Hi everyone. Long time member, first time Cummins owner. Very excited.

So, I recently got a 2007 with a 5.9 and an automatic transmission.

The previous owner appears to have been a very good one since the truck is practically bone stock. It does have a trailer break controller and aftermarket rear bumper, but that's it.

The previous owner does have a DSS installed and a stabilizer that I'm grateful for, but the transmission may have had work done since it shifts very well and shifts are very firm.

That was a surprise to me since the truck has over 200k miles on it.

So the question is, is there a way to tell if a transmission has had anything done to it other than having the records saying what was done?

Dumb question, but Carfax doesn't have anything and I can't tell anything visually, but you guys have a lot more experience with this so I thought I'd ask.

 

Without tearing it apart or checking the programming, I don't think there is anyway to tell.

 

Firm shifts are a good thing and the PO may have turned the line pressure up, which is a good thing to do in my opinion. Can you ask the PO about it?

Chris

 

Sadly no. Got it at a dealer that took it as a trade. The more I drive it the more I think it has tranny work done. I've looked online and the behavior (firm shifts, hard TC lock) are signs of something being done to it.

The PO appears to have only done mods that kept the truck in good shape to tow a 5th wheel so I'm thinking that it may have towing parts in it.

 

Sounds like you got lucky and should enjoy it.

Chris

 

These trucks are getting old. Who knows what mods or whose built trans is in the used truck?

Who knows what engine and what engine internals are in there? Whose injectors and what size?

Who knows what program is in the ECM?

 

Well, I took my truck to Altered Diesel Wurks (ADW Motorsports) in Marble Falls, TX the other day to have them do a once over and let me know what things needed to be addressed and I got some great news.

I AT LEAST have a Suncoast billet converter and with my line pressure at idle being 75psi and full load 174psi they thing it has a shift kit or full VB. No telling on internals, but I plan to check all the Suncoast dealers in the DFW area (where the truck came from) and see if I can get an exact parts list that's in the tranny.

Yay me.

I do think I need to replace the governor pressure solenoid since I have shutter shift due to the increase in line pressure, but that isn't a big deal. They suggested a GM conversion since it appears to be a more robust unit.

I don't know much about that and would like to hear opinions.

EDIT: I found that Suncoast makes one as well. Looks similar to the GM unit.