Rearend
Junior User
Joined: Sep 2001
Posts: 97
Likes: 0
Originally Posted by Poulsom
I have a 1974 ford truck with a 3:0 rearend and would like to swap it for a 3:5 limited slip. The question is how many spline rearend is it.
I think your '74 is right around the time they started putting 31 spline in the trucks... maybe '73? I'm not sure, it really would be best just to pull an axle and see what you have. If you're talking about a Bronco you probably have the 28 spline - you didn't specifically say it was a F150.
Post Fiend
Joined: Mar 2005
Posts: 8,542
Likes: 5
From: Louisiana
all the early model broncos had the 28 spline 9" until 71(when they were suposed to come out with the big bronco, but things changed) and after that 71-77 had 31 splines and then the big bronco came out in 78 and had 31 Spline 9" until 82, then they went to the 8.8 rear axle.
Posting Guru
Joined: Feb 2002
Posts: 2,404
Likes: 3
From: Cleveland, WI USA
Originally Posted by satx77stepside
Are all 73-79 non-bronco 9"ers 31 spline?
I read somewhere that the trucks with the lighter load capacities had 28's, and the heavier trucks had 31's. I can't confirm that though.
The use of 28 and 31 spline axles in F150s seems totally random. I'm guessing that's why most people say to pull the axle and count 'em.
Kevin K.
Fleet Owner
Joined: Jan 2004
Posts: 26,007
Likes: 575
From: Brentwood,CA
yes it all went by GVWR my f150 has 31 splines. your 74 could be either but 28 would be the likely choice.
Trending Topics
Senior User
Joined: Nov 2003
Posts: 160
Likes: 0
From: Mt.Morris Mi.
I have 1973 XLT 9'' I would like to know what the tag on it means
WDM-AH-3DA and 325 9 328A Is it a trac-loc and what gear ?
WDM-AH-3DA and 325 9 328A Is it a trac-loc and what gear ?
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Cargo Master
Joined: Dec 2003
Posts: 2,734
Likes: 38
From: Sunny Florida
Originally Posted by Bob Crain
I have 1973 XLT 9'' I would like to know what the tag on it means
WDM-AH-3DA and 325 9 328A Is it a trac-loc and what gear ?
WDM-AH-3DA and 325 9 328A Is it a trac-loc and what gear ?
Elder User
Joined: Aug 2002
Posts: 662
Likes: 0
From: CA
My '73 9" w/3.50 gears is a 28 spline. The only way to tell for sure, as was mentioned before, is to pop an axle and count them. However, if you have 28, and can find 31 spline axles at the right lengths, and 31 spline side gears, the swap is wasy!
New User
Joined: Jan 2008
Posts: 0
Likes: 24
Actually you don't even have to count them.
If the splines taper down from the smooth machined area it is a 28 spline.
if the splines run without a taper it is a 31 spline.
These WDM-AH-3DA & 328A
are Ford application numbers for bearing sizes & plant codes.
If the splines taper down from the smooth machined area it is a 28 spline.
if the splines run without a taper it is a 31 spline.
These WDM-AH-3DA & 328A
are Ford application numbers for bearing sizes & plant codes.
Cargo Master
Joined: Sep 2005
Posts: 2,954
Likes: 64
Originally Posted by MBBFord
all the early model broncos had the 28 spline 9" until 71(when they were suposed to come out with the big bronco, but things changed) and after that 71-77 had 31 splines and then the big bronco came out in 78 and had 31 Spline 9" until 82, then they went to the 8.8 rear axle.
9"
<TABLE style="BORDER-COLLAPSE: collapse" borderColor=#111111 cellSpacing=0 cellPadding=0 width=161 border=0><TBODY><TR><TD style="PADDING-RIGHT: 2px; PADDING-LEFT: 2px; PADDING-BOTTOM: 2px; PADDING-TOP: 2px" align=middle width=103>Vehicle Model</TD><TD style="PADDING-RIGHT: 2px; PADDING-LEFT: 2px; PADDING-BOTTOM: 2px; PADDING-TOP: 2px" align=middle width=50>Year</TD></TR><TR><TD width=107>BRONCO</TD><TD align=middle width=54>67-86</TD></TR><TR><TD width=107>E&F 100&150</TD><TD align=middle width=54>57-86</TD></TR><TR><TD width=107>E200</TD><TD align=middle width=54>68-74</TD></TR></TBODY></TABLE>
Post Fiend
Joined: Mar 2005
Posts: 8,542
Likes: 5
From: Louisiana
That the same thing with the transfer cases, they were suposed to have a NP208 until 86, but I have seen people have the borg warner t case in a 84. I have also seen some 8.8 in earlyer models than 86, there was nothing set!
Cargo Master
Joined: Dec 2003
Posts: 2,734
Likes: 38
From: Sunny Florida
I am not 100% sure any early bronco got 31 splines axles. I was under the impression that they just got the big bearing and bigger brakes but not 31 spline axles. I'm pretty sure all EB's had 28 spline.
Ford started using the 8.8 around 84 and used both the 9 inch axle and the 8.8 axle until 86 which at that point the 9 inch was fazed out.
Ford started using the 8.8 around 84 and used both the 9 inch axle and the 8.8 axle until 86 which at that point the 9 inch was fazed out.
Thread
Thread Starter
Forum
Replies
Last Post
Ford_Eddie_Bauer
Clutch, Transmission, Differential, Axle & Transfer Case
3
Aug 14, 2005 06:47 PM