2/71 fj40 axle swap with 1979 fj40 (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Joined
Sep 21, 2021
Threads
8
Messages
32
Location
Missouri
Hey all,

I’ve been looking and can’t seem to find a straight answer to if a 1979 axle with disc brakes would be a simple “plug and play” swap into my Feb. 1971 with a 1971 axle (with drum brakes). I am really wanting to get disc brakes on my 71 and have heard this might be the easiest way to do it. I then have read about different splines and other things. Could someone please advise me on the ease of doing this. I am not a mechanic and have only a very basic knowledge of these machines. I have owned this FJ40 for about a year and am slowly trying to make it what I want it.

Thx.
 
The 79 has differ gear ratios. 79 was the 1st yr for 3.70:1. Your early frt end has 4:11. You can swap knuckles out though.
 
If you have a dual circuit master you want to remove the residual valve from the frt resoiviour. I you don't, you should upgrade to dual resoiviour. 79 knuckles are desirable because they are the stronger large pattern versions.
 
you need to determine if the 79 axle was still from a rig in Dec 1978 or from January 1979
the early 1979's were basically still 1978's and had the same ratio as your 1971
if it is the later January 1979+ it will have the large knuckle bolt pattern and 3:70 diff ratio

measure the bolt pattern on the steering arm and that will tell you what version 1979 that you have
 
To start go to FAQ's at the top of this section. Scroll down to frt ends and read. Use the search function too. Swapping knuckles isnt that difficult it's just messy. At some point you'll have to service the knuckles anyways.
 
Last edited:
The short answer is yes.
You may have to swap the third member.
Your brake MC may need to be modified if dual circuit, replaced if single circuit.
 

Users who are viewing this thread

Back
Top Bottom