10.5 & 10.5 gears interchangeable... bearings too?

[ZeroOne]

Quick question about axles... and can't seem to find a straight answer. I'm in the middle of a 6 month fiasco on a gear swap and am trying to get to the bottom of why it can't be set up properly or not go through bearings in 4k miles.

It seems that when regearing a 10.5" axle, most companies use the ring and pinion from a 10.25 unless you go OEM. What about bearings? Do you also use a master install kit from a 10.25?

I got a Yukon 4.56 ring and pinion (from Randy's Ring & Pinon) that went into an F350, as they suggested (model F10.25-456). They also said to use the install/bearing kit from a 10.25 (model YK F10.25).

Can anyone tell me if this is the correct procedure?? Or should the bearings match the HOUSING because of the races (10.5) and not the gear set (10.25)?

It's been a pain since day one. Original installers had a hell of a time with fitment issues on the pinion. Got it to work, pinion worked loose somehow, took it to a second shop (because the first was 500mi away at the time) and they reset everything. 4k miles later, its failing again. This time it sounds like carrier bearings. Still in, and no call yet... so the verdict is still out.

[Dusten]

there is a yukon kit specifically for 08+ rear ends.... and there are three other kits for the 10.5 and only 1 for the 10.25, you are going to the wrong shops.
Auto Parts: YK F10.5-B - 10.5 FORD 2008 & UP MASTER OVERHAUL KIT (incl SIDE SHIMS ) .

[ZeroOne]

Originally Posted by Dusten

there is a yukon kit specifically for 08+ rear ends.... and there are three other kits for the 10.5 and only 1 for the 10.25, you are going to the wrong shops.
Auto Parts: YK F10.5-B - 10.5 FORD 2008 & UP MASTER OVERHAUL KIT (incl SIDE SHIMS ) .

Randy's is actually the one saying to use the 10.25 kit. Their take was, you're swapping to a 10.25 gear set, so you must use the 10.25 bearings, and that it will work in the 10.5 housing. Other people are starting to chime in on other forums who have done it and say the same... with slightly older trucks.

But I had the same question that you've just posted here... If the 10.5 can be split into pre/post 2008... then the "old way" of using the 10.25 swap might not be working on newer vehicles, since you'd need a special 10.25 kit for 2008+ vehicles... that doesn't even exist yet? Or will it ever? They don't even USE the 10.25 housing anymore, right?

It's starting to look like 08+ trucks will be limited to OEM style 10.5 ONLY, which would limit your gear choices. Hopefully someone who has regeared to a non-Ford ratio can chime in with their results.

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Last edited by ZeroOne : 01-06-2009 at 10:41 AM.

[Dusten]

correct, the 10.25 stopped in 97. Its the same housing, our diff dover even bolts on to theirs.

[ZeroOne]

About that noise I mentioned... it wasn't bearings I was hearing.

4k miles, NO abuse whatsoever, this is what happened. Normal stop and go, one 200mi highway trip.

[PGreenSVT]

That doesn't say much for Yukon gears.

[CobbsDieselPerformance]

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

[ZeroOne]

Originally Posted by PGreenSVT

That doesn't say much for Yukon gears.

To be fair to yukon, this 10.5 -> 10.25 gear swap that everyone else seems to do on previous model years never really fit the way it should have. The release of two separate 10.5 install kits (one for 2008-up) shows that there is in fact a real difference between pre and post 2008 setups.

With these 10.25 gears, the pinion never wanted to tighten. The second shop found a way, but in my opinion, at the expense of an acceptable wear pattern. I feel that the pinion is riding on the high outside edge of the ring gears drive side (possibly because the pinion is too far from the rings centerline after tightening it the only way they could). There may have been no other way because there is no 2008-up 10.25 kit.

Going to Ford 4.30's next, I think.

Look at the last photo I posted. You can see the upper, outer edge of the drive side's teeth being worn on in an odd way, on the teeth in the background. Almost as if the pinion is pulling on that edge to propel the truck.

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Last edited by ZeroOne : 01-14-2009 at 07:52 AM.

[CobbsDieselPerformance]

Yea, the wear pattern is terrible on that set of gears.

[stunya]

thats interesting...i had a set of yukon 4.56s (for 10.25 in a 10.5) in my 02 running 41 in tires and never had a problem in 50k miles...

so whats the difference then with the 08 housing?