TFLtruck is reporting about a 3/4 float version of Ford's 9.75" axle for the F150 as something new. I know that the 9.75" axle has been around for ages but other than that I have no familiarity with it. Is this version actually something new? I have noticed in that through the 2020 model the highest tow ratings were not available with the 3.73 gear ratio that is often associated with the 9.75" gears but that changes with the 2021 model. Is this related? TFLtruck really doesn't seem to know much about it other than it is holding up deliveries.TFLtruck on 3/4 floating axle

So a 6-lug full floater? One more step to making the 250 unnecessary...maybe the marketing guys are moving toward eliminating the 150/250/350 lineup and just having 2 models, light duty and super duty. Would that be a bad thing? Most folks post here that the only difference between the 250 and 350 is the rear spring pack.

F-350 comes with a 10.5 inch diff.Dana 60 in the front.

If it’s what I think it is, it may be similar to the old Jeep Grand Cherokees where the bearings and seals were pressed into the axle shaft. This is the same design the 9” used and the old Chrysler 8 3/4, although those had a drop out center section.

looking at the design in the clicky shows the 3/4 full floater uses ball bearings instead of tapered roller bearings like a HD full floater. Having come from the era when ball bearings were much in use on those old cars and light duty trucks I would pass on having them on my truck. Granted ball bearing have much less rolling resistance than roller bearing but at what cost in long term reliability.

"One more step to making the 250 unnecessary...maybe the marketing guys are moving toward eliminating the 150/250/350 lineup and just having 2 models, light duty and super duty."All depends on sales volume. Possible.

New version of Ford's 9.75" axle? | Good Sam Community

18 Replies

JIMNLIN
Explorer III
Dec 17, 2020
The subject is F150 trucks not dump trucks...heavy commercial trucks. Apples vs pickles in the truck being discussed.
My reference to Fords F150 was their using 6 vs 7 lugs on their F150HD trucks with the 9.75 rear axle assy. I assumed Ford went with larger diameter lugs
blt2ski
Moderator
Dec 17, 2020
I was about to say, a 6 lug can carry a lot of wieght. My Navistar has 6 lugs. Rear is rated to 16500, front 8000. Most axles these days have 10 lugsin the HD/MDT applications.

Marty
rjstractor
Nomad
Dec 17, 2020
JIMNLIN wrote:
Looking at F150 fleet Ford specs shows the 4800 rawr has been around since the '00s

Those specs also show the F150 with a 8200 gvwr and 4800 rated rear axle as a 7 lug 9.75" in 2014.

Then in 2015 Ford dropped to a 7850 gvwr with a same 4800 rawr and a 6 lug 9.75HD rear axle assy.

Six larger diameter lugs no doubt will carry same weight as 7 smaller diameter lugs...just assuming here.

Good assumption, since there are six lug axles in commercial trucks that are rated at 14K+ pounds. Obviously those are full floating axles.
JIMNLIN
Explorer III
Dec 16, 2020
Looking at F150 fleet Ford specs shows the 4800 rawr has been around since the '00s

Those specs also show the F150 with a 8200 gvwr and 4800 rated rear axle as a 7 lug 9.75" in 2014.

Then in 2015 Ford dropped to a 7850 gvwr with a same 4800 rawr and a 6 lug 9.75HD rear axle assy.

Six larger diameter lugs no doubt will carry same weight as 7 smaller diameter lugs...just assuming here.
Groover
Explorer II
Dec 16, 2020
JIMNLIN wrote:
Ben wrote:
As for ball bearings vs rollers vs tapered rollers is that the balls have a smaller contact point with the race. Therefore lower rolling resistance

Rollers have a larger contact point and has a higher load rating vs a ball, but in regards to dia, the roller is rated to carry more

Yeah that small single contact point on our older light duty pickups is a big reason they moved away from using them on our LDT size axles and went with a roller on full and semi floating axles.

Fords F150 still has a 4800 rawr as tops for the HDPP trucks so no worries about the 3/4 ton going away anytime soon.

The last I heard is that the rear axle with the Max Payload Package is limited by the 6 lug wheels. The 2014 and earlier trucks with MPP had 7 lug wheels and a higher rear axle rating. When Ford went to aluminum bodies they decided that with the weight savings on the body they could drop to 6 lugs and retain the same payload rating.

I have not heard of any axle issues with the older trucks and their higher axle ratings.
Groover
Explorer II
Dec 16, 2020
FishOnOne wrote:
I can't see a full floating axle in that picture.

It is described as a 3/4 float.

My question is about whether that is new or has been that way all along. TFL seems to suggest that it is new but they don't seem to be sure.
JIMNLIN
Explorer III
Dec 16, 2020
Ben wrote:
As for ball bearings vs rollers vs tapered rollers is that the balls have a smaller contact point with the race. Therefore lower rolling resistance

Rollers have a larger contact point and has a higher load rating vs a ball, but in regards to dia, the roller is rated to carry more

Yeah that small single contact point on our older light duty pickups is a big reason they moved away from using them on our LDT size axles and went with a roller on full and semi floating axles.

Fords F150 still has a 4800 rawr as tops for the HDPP trucks so no worries about the 3/4 ton going away anytime soon.
Edd505
Explorer
Dec 16, 2020
BurbMan wrote:
So a 6-lug full floater? One more step to making the 250 unnecessary...maybe the marketing guys are moving toward eliminating the 150/250/350 lineup and just having 2 models, light duty and super duty. Would that be a bad thing? Most folks post here that the only difference between the 250 and 350 is the rear spring pack.
Maybe they are building a F250 on a 150 body, so you have a F250.
FishOnOne
Nomad
Dec 16, 2020
I can't see a full floating axle in that picture.
BenK
Explorer
Dec 15, 2020
Agree with everyone and add :

The old 3/4 ton Suburbans (GMT400) had the same AAM axle assembly as the 1 ton dually of the same year. Only difference is in the leaf spring pack/hangers/brackets and the brake cyclinder/MC

Why parts counter will ask how wide your GMT400 3/4 ton Suburban has....there two and the difference is in the width of the shoes and drum. The wider shoe/drum also is a full floater rear end.

As for ball bearings vs rollers vs tapered rollers is that the balls have a smaller contact point with the race. Therefore lower rolling resistance

Rollers have a larger contact point and has a higher load rating vs a ball, but in regards to dia, the roller is rated to carry more

Tapered rollers has a much higher axial thrust load rating. Straight rollers almost none and balls has some.

Been advocating tossing the marketing nomenclature (1/2-3/4-1 ton, 150/250/350, 1500/2500/3500, etc) for years and just go with their GVWR. If they toss the 3/4 a step in the right direction, IMHO