ngr5011

Auto tranny and Diff change...should I do it, and what fluid should I use?

Merkin

OE tranny fluid and M1 gear oil for the diff

Audi Junkie

Not easy.You can use good aftermarket MultiVehicle ATF like MaxLife,Mercon V,Castrol Hi-Miles,AMSoil

Merkin

no M1 ATF? are there studies showing why ZF trannys need certain fluids

diagnosticator1

I found that it provides faster clutch engagement. Depending on were purchased, is less expensive than the OE "ESSO LT71141" ATF.

diagnosticator1

ZF's requirements are the only thing that "Officially" matters.

Audi Junkie

Deposits are not a big issue since trans are sealed. Wear on metals is basicly a non-issue, addressed by visc and additives so all you have clutch pack wear. Coefficient of friction allows the clutches to grab, and different clutch materials require different friction.

The way Multi-vehicle ATFs work, supposedly, is that the FM (friction modifier) additives are "selective" and react correctly in the presence of the various materials. Ok, fair enough, but my take is the the friction levels change (basicly, they rise) over time anyway, so how hard is it to blend for a happy medium of all the various fluids?

Honda ATF Z1 is a propritary fluid, but not really special. Basicly all new oem (Dex 6, Merc V and ATF+4 are synthetic as well as MV ATFs. They are either friction-modified or not, with Dex being on the non-FM end of the spectrum. The ZF spec is FM and synthetic. MaxLife, Valv Merc V, Castrol HM and AMSoil all claim ZF, and they work fine. They work in Honda Z1 too, I use AMSoil in my new Accord and Catrol HM in the old CRV. fwiw, the visc index of Castrol HM is an amazing 200, as good or better than oem ZF.

diagnosticator1

Your unique knowledge of the various lubricant base and additive chemistries and properties is very interesting, thanks for the comments.

Audi Junkie

a better fluid with a longer interval might be better for most Tip drivers who do not DIY. On my Hondas, they take a 3/8" square to drain the ATF w/ a magnetic plug. 3/8" square as in a ratchet wrench, no socket even required and def no special tool bull**** like the Tip.

When servicing an old trans I like to flush it out with cheap generic Dex or MultiVehicle for a few 1000 miles before putting in the prefered expensive fluid. I just did the Volvo trans for my nephew. 10q of Pennzoil Dex thru the trans cooler lines plus some Auto-Rx. Took like 15 minutes. We'll redo it with Mobil 1 in 6 months. My A4 trans services were $350.

Audi Junkie

Mobil 1 ATF is more on the Dexron end of the friction spectrum. I'll use it in nephew's Volvo as Dex