1976 FJ40 Axle Mod or Swap (1 Viewer)

[dbransco]

Hello,

Just beginning to tear down my 76 FJ40. My intention is to tastefully restomod with Cummins 2.8l and 4 link rear, 3 link front. I don't plan to beat in this, just want a reliable daily driver that can comfortably handle the offroad. I am imvetween 33" and 35" tires; however, leaning toward 35".
My current axles are all disc. Would it be a better idea to rebuild the current FJ40 axles with ARB lockers and RCV 30/30/30 trussed/reinforced or at that point, would it be better to go with FJ80 axles, dana 60s or other?
Thanks!

 

[cruisermatt]

You say don’t plan to beat it off road but list a bunch of parts for beating it offroad.

I suggest you just get the engine swap done first and then go from there and see specifically where you want to improve the chassis/suspension afterwards.

You probably don’t need to go crazy with axles for what you want.

 

[White Stripe]

The weak link would be the axle shafts on the reae and course spline pinion. 4plus makes a rear full float kit and you could run aftermarket shafts. You stock axles would hold up for a while as is if your not too hard on them.

 

[dbransco]

You say don’t plan to beat it off road but list a bunch of parts for beating it offroad.

I suggest you just get the engine swap done first and then go from there and see specifically where you want to improve the chassis/suspension afterwards.

You probably don’t need to go crazy with axles for what you want.

Thanks! Just trying to be honest that I'm not going to be rock crawling with the thing, but I would like to built it out to be as durable/strong as within reason.

The weak link would be the axle shafts on the reae and course spline pinion. 4plus makes a rear full float kit and you could run aftermarket shafts. You stock axles would hold up for a while as is if your not too hard on them.

Thank you for this info.! I don't mind putting some money into them and would rather do it right from the beginning.
I appreciate it and will take a look at 4plus!

 

[cruisermatt]

Thanks! Just trying to be honest that I'm not going to be rock crawling with the thing, but I would like to built it out to be as durable/strong as within reason.

Thank you for this info.! I don't mind putting some money into them and would rather do it right from the beginning.
I appreciate it and will take a look at 4plus!

I would suggest a FJ60 rear axle and flip your rear springs. and 1" wheel spacers on the front or IFS hubs/Tundra brakes. IT will gain you about 3" all round, fine spline rear stuff and the better rear parking brake. a basic 2.5" OME/Bilstein lift and flipped rear springs (especially with lockers) will go pretty much anywhere you want very comfortably without being a massive project. You should do a basic setup like this first while you work out the teething issues with the diesel swap (That you WILL have) and you will probably be very happy with it.

 

[Mike Shull]

Those stock 40 or 60 axles should hold up to 35” tires under your driving conditions. Mine lasted 43 years with only one blown carrier bearing and two axle shaft replacements. It was on 33’s most of its life until getting 35’s, a 300hp SMC stroker and a SM465 at 198k miles in 1998, which is when I started hitting harder trails like Pritchett Canyon in Moab. This truck has been off-roading since rolling off of the lot in 1978 without routine maintenance (not proud. Just reality). It had 260k miles on it when I pulled the axles for 1-tons.