transmission Slipping

[GatorRam]

I've had my latest power mods and my transmission done for about 5-6 weeks now. On the way back from Georgia after I had been running on the Interstate for a while, the transmission would slip on acceleration at 75+ MPH. It feels like the the TC is slipping. I had SUNCOAST go through the whole thing when I had it up there and it looked good but I had them fix anything that might become a potential problem. I know there are a lot of people out there running more power than me and I was just wondering if anyone has experienced the same thing. I have done nothing out of the ordinary to tear this thing up and after having other problems with this transmission upgrade I'm getting a little tired of it to say the least. Don't mean to offend anyone just looking for answers.



Thanks,



Adam

 

[rrausch]

You might check your TPS. Mine used to do the same thing before I got my ATS, and before I began to regularly clean my TPS with electrical contact cleaner. What would happen in mine is that the dirty TPS would give a false reading and cause the TC to unlock. The rpm's would increase and it would seem as though the clutches were slipping.

 

[BillGotthelf]

GatorRam-check out www.Happibox.com. Their box has fixed the same problem you have mentioned including mine.

 

[GatorRam]

Thanks guys,



I was just wondering if you were experiencing these conditions all of the time or after you had been running for a while. It would not do it today and hasn't before but it did on the way to Georgia and on the way back also. It only started happening after I had been driving for over an hour.



Adam

 

[BillGotthelf]

Gatorram- electrical interference is the largest reason for TC "slippage". Actually what is happening is the TC is locking and unlocking hundreds of times every minute. The electrical signal to the lockup controller spikes up and down(in hundreds of a volt) causing this. This signal can come from a number of places as the truck ages. Batteries, Alternator, lift pump, injector pump, aftermarket addons-anything that uses electricity can cause slight electrical interference. Some vendors sell filters that cut off the peaks and valleys of the electrical signal from the TPS-ECM-PCM. Sometimes they seem to work but on a computer graphing scanner you can see that the TC is still locking and unlocking-just unlocking less. The only vendor item I have seen completely eliminate this is the HappiBox. I am not part of there group, nor do they pay me I just saw a good product that fixed my TC problems.

 

[shendren]

you don't need a happy box. search on the tdr for my name and all of the problems i had.



the fix is simple.



tap the power wire (it feeds other things) and run a new one.

cut the signal return wire and run a new one.

done.



you don't need a box full of capacitors.



just get the wires out of the harness.



good luck.



ps. bill kondolay sells the same thing.

pss. you don't need a snapon scanner to monitor your signal. i just use my dvm driving down the road.

 

[BillGotthelf]

shendren-The 2nd gen 24 valve is alot different than the 12 valve. Do what you suggest on the 24 valve and you will need a tow home because you will end up in the limp mode. Also DTT sells a filter for the problem.

 

[shendren]

that's right. i put that in my post about bill selling one.



how many wires to the 24v tps? what are they?

 

[shendren]

bill's filter didn't help my problem. too much noise in the harness.

 

[BillGotthelf]

Shendren-You did not read my post. BillK among other people sells a noise filter that electonically cuts out peaks and valleys of the electric signal sent by the pcm to the transmission. The Happi Box is Not a filter but replaces the fluctuating signal with a clean signal and also makes the ECM/PCM believe the signal is getting thru-hence no codes or limp mode. The 12 valve auto and 24 valve auto are not the same period.

 

[shendren]

just curious, what components are inside a "Happi-Box" ???

 

[BillGotthelf]

I do not know. I helped them with some test trucks from the TDR (do a search and you will see my posting requesting volunteer trucks) membership. They also tested one on my truck. I saw my TC locking and unlocking hundreds of times every minute on a test drive with a laptop connected into the scanner port. We also tried moving the wires out of the harness, checked batteries, disconnected batteries, changes TPS, cleaned plug in contacts behind factory air filter, checked feedback (electrical) from alternator, lift pump, injection pump, aftermarket stuff and nothing worked. We even tried one of those filters DTT sells, still nothing. I just know the box works and works on 24v 98. 5 to 02 autos. In trying to come up with a mystery switch for my 99 like the one for my 96 I threw many codes and put the trans into the limp mode. I have solved that with a ATS trans controller. I have had all 4 generations of CTDs and have worked on dozens of them. I am not trying to flame you just tell you my experiences. Their box fixes only 1 problem of the many that our trucks experince. Also it only fixes about 75% of the trucks it is put on. The other 25% have other problems with the trans not associated with locking and unlocking caused by voltage fluctuations.

 

[shendren]

Bill,



when you moved the wires out of the harness, did you completely remove the wires from one end to the other?

 

[BillGotthelf]

Yes. Also another source of the electical interference is where Cummins located the voltage regulaor for the alternator. It's located in the same board/box as the ECM. As age, heat and vibration take their toll interference from the regulator bleeds into the computer chip for the ECM. Remember that a fluctuation of only . 04 volts will lock and unlock the TC.