Gear swap question

[geokots]

I've been reading about what people like or dislike about the different gear options. I have the 3.31 gear ratio on my EB Premium. What is involved with upgrading to 3.55?

The part on AM isn't very expensive (assuming it's correct)
http://www.americanmuscle.com/frpp-355-gears-2015.html

Any estimates on service time needed? Any gotchas I should know/consider?

Sponsored

 

[arrow94]

Differential gets drained, axles get detached pumpkin with ring gear slides out, remove driveshaft, loosen pinion nut, remove pinion gear, replace pinion gear with new ratio pinion , unbolt ring gear from pumpkin, replace ringear with new ratio ring gear, reinstall pumpkin with correct shims. Bolt up driveshaft and attach axles. Refill differential.
You will also need a bearing puller/press to remove and replace the bearings that the gears ride on.
Its about a 1000 dollar job with the price of the gears included at a shop

 

[analogman]

The mechanical work is the easy part of the job. I've been looking into this in great detail, thinking of swapping the 3.73 in my car for 3.31. The biggest problems are the Engine Control Module (ECM) and Body Control Module (BCM).

Apparently, the rear end gear ratio is coded into both the ECM and BCM. Both would need to be either replaced, or have their software re-flashed, to reflect the new rear end gear. Otherwise, the speedometer reading will be off, and other functions like traction control might also be affected.

As far as I know, unfortunately, right now Ford has not made the software available to do this. The performance shops in my area don't know when it might be.

Good luck, and keep us posted if you're able to find the right software and are able to do this.

 

[geokots]

Thanks for all the info. I'll still consider it as a future upgrade but I'll wait and do a few other items on the list.

 

[Jamo]

It costs thousands of dollars.

 

[arrow94]

The mechanical work is the easy part of the job. I've been looking into this in great detail, thinking of swapping the 3.73 in my car for 3.31. The biggest problems are the Engine Control Module (ECM) and Body Control Module (BCM).

Apparently, the rear end gear ratio is coded into both the ECM and BCM. Both would need to be either replaced, or have their software re-flashed, to reflect the new rear end gear. Otherwise, the speedometer reading will be off, and other functions like traction control might also be affected.

As far as I know, unfortunately, right now Ford has not made the software available to do this. The performance shops in my area don't know when it might be.

Good luck, and keep us posted if you're able to find the right software and are able to do this.

Yeah i forgot about that, i had to buy a tuner to set my gear ratio correct on a 99 f150 a couple years ago. Luckily its an sct x4 and i can use it on the stang too.
So in all reality its a 1500 dollar job.

 

[Mark5825]

I've got a 3.15 automatic and looking to change to 3.73, I already have a tuner and from everything I've heard it will be a huge difference (I don't care about MPH). What are the recommendations on tires and I guess half shafts & axles? What's the difference between axles and half shafts? Can I run street tires still or would I have to use drag radials? Got quoted $650 and $1000 from 2 shops on the gears.

Sponsored