somewhere to get it of the road I might have done

Re: Auto gearbox help.

Posted: 05 Dec 2016, 10:38
by New Kentish Campers
I think you last post was deleted? But here's my reply to it anyway... :)



Jeez. I hope thats not the same mob who did that welding work is it? :x

Could this firm be of use as they are on your doorstep: http://cartechautos.co.uk/automatic-tra ... 7QodS88FXg" onclick="window.open(this.href);return false;

I googled auto box repairs and they were 2nd listed, though the first looked better, but are in Hertfordshire:

http://www.stephensengineering.co.uk/?g ... 7Qod3l4MXg" onclick="window.open(this.href);return false;

Might be a better bet to get it there if they get it right first time? I know the logistics won't be too clever but...?

I hope it works out

:ok

Re: Auto gearbox help.

Posted: 05 Dec 2016, 10:43
by Sir Brixalot
Sorry mate. I reposted my comment on one of my threads so I didn't hijack this thread

Re: Auto gearbox help.

Posted: 05 Dec 2016, 10:43
by New Kentish Campers
:ok

No worries, hope you get the thing sorted out!