Another 31 Spline Axle Interchange Question
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Fleet Mechanic
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From: MA
Another 31 Spline Axle Interchange Question
So I was at the junkyard today. My 79 F100 has 28 spline axles (found that out after pulling one). Went on the hunt for some 31 spliners. 4x4s with dana's don't help me, I pulled one from a 78 Bronco that was alllll wet, and the nut/stud size on the axle retaining flange was larger than my truck.
Also pulled one from a van.. idk, 75-91? Big van. It used a very odd wheel bearing setup, almost like a tapered bearing for the front spindles.. My truck uses a one piece sealed style bearing.
What else can I look in? He has some 80s trucks, I didn't go digging in those for fear of running into that bearing setup again.
Do early/mid 80s F trucks use 9" rears still, and will they have the proper bearing I need?
Also pulled one from a van.. idk, 75-91? Big van. It used a very odd wheel bearing setup, almost like a tapered bearing for the front spindles.. My truck uses a one piece sealed style bearing.
What else can I look in? He has some 80s trucks, I didn't go digging in those for fear of running into that bearing setup again.
Do early/mid 80s F trucks use 9" rears still, and will they have the proper bearing I need?
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The van had a "full floater" axle. It's the same on many heavy trucks...the axle is independent of the hub. The Ford 9" was not a very HD setup. I blew mine some time back and all that could be salvaged was the axle housing and axles. Carrier, diff and all gears went south. Salvaged a 28 spline from a police cruiser but needed a 31. Lucked out when I found a guy with a car who had a 31 spline but needed a 28 spline...we did a straight swap.
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From: Bison SD
Why are you wanting to go to 31 spline? I run 28 spline and 31 spline in race cars and they both work as well as the other. An axle is an axle so if your hold up is the bearing then just go to parts store and get bearings for your application. Make sure you measure the length of your axles and compare to the axles you find. Lots of different lengths also long and short sides usually sometimes they are both the same length though. 9 inch are a good rear end for durability.
Luke
Luke
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Fleet Mechanic
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From: MA
Perhaps because I swore this truck had 31 splines and got a center section built for 31 spline. Imagine my delight when I came up 3 short. I'm still going to have to get axles/bearings/have them pressed on.
So I'm looking to bypass all that. Jegs has axles that are listed as 74-86 F150/E150. I'll check the later trucks I suppose.
So I'm looking to bypass all that. Jegs has axles that are listed as 74-86 F150/E150. I'll check the later trucks I suppose.
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From: Bison SD
Some of the LTD s and Gran Marquis had the 31 spline axles in them if you could find a lincoln you could even update to disc brakes. Axle length will be the hardest to match up. It is funny that a pickup has the 28 spline axles most had the 31 spline as you assumed. Is your bolt pattern the 5 on 5 i assume other options are 5 on 5 1/2 4x4 and 5 on 4 1/2 most cars. Good Luck
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Fleet Mechanic
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From: MA
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Fleet Mechanic
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From: MA
Just a thought... rather than hunting axles.. I could just swap entire housings from say, that van, no? I'd assume that the full floater setup is a little more durable?
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From: Southern Delaware
the 31 spline axles use different bearings. they are tapered. the 28 spline axles use a sealed/ball bearing type. You have to install the race into the housing and should get new seals pressed on with the bearings.
Butt-Head
Joined: Apr 2004
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From: Reed Point, MT
Axles from a full-size half ton van won't work either. 31 spline or not, they are longer. 
I had a perfect rear axle out of an 83 van (9" 31 spline) with 30K miles. The axle splines were in perfect condition and I wanted to put them in my 77 F150 rear.....no go. The bolt-on flanges wouldn't go in that last 3/4".
Oh and as far as 9" axles go (28 vs. 31 spline), a drag racer friend of mine used to do some pretty strange experiments. He switched from 28 to 31 spline and couldn't figure out why he kept breaking axle shafts afterwards so he painted straight lines down the length of the shafts and ran them a few races......
The 28 spline axles showed signs of twisting (as the painted lines were no longer straight). The 31 spline shafts always snapped at the end of the splines (smallest axle diameter). He came to the conclusion that since the 28 spline shafts had a smaller diameter all the way down the shaft, that they twisted and absorbed the shock loading during launches and therefore saved the shafts.
I had a perfect rear axle out of an 83 van (9" 31 spline) with 30K miles. The axle splines were in perfect condition and I wanted to put them in my 77 F150 rear.....no go. The bolt-on flanges wouldn't go in that last 3/4".
Oh and as far as 9" axles go (28 vs. 31 spline), a drag racer friend of mine used to do some pretty strange experiments. He switched from 28 to 31 spline and couldn't figure out why he kept breaking axle shafts afterwards so he painted straight lines down the length of the shafts and ran them a few races......
The 28 spline axles showed signs of twisting (as the painted lines were no longer straight). The 31 spline shafts always snapped at the end of the splines (smallest axle diameter). He came to the conclusion that since the 28 spline shafts had a smaller diameter all the way down the shaft, that they twisted and absorbed the shock loading during launches and therefore saved the shafts.
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Fleet Mechanic
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From: MA
Originally Posted by cleatus12r
Axles from a full-size half ton van won't work either. 31 spline or not, they are longer.
I had a perfect rear axle out of an 83 van (9" 31 spline) with 30K miles. The axle splines were in perfect condition and I wanted to put them in my 77 F150 rear.....no go. The bolt-on flanges wouldn't go in that last 3/4".
I had a perfect rear axle out of an 83 van (9" 31 spline) with 30K miles. The axle splines were in perfect condition and I wanted to put them in my 77 F150 rear.....no go. The bolt-on flanges wouldn't go in that last 3/4".
I wonder if the housings themselves interchange?
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Fleet Mechanic
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From: MA
So.. some research came up with this..
Regardless of year, 28 spline axles had the cylindrical style sealed bearing 31 spline axles had the tapered bearing.
SO.. knowing this information...
What rear axle housing assembly will swap in and allow me to use my springs?
The van I found? a 78/79 Bronco?
Help is needed!
Regardless of year, 28 spline axles had the cylindrical style sealed bearing 31 spline axles had the tapered bearing.
SO.. knowing this information...
What rear axle housing assembly will swap in and allow me to use my springs?
The van I found? a 78/79 Bronco?
Help is needed!