Northeastconfederate

it says, "Check in PARK" just like every other transmission dipstick I've seen. I didn't THINK I was crazy....

In any case, more fluid seems to have been the answer. I haven't road tested it yet, but after adding another three quarts, the wheels go forward and back when they should while it's on the lift. I'm fixing to road test it right after lunch. The trans has 13 quarts of fluid in it now, total. Shows a little high on the stick, but I doubt all the accumulators are full and for sure the clutch apply pistons for 3-4, overrun, etc aren't either. We'll see how it looks after a road test. Hopefully all the shifts are good!

Northeastconfederate

Well, I'm unable to road test. The truck barely moves. It tries to, but it's as if a clutch pack isn't fully engaged both forward and reverse. I must be leaking pressure somewhere? I have to Rev the motor to get it to move. Not gonna do that anymore, I'm afraid I'll smoke my new clutches.

I'm going to see if I can find a transmission pressure gauge set and check pump pressure before I start taking anything apart.

I tried to run it through all the gears on the lift, tires in the air, but the traction control system won't allow it, even when switched off.

So.... What gives? Anybody got any clues??? I read that the most common failure is cut reverse drum apply piston seals. I'm almost positive I didn't do that. Or rather, I did the first go-round and I knew it. Immediately took the drum apart, ordered and installed new seals. I'm close to 100% positive I didn't hurt them the second time.

I'm baffled.

Northeastconfederate

Ok, I got a trans pressure gauge set. I have close to zero line pressure. When the engine first starts, pressure "spikes" up to about 30 psi, then falls quickly. It isn't steady zero, the needle fluctuates a little bit. This makes me think maybe the filter isn't seated correctly and the pump is sucking air. I forgot about that: I have a Jeg's cast aluminum deep pan. It's nominally 4" deep but measures just about 3-3/4" from the pan rails to the bottom of the pan. The pan came with 2 different adapters but neither worked with the filter that came with the rebuild kit. The filter is obviously for a deep pan, but apparently not as deep as mine. I installed the filter without an adapter, which made it about a half inch short of the bottom of the pan. I bet this is the problem. Or I hope it is, anyway. I'm going to drain and recover the fluid, drop the pan and have a look.

Northeastconfederate

Final update on this project: the filter fell out. I bought a Jeg's aluminum deep pan (which I'm pretty sure is made by TCI; or in the same foundry and to the same specs). It's 3-3/4" deep from pan rail to the inside bottom of the pan. The filter that came wit the rebuild kit was for a deep pan, probably the factory deep pan. The Jeg's pan came with 2 different adapters for shallow and deep filters, I guess. But the filter I had didn't work with the shorter adapter; the pan was 3/8" away from the pan rails. So I installed it without an adapter, which didn't work.

what I did is carefully measure and cut the filter tube 3/8" with a little pipe cutter, and use the shorter adapter that came with the pan. Now all is good. The put about 10 or 15 miles on it this evening. All shifts are excellent! The Sonnax upgrades work exactly as advertised. Shifts are quick and crisp but not hard at all at light throttle, "normal" driving. The shifts get harder the harder the gas pedal is stepped on. It chirps the tires a little bit at full throttle, but still doesn't feel like a crash. It took far longer than I thought it would, but it's a success.

RB04Av

Northeastconfederate

I've now been able to put maybe 100 miles on the truck, pretty much around town. Maybe not quite 100, but close. Now that I've driven it from cold, and under all kinds of throttle conditions, including very light, I am not happy with the 1-2 shift. It is WAY too hard. I expressed concern about this to one of the Sonnax techs I spoke to along the way, who suggested that if it was too hard, I could remove the 1-2 accumulator wave spring (which came with the Performance Pack) and that would soften it up some. I question whether this will be enough. It's relatively easy to do, though it's a bit of a PITA, since the crossover pipe has to be removed in order to get the pan off. @MaroonMonsterLS1 I hope you have some input on this. Keep in mind, on the advice of Nelson at ACC Performance/Boss Hog Torque Converters, I'm running Type F transmission fluid. I'm thinking of maybe removing the wave spring and replacing the Sonnax spring in the 1-2 accumulator with the stock spring? It will still have the Sonnax pinless piston if I do that. The problem with that plan is, I am pretty sure I tossed the stock spring, though I can probably grab one easily from a local junkyard that has a couple of 4L60E's partially disassembled, though they're older than mine. If worst comes to worst, I could order a new spring from Chevrolet. Or, should I stick to racing wisdom and change only one thing at a time? It's funny, it shifts VERY hard at light throttle, especially when cold. Once it's fully warmed up, it's less brutal, but still very hard. It seems much less hard when shifting under hard throttle. chirps the tires, but doesn't seem violent like it is at low speeds.

Also important to note, at idle, the pump pressure (in park - it doesn't change much in gear) is much higher than I expected, especially with Sonnax's supposedly progressive pump pressure control. It holds steady at 240psi at idle. I expected to see more like 100. Is this normal for the modifications I've done?

RB04Av

Should be something you can do to the servo that's not quite ... so ... invasive.

240 psi at idle isn't right. That may also be part of the problem: the pressure in 1st is supposed to be low, then it goes up in 2nd, up more in 3rd & again in 4th. Instead it's almost maxed out to start with. Almost sounds like something isn't right with the regulator or boost valve. Might be worthwhile to track that down before messing with anything else.

MaroonMonsterLS1

If you have 240 psi in park you have an issue

Do you record pressure while driving?
Does it ever come below 200?

First and foremost if you fix why it has high pressure at low throttle...you'll likely fix your harsh 1-2 at light throttle.
Higher pressure=firmer shifts.

Northeastconfederate

Thanks for the replies. I called Sonnax this morning also. The tech there suggested reducing the pump duty cycle via tuning. I need to call the guy who did the tune when the blower, etc was installed and see if he increased the duty cycle at that time. I think so. The truck shifted very hard 1-2 after getting it back from them until the band started to give up. I'm hoping this can be dealt with via HP Tuners...

I have not monitored pressure while driving. I'll have to get creative with routing my gauge's hose, or get a longer one.

Am I risking damage driving it as is until I can get this dealt with? I'm leaving Wednesday morning and will be driving 1800 or maybe close to 2000 miles round trip. We could take my wife's car if need be, but we normally travel in my truck.

Edit: I spoke to the shop that tuned the truck. The owner/tuner himself is not in the shop, as he's on the Power Tour, but the fellow I spoke to confirmed that yes, adjusting pressure via the tuning software would certainly have been part of the tuning. I have an appointment with them for 6/25, soonest I could get, and after we return.

Meanwhile, as an alternative, I spoke with a shop I've dealt with before where we used.to live and where we'll be next weekend. I'm pretty sure they'll be able to get me in while we're up there, though time is going to be very limited. I'm waiting for a firmer answer from them about that. But if they can get me in while we're there, I'll drive the truck up there and have it dealt with there.

1redta

mine did the same thing even after using the smaller drill sizes. I used hp tuners under the transmission function and used the relearn feature which made things “wife approved