Trans. Code 50735 Incorrect 5th gear ratio

kcarson · 12-31-2006, 05:36 PM

I got a "50735 code--Incorrect 5th gear ratio" Does anyone know what this means? I was pulling a load on level roads, and all of the sudden I felt a small thump and I got this code. I've disconnected the batteries, and tried to clear the code with a reader but it always comes back just after starting the truck. Thanks

**ob_1jr** · 12-31-2006, 06:53 PM

could be a NSBU switch (on the side of the tranny). Any mods? You could have slipped 5th gear too. When's the last time you serviced your tranny? Changed fluids and filter?

kcarson · 12-31-2006, 06:59 PM

I've got the Edge Juice. I just changed the fluid with in the last 1500 miles. I checked another site and it said that was an invalid code number. The truck is pulling fine now but the CEL will not go out so I'm thinking there may be a more serious problem.

duramaxdavid · 12-31-2006, 08:16 PM

are you sure its not a P0375?

kcarson · 01-01-2007, 04:11 PM

turns out that must have been a "P0735" code. but what does that mean? and how do I go about straiting it out?

LBZ Farm Truck · 01-01-2007, 04:23 PM

i would get rid of the edge box i had one on my 05 and they had to replace the tranny do to it (good dealer) i now have an 06 with a bully dog and i love it no funny shifting or codes like my 05 it always went to limp mode id can the edge

duramaxdavid · 01-01-2007, 07:31 PM

YOuve slipped something and i wouldnt to much worry about it. Ive gotten it a couple of times.

Mike L. · 01-01-2007, 08:40 PM

You limped your Alli. Incorrect 5th gear ratio means you slipped it pretty good. Limps will come easier from now on. You have 2 choices; remove the power or build the trans. Your C3 clutches are damaged.

budman1 · 01-08-2007, 08:49 AM

I thought the Allison tranny was supposed to be bulletproof...i know two people who have had issues, 1 completely burned up, the other had a horrendous 1-2 gear shift. Local trans shop says they see more Allison problems than the Ford Torqueshifts. Who knows. Hopefully they'll work the bugs out soon.

**ob_1jr** · 01-08-2007, 09:33 AM

No tranny is bulletproof. In stock form, the allison is pretty close to bulletproof. When you start adding power to a tranny it is a tall order. I bet almost all the problems that your tranny shop has seen was on vehicles that had programmers on them running at least 85 hp or more. You got to look at it this way...a LLY has about 310 hp....lbz has 360. You add 100 hp to it and you add nearly 200 lb/ft of torque....something has to give. You wonder why your local tranny shop sees those guys and not the dealer? If it was truely a problem with the tranny, guys would be going to the dealer and not a tranny shop in most cases.