I was towing a trailer yesterday and noticed that it wasn't putting power to the ground as well as normal, didn't think too much of it. Had probably about 6k on the trailer and trailer itself is around 2500lbs.

On the return trip, empty trailer I realized something was wrong. I'm holding at 2000rpm and only doing 65. Normally 2000 rpm is ~70.

Seems that the torque converter clutch is slipping. If I lock the converter and let it slow down, then get on it a bit the RPMs shoot up like it wasn't locked. Normally it will load down the engine hard if I do that. Acting just like a worn clutch on a manual trans.

I'm not sure why all of sudden this would happen, trans was built about 3 years ago and the converter is a billet lid single disc clutch.

I'm trying to figure if there is a way to stop the converter from locking? I need to travel 80 miles a day to work and back and right now it's the only thing I have. Searching C-List for a beater with a heater but it might be a few days till I find something.

 

Well, you need to check for codes and make sure there isn't anything wrong with the lock up solenoid or worse, the computer is not commanding it to lock up. From there, if the converter is attempting to lock up then you will be pulling the transmission. You could pull the pan and see how much material is in there. If the clutch is burnt, you'll see the crushed up ashes of it. As for forcing it to not lock up, not really sure how you could do that without loosing OD as well, or at least pulling down the pan and cutting the wire to the lock up solenoid.

 

The TCC is slipping that I know. I'm going to pull out the ATSG book I have in a bit and see if I can figure something out. May just pull the pan and unplug the TCC solenoid, not that big of a deal.

Think I may be able to get by with just putting a new convertor in, but I'll have to see when I pull the pan. Either way parts are 2-3 weeks out.

 

Yeah, palmer is not the easiest place to ship to from down here. I spent some time there, nice place, at least in summer. Haven't been up there for the winter.......

Let us know what the pan tells you. How many miles on the rebuild/converter?

 

Little over 35,000 on the rebuilt trans. Upgraded to 48RE parts where possible, Trans Go shift kit, billet input and output, etc. Convertor has a billet lid, but single disc lock up clutch.

Trans is still shifting fine and works normal other than lock up. I want to get a pressure gauge and hose to check line pressure though. Do you happen to know what size the fitting is on the case? 1/8" NPT??

 

All test ports are 1/8" NPT. Depending on how aggressive your Trans Go kit is set up, you should only need a 100psi or 150 psi gauge. However, if your transmission is shifting normal and not slipping, just in Lock Up, then I would have to suspect

Failed Lock up clutch
Stuck lock up valve in valve body
failed or failing seal on input shaft

When you drop the pan and VB to disconnect the solenoid, try moving the lock up valve by hand and see if its stuck.