22.5's on a F550

[B.Warning]

I'm looking to lower my rpm on the hwy. As of now I'm cruising at 70mph @ 2700rpm. I'm thinking of doing 22.5 with a 255/70 that measures out at 36.5"tall. Who makes a adapter for these trucks? Its a e99, iirc its a 8x200 but don't know for sure. Also I've heard there was a kit of some sort to give me a 2spd rear end. Anyone know about that? I'm not one to b!tch about mpg but 7mpg sucks out of a daily drivin rig.

Any advise?

 

[davey99ps]

What about a gear vendors od unit?

 

[B.Warning]

I thought about a gear vendor but the reliability of one has me concerned.

 

[qcfarmer]

You could probably swap gears to 4:10 for cheaper than rims and adapters, unless you want that look anyways.

 

[B.Warning]

They don't make 4:10 for this rear end. My only option is 4:30 and according to the math my mechanic did 4:30 will only drop my rpm by 250rpms at 70.

Can any body do the math for me and tell me the difference in rpm between a 225/70/19.5 and a 255/70/22.5?

 

[Demon]

Open up google, and type in gear ratio calculator.

Sent from my HTC Desire HD A9191 using Tapatalk 2

 

[jus10keith]

If I figured correctly, a 22.5 (36.5) is 1.14 times bigger than a 19.5 (31.9) Where 36.5/31.9=1.14...So your 2700@70 divided by that 1.14 should be your new RPM of 2368. That is just by going off of percentages.

 

[Zmann]

there is a calculator on this site

http://powerstrokearmy.com/forums/calc.php

 

[5fifty]

I'm looking to lower my rpm on the hwy. As of now I'm cruising at 70mph @ 2700rpm. I'm thinking of doing 22.5 with a 255/70 that measures out at 36.5"tall. Who makes a adapter for these trucks? Its a e99, iirc its a 8x200 but don't know for sure. Also I've heard there was a kit of some sort to give me a 2spd rear end. Anyone know about that? I'm not one to b!tch about mpg but 7mpg sucks out of a daily drivin rig.

Any advise?

Did you end up getting the 22.5's?
I am in the same boat and I am toying with the idea. My 19.5s are shot. Search for dominator 10x10 adapter s on Google. BThey make them for the 550's

 

[OldschoolPSD]

A local diesel mechanic has 22.5's with low rubber on his '08 F-550. His truck is heavy as hell and it still gets up and goes. He's got the 6 speed though.

 

[Corb@CorbinShipping]

I thought about a gear vendor but the reliability of one has me concerned.

If you tow heavy with it regularly, I would stay away form the GV. I almost installed one, and I'm satisfied that I did not...

Just keep in mind that tall of a tire, will lift the rig up a few inches, and possibly need a lift kit of sorts. And will not help your fuel mileage much. As there will def be more rolling resistance, and a taller front end catching more air than previous... But it WILL lower your rpms... LOL

You still have a dana 110 in the back of that rig, right? If so, Hallers did a swap for 3.73s..... And they have a parts list. But it is over 3 k..... Prob cheaper than 22.5s though... LOL

 

[fordfreak4life]

If you tow heavy with it regularly, I would stay away form the GV. I almost installed one, and I'm satisfied that I did not...

Just keep in mind that tall of a tire, will lift the rig up a few inches, and possibly need a lift kit of sorts. And will not help your fuel mileage much. As there will def be more rolling resistance, and a taller front end catching more air than previous... But it WILL lower your rpms... LOL

agreed on the gv I looked at that route for my dually, then heard about the failure rate n said f that

Sent while spinning 18 wheels

 

[B.Warning]

Did you end up getting the 22.5's?
I am in the same boat and I am toying with the idea. My 19.5s are shot. Search for dominator 10x10 adapter s on Google. BThey make them for the 550's

I haven't done anything yet, I'm debating on keeping the truck or not and have a lot of others things going on to worry about a little rpm change and fuel mileage.

A local diesel mechanic has 22.5's with low rubber on his '08 F-550. His truck is heavy as hell and it still gets up and goes. He's got the 6 speed though.

Yea mine is a 6spd also. The tires ate your typical low pro 255/70/22.5. Around me they're a dime a dozen and easy to find used everywhere.

If you tow heavy with it regularly, I would stay away form the GV. I almost installed one, and I'm satisfied that I did not...

Just keep in mind that tall of a tire, will lift the rig up a few inches, and possibly need a lift kit of sorts. And will not help your fuel mileage much. As there will def be more rolling resistance, and a taller front end catching more air than previous... But it WILL lower your rpms... LOL

You still have a dana 110 in the back of that rig, right? If so, Hallers did a swap for 3.73s..... And they have a parts list. But it is over 3 k..... Prob cheaper than 22.5s though... LOL

That was my concern corb, I wasn't sure about the gv and I'm found of simplicity. Adding pretty much another trans on it I was leery of.

The truck actually sits higher than a stock 4x4 f350 dually so I knew they'd fit without a lift. I've ran several sets of 22.5's before and they usually lift the trucks roughly 3"by themselves.

I'm still running the d110 and plan on keeping it. On my work trucks I'm kinda hard on axles with the weights I tow. I thought about a gear swap but with my access to wheels, and tires I opted out of it. I can run 22.5's including adapters for less than $2k.

I need to get that axle you brought me installed and everything swapped over on my kr. Is still sitting in the same spot we dropped it. I'll go ahead and blame you too for me wanting a new truck after seeing yours and jareds truck up close. There is a reason why I stay far away from the Ford dealer. LOL

 

[Corb@CorbinShipping]

I haven't done anything yet, I'm debating on keeping the truck or not and have a lot of others things going on to worry about a little rpm change and fuel mileage.

Yea mine is a 6spd also. The tires ate your typical low pro 255/70/22.5. Around me they're a dime a dozen and easy to find used everywhere.


That was my concern corb, I wasn't sure about the gv and I'm found of simplicity. Adding pretty much another trans on it I was leery of.

The truck actually sits higher than a stock 4x4 f350 dually so I knew they'd fit without a lift. I've ran several sets of 22.5's before and they usually lift the trucks roughly 3"by themselves.

I'm still running the d110 and plan on keeping it. On my work trucks I'm kinda hard on axles with the weights I tow. I thought about a gear swap but with my access to wheels, and tires I opted out of it. I can run 22.5's including adapters for less than $2k.

I need to get that axle you brought me installed and everything swapped over on my kr. Is still sitting in the same spot we dropped it. I'll go ahead and blame you too for me wanting a new truck after seeing yours and jareds truck up close. There is a reason why I stay far away from the Ford dealer. LOL

LOL Right on... I accept full responsibility... And if you can get 22.5s like that, then hit it up!