Trans swap and MPG's took a dump

Buddy had same thing happen...they was like no we didnt touch ur ecm, uh huh he had ecm checked and sure nuff it had been put back to stock and updated, he bout got the police called on him when he went back to cat haha

 

Page 21 of this Eaton Spec sheet shows both transmissions with the same final drive ratio. Either of the transmissions should have been filled with a 50 weight synthetic gear oil. Not many shops carry the 50 weight mineral based oils anymore for them. I also don't believe the mineral base oil would hurt fuel mileage and I have known guys that have run it without issues over the years. The big difference is Eaton will warranty the transmission for 5 years 500,000 miles if it was installed at the factory with the synthetic. If it has a 50 weight mineral base oil, then it needs to be changed every 100,000 miles if I remember correctly.

http://www.roadranger.com/ecm/group...roadranger/documents/content/rr_rrsl-0001.pdf

 

Top ratio of a 13 "A" is .85 and top ratio of a "B" 18 or 13 is .73 so if you run the splitter back when in 8th it would be the same ratio as the old "A" in overdrive.

 

The simplest solution is probably the answer. The only hard-parts change to the truck was to swap one transmission for another, with both having the same top several gear ratios (thanks cetanediesel), but your cruise power and mpg went down? Pretty much spells "E C M" to me, and reinforced by it being a policy to do so, whether they say they did it or not.

But I have no idea what I'm talking about...

 

It can only be the ECM, The fact that you went from a 13 to an 18 is the problem.. When you changed gears in the 13 you did it at a high rev count. Changing with an eighteen you have to change more often and at a lower rev count than the 13. That means the ECM needs to be calibrated to the new Gear Box.

Plus someone posted earlier that they wished they had a gear between 17 and 18, Well the Road Ranger is a range change with a splitter, that means every odd gear is 1/2 a cog. Are you now saying you want an extra 1/4 gear giving a total of 36 Changes...... (Each full gear would consist of 4 cogs x 9 = 36 )??

 

What the helll are you talking about?

We need to know the exact tag on both trans. models, IE, 18913a, 18913b, 18918a, 18918b.

 

Yep... They're spinning you...