The semi floating 10.25 in my 88 f250 has a lot of play in it. Replacing the rear end is a lot more cost effective than rebuilding it.

I know where I can get a full floating 10.25 from a '97 f250 HD pretty reasonably. I understand that would be a direct bolt in for my truck since the HD's are the same. I haven't measured the pads yet, or checked for play in it, but I know the full floaters are pretty durable and it should have the longer pinion so I am hopeful it will be ok. Both rearends are 3.55, I have antilock, not sure if the full float does or not but I'm not overly concerned about that. I believe it has the springs with it, but don't know for a fact.

So, question #1, am I correct in assuming it will bolt in?

and #2, if it does bolt in, is it just a matter of figuring out which ujoint I need?

Couple of related questions:

I have the mazda 5 speed trans and the aluminum driveshaft. I am guessing the mazda would never have been paired with the full float rear?

I looked online at ujoints and there are a lot of options so I'm hoping I can find one that works, but failing that could I possibly switch caps and bearings from two ujoints to make one that does work?

If anybody knows the answers to my questions I would certainly appreciate the response. Thanks.

 

Not much help, sorry, but maybe save you some headaches....... impish

 

When I swapped in a FF for the semi-floater in my F250, I had to use one of these 'conversion' u-joints for the axle end of the drive shaft. I've had no issues with it, I just went to a drive shaft shop, gave them the dimensions of the yoke on the FF axle and the dimensions of the stock u-joint, the guy came back in 2 minutes w/ the correct u-joint for me.

 

Impish, from what I can tell the f150s changed in the '97 production year, but the 250 & 350 HD's remained basically the same. I do not know this for a fact though, I have just picked it up from reading the forums here.

Also, when I go to carpart.com it lists the '97 250s and 350s when I search for my 88 and tell it I want a 3.55 with antilock. Carpart isn't an interchange by any means, but I have found it to be generally accurate in the past if you watch out for the misentered vehicles. Now that I think about it I can have the upullit run an interchange for me, wish I had thought of that a couple of days ago when I was there.

I can get whatever rims fit the rearend for nothing, or very little, but I will include if they fit or not if I get the rearend installed and update this.

Sorry, I should have said longer pinion gear. After reading a few references to this I hunted up a really good article on the differences between the years of the 10.25 sterling rearends and I believe in 93 or 94 they changed the internals of the rearends, and the rears from then til '97 are considered the best.

On the flange/yoke issue, I'm sure somebody will correct me if I'm wrong but I believe all the 10.25 sterlings are the ubolt type. I do know the 8.8 rears in 150s sometimes have a bolt on flange and sometimes the ubolt type. No clue why this is so, but I have seen both types.


firewood truck- thank you for the suggestion about a driveshaft shop. The one we used to go to around here has closed I believe. There is probably another one around somewhere. The good news is that you were able to find one that worked. I would rather not have to have a driveshaft made if I can avoid it.

I Thank you both for your input.

Now if I can just get the owner over to where the rearend is being stored so I can buy it.