10.5 & 10.5 gears interchangeable... bearings too?

[ZeroOne]

Originally Posted by Live2Crawl

So what rear end do I actually have a 10.50 or a 10.25?

I'm assuming its an 09 F350, single rear wheel. It's a 10.5. They all are now. The only difference between a 10.5 and a 10.25 is the gears and bearings.

4.56 gears are only made in the 10.25 type, which has more ratios to choose from.

10.5 ratios are 3.55, 3.73, 4.30, and possibly 4.88.

When you do this gear swap, it is essentially a conversion to a 10.25 axle since the only difference are gears and bearings. For years people have done this with no issue. From '08-on, there is a slight change in something (possibly the housing) that requires the use of a pinion spacer. If you go onto a website like Randy's Ring and Pinion and search by differential to find the installation kits, you'll see that the 10.5 has been split into pre / post '08 axles. This reflects the change in pinion setup. The 10.25 kit that you got needed to be updated for '08 and up. There is no 10.25 kit listed for '08-up on Randy's but if you call them, they will get the correct parts together for you. It may be possible for you to just get the spacer itself to add to the kit you already have.

[stunya]

zeroone...thanks for the input and advice...one question maybe you can answer...

if i get a FORD 4.30 ratio for my rig, will aftermarket lockers work with that gearset? or are they specifically designed for the 10.25? or does it not matter either way?

Thanks for the guidance...we will all grow from your issues!!

thanks!

[ZeroOne]

Originally Posted by stunya

zeroone...thanks for the input and advice...one question maybe you can answer...

if i get a FORD 4.30 ratio for my rig, will aftermarket lockers work with that gearset? or are they specifically designed for the 10.25? or does it not matter either way?

Thanks for the guidance...we will all grow from your issues!!

thanks!

The carrier (locker) should work with either gear set, but watch out for your specific truck model.

The ring gears for both 10.5 and 10.25 gears both fit on the same carriers. The only difference between the 2 rings is the 1/4" in height, but the carrier bearings are the same, if I recall, since the gear swap really doesn't even effect the carrier itself. The issues I had were with pinion bearings, which ARE different, since the pinion directly mounts into the housing (unlike the ring just riding on the stock carrier).

Your truck type makes it more difficult to select a locker. F350 srw trucks have a 37 spline axle shaft, where the F250 has a 35 spline. (I will double check that but am 99% sure that is accurate.) Something to keep in mind when trying to find a locker. I thought I remembered people having more limited selection because of the spline difference.

EDIT:
Just looked up the info in a pdf...
Both Ford/Visteon 10.5" rear axles

F250 SRW rear axle:
spline minor dia. 1.36"
spline major dia. 1.5"
no. of splines (hub end) 35

F350 SRW rear axle:
spline minor dia. 1.50"
spline major dia. 1.57"
no. of splines (hub end) 37

The difference is listed as "hub end" for the spline count so I'm really not sure if that affects the carrier. There is also a size difference listed for the axle shaft as a whole and in the splined section. If that size difference is also on the carrier end, you'd definitely need an F350 specific carrier if that is which type of truck you have, since the splines slide into the carrier.

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Last edited by ZeroOne : 02-18-2009 at 03:06 PM.

[stunya]

i had heard the same thing about the 37 spline count. im not even sure who is making lockers for this setup yet. Glad to have the bigger axles, but sucks to not have aftermarket support yet...

guess i really need to find out if it is hub side or carrier side before i complain though...im sure someone on here can answer that!

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Last edited by stunya : 02-18-2009 at 04:10 PM.

[ZeroOne]

Everything I'm finding says that nobody makes a locker for the newer style 05-up 37 splined F350's yet. The only option may be either the factory LS or to get an open factory carrier and weld it up.

[justinbaldwin69]

Originally Posted by CobbsDieselPerformance

Motive makes Ford 10.5" Gear Sets I can get them as well..........

i need a set of 456s for a 2003 f250 7.3 front and rear and i want to get limited slips for the front and rear,right now i have 373s with open diffs,
my truck has 50000 miles on it do you think i would need complete install kits or just shims,since my truck doesnt have that many miles on it
can you give me a price on every thing i need shipped to 26164

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Last edited by justinbaldwin69 : 02-25-2009 at 06:39 PM.

[Live2Crawl]

WEll its been 2 weeks, the rear is finally done, but motive sent me the wrong front pinion... Motive gear has been awful.... i would not recommend getting gears from them. I have re geared 15 different trucks, and between the combination of these retarded ford differentials and motive gear it has been an udder nightmare!!!!!!! Ford needs to smartin up on these diffs and motive needs to ship the correct parts!! my .2 cents