Predator @65HP setting

[Ponderosa JT]

I recently upgraded my 02 with a 4" exhaust, intake, and Predator (about 3 months ago). I set the Predator on the 65hp setting. Everything has been great, but I'm starting to see some trans slippage. Haven't limped it yet. What I've read here is that the 65hp setting should be safe for the alli to handle. Is it possible the exhaust and intake gave me an extra 20-30hp? Can the trans un-learn the power if you are easy on the accelerator over a long period, even though the 65hp setting has always been there? 3rd gear seems to be the most noticable for slippage. But it does remind me of the 1st week it was on the truck and the trans was still learning. I'm going to lower to the 40hp setting for now. Any thoughts?

Jeff

[DmaxMaverick]

How are you detecting slippage?

You should not be seeing any tranny slippage in 3rd gear and non T/H. If you have enough pedal to increase the torque enough to cause a slip, the torque converter will have unlocked, if it's even possible to lock it up in 3rd and non T/H with significant pedal input. This can only occur near readline RPMs, as the lockup speed and RPMs are there. The slippage you are seeing is probably the TC speed differential, which would be quite high in 3rd with power on. Meaning, it is an engine speed and tranny output differential, not actual clutch slippage.

If you are in 3rd and T/H, there should still be no detectible slippage. There just isn't enough torque at the 65 HP setting. In OD with a heavy load, however, it can slip with enough throttle and little acceleration, like on a grade, long overpass, or passing w/o a downshift. If you aren't towing, and the truck isn't loaded, I don't see how you could be slipping in all but OD up a long, steep grade.

That said, if the control/main filter (spin on) is near it's useful life, the pressures (flow) can decrease enough to cause slippage under certain conditions. At the same time, all auto trannies slip to some degree under load. IIRC, the TCM considers ~1% slippage completely normal. The stock TCM program is pretty sensitive to excessive slippage, so if you aren't limping, it's probably not something to be too alarmed about.

It is possible for your intake/exhaust upgrades to have increased the torque rise enough during a specific range to put it outside the envelope. I haven't seen it, but it's not impossible. My setup is very similar to yours, but I haven't seen a problem with over 113K on the clock, towing very heavy or empty.

[Ponderosa JT]

Slippage in this case is the RPM rising quickly after a shift without the truck accelerating like it should. I guess I should use the Predator to give me an actual readout in percent. Do you suggest someone rides along to watch the Predator readout? It may be just be the torque converter. My truck has 65K on it, the spin on was replaced at 55K. I don't really thrash the truck, but on occasion when the road is empty at a 4 way stop, well you know, I might indulge a little.... I'll try tow haul mode over the weekend to see if it acts any different. Has anyone tried the Bully Dog shift enhancer?

Thanks
Jeff

[DmaxMaverick]

If you were in non T/H mode and 3rd gear, you were seeing the torque converter differential. That is completely normal.

Your predator won't show your tranny slippage. It will only indicate if a TCM code is present, but doesn't give any details. If you aren't seeing a P0700 DTC, then you aren't slipping. Well, not enough, anyway.

[Ponderosa JT]

Thanks DmaxMaverick, I feel much better about the trans. But the question now becomes, what will firm up the TC so that it doesn't lag so much between shifts. Second is pretty solid, but 3rd and 4th seem to take awhile to catch up with the rpm's. Is this what the TCM "learning" should do? Should I just use T/H when I'm looking for more firmness in the shifts? Or does one move up to a triple clutch TC? $$$.

Jeff

[DmaxMaverick]

I don't think a triplelock TC is a good idea. You need the TC to take up the slack between the engine and a stock tranny. Take that away, and the tranny will become a failure point. The learn process will firm it up a bit over time, but will not be as firm as with stock power levels. The TC is calibrated for stock power, so forcing more through it will cause the slop. Use T/H if you want a more firm connection.

The alternative is to upgrade the tranny and TC. The performance grades will hammer gears like a manual.

[FBJR]

I am running the same tune and mods in my 06 LBZ, but never felt any slipage.

Would the Transgo Jr be enough to overcome this issue and get a really solid feel? I can feel the defueling during shifts now, perhaps this is all Jeff feels?

FB