Originally Posted by Lscman
No way, it is not silly to state that certain fluids are not compatible. That is an ignorance-based position that will cause harm to member's hardware. This I know after working in the petroleum industry and rebuilding manual transmissions for 35 years. There are fewer than five 6spd getrag BMW M3/M5/540i tranny rebuilders in the USA and I'm one of them. The additives in GL5 hypoid gear fluids eat modern yellow metal, sintered or carbon-wrap synchros widely used since the early 80's. You can change the fluid daily and the chemistry will still be wrong. If you get 5 years out of the tranny you'll be lucky. This reminds me of my buddy who used gear lube in his beautiful $6K Husaberg one summer and it ate the nikasil bore coating. The drain pan looked like aluminum paint. Being around a race team does not make anyone a transmission or lubricity expert. All it does is coerse people into falsely assuming that race fluids are better or even OK for street. Redline is not approved for use in ANY street car, period. It is a competition fluid for competitors who are willing to wear out and rebuild their hardware on a seasonal or frequent regular basis simply to achieve fractional horsepower gains. I'm not going to rebuild my street car more often just to gain a couple HP or less. If you want your motor or tranny to last more than 10K miles, choose recommended fluids with proper certifications, ratings and formula. The factory fluid is $20/qt for a reason. The MTX-75 will easily last 300K mi with the proper lubricant and changes once every 100K mi. With the GL5 hypoid stuff the synchros will disintegrate until clearances exceed spec and it chronically grinds. My MTX-75 will never need rebuilt because I run the appropriate lubes. The chassis will rust away first. I've rebuilt over 20 track trannys and I know what the wrong lubes will do. The Supra, Mustang and BMW communities learned this long ago.
Add me to the list of 5 guys in the US that build the Getrag SVT Trans , I have a SVT Getrag making over 300HP to the wheels with Mobile 50 wt oil and has seen over 10,000 miles or hard road track use ( mostly VIR) over 500 1/4 mile passes , 100 1/8 mile passes runs a 1/4 in 12.99 @ 111 mph and tens of thousands of miles on the road as a daily driver , I have over 200 SVT customers running this same oil 100% issue free and most of them boosted where the SVT Getrag is exceeding its load limits set by Getrag over 300TQ at the wheels , I build mostly daily drivers not race cars and I do not work for a race team , I own my own engine shop , trans business , tuning and dyno business as well as fabrication
the claimed "wrong fluids" at your # they should be 150+ out of the 200+ I have done that should of gone bad and none have , kinda throws a wrench into your scare tactics , a MTX-75 with over 150,000 miles turbocharged track / DD car with Mobile engine oil 50wt Syn , 3 clutches but never any trans issues ,
This many Foci with "the wrong fluids" and no issues has to say something at least to the point they dont brake if you dont use the Ford fluids