1. The first reason is that "mechanics have been using ... 50 years...". Well, not a good argument. Mechanics have been doing countless stupid things last 50 years. Especially on the dealerships. Especially - on the
Isuzu dealerships <img src="/forums/images/graemlins/smile.gif" alt="" />
Well, I've been using the automatic tranny fluid for quite a while... based on my fathers recommendation. Just incase you don't know, my father is Jerry Lemond. He's used this method for as long as I can remember and has never had any ill effects. As an Isuzu factory person for the last 23 years and a Master ASE tech for the past 30 somthing years, I think I'll stick with his recommendations.
2. ATF was designed for the transmissions, engine oil was designed for engines, engine flush fluids was designed to flush engines. This is quite strange to assume that we can discover better fluids than specially designed fluids. Well, you can discover that you particulary like the taste of mustard in the cofee, but I doubt that this is good for everybody...
Apparently, you don't know what is contained in engine flush treament chemicals or as you call them "specially designed fluids." Most all engine flush chemicals are mineral spirits or kerosene with some other detergents added in... Last time I checked, mineral spirits and kerosene wasn't designed to be used in a crankcase of an engine either.
3. The last and the most important problem is that I have an experience with this method, and it proved to be very dangerous. On my old Mercury Marquis 1985 with 3.8 Ford engine, I used 1QT of ATF, once, to clean the engine before the oil change. After about 10 miles of the driving with the ATF in the crankcase, I felt something strange, I stopped and I discovered rather large metal particles (about 1/16" - 1/8") on the engine oil dipstick. I immediately changed the oil, but the engine had never been as good as before the ATF "treatment".
I would have to say that is a coincidence. Inside of 10 miles you lost 1/8" pieces of the motor? I highly doubt that was caused by your tranny fluid, UNLESS you went with straight tranny fluid and had no oil left in it... even then I would find it hard to belive that was the cause.
I have three vehicles, 2 '89 Isuzu's and 1 '91 Isuzu and all have over 230,000 miles and each one has had the tranny fluid flush every 4th oil change and there is absolutely no ill effects... None of the three use oil and run just as strong as ever.
