For the DIY guys on the board, what fluids are recommended for the manual transmission and rear diff? I see that Audi sells a special proprietary fluid for changing the Haldex fluid along with a new filter. Thanks in advance.

 

yeah, i'll be doing my Haldex tomorrow. fluid and filter came to $63. Not cheap. Also, need the special wrench, you can find them on modshack.info Again, not cheap ('bout $40), but unless you have a vice-like grip, and can open stuck pickle jars with 1 finger, you're not getting the filter off without it.

As for tranny, I'll be using redline when I can afford to, but according to some searching on the audiworld forums, the stuff Audi puts in at the factory is considered lifetime. Its synthetic, and you don't need to worry about it. The redline is just a little nicer.


Synthetic Manual Transmission Lubricants


Red Line Oil's MTL and MT-90 are designed to provide excellent protection and improved shiftability for manual transmissions and transaxles, having cured the problem of hard shifting in thousands of transmissions with shifting troubles. How? They have the appropriate coefficient of friction for most manual transmission synchronizers (many gear oils, engine oils, and ATFs are too slippery for proper synchro engagement). And, the wide viscosity of MTL and MT-90 allow proper shifting over the entire temperature range which the transmission will experience. The synthetic base oils used have a very high viscosity index which provides relatively constant viscosity as temperature changes. MTL is a low 70W at very low temperatures and a high 80W, nearly an 85W, at elevated temperatures, providing adequate viscosity to prevent wear and deaden gear noise. MT-90 is a thicker 75W90 version of MTL. The shear stability and oxidation stability of these products are excellent, thus the physical characteristics of Red Line MTL and MT-90 will change little with use.

 

Manuel transmissions do not require service. Dont waste your money. As for the haldex. It should be changed every 20k miles. You will definatly need that wrench to change the filter. Its a good investment considering the alternative. You dont want to know what one of those haldex units cost. Getting the fluid into the rear can be a bit tricky. You have to shoot it into the rear and then hurry up and stuff the plug in the hole.

 

I find it hard to believe that Audi has some sort of "unique" transmission fluid that will last the life of the transmission. Is this the case for the rear diff as well? Every other manufacturer I've been familiar with recommends transmission fluid changes around every 15k miles. I mean fluid breaks down over time and I wouldn't trust to leave the same fluid in a transmission for its life. The Redline is a good fluid as I used it in my previous car. The trans in my 2000 TT feels a little notchy and I think this, along with a possible adjustment might help fix that.

Does anyone know how much fluid the manual trans takes? What about the rear diff? Thanks guys for the comments and discussion.