differential replacement

[kipandbob]

Has anyone out there replaced a 3.73 differential with a 4.10, specifically in a F-250? If so, did you replace the entire housing, springs, etc? I don't know if the 4.10 guts would bolt into the 3.73 housing or if it'd cost more that way. Does the rear half of the U-joint mate up with the drive shaft?

Thanks again,
-Bob

[racerjoe]

It would be much cheaper to just replace the ring and pinion set,should not be any problem for a good dealer or a large transmission shop. The u-joint will not be an issue. One question, do you have a 2 wheel or four wheel drive ? then it is two changeout job. to answer your question you do not have to replace the whole assembly

[noneck]

As racerjoe says...if your DIY it needs to be carefully set for gear mesh via spacer insert else you get really bad diff whine.

[tbhd2]

This is not an easy job if you don't have the proper tools. The pinion,(input gear) has a "crush washer" that has to be torqued to massive amounts of torque, like somewhere between 250-300 pounds, When you put the yoke on. Then you need some super long large allen wrenches to set the torque on the ring gear bearings. You're better off to either replace the whole differential or have it done.

[Tom S.]

IIRC, Ford uses the same housing for the 4:11 as the 3:73, so swapping ring and pinion is the way to go. Have a qualified shop do the work for you. Setting gears isn't something for a DIY'er to do without someone knowledgeable looking over your shoulder. Remember, if you have 4 wheel drive, you have to do both front and rear axles. If you don't have a locking rear axle, this would be a great time to add one.

Labor cost vary so much, depending on where you live, but I would guess around $400 plus parts for the rear axle.

[JimF]

Ring, pinion and bearings are about 800, labor about 4 to 5 hundred, so there you have it, look for a replacement rear end or do the gear thing, take your pick. Lucky my labor is free, son is in that business, gears cost 550, didn't need the bearings. was cheaper to replace the gears for me.

[kipandbob]

Thanks much to all who replied. A wealth of info out there, as I've come to anticipate.

To answer "racerjoe's" question, yes, my 250 is 4x4. Thanks for that tip; I didn't think of that!

Cheers,
-Bob

[paddler67]

.
changed my 97 f-250 over to a 4.10 and was happy with the pulling power. i didn't see any change in the MPG which was a surprise to me. make a trip to AK. with good results.
happy traveling
gene