Pirate 4x4 banner

1 - 8 of 8 Posts

·
Registered
Joined
·
386 Posts
Discussion Starter #1
I have a 71 FJ-40 with stock drums in front. I also have a 79 parts truck that i bought. Would there be any problems swaping the 79 disk brake axle into my 71? I know that the gear ratios are difrent (4.11 v/s 3.7?). would it be possable to just swap 3rd members and will the axle shafts be compatable.

Thanks Michael
 

·
Moderating Midget
Joined
·
27,537 Posts
You will not even need to pull the 3rd member out of your 71 to do this.

Just tear your front axle down to the bare knuckles and then rebuild it with your 79 parts and Birfields.

Pitch everything from your '71 except the inner axles. The rest is CRAP!

The only thing you will need to do it gring the inside of your knuckles to allow the larger 79 birfields to fit.

You will figure that out when you get there, it is straight-forward too.

Good luck on a great swap.
 

·
Registered
Joined
·
4,072 Posts
Nolen is right...since you are gonna have to strip both axles down to the knuckles to remove the pumpkins, may as well save the effort and leave the early housing under the truck in the process.

Test fit the 79 birfields BEFORE assembling anything on the 71 housing...you want to grind before any bearings are installed.

And while yer in there, replace all the seals and bearings...may as well only tear it down once.
 

·
Registered
Joined
·
3,394 Posts
Or, just a suggestion, put the whole new 79 front end in, then swap the rear third member for the 4.10's
That way you get some more gearing too. Probably less work than rebuilding the outers on the front, too. Just an idea...

Good Luck!!
 

·
Registered
Joined
·
1,009 Posts
Originally posted by elf_cruiser:
<STRONG>Or, just a suggestion, put the whole new 79 front end in, then swap the rear third member for the 4.10's
That way you get some more gearing too. Probably less work than rebuilding the outers on the front, too. Just an idea...

Good Luck!!</STRONG>
Elf cruser the problem with that is it's backwards. the 79 stuff is 3.73 and if he put the 79 difs in he would loose the 4.10's.
you want to keep the 4.10.

i would still put the whole 79 front end in, but put the 71 3rd member into it, that way the knuckles match the housing, and there is a little less stuff to take apart.
There is one thing though, you have to change out the Brake junction where the flex hose comes to the axle from the frame, it has a different fitting than the 79, and if you want to use the 71 flex hose you just have to swap them. It's real easy.

Ian-
 

·
Moderating Midget
Joined
·
27,537 Posts
Yeah, but you have to take out all that stuff to get the third member out if you put the 71 third into the 79 axle....they are both going to have to come completely apart that way. Oh well, all it will do is add another hour to your swap, probably the same time it will take to grind the housing and clean up all those metal shavings!

Your choice....
 

·
Premium Member
Joined
·
1,534 Posts
I would keep your early housing under there.
Swap over the knuckles, birfs., brake master
cyl. & booster. You'll need to retack the
brake line junction on the housing over to
the driver side. When setting up the preload on the knuckles, use a fish scale to
determine the amount of shims to stack
under the steering arms. Get out your manual
for this procedure if your not familiar with
this step. As mentioned above, a little bit of grinding for birfield clearance will be
needed. Stuff a rag in the end of the tube.
I can't remember if I used the same brake lines at the firewall for the larger
booster or just rebent them. Also, I think
you may have a tie rod/wheel conflict due to
the drum front having more offset if you
decide to run your early wheels. It's been
quite a few years since I did the swap myself, but I think that pretty much covers it <IMG SRC="smilies/beer.gif" border="0"> <IMG SRC="smilies/blender.gif" border="0">
 

·
Registered
Joined
·
1,729 Posts
One reason for keeping the axle housing from the '79 with the original knuckles is that the shim packs for the knuckle bearings are set up for that particular combination and may not be correct with the earlier housing. It isn't easy to properly set up the shim pack without a special service tool from Toyota. I know people don't worry too much about this when they swap mini truck parts and things generally work out OK, but if the shim pack is not correct, the oil seals on the inner axle may leak.
 
1 - 8 of 8 Posts
Top