A5S300J ... not A5S310Z !!!

Hi All

I have decided that it may be a good thing to change the fluid and filter on my autobox. I took it to a specialist and he says that from the feel of the car, there is nothing really wrong with the auto, although a fluid change might not be a bad thing. Anyway, it seems that my box takes normal Dexron II and not the lifetime fluid??? I have been gathering tons of info on the box that I thought I had (A5S310Z)!!! It now turns out that I have a A5S300J (Jatco) box!!! Now, I have 2 questions...

1. What the hell is a "JAPANESE" transmission doing on what was a HUGELY expensive German car??? (Transmission made by Jatco).

2. Does anyone have any info on the procedure for servicing it? I cannot find out what fluid it uses or what the correct fill levels are???

Many Thanks

BB

Don't knock it, the japs know their stuff and it pains me to say it but if Germany didn't exist, japs would be making the most reliable cars on the planet. Afriend of mine once went for a job interview at a Honda garage and asked what the main type of work they did was. The guy said 'just service work and crash repairs really because the engines are rock solid' He declined the job because he wanted engine re-builds and stuff!

Look out germans, the japs are coming!

Mike

Incidentally looking here

http://www.realoem.com/bmw/partgrp.do?model=DD42&mospid= 47539&hg=24&fg=05

When you click on the tranny labelled A5S300J it lists this as being the tranny for Japanese and South African E39s!

These are the tranny options for my car.  The third one A5S310Z is the one fitted to my car.  Which I know is a ZF bit of kit, which ties in with the Z at the end of the description.  So you being in South Africa will most probably have a Japanese tranny, provided the E34 parts are similar to the E39 parts logic.

The 5S stands for 5 speeds and the 310 is the maximum rated torque input to the tranny.  Hence why if you mess with your engine power/ by chipping/chaving the engine you run the risk of seriously damaging the automatic gearbox. 

The supercharged option for the 528i E39 leaps to mind.  Aye very good, but you know have silly amounts of horsepower but can the tranny cope with the increased amounts of torque!

Andrew

Dexron II had been replaced years ago by Dexron III.  Car and tranny manufacturers still go on about Dexron II but the oil manufacturers all make Dexron III so it would not surprise me that the oil guys have changed to Dexron IV!

The only source of what type of oil and how much to put in etc can generally (for BMWs) can only be found by speaking to Automatic Transmission Specialists.  Nobody else appears to know!

Andrew

PS I'm sure this has come up before that E34s were fitted with a GM tranny.  I find this difficult to believe as why would BMW want to fit a General Motors/Vauxhall/Opel transmission to their cars?

Interesting link there.

Remember that USA is full of Automatics so there will be a huge support from specialists and therefore there will be more knowledge of autoboxes.

What is the ratio of auto to manual cars in SA?  Here in the UK the vast majority of cars are manual so Automatic Transmission Specialists are relatively thin on the ground and knowledge is also thin on the ground compared to the USA.

There is a danger of you not being able to re-fill the tranny after removing the sump pan.  Not all E34s and none of the E39 autoboxes have a dipstick and therefore ways and means of filling and checking the tranny fluid level.  Specialists fill these kind of trannys under pressure thru a special port/blanking plug on the side of the tranny.

If the jolt in sports mode between 1st and 2nd is when the engine is cold then I wouldn't worry about it!

HTH

Andrew

Found the most promising link yet about the oil to use...

http://www.bmwclubmalaysia.com/forums/showthread.php?s=07551 133ec4c59ca1bd96bf1b012d6d8&p=152086#post152086

They mention something called Petronas ATF D3???

BB

I decided to do a proper test of what the car felt like in Sport mode thie evening on the way back from the office. I left it in that mode the whole way and it seem to feel worse than when I did this before... Everytime I pull away now, the car will accelerate and rev up to about 3500RPM, upon which point the transmission shifts into second gear and pretty much gives dislocates a vetebrae in my neck ... Funnily enough, shifts from 2-3 and 3-4 and 4-5 are so smooth that I hardly notice them, yet 1-2 feels like a massive kick from the rear!

I guess I am going to have to bite the bullet and be the first, documented one it seems on the internet to attempt a fluid and filter change on a Jatco A5S300J transmission!!!

I will be going to my dealer tomorrow to get the filter and try and see if they can supply me with the correct fluid. I will have to do the 4 step method of draining, driving, draining, driving and so on until all the oil is changed. If I cannot come right at the dealer with the fluid, I will try and get hold of the best Dexron 3 that I can...

I guess I am pretty much looking for a conclusive answer that this will work and all will be ok, but an answer like this does not seem to exist anywhere on the internet! There are as many people against changing the fluid and there are for it!!! I just wish I could get some more conclusive results that people have tried it on a Jatco transmission and that it has worked!

All I can tell is that my transmission seems to be getting worse. Something I did not notice before is that it now seems to be slamming into first and second gear, when coming to a stop...to the point that I can feel a sharp thud as the gear engages ...

I will report back on my fact finding mission to BMW tomorrow...aswell as when I do the actual service...

Watch this space...

BB

it pains me to say it but if Germany didn't exist, japs would be making the most reliable cars on the planet

Even with the existence of Germany, the Japanese make the most reliable cars on the planet

They just struggle to inject any soul into them.