A couple weeks ago, I had a local reputable shop build up my transmission with a new TC and VB. I originally went with Suncoast, however when they went to install the Suncoast TC, there was something wrong with it and had to send it back. Instead of waiting for that to come back, we elected to just use an ATS torque converter that he had in stock.

Here are the problems that I have had since:
1. The transmission would shift into 2nd fine, but would then immediately shift into 3rd a few seconds later at around 20-25 mph. --This was fixed with a TPS adjustment.

2. Then, the transmission started going into limp mode and it wouldn't start out in 1st gear. --This was fixed with a resistor/electrical filter (I think that's what they called it).

3. Now, my current problem is that I don't think the tc is locking up in 3rd and it takes a little manipulation on my part to get it to lock up in overdrive. When in overdrive, if I'm on the fuel, when it shifts to od the rpms are around 2,000 when going 60 or so. If I let off the fuel and then get back on, the rpms go back down to 1700-1800.

What could be causing the TC to not lock up?

 

3.55 gear. I'm thinking 1700-1800 rpm in what you think to be OD lockup sounds a bit off for the 60 mph you quoted. You sure you are achieving OD? From what I read it sounds like you are seeing "3rd" and "3rd lock up".

 

Confusing? My 02 is in full lock up in OD at all times. This is controlled by Dodge's PCM... not by the brand of tranny or convertor.

Suspect 'JBody' is correct.

RJ

 

It is really strange. I have the overdrive locked out and I never feel it lock up in 3rd. Once I hit the overdrived button, it does change gears to overdrive (or maybe 3rd locked). However, it feels more like it goes into overdrive but not locked in overdrive.

If it's the PCM, I don't know why it would start doing this when I upgraded the tranmission.

 

I doubt it's the PCM. Watching what happens with the DRB scan tool would be nice. It would at least show you if/when the pcm is allowing the 3-4 shift and tc lockup. That was my greatest fear in building my trans. With all the valve body mods, addition of the VBA I'm really not sure where my "stock" diagnostics fall into place. So far mine has worked.

.....speaking of VBA (valve body assister.. came with my Goerend pieces. Hooks into the trans wiring so the pcm won't see the actual psi that the trans is now running as it would be too high and would make the trans go into fail safe mode)....did your valve body that you installed require any wiring mods? I would think a resistor or VBA would have been a must, but I'm not familiar with what vb you are using. Just food for thought.

 

IMO you can't confuse 3rd gear lock up with OD. 3rd lock is a 200 rpm change..... going to OD is 500-600 rpm difference (from 3rd lock up... even more if 3rd is unlocked). Hope this helps you figure which you have?

RJ

 

I'm positive it isn't going into lockup in 3rd at all and only goes into lockup in overdrive when I let off the gas and then get back on it. I'll take it back and have them run it with the DRB scan tool to see what is going on.

Also, just to make sure I understand things correctly. For those of you who have built up your transmissions, do you actually feel it shift to 3rd and then 3rd locked with the overdrive button turned off? I know that with the built up transmissions, more of the power is getting to the ground but don't know if you can still feel the difference between locked and unlocked in 3rd.

 

Can't miss it if it's working right! Makes no difference if OD is locked out.

RJ

 

Thanks for your help!

 

Kevinn,did you ever find the problem, mine is doing the same,just started acting up last week

 

I am interested too as I am having simular problems

thanks

 

If you are careful with it you can wire in a lockup switch for diagnostic purposes. If it locks up with a lockup swithc you see that the tranny itself is working correctly.
Then the question remains why it refuses to lock up. Usually it's the PCM seeing throttle movement that makes it think that you aren't cruising and it will not order lockup.
This is usually caused by electrical noise on the APPS input to the PCM. DTT sells a noise filter that helps. Many times cleaning all the contacts, battery posts and grounding points will do the trick too, so do this first.
Another possibility is that the trans lockup relay is shot- you can swap it with the horn relay and go for a drive- will only take a minute to swap them.

HTH

AlpineRAM

 

What we eventually did was take out the ATS Torque Converter and put in a new Suncoast as originally planned. This took care of the problem. However; about 2 months after all of this, I towed a small atv trailer and the transmission started going into limp mode again while it was hooked up. As soon as I unhooked the trailer, the transmision would work fine again. I think that trailer wasn't wired correctly.

I then took the truck to another transmission shop that seemed to be well aware of this problem and they did a ground service where they cleaned off all the grounds etc. I have yet to test it again with that trailer.

 

I did the battery terminal cleaning and reset the APS,switched the relay and still is not locking up,I'm going to clean the rest of the grounds,I also have a SMR shift kit with a resister to lower the volts so there is no 2nd gear starting out from a stop,I think I better check that conection also,,Thanks for the imput guys. Can torque converter failure cause this? So far,,I havent heard any strange noises coming from the tranny.