Zf5 vs zf6 strength/durability

ken6881 · Dec 30, 2015

I'm building a truck and looking at the gear ratios I don't see it making a difference of 5 or 6 speed as having the extra gear doesn't mean much to me so it comes down to strength is there a difference? Truck will be a 4-600 hp 12v cummins

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ken6881 · Jan 1, 2016

No opinions?

powerstroked08 · Jan 1, 2016

I don't know about the 5 speed. But the 6 speed your not going to break with a 600 horse truck. Unless you do something really stupid. There is several guys running well above that power and no issues. The only thing people have trouble with is towing heavy with a lot of power they can overheat the oil and burn up the trans. But that can be helped with another tranny cooler. Just my thoughts on it.

ken6881 · Jan 1, 2016

If I find a zf6 reasonable that's the way i will go but I have seen some zf5 cheap and if its as strong as the zf6 it doesn't bother me to loose the gear. I plan to run a temp gauge and cooler.