Rear end specs?

Hi,
Can someone tell me what type of rear end our econolines originally came with? Are they 7.25" or 7.5"? I've read both in different locations. I have a rear pinion seal that is leaking. What is the best place to buy replacement parts for these rear ends???

Has anyone replaced their pinion seal? Is it just a matter of removing the drive shaft yoke (marking location of retaining nut) and swapping seal? I also read somewhere that we need to go in through the back, remove differential cover and pull out the gears to replace pinion seal....YIKES!

I bet the shop manual explains the procedure.
I replaced one on a Chevy. It was fairly easy, but you do need the torque specs.

Some Econos came with 7" and some with 9" rears.

I believe the Peanut has a 7.25" ring gear. Am not sure how the driveshaft yoke separates from the pinion gear, but I believe that once the pinion nut is removed, you can remove the yoke, pry out and replace the seal, and replace the yoke.

61's" and maybe some 62's had 7". All the rest are 7-1/4" unless you have a 9". Perhaps your seal can be replaced but most all repairs require the removal of the rear and not to many people left that can fix them without wrecking them.
The 9" is the way to go if you can find one

I replaced the pinion seal in the kid's peanut differential by removing the nut, sliding the yoke off the pinion splines, popping out the old seal, replacing it with new, and reinstalling the yoke and nut. Marked the nut relative to the threads on the pinion, and tightened the nut back to that position.
Sealed up, but he took out 3 teeth on the ring gear and I went 9" anyhow....

Something about that nut. Are you saying it did not leak but then blew up? I have a spare 9" for me.

The new seal worked great... no leak. The kid decided to try a burnout a few weeks after and lightened the ring gear by 3 teeth, so I can't tell you long term how it worked.

The pinion gear is held in position by a one use only crush sleeve. Technically if you remove the nut you should replace the sleeve and readjust the pinion position - a significant job. If it were me I would pull the yoke fit the new seal, and use some permanant locktite on the nut. You don't want to tighten the nut beyond its original position or you will move the pinion out of position. I rebuilt my 7.25 rearend, all the parts were available online. I am trying to keep my van original so I kept the 7.25. They are a really funky design. Like most people already know, moving to the nine inch is the best way to go.

Thank you or the heads up on the crush sleeve. Providing that I position the nut to its original position, what am I risking by not replacing the crush sleeve? Again, for now my goal was only to stop the leak I have. Thanks

The sleeve is what is used to set the correct contact area of the pinion gear and the ring. In a rebuild, you tighten the nut, crushing the sleeve, until you have the right position between the ring and pinion. So its like an adjustable spacer. If you over tighten it the contact area won't be right and you'll get noise and premature wear. You can't just back it off because the spacer has been "crushed" so if you back it off, the pinion would be loose. I don't know if for a fact, but I would think that if you tightened the nut just snug and used loctite, it wouldn't crush the sleeve farther and the loctite would keep the nut on. I can't remember if you can get the sleeve out through the front or not, but if you could, I would think you could measure the length of the already crushed sleeve and make a non crushable spacer to replace it. Then you could just tighten the nut up.
Steve

The peanut isn't the best setup for lighting up the tires... not surprised it blew up. But yeah, if it's not properly torqued (which might be moot, because of the crush spacer and absence / presence of crud on the threads, it makes it harder to ensure you still have the proper depth on the pinion gear.

AND THEN if you go 9", it's best to get one from a donor Econoline so it requires no modifications (shortening axles and tubes, etc.).

I say replace the seal, try to match the depth of the pinion nut on the threads in hopes of not moving the pinion gear out of place, and don't bag on it. Try to get a 9" to rebuild and swap on later. 9" have more gear ratio choices anyway (Peanuts only had 3.5 and 4.0 to 1 IIRC, and the Falcon Six engines scream with the typical 4.0 which was most common at highway speeds).

The gears in the light-duty axle were 7" from '61 to '64 and 7.25" from '65 to '67.

The heavy-duty rear ends had either 8.75" or 9" gears from '63 to '67.

The tag on the rear axle should have a code that looks something like this. WCC-A

That code can tell you a lot of things about your rear axle and gears, including what parts are appropriate.

ALL of the big rear ends were 9"ers,, and the only way to go. You can swap out a third member on one in an hour if you are slow.
The correct way to replace a crush sleeve takes an inch pounds torque wrench. Once you over tighten the crush sleeve you have to put in a new one and try again. You slowly tighten the nut and then rotate the unit with the inch pound torque wrench which will give you the resistance torque, continue until you come up to specs. That sets it for you.
If the seal is leaking, consider that rear end was a weak rear axle when it was new, and after 50 years of use the pinion bearings are going to be pretty loose. If you put n a new seal, that may temporarily stop it, but if the pinion bearing and all is loose, it may not last very long.
This would be a very good time to seriously consider all the advantages to the 9" rear axle, perhaps better use of the money you are investing in the smaller and much inferior small axle. Also, one more benefit is the 9" has 2 1/2" wide shoes, versus 2" on both the small rear axle and the GENII rear axle. Our 9" backing plates and drums are highly sought after by the Mustangs crowd,,,
To rebuild the small rear end, you need to completely remove it from the truck and rebuild it on the bench.
Our 9" rear axle is commonly referred to as a "small Bearing" 9", with 28 splines. The GENII's third members are a direct swap but mostly in the 3:25, however a few at the better 3:50 for the small sixes. Please don't confuse the above as I was only talking about the third member and NOT the whole GENII rear axle assembly. Typically you can get a used third member for about $80 bucks now as the price as gone up a little lately, and as hard as they are to break not hard to find a good used third.

Vic

63 and 64 H/D's had a 9", as well as all the other H/D's.
The 63 and 64's used a special drive shaft, with a small front yoke and u-joint, and the larger 9" rear u-joint. That drive shaft is not easy to locate, HOWEVER you can swap output yokes on your tranny and make the swap easier that way.
ALSO,,, the 61 to 63 trucks used a single one piece e brake cable and the mounts for them are in a different location than the 64 to 67's,,SO, if you are swapping out to a later with the two e brake cables, its easier to also swap your small rear axle e brake cable and use it. The cables will interchange either way into either backing plate, and much easier than monkeying around with two also different e brake hdws...
vic