Wanting input on my high hp 48re set up

Marq92 said:

Reb Brown said he has never really bothered with doing a bolt in sprag or drilling the case for more oil. He's only had a sprag issue from neutral dropping and never saw the need to drill the case because other areas in the transmission will just have less pressure.

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Boosted 1st gear launches are hard on the sprag unless you drop it down in 1st manual where it will apply the low/reverse band to help the sprag.

IF you regularly launch your truck in drive racing or otherwise and not in manual 1st gear which commands the low/reverse band, you will eventually tear the sprag out of the main case. A full manual VB obviously commands the low/reverse band so sprag failure is less common. Launching a 700 HP 7000 lb truck 2 times a year usually does not destroy the sprag when launching in drive meaning all the load is on the sprag and not shared with the low/reverse band. Launch it regularly, especially with 6000 lb+ 4x4 truck and 800+ HP and the stock sprag race will spin and fail.

So what is a sprag failure going to feel and sound like? Suspecting loss of forward. I don't do boost launches, but have several full throttle runs on the ford with the power above 600.

Usually when the sprag fails it'll spin the sprag race and break it free from the main case. You will lose 1st gear in drive if the race is spinning. Sometimes when the race spins it breaks the main case and makes a large leak at the same time. If it slightly cracks the race and locks up the sprag rollers, you'll have 1st and reverse but it will transbrake when it tries to shift into second gear or 3rd gear.

I raced my Junker Drag Truck for a couple years launching in drive with the stock sprag race setup, even got a couple high 10 second passes, but eventually it broke. I feel being 2wd and lighter weight helped it last longer than a heavier 4x4 with lots of traction!