Anybody know the weight of the 8.8 and 9.75 rear? Also light duty vs. heavy duty frame? It looks like the light duty frame is thinner sidewall and a smaller rear section about 5" or so height.

 

I read here that my maxtow has the HD frame and 9.75 rear end, but never saw anything in the literature, options, or even e-brochures. How do you know for sure what the heck you have? Although with the paltry 1,458 lb payload my truck has, it should have both .

 

From what research I have done it appears the 8.8 assembly is 69lbs lighter.

 

The max tow gets the HD frame. The 3.73 locker gets the 9.75 rear axle and the HD frame. The 3.55 locker gets the 8.8 rear and the light duty frame. The frame is slightly thicker and wider on HD and even bigger on HDPP. The measurements are ----------- Model Wheelbase (in.) No. of Crossmembers Maximum Side Rail Section (in.) Section Modulus (cu. in.) Yield Strength (psi) Regular Cab 4x2 122 8 9.06 x 3.58 x .087 (LD) 9.06 x 3.58 x .1 (HD) 4.95 5.73 49,300 49,300 141 8 9.06 x 3.58 x .087 (LD) 9.06 x 3.58 x .11 (HD/HPP) 4.95 6.28 49,300 49,300 Regular Cab 4x4 122 8 9.06 x 3.58 x .087 (LD) 9.06 x 3.58 x .1 (HD) 4.95 5.73 49,300 49,300 141 8 9.06 x 3.58 x .087 (LD) 9.06 x 3.58 x .11 (HD/HPP) 4.95 6.28 49,300 49,300 SuperCab 4x2 145 8 9.06 x 3.58 x .087 (LD) 9.06 x 3.58 x .1 (HD) 4.95 5.73 49,300 49,300 SuperCab 4x4 145 8 9.06 x 3.58 x .087 (LD) 9.06 x 3.58 x .1 (HD) 4.95 5.73 49,300 49,300 SuperCrew 4x2 145 8 9.06 x 3.58 x .087 (LD) 9.06 x 3.58 x .1 (HD) 4.95 5.73 49,300 49,300 SuperCrew 4x2 157 8 9.06 x 3.58 x 0.87 (LD) 9.06 x 3.58 x .1 (HD) 9.06 x 3.58 x .11 (HPP) 4.95 5.73 6.28 49,300 49,300 49,300 SuperCrew 4x4 145 8 9.06 x 3.58 x .087 (LD) 9.06 x 3.58 x .1 (HD) 4.95 5.73 49,300 49,300 SuperCrew 4x4 157 8 9.06 x 3.58 x .1 (HD) 9.06 x 3.58 x .11 (HPP) 5.73 6.28 49,300 49,300 SuperCab 4x2 164 8 9.06 x 3.58 x .087 (LD) 9.06 x 3.58 x .11 (HD/HPP) 4.95 6.28 49,300 49,300 SuperCab 4x4 164 8 9.06 x 3.58 x .11 (HD/HPP) 6.28 49,300

 

My 2018 SCrew Max Tow/FX4 has the HPP frame and the 9.75 rear end with the standard 3.55 gears. All 9.75 rear differentials come with the E-locker so that option will not be on the build sheet for the truck even though it is listed on the sticker. The gears can be upgraded from the 3.55 gears to the 3.73s but I do not know what that costs off the top of my head.

From what I saw in another thread, this is common for the HPP frame to be used with Max Tow SCrew configuration. The only way to know what frame is under your truck is to actually look at the sticker on the frame rail under driver's side door. On the bad side, my payload is only 1305 lbs and my fuel economy...... Well, I have a Ford Fiesta to buzz around in town if I need to conserve fuel because it is less a little less than the figures on the monroney.

 

Did the 2017 Super Crew 4X4's with the Max Tow package also have the HD Frame?

 

From what I have been reading, the 9.75 rear axle is ridiculously random. I have heard of people with the 3.73 gearing not having it at all.
There is no clear indication to what builds will get this axle or not.

I have it on my truck. 3.73 gearing with the 5.0 engine. Max payload is 2020lbs.

 

Depends on the motor/gearing combo. The 3.5 ECO gets it. Don't know if you can get the 3.5 ECO without one as all I have seen on the lot had it. The 5.0 with 3.73 elocker gets it. Don't know about 2.7 ECO or non ECO motor.

 

In 2018, the 9.75 axle was only available with the through the Max Tow Package which required the 3.5L EcoBoost Motor and came standard with the 3.55 gears and e-locker. I know it was available on other motors in prior years, but I am not sure what it took to get the axle.

I am curious as to whether it will be available with other motors in 2019 or only the 3.5L EcoBoost Max Tow configuration.

 

From everything I read you can tell the 9.75 from the 8.8 by the number of bolts on the cover. 10 for the 8.8 and 12 for the 9.75, does anyone know if this is true? I have a 5.0 with 3.31 gears and the cover has the 12 bolts, I have been thinking of doing a gearing swap ever since increasing my tire size but couldn't find much for the 8.8, then checked the bolts and can find any combo I want for the 9.75.