Axle swap in 40. From stock to an94 80series rear (1 Viewer)

[Mace]

Of course opinions will vary, things that are acceptable to some won't be for others. But there is a reason the factory does not make standard 4wd trucks wider in the rear. As long as it works for you then great! That's all that really matters.

 

[LAMBCRUSHER]

Can you expand on this? Would a couple of inches make any significant difference?

I am planning and 80 series rear and a 62 front. I haven't decided on narrowing the rear yet.

Narrow it, yes a couple inches will make a difference.

On most trucks the rear axle is narrower by a couple inches. This is done to allow the rear end to track evenly with the front end.

I had a horrible time getting the rear end to keep the line I wanted on my 40 with a Tacoma rear and FJ40 front.

I narrowed my FZJ80 rear to 59 3/4"ish WMS-WMS and slapped some 1 1/2" spacers on the front of my late FJ55 axle to get about 60"ish WMS-WMS up front. the rear FZJ80 is 63" WMS-WMS. The FJ60 front is 60" IIRC. some 1 1/2" spacers on the front and you'll be square to a stock FZJ80 rear- you might go 1 3/4" spacer to gain a bit of wider tack up front ala OEM. If I could do it again,. I would keep the ZJ80 rear housing stock length and have gotten a wider front axle so 1 1/2" spacers would keep the front biased track width...the FZJ80 rear will need 16" rims- the factory FZJ80 rims sit back further onto the hubs so the track width at the TIRE is actually narrower than the WMS numbers- by using stock length fzj80 housing and stock fzj80 rims, you're only growing wider by about an inch at the TIRE TRACKing point than the stock fj4X/55/6X...HTH

 

[Howard705]

Is it actually for tracking geometry or just to make enough room for axle joints, steering components, trailing arms, and tire swing when turning?

Sent from my LG-LS970

 

[Mace]

Tracking geometry and "pushing" through corners.

Why does my front axle have a wider trac than the rear? - Ford Truck Enthusiasts Forums

 

[hoser]

List of vehicles, front to rear track width measurements.

Wheelbase, track width, and differential measurements