Yes, I wish I could have ckd pressures, but it broke before I could do that. More to the story so I'll explain. Trans was in a 11 second truck (5500lbs) and was holding up. The guy had 1000 miles on it since it was freshened (broke a converter hub), but was selling it to go to a 4L80e along with the twin turbos on his new combo.
Both of our trucks are AWD and supercharged. His was a vortech and mine is a magnacharger. WHen I got it together and had this symptom, I didn't have time to do much with it (1 day). Driving home the next day and I stepped on it to get around a toolbag and it jumped out again and then would barely move. Felt like it was taking off in 3rd or something with no torque multiplication and would rev way up.
NOTE: My converter was supposed to stall at 2600-2800, but before it broke I brake torqued it and it would go to 3800!!!! That is why I was wondering about the converter. Never felt like it multiplied torque very well (soggy) considering the stall and it was wayyyyyy off from where he said it would be. He just cut it apart today and said it was perfect. He has the same converter behind a 900 hp turbo combo and it only stalls to 4,000 and of course it is holding up fine behind that combo.
I pulled the trans apart and basically it blew the snap ring out of the forward clutch and 3/4 clutch! I knew the pressure was too high---the trans shop that built it recommended stock settings in my tune, but I used the guys tune since it seemed to be working so well and he had the pressures jacked up a little for the pump, shifts, etc. Plus the trans shop have the pressure solenoid pressure turned up a little as well to hold up to the 800hp he was making. I think the combination of my lockup converter (triple disc) SLAMMING during lockup due to the too high pressures and no pulsewidth modulation (trans shop disabled it in the valvebody) and whatever was giving in the trans that was causing it to slam was what broke the lugs out of the input drum.
Both sprags show wear, but actually look better than my original ones in my old trans (it took out the 3/4 clutch). Certainly no signs of skipping like I was expecting. I'm wondering about a forward clutch problem --- maybe the piston over extending or leaking under the boosted pressure????
Thanks for the help.
Converter will not give you those symptoms. Before you pulled it you should have attached a gauge to see if it was caused from low line pressure.
2 wl drive or 4x4?
From a dead stop, the low roller fwd sprag & fwd clutch are the only thing applied or holding. If it goes away in manual low, that would indicate a bad low roller-how ever pressure is boosted in 1-2, so it could also be low line.
Inspect both the fwd sprag and low roller for any wear. I always replace them regardless if they look bad or not. Change the molded pistons in the drum, and inspect the input rings and inside of the stator support for wear/slop/damage.
When you get done and reinstall it, attach a gauge and monitor line before you drive it
Hope that helps.
