High Trans pressure = Thrust Failure?
10-10-2017, 10:54 PM
#1
Staging Lane
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High Trans pressure = Thrust Failure? so a little history. Trans is th400 been running this trans and engine combo all year up until about a month ago. I ended up breaking the sprag on the trans and went and bought a new one with an ultrabell. So i swapped it along with my converter, everything was working good but I just noticed the pressure was high, under light throttle it was pegging my gauge 300+ id guess 350-400 psi. Under full throttle it was 220-250 (Which was the same psi as my old trans) Called the builder said it was nothing to worry about.
about a month after running this trans i started to drop engine oil pressure out of nowhere. It was weird though, no metal in the pan at all but crank has play. I changed the oil and went for a drive, 2 miles later it slowly went down from 60-15, still climbed a little with rpm but never got over 20ish, oil was black only after a few miles and no metal.
Things I should look for? Engine and trans are out and being gone through. Here are some clips of light throttle like 4-15%
about a month after running this trans i started to drop engine oil pressure out of nowhere. It was weird though, no metal in the pan at all but crank has play. I changed the oil and went for a drive, 2 miles later it slowly went down from 60-15, still climbed a little with rpm but never got over 20ish, oil was black only after a few miles and no metal.
Things I should look for? Engine and trans are out and being gone through. Here are some clips of light throttle like 4-15%
10-11-2017, 09:14 AM
#4
Sounds like you got a hold of one of those "killer 400s". I will tell you what I did when I built mine, and it only cost $.50 In parts. And to be clear, I did not come up with the idea. But all it takes is restricting the converter feed circuit. Look it up and you will find articles on it. Now there will be people that try and make it much more complicated than it really is, but I did the mod to mine... and have no bearing issues whatsoever and the trans works fine. The reason 400s are hard on thrust bearings is, the converter is over fed.
10-11-2017, 11:55 AM
#5
Staging Lane
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Sounds like you got a hold of one of those "killer 400s". I will tell you what I did when I built mine, and it only cost $.50 In parts. And to be clear, I did not come up with the idea. But all it takes is restricting the converter feed circuit. Look it up and you will find articles on it. Now there will be people that try and make it much more complicated than it really is, but I did the mod to mine... and have no bearing issues whatsoever and the trans works fine. The reason 400s are hard on thrust bearings is, the converter is over fed.
