Hello,

Have been doing a lot of research now that the time has come to rebuild the rear end and rework the drive shaft.

I have read that the 1985 F-250 had a short spline and this was identified as a weak area and it was recommended to go to a long spline.. I have identified a Yukon Ring and Pinion with the long spline, P/N YK F10.25-355L but have been unable to positively identify the associated Long spline pinion yoke I will also need (would like this upgraded to be able to use the 1350 U-Joints also). Can anyone advise. Its might be one of the Yukons also but am unsure which.

The same article (from June 2005 Four Wheeler magazine) stated it was also good to replace the Sterling 10.25 Two Spider gear arrangement with a three Spider Gear arrangement. They mention Custom Differentials as a shop knowledgeable in doing this but I have been unable to get a response from them.

Does anyone have any info on doing this and/or where I can get the necessary replacement kit that will work. I know its used on the 10.50 axle but I'm not sure that the three spider gear arrangement used on the 10.50 will work in the 10.25

Thanks for any info

Rgds

nonrev

 

I hadn't heard anything about it, and couldn't figure anything thing out in the catalog as there's no mention in the 80-89 catalog of a replacement pinion. Turns out, according to this write-up in FourWheeler, that the change came in '93, so I wouldn't see a new spindle in my catalog.

And, I'm assuming that's one of the things you are reading as it fits what you said. So, I can't help because we are reading the same things. Good luck.

 

That article overstates the 10.25's "issues" greatly.
If you are doing gears anyway I can see upgrading, but I would not tear apart a good axle to do it.
All 93+ axles have the long pinion. I have 93 factory gears and yoke in my wheeling rig's stock 86 axle.
The three pinion carrier is a 99+ 10.5 part, but it will go in a 10.25 just fine.
Again, the issues that article lays out are greatly overstated. Yes, the short pinon nut can come loose, one of mine did that, but as for the rest of it, I have never seen any of those issues mentioned without reference to that article.

 

Hi 82F100,

The truck has about 200K on it but has been well maintained. It used to pull a 5th wheel of some type as the mount is still in the bed. My wife and I intend on rebuilding this and pulling a travel trailer around for a few years to see America and Canada so I wanted to do a good rebuild job now and be pretty sure I wouldn't have any issues on the road.

So I can use a 3 spider setup from a 1993+ 10.50 and the Pinion yoke from the same and it will work / fit good on the 85 10.25 with no issues. is that right? Just want to confirm before I go out and spend some more $$$

Thanks

Rgds

nonrev

 

What's the setup you're thinking of going to cost? How's that compare to a Tru-trac at $559?

 

Hello,

Right now I have lined up the Yukon Ring & Pinion 3.55 Long spline set YK F10.25-355L, the Master overhaul kit YK F10.25 and the Detroit True-Trac model 915A550. Truthfully I'm not that familiar with the mechanics of differentials and am going a lot by what I'm reading is good to do.

I read that the modification to a 3 spider gear from the stock 2 spider gear is a good Mod BUT just today read another article that said that the benefits of this were overblown. So I'm thinking of dropping the spider gear/pinion modification to 3 spider gears and just going with the longer spline Mod.

Right now I have the longer spline of the ring and pinion set (above) but am having a hard time identifying the correct Yoke with the longer spline. I'd also like to go with a beefer U-Joint, maybe a 1350 (vs the 1330) so that's also something I'm not sure how I would accomplish. Any advise would be appreciated

 

If you're adding a Truetrac you'll be replacing the open diff carrier, which is where the spider gears are. So you won't be using either the 2 or 3 spider gears. That's only a consideration if you're staying with an open diff.

 

Thanks for the info. Shows how much I know about a differential.

Last thing to find now is the long spline Yoke that will also accommodate a beefer U-Joint (1350) and fit on the stock equipment

Thanks

 

Yeah, that's why I was asking about the cost of the conversion, it might be more cost effective to go with the tru-trac given it eliminates the spider gear weakness.

 

Any 92-97 460 or diesel truck will have the yoke you are looking for. Use say a 96 F350 with a 7.3 for an application if you are looking for a new one.
Most anywhere that can supply you with long spline gears will have the yoke available as well.

 

Thanks to everyone who assisted in setting me on the correct path

Rds

 

Got sick of breaking 1330 joints. I found a local shop and had then make me a new two piece shaft with 1350 joints. Was a bit under $700 and took a couple days. At minimum put a crush sleeve eliminator kit in the Sterling (9" kit from Summit fits with radusing the inside of thick spacer) or better yet get a long pinion gear set and long pinion yoke.

Bottom line 1330 joints have no business in a truck. Kinda wish I went 1410 as the 1350 joints wear quickly, though I haven't broken one.

 

Hi, Thanks for the info.

I did get a long pinion gear but having a bit of a hard time identifying a long pinion Yoke. Am still considering a new shaft as I also would like beefer U-Joints.

Thanks

 

Keep in mind that the U-joints need to fit the yoke on both sides. So to upsize the U-joint on the rear end of the 'shaft you neer a new pinion yoke as well as a new yoke on the drive shaft.

Same in the front. You'll need a new yoke on the rear of the transfer case. The exception to this is if your transfer case has a slip yoke. Then both U-joint yokes are part of the driveshaft. But I think an '85 would not have a slip yoke.

 

Who is going to be setting this up for you?

You do realize this is NOT as simple as just bolting this all together, right?