4L80E/TH-400 question

[Cowboy_Customs]

I have a couple questions, I guess to start, I dont think my torque convertor is locking up on the 4L80E, I have no codes or anything, and the tranny is STOUT! How do I test it?

Second, the 4L80E is basically a TH-400 with OD, so can I use a torque convertor from a TH-400? Reason I ask is I am going to be doing a Cummins conversion and want to keep the 4L80E. By the time I buy and source all the parts for a dodge 47RH trans I will have just as much into the adapters to run my current trans. not to mention a friend of mine has what I need to mount my tranny behind my Cummins.

[joesgarage71]

I'd have to say No on the TC.You can find more info here

http://www.4btswaps.com/forum/index.php

http://www.frybrid.com/forum/forumdisplay.php?s=9eafc4a5e002a7560f4950ab01ecfd47&f=93

http://www.turbodieselregister.com/forums/cummins-diesel-conversions/192538-95-suburban-2500-6bt.html

http://www.dieselplace.com/forum/index.php?s=796625cd8aee7c0f8ab4bbc0eaf5e2ea

[Captkaos]

No on the Torque converter.  There is a member with a Diesel conversion on here.

[Fishtail8]

Who's kit did you use to run the 80E? Did it come with the controller? If you've got a tach, watch and feel the shifts. If you feel 1-2, 2-3,3-4, and one more, then the lockup would be working. It depends on if it's programed to lock in 3rd or 4th. At least that's how mine works.

[Captkaos]

Cowboy has a 91 truck.  It was an option that year, the Factory ECM controls it.  I have a 4L80E in my 91 Crew also.

[VileZambonie]

cummins over a bb? why? 
To test the converter clutch, when you are driving on the highway in 4th gear, maintain cruising speed and apply the brake pedal with your other foot just enough to turn the brake lights on. You should hear the engine RPM increase and decrease when you remove your foot from the pedal.

[Cowboy_Customs]

Thanks for the input, i'll look into it today, I do have a tach in the truck too. It will be awhile before I start the conversion, but in the mean time I would like to check out this TC lockup issue. I can watch the tach gain a few RPMs in OD when I step on the loud peddle, from my experience the RPMs are not supposed to move at will, but with speed when in lock-up. I know the tranny isnt slipping, maybe the TC lockup clutches have just had it? Truck has almost 200K, as for the trans, im not sure, doesnt leak and is the best shifting unit I have EVER driven so.... I have driven so many trannys that get the engine out of its effincincy range it rediculous, this one keeps the 454 where its happy. Unless I let loose then its around 3500-4000 with a firm, FAST shift.

Well, I love having a BB, I have ideas I would like to do with it (TBI injected single carb charger.... ) Anyway, I had a 93 Dodge cummins a few years ago I wrecked, and just remember how much fun the Cummins was. Not that a 454 isnt fun, but I miss the power, mileage and relibility.

I did have a failed attempt at making the win aldl cable, im just waiting a week or 2 now that money is comming in again, and going to buy the premade cable. I saw on one of the programs i downloaded to the laptop it has info on the trans.

[Captkaos]

How much is the cable going to cost you?  I have like $10 in mine because I used meter probe ends to plug into the connector.  In fact I probably have a some spare resistors that I got for like a $1

[Cowboy_Customs]

This is the one I plan to get: http://www.aldlcable.com/sc/details.asp?item=aldlobd1u
Its a molded OBD1 connector with a USB connection.

Did go for a ride, the TC deffinatly is NOT locking up. Tried the brake test nothing happens, and once it goes into OD if you give the peddle a tap it will accelerate, but also raise RPMs 500 too.

[VileZambonie]

Bypass the tcc brake switch and see if it locks

[Lt.Del]

My 4l80e in my 91 sub locks up, but, the speed needs to be there to do that.  I don't know how many sensors the ecm  reads prior to the 4l80e lockup, but, in addition to the brake sensor that vile mentioned, I am guessing the VSS is used as well....does your cruise control work?   There's probably another sensor for vacuum or some kind of intake data that is required, therefore, when you punch the gas, the converter lock up disengages.   In short, find out all the sensors and check them all.

I agree, the 4l80e is STOUT.