Bronco II rear axle is wider than a Ranger axle

[franklin2]

Found this out the hard way. Kept finding the pass side axle shaft is longer, but nothing is said about the complete axle is wider, including the spring perch mounting. I finally found on another site an obscure note that the Bronco II axle flange to flange is 1 1/4 inches wider than a ranger axle.

Pressing forward anyway, I forced the ranger axle to fit, taking a come-along and pulling the leaf springs together till things lined up. It looked to be about 1/2 inch on both sides. Now both leaf springs have a slight twist to them, I am going to see how it rides after I get it all together. If I have to cut the perches off and move them in, I will.

 

[RonD]

Thanks for the heads up

So this is wrong: https://therangerstation.com/tech_library/Ford-7_5-axle.shtml

"The right side Bronco II axle shaft is 1-5/8" wider than the 1983-1992 Ranger shaft. All of this additional width is on the passenger side. The drivers side shaft is the same length in either axle assembly. "

So over all width would have to wider but just on passenger side, by 1-58"

The spring perch is listed as wider on the B2 in the above link, Ranger 38.5", B2 40.5"

 

[franklin2]

In my google searching I never found that chart. I probably would have missed it anyway if I had found it. I would have thought even though the axle was a different width, the frame certainly would have been the same width as the ranger along with the springs and perch to perch distance. I wonder why they made it different?

I also found out the springs are totally different. The 84 Bronco I have has many leaves stacked together, and it's not a progressive spring. And the spring pack sits right on the axle perch with a short u-bolt. The ranger has just a few leaves, and it is a progressive spring pack with a few curved leaves on top and a thick straight leaf on the bottom. And right below the spring pack is a very tall spacer block with the arm that contacts the rubber bumper, and it has very long u-bolts that mount all this and the block to the axle.

 

[adsm08]

This is actually documented information. The total axle width I believe is the same, or close, but the frame of a Ranger is tapered into a slight V, while the B2 and Explorers are straight. This puts the spring perches in the wrong spots.

I have an FX4-L2 axle for my B2 waiting for the spring perches to get moved.

 

[franklin2]

If I hook my tape measure on one backing plate and measure to the other, the overall width is wider also on the Bronco axle. About 1.5 inches. Your link above has the perches 2 inches wider which may be true, it's difficult to get a accurate measurement perch to perch on the axle with the pumpkin in the way. I was afraid my tires may rub the leaf springs, since the overall ranger width is more narrow and I am using the wider perch distance of the Bronco, but hopefully I will be ok. From the backing plate to the perch, there is slightly over 1/4 inch less room.

If I run into problems I will have to move the perches also. I was eyeballing the trailer perches that tractor supply sells. They sell 3 inch ones which from my reading are too large, but they do sell a smaller diameter set also. Not sure if they would be close enough to work.

 

[BlackBII]

I have a Bronco II axle in my ranger and I had to cut off the spring perches and weld on news ones. I don't recall which side was wider but it was definitely off center.

Make sure you set the pinion angle when you weld on the new ones.

 

[franklin2]

It was pretty much 1/2-3/4" off on both sides. I got it going today, everything hooked back up. Forcing the springs didn't seem to hurt anything, but you are right, the pinion angle is too low. I get a vibration right after take off, and a pretty bad vibration slowing down. I am thinking it's a little less when accelerating because the pinion will naturally rise a little bit applying all that power from the 2.8 .

I normally could shim it to get the pinion angle, but I can't the way I have the springs forced over. I have the centering pins in the holes in the perches, and then the whole thing clamped tight, I can't loosen it a put a shim in there without the whole thing getting out of wack.

So last night I went by tractor supply and bought some spring perches for a trailer. They sell some that are too small and some that are too large, the axle we have is slightly less than 3 inches. So I bought the 3 inch perches, I think I can use a grinder to make them fit a little better. Or just fill them a little bit with weld if the fit is not too far off. The tractor supply ones are also not as wide as the original perches, but I don't see why they will not still work. I figure when I take the torch to the old ones they will be basically destroyed.

I plan on letting the springs relax to their home position, measure and center the axle side to side, and then snug the new perches and u-bolts down without welding. Put the tires on, put the weight down on the whole thing, and then get my angle finder and a hydraulic jack, and jack up on the nose of the rearend till I get about 9-10 degrees up on it. That seemed to be what the old one was, and what the manual calls for. It almost puts the nose of the rearend inline with the driveshaft. Once I get that I can weld it in place. I found out putting the weight of the vehicle down on the springs really changes the angle of the pinion.

 

[alwaysFlOoReD]

I made some 1/4" plates that centered the axle on the original perches. I was going ranger axle into b2. It was still going strong when I sold it a couple years later. One of the u-bolts went thru holes I drilled in the plate. The plate was tacked to the old spring perch. Its in one of my b2 build threads. Is provide a link bit I'm on my phone and its too hard to find stuff.

 

[franklin2]

I made some 1/4" plates that centered the axle on the original perches. I was going ranger axle into b2. It was still going strong when I sold it a couple years later. One of the u-bolts went thru holes I drilled in the plate. The plate was tacked to the old spring perch. Its in one of my b2 build threads. Is provide a link bit I'm on my phone and its too hard to find stuff.

With the adapter plates, you did not have any problems with pinion angle? Or you incorporated that into your plates? That is the only problem I have really, the pinion angle. That is forcing me to redo it the right way and weld on new perches to the axle.

 

[alwaysFlOoReD]

I never noticed any problems. The pinion angle was whatever the factory had used. The plates did nothing to change the angle. Unless you have a double c ardan joint the centerlines of the pinion and the trans should be parallel. The ranger axle was from an 87 STX HiRider. It happened to have the correct 4.10 gear ratio to match the front.

 

[franklin2]

I am thinking most Bronco II's had the double cardan, or I have a factory 86 manual and they have some sort of CV joint up near the transfer case. Mine has the double cardan joint. The factory manual calls for approx 9 degrees tilt up on the Bronco pumpkin. I can't remember, but I think the ranger was around 3 degrees upward tilt. I am wondering if all that tilt sped up the failure of the original axle? It's going to be more difficult for those pinion bearings to be properly lubed tilted up high like that. After I get it done I am going to top the oil level off and hope for the best.

P.S. I see the parts stores sell a replacement conventional driveshaft with regular u-joints on each end. I don't see how that would work when one, the original was setup for the double cardan and two, the driveshaft angles would be awfully steep for a conventional shaft. I have a f250 with a 4 inch lift, and always had a vibration in 4x4. I finally got enough parts together to convert the front shaft on it to the double cardan shaft used on the dana 60 frontend on the f350, and it cured the vibration problem on it. So right now I am a believer in double cardan joints.

 

[BlackBII]

Are you going to be using a double cardan? If so, you want the single u-joint at the pinion end to be at 0 degrees(1-2 degrees lower to account for axle wrap), so the pinion will be pointing directly at the transfer case, where the double u-joint end will be.

https://www.therangerstation.com/tech_library/pinionangles.shtml

 

[franklin2]

Yes, I am going to be using the double cardan shaft. You are correct, when you set the rearend to point up about 9-10 degrees from level, it is pretty much pointing inline with the shaft like your picture. I don't have that now with the ranger rearend and I get a vibration at a certain road speed.

I am in the middle of changing this right now, getting ready to cut the factory perches off the housing. I just tried the 3 inch trailer perches that I got from Tractor Supply and they fit the housing to perfection. I don't know where someone's wires got crossed, Tractor supply says they are for a 3 inch trailer axle, and the ranger rearend is supposed to be smaller than 3 inch. I am too busy to figure it out, but I quickly plopped them up on the axle and the fit is excellent. They are a little narrow though. I will have a little overhang on either side of the spring. I don't see that being a problem.