'69 F100 with 9" and I broke the rear driver side axle hauling a load of dirt. I don't have it apart yet, so I don't know where it broke. I have a '78 F150 parts truck that has a complete rear-end, not sure if it's a 9" or not. If it's a 9" on the '78, will the driver side axle be the same length and "bolt-in"? If not, can I just swap the whole rear?
I had planned at some point to get a limited slip (Trac-Loc) installed one day, so maybe this is my opportunity to do so. But which rear-end?

edit: I don't know what gearing either of them have...

edit 2: I think I'll buy my grandpa's lifted '89 F350 Custom Dually with a 460 for my future dirt hauling for $1,500.

 

Remove and replace the axle. Bumps are typically a dime per dozen in the yards. I'd simply head to the yard and do the R & R.

IIRC, a 78 has different perch widths plus it has 31-spline axles. A 69 will typically have 28-spline axles.

 

As long as the spline count is the same, lenght should be good. If the old one has 28 spline, you could change the differential and both axles, which would be a good upgread to the stronger axles. The gearing may change, that would be the only thing to consider.

 

I think the 78 trucks had a wider rear axle. They widened it either in 73 or 75 to come closer to matching the wide twin I beam front end.
The axle assembly from the 78 should fit under it, moving perches isn't a big deal on the rear axles.

 

I have a Dana 60 out of my 67 F250 sitting here with I believe the tag said 3.73 Ratio but I'm at work right now so could check later,, I'm in Vacaville about 30 miles or so west of you

 

^ ^ An F250 uses a Dana 60 rear axle ^ ^ No F250 has the same axle ratios as a 9 inch. ^ ^

Be aware that there were two different 9" rear axles used in 1968/72 F100's.

One has 28 spline axleshafts, the other has 31 spline axleshafts.

31 splines: Even though classified as a 9 inch, this rear axle has a 9 3/8" ring gear and Traction-Lok.

Only 5 internal parts are the same as a 9 inch: Housing gasket, pinion seal, pilot bearing retainer, one pinion bearing and race.

EVERYTHING else is different including the axle seals.

1973/79 F100's & 1975/79 F150's have 37 1/2" wide rear frame rails (behind the cab). 1972 and earlier F100's have 33 1/2" frame rails.

Some 1973/79 9's have 28 spline axleshafts, some have 31 spline axleshafts as it depended on the applications.

Some 1974/79's have an axle seal/bearing combination, some have the same setup at 1957/73's, separate bearing and seal, and...

Some 1977/79 F100/150's have Dana 44 rear axles with 2.73-1 & 3.00-1 ratios. Ford installed these in an effort to improve fuel economy after the first Arab Oil Embargo ended in 1974.

btw: The most common rear axle ratio used 1965/72 was 3.25-1. 1966/72 F100 = If the AXLE code on the Warranty plate is 17 = 3.25-1 w/o Limited Slip.

 

Confirmed the tag reads 3.73 thats all I know except I took it out because I have a Dana 70 I put in.

 

Well, the same thing just happened to me 2 weeks ago, and I followed Number Dummy's lead on this one and took what I needed from a 72 f100 so that the width of the rear end, length of the axle and spline count would work.

I think that the cheapest route would have been to just simply swap out axles from a donor truck at the U pull it, but in my case I gouged the housing as well so any bearings would not have seated properly. So I needed the whole thing anyway.

I went to the junk yard and the price for a COMPLETE ford 9" rear with both axles and both drums included was $160, while just one axle would have been $110. It was a bit more work but I found a donor truck with a 9" and took the whole thing off and swapped it with my original.

Listen to Number Dummy's post - especially about the 9" rears that will fit on your truck. I pulled mine from a 72 and it was exactly the same. Of course, you need to pull out your own axle, count the splines on it to see what you have and then make sure that correct one is on the donor truck.

I thought it was going to be a big deal, but it was actually quite simple. I replaced the bearings and seals on both axles of the junk yard unit, and cleaned out the differential and put in new gear oil. It runs great now.

Oh, I found the tags on the diff that gave me the gear ratio, but I hear that you can't rely on that. When I had the diff out, I counted the teeth on the big gear and then counted the teeth on the little gear to get the ratio from that. So cool what you can learn to do on this forum.

Hope this helps,

andrew

 

Thanks guys. I don't think I'll swap the complete rear-ends now (thanks Numberdummy) because of the frame widths. I know my truck doesn't have Trac-Loc, and I can only assume that my Grandpa didn't put a different rear-end on it. So I should be able to go find a 28 spline at Pick-n-Pull and just swap the new axle in. My truck is parked about 60 miles away, so I can't verify the spline count now...argh. But, I can always trade the axle for a 31 spline if I get the wrong one. I think the axle will be $55.

 

Well, turns out it was only $48. Pretty quick trip to the pick-n-pull and now I have a 28 spline from a '69. Spent half my time there just trying to find a suitable dang truck!

 

Congrats.

Pick N Pull (a division of Schnitzer Steel) is awesome. Their website lets ya check the inventory AND they post their prices online so you know what yer gonna pay.

There used to be a yard in Pittsburg (CA) called JM Autowrecking. The obese guy behind the counter was a total A-hole and would ask exorbitant prices if ya looked square at him and then he'd turn around and charge the next guy less for dang near the same part like a tail light lense. He got arrested and the place eventually shut down. He was apparently dealing with chop shops and got what he deserved.

Anyhow, my kudos to Pick N Pulls everywhere... organized, up-front, and professional as professional wrecking yard can be.

 

Well hell, turns out the axle isn't broken after all. The retainer ring just came loose and let the axle slide out, anyone ever had that happen? Since I didn't have a press near me I was just going to use the axle and bearing I pulled yesterday, but when I try and insert it about 1/2" or so of the bearing hangs out of the axle. It's like the axle is too long or the bearing is pushed too far onto the axle. What gives? The axles appear to be the exact size, I'm stumped. The only difference between the two axles appears to be the retainer plate.

 

I was wondering that when I first read your post. I have squirted a few axles in my time but never broken one, then I started watching for it. It always happened to me going slow on my ROUGH WASHBOARD dirt road, with a load of water in my truck (I hauled water till I could afford a well). Wore out a few axles this way, the retainer wouldn't hold anymore after a while. Put Currie axles in it and never had a problem again.
I've heard of some accidents from axles coming out at high speed.

 

I put a little grease on the end of the new axle and then tried to install it as far as it would go. When I pulled it out it was obvious that the end of the axle reaches as far as possible because the grease was smeared around. So that means the difference in the axles must be on the bearing side.
The original axle has a little shoulder that looks like it sits flush with the bearing. I've not taken the donor axle bearing off yet but maybe this little shoulder is the difference? Ring any bells for anyone?
I'm thinking now that I can clean up the old axle and use a center punch around the shaft to make the bearing and retainer ring sit tighter and put it back on. The bearing can be pounded on with a long rod right? How about the retainer ring? Does that have to be heated or can it be pounded on too?

 

I should re-title this thread to "Stories of the inept mechanic" sheesh. Turns out the axles were pretty much the same the whole time and both were seating properly...the 3/8" of bearing that was hanging out of the axle housing was for the BRAKE DRUM! Doh! Man did I feel like an idiot after finally noticing that. So the truck is back together now and was running fine until I decided to fix an oil leak from the valve covers...new thread from the inept mechanic forthcoming...