MK4 GTI Gearbox oil change recommendations

[Sirocco20348]

Hi,

I know vw says the gearbox oil is sealed for life.. but the box can still be drained and refilled with replacement fluid.

My car has 161,000km.

Should i change the fluid if im going to be doing track days?

Whats the stock fluid weight?

and

What should i change it too?

Thanks

[Blitzen]

It should have been changed long ago. Look at Redline MTL. It's a 75/90 gear oil, and great for older boxes.

[Sirocco20348]

Hey Blitzen,

I found this tutorial:
How to change your gear oil..........DIY w/ Pics. - VW Forum :: Volkswagen Forum

and in the tutorial it mentions:

If you are shopping for oil for a MKIV or an Audi with the 01A transmission (quattro), or MKIV O2J, you want the MT-90 because it's the proper 75-90W, GL-4 spec. DO NOT BUY MTL, and DO NOT BUY ANY GEAR OIL THAT IS GL-5 SPEC.

So now im lost...

Something about MTL or GL-5, being too harsh for some of the components in the gearbox?

[Blitzen]

I have had MTL in my Polo GTI box (similar/same box) for about 60,000km, and I have had no problems with it. I had this suggested to me by JMAC here on the forum, and several others. On the other hand, I have been told that MT-90 is good for older boxes, so this may be the go for you.

You will find that in the quote you have above is talking about the O2J gearbox, which is a 6 speed AWD box, and is not the same gearbox as found in the Golf/Polo GTI.

[Sirocco20348]

Ok from further research we have:


1) VW transmission guide
http://zelek.com/diagram_charts/diagramlist.htm

This link specifies that the AGU 1.8t golf has an 02J manual transmission

2) Volkswagen 02j overhaul
http://www.vwmotorsport.com/vwtech/g...J_overhaul.pdf

This link from vwmotorsport (which you think would be a reputable source) states that...

Use synthetic gear oil (G50, SAE 75W/90). Capacity is 2.1 qts. (2.0L).

3) Difference between Redline MTL and MT-90
http://www.stealth316.com/2-mtl-tech.htm

Red Line MTL is classified as a 75W/80W gear lubricant satisfying the API Service requirements of GL-3 and GL-4. MTL also satisfies motor oil viscosities SAE 5W/10W/30, and the viscosity requirements for ATFs. MT-90 is a 75W90 GL-4 and also satisfies motor oil viscosities SAE 10W/1 5W/40

Using the above information the correct Redline Transmission oil is MT-90.

If any of this stuff is wrong please let me know... I just spend hours trawling the net for answers.

[Blitzen]

Mate, it's up to you with your car. I took the advice of JMAC, one of the best VW mechanics I know, and I have never had a problem. If you are still unsure, give the boys over at Canberra VW Center and see what they think.

Edit: the AWD 6 speed is the 02M, not the J... Sorry about that.

[Sirocco20348]

Nah its all good Blitzen! I thank you for replying in the first place Gave me something to work from.

If you are still unsure, give the boys over at Canberra VW Center and see what they think.

I asked Peter and he said the same 'sealed for life' motto....lol... I dont know .. i just dont believe transmission oil can last forever.