Max tire size for a Ford 8.8 rear axle???

[atomicjoe23]

What is the max tire size you would recommend running on a Ford 8.8 axle. . .let's say two scenario's:

Scenario 1: stock 8.8 from a '96 Ford Bronco

What is the weak point in the 8.8. . .i.e. what will break first from using large tires?

Scenario 2: upgraded 8.8 to remedy the weak point above.

Thanks!

 

[Ryabac18]

What gearing do you want to run? example 4.11, 4.55 etc thats a big factor. The bigger tire you are going to run the slower the acceleration so you have to factor in for that.

 

[isdtbower]

Vehicle use and weight and HP?? They have survived in some lite weight sand buggies with reasopnable paddles, but not much offroad or sand with weight.

 

[atomicjoe23]

1996 Ford Bronco. . .stock 5.8 engine; haven't thought about the gearing yet. . .figuring out gearing will happen after determining tire size so the two are complimentary.

 

[Ryabac18]

I know its kinda broad but here is a basic guide on what you can run at what tire size to run with what gearing in the rear end.
RPM vs. Gear Ratio and Tire Height

 

[isdtbower]

If you are thinking KOH like your other posts, a 8.8 won't work for any of it. Minimum is probably a 9" and built to accept 37-40" depending on class. $16k+ axles are not unusual. A $40K rig was a good number for the first couple years. Now, I doubt that is good for any competitive/finishing rig in any class.

 

[atomicjoe23]

isdtbower I won't be running in a KOH event ANY time soon, but with the '49 Willy's pick-up body I think that is the build direction I will be going. . .

. . .I've flip flopped about solid axle conversions back and forth so many times it's not even funny; wondering if it woudl be better to swap the D44HD front (Dana 60 would be better I know, but I don't have one right now)/GM 14-bolt rear that are under it now onto the Bronco chassis or keep the D44 TTB and go with a Ford 9' (like a TTB Ultra 4 car instead of A-arms). . .

. . .I think I need to get the body swap done first and foremost just so I can actually enjoy driving the thing for a little while before I sideline the project for even longer. After I get to enjoy the truck for a while I will upgrade the rear axle to a Ford 9" at the very least. . .what I ultimately do with the front end will determin what rear axle I end up going with.

 

[Josh 8]

8.8 are notoriously weak. I have blow the spiders gears out of one in a bronco doing some "mild" prerunning. swapped to a 9" out of an old pick up with 28 spline axels and it was way stronger. This axle had the old Edsel housing. Total junk yard find. I even preran the b1k with this axle setup once years ago. Of course I took it easy on it on it and ran about the same pace as i did with the 8.8 and it always got me back.

A few years back I built up a real 9" rear end using grand national parts from speedway engineering.

Any way, when I blew the 8.8 up it was a basically stock bronco with 35" tires and 3.55 gears. The spiders made holes in the back cover. They cant take any shock load.

 

[atomicjoe23]

Thanks for sharing!

 

[jon coleman]

What is the max tire size you would recommend running on a Ford 8.8 axle. . .let's say two scenario's:

Scenario 1: stock 8.8 from a '96 Ford Bronco

What is the weak point in the 8.8. . .i.e. what will break first from using large tires?

Scenario 2: upgraded 8.8 to remedy the weak point above.

Thanks!

ran one in stone stock, 35×12.50. not properly truss'd, 4.56 c6, ford gt 40 crate 400hp. ran perfect at parker but ate a r& p.stole one out of chase bronco & finished.bronco made it home fwd.still not truss quite right and didnt check axels 31spl after parker and broke axle at san felipe, then after driver swap, ( fixed first axl), second broke.in the nasty wash.dnf.8.8 set up right can work decent.its all in right foot & what part of earth u hit....

 

[jon coleman]

ran one in stone stock, 35×12.50. not properly truss'd, 4.56 c6, ford gt 40 crate 400hp. ran perfect at parker but ate a r& p.stole one out of chase bronco & finished.bronco made it home fwd.still not truss quite right and didnt check axels 31spl after parker and broke axle at san felipe, then after driver swap, ( fixed first axl), second broke.in the nasty wash.dnf.8.8 set up right can work decent.its all in right foot & what part of earth u hit....

junkyard hot find e ford van ,9", 31 spline, wider, big bearing& i believe big bearing housing, can go 35 spline max before after market housing

 

[atomicjoe23]

Thanks Jon Coleman!!!

 

[Travisfab]

The weak point (externally) is where the axle tubes slide into the cast center section.. Weld the tubes and more importantly, add the truss from Desolate. Internally, you have c clips to deal with, 31 spline axles, and the factory limited slips seem to just be ok. With a truss, and 35" or smaller tires, I would be totally comfortable in a mild prerunner.

 

[jon coleman]

The weak point (externally) is where the axle tubes slide into the cast center section.. Weld the tubes and more importantly, add the truss from Desolate. Internally, you have c clips to deal with, 31 spline axles, and the factory limited slips seem to just be ok. With a truss, and 35" or smaller tires, I would be totally comfortable in a mild prerunner.

also sleeve inside of axle tubes w- cro mo into center cast , roset weld in place, tie outer into big bearing cups and Ditch c clips!!!!!, they are outlawed here!!!!