Axle confusion

[Sneezy]

After an afternoon of aimlessly browsing the forums the other day I stumbled upon a thread that mentioned all trucks with 3.73 rear ends have the 9.75 rear axle. After looking underneath my truck it visually appears that mine is an 8.8 axle, but my window sticker says it’s a 3.73. I’m not worried about which axle I have, since I have the 3.3 V6, neither are going to be severely taxed. I’m just curious if the lower powered engine gets the higher ratio with the smaller rear end

Here’s my window sticker and a picture underneath my truck

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[KBKEITH]

All I can add here is that my former 2016 with the 2.7 and 8.8 axle came with the 3.73 gears. I realize things have changed since perhaps, but that’s my story.

 

[TexasTruck]

As recent as last week I owned a 2023 XLT 3.5 EB for a week (don’t ask). I was surprised to see it had a 9.75 with 3.31 gears. So, yes, you have a 8.8 (Super 8) with 3.73 gears to help get your load moving with your 3.3. I wish I had 3.73

 

[Snakebitten]

What's your axle code?

 

[Sneezy]

As recent as last week I owned a 2023 XLT 3.5 EB for a week (don’t ask). I was surprised to see it had a 9.75 with 3.31 gears. So, yes, you have a 8.8 (Super 8) with 3.73 gears to help get your load moving with your 3.3. I wish I had 3.73

Yeah the 3.73 combined with the 10sp really wakes this motor up. It’ll never be a V8 or EcoBoost but it’s definitely more capable than the 5.4 Triton I had in a previous 06 F250 with a 4sp

 

[Sneezy]

What's your axle code?

Awesome thanks Snakebitten for posting a pic of the door sticker. I completely forgot it’s listed there

Mine says 26 for the axle code, all of those axle charts really helped!

 

[rpold150]

The way I read this, the 3.31, 3.55, and 3.73 (all non-HDPP) could have come in the 8.8 or 9.75 pumpkin. What determined which rear they put in? The difference is a little more GAWR (3,400-3,800 versus 3,800-4,050).

 

[Snakebitten]

I am not saying that Ford's documentation is accurate, but it does imply that the GAWR is the deciding factor for an otherwise identical axle ratio.

 

[Buyer2021]

I am not saying that Ford's documentation is accurate, but it does imply that the GAWR is the deciding factor for an otherwise identical axle ratio.

I'll posit that the underlying determining factor for both the RGAWR and associated ring gear diameter is the GCWR that Ford wants to provide for a given F150 configuration.

There's marketing gold in those advertised high maximum trailer towing capacity numbers, whether folks really need it or not.

 

[Snakebitten]

I'll posit that the underlying determining factor for both the RGAWR and associated ring gear diameter is the GCWR that Ford wants to provide for a given F150 configuration.

There's marketing gold in those advertised high maximum trailer towing capacity numbers, whether folks really need it or not.

And since we know that the Powerboost gets the heavier duty rear axle, perhaps the document called "Rear Axle Specifications" should better say ">4050", rather than just list the HDPP 4800?

My Powerboost GAWR is 4150lb, so it is beyond the range, 3800-4050, that Ford shows for the regular 9.75 rear axle.

And a good example of @HammaMan 's argument that Ford purposely gimps the specs of the Powerboost to artificially place it where they have decided to position it.

Or put another way, its published performance AND engineering stoutness is at least a tad pessimistic compared to the same specs its siblings are reported to achieve.

I'm not complaining though. Nothing I have asked from my Powerboost has taxed it in any way. It does EVERYTHING my 2018 KingRanch Ecoboost did with less effort and more composure.

 

[tony72cutlass's']

The super 88 (or whatever the marketers call it now) is an awesome axle. If I had a crystal ball I’d predict the axle is the component that will outlast the truck by a mile.

That being said, This is the first time I have ever seen a 8.8 with 3.73 gears in a 2021+. I’m basing this off the probably hundreds of posts people have made (including myself) that said ‘3.73 means you have the 9.75’.

Turns out we were wrong!

 

[Buyer2021]

And since we know that the Powerboost gets the heavier duty rear axle, perhaps the document called "Rear Axle Specifications" should better say ">4050", rather than just list the HDPP 4800?

My Powerboost GAWR is 4150lb, so it is beyond the range, 3800-4050, that Ford shows for the regular 9.75 rear axle.

So is the "9.75HD" supposedly the designation for the 9.75" 3/4-float axle (distinct from the 9.75" semi-floating axle)?

I ask, and perhaps add to the questions about the 'correct-ness' of that e-SourceBook table, by pointing out that like your PB my 3.5EB has the 9.75" 3/4-float axle (no question, the end-bolt unique to that axle is obvious), in the L9 ratio (3.55:1), with electronic locking. All that by virtue of the Max Tow package content with that engine.

But, my RGAWR is 'only' 3800#; and with a GVWR of 'only' 7050#, and omission of mention on my window sticker, I clearly do not have the "Heavy Duty Payload Package" mentioned in footnote (1) of that table.

It would seem that no matter how one slices it, there's some error or omission of detail in that e-Sourcebook Table relative to what's actually able to be built. I guess that's why there's the caveat

NOTE: Specifications and descriptions contained within are based upon the most current information available at the time of release. Content subject to change.

 

[Snakebitten]

Don't get me to lieing!

If the 9.75 axle that you and I both have, based on the now infamous bolt that designates it as the 3/4" floating axle", is NOT the "regular" 9.75, NOR is it the 9.75HD, then shouldn't there be 3 different 9.75 axles listed?

I admit that I'm reluctant to declare anything as absolute based on the confusing publications.

 

[Buyer2021]

Don't get me to lieing!

If the 9.75 axle that you and I both have, based on the now infamous bolt that designates it as the 3/4" floating axle", is NOT the "regular" 9.75, NOR is it the 9.75HD, then shouldn't there be 3 different 9.75 axles listed?

I admit that I'm reluctant to declare anything as absolute based on the confusing publications.

I'm standing with you 100% Good Sir!

Bottom line, IMO we both know what we've got in terms of ratio, ring gear size, etc, etc ... e-SourceBook tables notwithstanding!

 

[cjreyes]

Don’t want to hijack the thread but can you all help me out in identifying my axle and if I am effected by the sheared off bolt issue? I just had my tires rotated and I was looking at the rear axle and I cannot tell if there was a center bolt that is sheared off or not by looking at the pictures. Is there supposed to be a bolt in the center? It is a 2022 F150 Tremor 3.5 EB. I looked at the window sticker and it says I have the trailer tow package as an option. Nothing about an max tow option. Also on the door it says I have the L6 axle which is the 3.73 gears. Thanks.

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