SHOCKSEALSDOTCOM
Member
Im new here and plan to make my rig a Baja runner but accurate info is hard to come by since nobody is really tearing into a late model expedition for this.
So a lot of heresay when searching all over google so here are the facts on diffs, gears, stability control issues speedo adjustment, etc. I was told ABS/traction control/speedo/ was all controlled via wheel speed from some ford guys which is not true. Speedo is driven by something before the ring and pinion since the speedo is so far off. With just the larger tires it was 5% slow as expected.
I did a lot of google searching with no definite answer on late model expos and gearing changes or diffs that fit so I figured id roll the dice on $2500 for gears, diffs, programmer, labor.
Carl from Nitro gear learned that the side gears on the aftermarket diffs for the 9.75 rear end do not come machined for stub axles, but only C-clip axles. If you buy a C-clip axle diff(probably all aftermarket), you will need to machine the side gears with a chamfer on both sides and back bore so you can actually install the stub axles and someday actually remove them without a slide hammer. Other than that, no funny business.
Install bearing kit in rear was 11-14 F150 as that was unclear to the guys in the diff/gear world until tearing into it.
The front 8.8 Detroit trutrac 31 spline diff while made for the rear end, works fine in the front. I talked to eaton rep and he said there should be no issue since it is made for both IFS and Solid axle already has the machining required to the above carrier in the 9.75. Front 8.8 Detroit Trutrac installed without issue.
With the 4.56 gears and the OEM 2017 raptor take off wheels and tires (315/70/17) the speedo is oversped roughly 27%. Stock gears were 3.31. I ordered an SCT tuner to get the wheels and tires programmed properly.
Once the gears are broken in I will lay into this thing and test out the diffs with some trail runnin.
70mph at 2100 ish RPMS is perfect.
So far ive got gears, eaton true trac, programmer and fridgefreeze fridge.
To do are rock sliders, drawers, race radio, gps and some sort of gas tank skid plate.
I took out the stock spare, cut the trailer hitch tube flush, cut the thru tubes in the rear cross member flush and let the air out of the spare to 20psi and shoe horned it in the stock location. I may order a BFG 34x10.50x17 KO2 for the spare solely for ground clearance in the rear since the current 12.5" wide tire hangs low.
If you guys ever need shock seal kits, shockseals.com is my home business.
So a lot of heresay when searching all over google so here are the facts on diffs, gears, stability control issues speedo adjustment, etc. I was told ABS/traction control/speedo/ was all controlled via wheel speed from some ford guys which is not true. Speedo is driven by something before the ring and pinion since the speedo is so far off. With just the larger tires it was 5% slow as expected.
I did a lot of google searching with no definite answer on late model expos and gearing changes or diffs that fit so I figured id roll the dice on $2500 for gears, diffs, programmer, labor.
Carl from Nitro gear learned that the side gears on the aftermarket diffs for the 9.75 rear end do not come machined for stub axles, but only C-clip axles. If you buy a C-clip axle diff(probably all aftermarket), you will need to machine the side gears with a chamfer on both sides and back bore so you can actually install the stub axles and someday actually remove them without a slide hammer. Other than that, no funny business.
Install bearing kit in rear was 11-14 F150 as that was unclear to the guys in the diff/gear world until tearing into it.
The front 8.8 Detroit trutrac 31 spline diff while made for the rear end, works fine in the front. I talked to eaton rep and he said there should be no issue since it is made for both IFS and Solid axle already has the machining required to the above carrier in the 9.75. Front 8.8 Detroit Trutrac installed without issue.
With the 4.56 gears and the OEM 2017 raptor take off wheels and tires (315/70/17) the speedo is oversped roughly 27%. Stock gears were 3.31. I ordered an SCT tuner to get the wheels and tires programmed properly.
Once the gears are broken in I will lay into this thing and test out the diffs with some trail runnin.
70mph at 2100 ish RPMS is perfect.
So far ive got gears, eaton true trac, programmer and fridgefreeze fridge.
To do are rock sliders, drawers, race radio, gps and some sort of gas tank skid plate.
I took out the stock spare, cut the trailer hitch tube flush, cut the thru tubes in the rear cross member flush and let the air out of the spare to 20psi and shoe horned it in the stock location. I may order a BFG 34x10.50x17 KO2 for the spare solely for ground clearance in the rear since the current 12.5" wide tire hangs low.
If you guys ever need shock seal kits, shockseals.com is my home business.
