rear ends

1

12cliff23

Member
Merry Christmas all
I was at a friends house looking at his f1. he is thinking of putting a 9" ford in.
I have 2 setting around and was telling him I thought the axle housings were a different length on each side, making the yolk off center. are all 9" like this?
and if so why?

thanks Cliff
 
On most early 9 inch rears the right side tube is approximately 2 inches longer than the left to center the pinion. There are so many versions of the 9 inch it could be anything? On the 9 inch rears I use in my chassis business the tubes are equal to center the housing which puts the pinion 2 inches to the right. I've done many many 100's of rears this way over the years with no problems.
 
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just looked at mine and the drivers side is 2" longer and the yolk is off center to the pass. side? you can't put the punkpkin in upside down can you? if he centers the yolk the driver side is 8" outside the spring an the and the pass. side is about 5". there maybe something real obvious and I just can't see it.
 
hi; Wow! Since 1957 the 9" Ford has been built this way. A custom built housing will center the yoke. Lots of good articles over the years on this. HAMB and Magazines. Currie enterprises now among others build them. Newc
 
They worked just fine offset in the original cars and trucks. Install it and forget about it if the width is ok. Gary
 
The 9" is a very good axle, with plenty of gear selections. Unfortunately it's expensive, very heavy. Ride quality suffers, and there's not much you can do about it. So opt for the 8", but it's not much lighter and has the 5 on 4 1/2 wheel pattern. (except for the early Bronco) Gear selection is limited and expensive. An inexpensive alternative is the Jeep Grand Cherokee dana/spicer 44a with 3.73, very inexpensive right now.
 
If it has a Dana 44, I wouldn't even think about changing it. The Dana 44 has been around for many years and parts are available for it. If it has a Dana 41, I would only look for a Dana 44 after it gives up the goat. Changing a rear axle for a different model is a lot of work so I would carefully consider all options before going that route.
 
Centering a 9" differential housing results in the pinion being offset by only 15/16". The axle tubes will be about 2" different in length.
Most production vehicles with offset pinions also offset the engine/trans an equal amount. But if there are both horizontal and vertical pinion offsets with the engine/trans, the angles have to be calculated to obtain a true u-joint working angle.
 
I'm with Ol' Ron on this one. The 8" is the easiest swap. Plus the 9" will eat up about 10% of your horse power due to size and weight. That's a pretty good loss on a flathead.
 
flathead4rd said:
I'm with Ol' Ron on this one. The 8" is the easiest swap. Plus the 9" will eat up about 10% of your horse power due to size and weight. That's a pretty good loss on a flathead.
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The Ford 9-inch locates its pinion gear lower on the ring gear to improve tooth contact. This strengthens the rearend assembly but at the cost of approximately 2 to 3 percent loss of power to drive the gears compared to a 12-bolt. It has nothing to do with size and weight. I'd say 10% is a stretch. DD
 
Ol' Ron said:
The 9" is a very good axle, with plenty of gear selections. Unfortunately it's expensive, very heavy. Ride quality suffers, and there's not much you can do about it. So opt for the 8", but it's not much lighter and has the 5 on 4 1/2 wheel pattern. (except for the early Bronco) Gear selection is limited and expensive. An inexpensive alternative is the Jeep Grand Cherokee dana/spicer 44a with 3.73, very inexpensive right now.
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Every early Bronco I've owned ('67, '69, 2 '71's and a '74) all had 9" rear axles. Some were small axle bearings and some large bearing housing ends, but all were 9".
 
thanks all, a great learning experience for both of us.
he is just getting started on the truck. he was planning on a lot of changes till he read some of the barn posts about originality on the old stuff. now I think he is rethinking a lot.
cliff
 
I installed a early Bronco 9" under a 48 F1. Other then relocating the spring perches it was a bolt in. Even used the Bronco emergency cables.
 
I was referring to the 8" which doesn't have the 5 on 5 1/2 bolt pattern, except for some Bronco units. So I've been told.
 
i read a couple of years ago that the some ford vans 9" had the yoke in the center & the 5x 5 1/2 bolt axle. don,t know for sure
 
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