OK, I have decided to go forward with rear differential gear change. I am going from a 3.55 to a 4.10 this week.

Question - Will I need to do anything else to my truck after this change like have the computer reflashed or will the computer shift points simply remain the same with no need for any recalibration.

Thanks in advance,
FTO

 

I would absolutely suggest you get a reflash or a tuner that you can program in the change yourself.

CMOS

 

Thanks for the input. Will the Edge take care of this? That was going to be my next mod. I see no need to pay Ford for a reflash if the edge will do the job.

Also, can you give a brief explanation for needing the reflash? I may need to move the Edge purchase up a little.

 

FTO,

The current flash in the PCM is designed to shift the tranny at certain speeds and power levels of yuor engine. With the gearing changed (and 2 steps up to boot) if you keep the same flash the PCM will "think" it's shifting at a certain speed/RPM combo when it will actually be shifting at a totally different one = with the 4.10's (nice choice!) the truck will be at a much higher RPM for any given speed when compared to the 3.55's.

The CPM need to "know" this to shift at the right speed/engine power combinations.

Regarding the question abnout the Edge, I don't recall bit I *think* it can input the new gearing (tire sizes, etc....).

Good luck and please do post the results after you get the gear change, etc. It's good feedback for all of us.


CMOS

 

yes, the edge will allow you to tell the computer what gear ratio and tire size you are running. this will also all you to get an accurate speedometer, but only on the edge unit, and not the dash gauge. if you get the edge and gears at the same time, you will swear that you got a whole new truck !!!

 

Matt,
I am looking forward to that "whole new truck!!!" I have had my truck for a year now and I am tired of dragging around this 6000lb beast with the 3.55 gear. I still cannot figure out what Ford is thinking with these heavy trucks and the 3.55. On top of that, my truck came with tow package----what kind of sense does that make???? I believe I will get better gas mileage for my predominant around town driving also. I may lose a little on the Interstate but that's not where i am a lot.

Cmos,
Thanks to you for the explanation also. That was kind of what I thought your explanation would be. I will definitely let you guys know how this turns out. I may have to have Ford do the Flash and wait a while on the Edge depending on how much they want. I want both now but $650 for the diff. and $500 for an Edge is a little steep right here after Christmas. We will see.

 

Please let us know what the difference is with the gear change. I have ben thinking about the sane thing. I allready have the edge, I just want to know if the gear change is worth it.

I can tell you right now the Edge is worth it.

 

The hd package has the 4:10's for a reason, but you'll have to do front and rear pumpkins no? Seems like a lot of dough. Try the edge first and see where you're at. I have the 3.73's now and am picking up an '08 with the 3.55's. The only way they come with the available trucks out there now.

 

I went from 3.55s to 4.10s and it was the best mod Iv ever done!
OMG,,what an improvement!!!!

 

the original post was put up for a 2wd.... otherwise yes front and rear must be done or 1 of 2 things would happen..... either you could never use 4wd, or if you did, you would cause considerable damage to the transfer case.

 

i dont see the 2wd part...thought he had a 4wd

 

I am trying to get fit in to my local 4x4 shop schedule for this week. I will definitely let you guys know when it is complete.

I also seen a response below asking about 4x4 vs, 2 wheel drive......I should have specified but I am two wheel drive. Thank goodness I do not have to do front and rear. The Edge would definitely be out for a while if I had to do both right now. At this point I am going to try and swing the edge shortly after the differential. I hope it is like everyone is saying and this makes my truck a lot more fun to drive. Down side is my foot will probably be in the floor more thus burning more $3.00/gallon gas. Thanks for the responses. I am stoked about the changes.