Rear Diff Swap
Thread Starter
|
Fleet Mechanic
Joined: Oct 2007
Posts: 1,985
Likes: 107
Rear Diff Swap
Im swapping the 3.25s out of my 9in for a 2.75 trac loc out of a 77 F100.
I have never done this before but Im confident that I can do it without much trouble. I have a second set of hands to help.
Im looking for some advice.
My 66 F100 has a 9in with 28 spline tapered axles. Pretty standard.
The 77 donor is the same.
My axle seals do not leak.
Should I ease the axles out, do my swap, ease them back in and hope the seals do not leak?
Or should I just do bearings and seals and not worry about it.
I dont have the proper tools to remove and replace the bearings and seals so I would have to find a shop to do it for me.
Ive looked on the parts house websites and cant figure out the part numbers I need for bearings and seal, does anyone have the numbers handy?
I want to get this done this weekend, so I need to get moving.
I have never done this before but Im confident that I can do it without much trouble. I have a second set of hands to help.
Im looking for some advice.
My 66 F100 has a 9in with 28 spline tapered axles. Pretty standard.
The 77 donor is the same.
My axle seals do not leak.
Should I ease the axles out, do my swap, ease them back in and hope the seals do not leak?
Or should I just do bearings and seals and not worry about it.
I dont have the proper tools to remove and replace the bearings and seals so I would have to find a shop to do it for me.
Ive looked on the parts house websites and cant figure out the part numbers I need for bearings and seal, does anyone have the numbers handy?
I want to get this done this weekend, so I need to get moving.
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
Bossman, Are you sure about that? Most all rears by 73 were 31 spline, you may want to check that one out a little more and not be sol.
You probably can swap axles without damaging the bearings, but they are not pricey. just sayin
John
You probably can swap axles without damaging the bearings, but they are not pricey. just sayin
John
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 787
From: Simi Valley, CA
The only 31 spline 9" axles prior to 1973 were 1968/72 F100's that came with the optional heavy duty 3,600 lbs. capacity 9" with a 9 3/8" ring gear and Traction-Lok.
1973/79 F100, 1975/79 F150 9's could have either 28 or 31 spline axle shafts, as it depended on the applications.
28 spline axle shafts used 1957/67 are the same (B7TZ-4234-A) / 1968/72 is different than 1957/67 (C8TZ-4234-A) / 1973/79 is different again, and there's at least 5 different types.
1974/79 9's could have the ball type axle bearing that all 1957/73's came with, or the tapered roller bearing/seal combo. The only way to know which is present...is by pulling an axle.
1976/79 F100/150: Make sure it is a 9, because FoMoCo installed Dana 44 rear axles in some of these trucks, ratios of 2.75 or 3.00 with/without Limited Slip.
Posting Guru
Joined: Jan 2000
Posts: 2,281
Likes: 4
From: colbert washington
I agree with John. Whenever I do a clutch, motor change, or rear axle repair such as shadowrider is doing. I will change all the poriferals such as throw out bearings, rear axle seals and bearings, motors replace hoses, belts, anitfreeze. Just doing this when you are in there keeps you from having to come back and do it later. It can be very frustrating to have to go and do the same repair over 6 months to a year later. Ask me how I know.
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
I wonder if I should have said, by 1973 most all 9in rears had 31 splines, so it is very likely the one that you are referring to is a 31 & not a 28.
I doubt it make a lot of difference to some finger mashers, but I try.
John
I doubt it make a lot of difference to some finger mashers, but I try.
John
Thread Starter
|
Fleet Mechanic
Joined: Oct 2007
Posts: 1,985
Likes: 107
jo, Im as sure as I can be without pulling an axle and counting myself that this is a 28 spline.
My plan is to remove the pumpkin out of the donor before I touch my truck so there is time for me to be 100% sure.
Plan B is to relocate the spring & shock perches on the donor rear and use the whole thing. That gives me bigger brakes and I dont have to mismatch parts.
I only paid $65 for the donor rear and it will cost me less than $50 to modify it to use in my 66.
My plan is to remove the pumpkin out of the donor before I touch my truck so there is time for me to be 100% sure.
Plan B is to relocate the spring & shock perches on the donor rear and use the whole thing. That gives me bigger brakes and I dont have to mismatch parts.
I only paid $65 for the donor rear and it will cost me less than $50 to modify it to use in my 66.
More Turbo
Joined: Jan 2011
Posts: 620
Likes: 48
Trending Topics
Thread Starter
|
Fleet Mechanic
Joined: Oct 2007
Posts: 1,985
Likes: 107
More like 4 inches wider, two inches per side.
I have plenty of room under there.
I have plenty of room under there.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 787
From: Simi Valley, CA
1961/72: Width between inner frame rails behind cab is 33 1/2."
Width increased to 37 1/2" beginning in 1973, except F250 4WD (High Boys), F350: Cab & Chassis and on the 140" wheelbase.
Width increased to 37 1/2" beginning in 1973, except F250 4WD (High Boys), F350: Cab & Chassis and on the 140" wheelbase.
Fleet Owner
Joined: Jun 1999
Posts: 24,552
Likes: 74
From: Creedmoor, North Carolina
FWIW: I used parts from a 68 to get the larger brakes on my 66. Backing plates are different & need to be swapped. Since that brake size was used through 86, it helps me keep all parts under the chassis to 76 (matching the front) when ordering.
John
John
Ford Parts Specialist
Joined: Nov 2006
Posts: 88,826
Likes: 787
From: Simi Valley, CA
1968/79 F100's have 11" x 2 1/4" rear brakes as do some 1980/83 F100's and all 1975/96 F150's.
Thread
Thread Starter
Forum
Replies
Last Post
6t6merc
1961 - 1966 F-100 & Larger F-Series Trucks
3
Oct 21, 2013 08:30 AM
Eagle460
1961 - 1966 F-100 & Larger F-Series Trucks
6
Oct 23, 2010 01:00 PM