[Lil'John]

Since I was asked in another thread, I'll give some details about shortening an FJ80 rear full float to work in an FJ55.

Step one is getting a donor axle. Since I was planning all new brake parts, bearings, etc, I found this rough SOB:


Over a weekend, I spent approximately 16 hours disassembling and grinding most of the brackets off. That resulted in this:



I left the link brackets on the one side so I could use FJ80 link bushings for a track bar.

Stock FJ80 rear axles are 62" wide. Stock FJ40 axles are 55". So I needed to lose 7".

Unfortunately, the spindles are an odd size and most axle places didn't want to touch it. I found a local place (Lincoln Welding in Sacramento) that could shorten the housing and used a lathe to assure the axle housing was true.

[Lil'John]

I dropped the housing off and asked for 7" off the short side. This resulted in(actually, this is after I started cutting the stock truss for spring under spring perch):


This is a side view to show how thick the stock trussing is on an FJ80 axle housing:


Here is the short side with the spring perch welded on:


Here is the long side welded on:

[Lil'John]

From here, I took the housing to my local axle place that dealt with custom axle shafts(Bill Rowlette of WelderBillt in Placerville, CA). I took it with the third member, one of the wheel hubs, and both axle shafts. He took the needed measurements for length, spline, and seal surface. I then brought him 6 foot of 4340 and he made them.

I then bolted and assembled the housing with new stock parts under my FJ55:


I used longfield drive flanges in the rear as the picture shows above.

I did NOT use the stock ABS sensors. The rear wheel hub has the ABS "ring" machined into it.

The stock FJ80 ebrake cable can be easily shortened up and then somehow integrated into the FJ55 ebrake system.

Unfortunately, my choice of drivetrain forced me to go spring over and I didn't trust the land cruiser differentials to hold up to a 6.0L Vortec, NV4500, doubler type setup with 35"+ tires :(

Here is picture of housing and axle shafts:

You can see the seal surfaces on the shafts on the far left of the short shaft and far right of the long shaft.

[Lil'John]

I was VERY happy with the results and would absolutely take this approach again.

In the long run, it is MUCH cheaper to go his way rather than buy a "stock" FJ40 full float. Especially once you consider alloy shafts, disc brakes, ebrake, etc.

[lukebz]

what are the costs involved if i want to go this same route? please don't hold back.

[r083rt]

Looks great.

[Lil'John]

Funny you should ask lukebz... I was going to do a cost comparison post in here

If we are talking apples to apples comparison, lets first state the goal is to get a full float axle with alloy axle shafts and disc brakes in a 55" width(hell, 58" FJ60 width would be same price).

In order to do this with a stock FJ40 full float, you need to do the following:

• Full float housing and wheel hubs ($450 SOR)
• Disc brake conversion (lets be VERY generous and call it $200... more than likely will be in the $400 range)
• Chromo axles (one could get flanged from poly performance for $475ish)

The big assumption to the above is you got one of the not abused axles. You also need to supply a third member.

In order to do this with a stock FJ80 full float, you need to do the following:

• FJ80 rear axle complete(I saw them non-elocker for from under $500)
• Shorten housing(I paid $200)
• Custom axle shafts (I paid $700ish for double splined shafts)
• Long field drive flanges ($160)

We are almost apple to apple comparison... HOWEVER, there are three things to note:

1. My complete FJ80 rear axle comes with the stronger FJ80 third member. This has larger pinion AND larger carrier bearings than your standard FJ40-FJ62 thirds.
2. My FJ80 rear axle is priced with double splined and not flanged as the FJ40 pricing. If we did the same double splined shafts and drive flanges, the price difference between the two methods is almost a wash($650ish for DB converted FJ40/FJ60 vs $700ish for shortened FJ80 axle)
3. The FJ80 rear axle has a KNOWN working ebrake system. While the DB converted FJ40 does have the El Dorado caliper option(at $100 or so more), the El Dorado caliper ebrake system is often very suspect.

I will be perfectly honest though. The semi nice thing about the FJ40 full float method is you don't have to shell out a huge amount of cash all at once.

But once you get both of them to the same state, in my mind, this FJ80 method will be superior and has the easily auto store accessible maintaince parts.

[belaw]

Great write up John!

I'm still unclear on the mechanics of the shortening operation and how the spindles were reattached. Is the spindle flange sleeved into the axle tube like the ball end on a 40 front axle?

And was pitching the sensors all that was required to do away with ABS?

Brian

[Lil'John]

Originally Posted by belaw

Great write up John!

I'm still unclear on the mechanics of the shortening operation and how the spindles were reattached. Is the spindle flange sleeved into the axle tube like the ball end on a 40 front axle?

I won't swear on a stack of bibles to that effect as I didn't get to see the work done. But in chatting with the guy, I believe that is the case.

Originally Posted by belaw

And was pitching the sensors all that was required to do away with ABS?

I wish I had a good picture of the wheel hub.

But the only thing you need to do to "not have ABS" is not wire the ABS sensor in. The reason I pitched mine was because they were burnt to a crisp

[belaw]

Originally Posted by Lil'John

I won't swear on a stack of bibles to that effect as I didn't get to see the work done. But in chatting with the guy, I believe that is the case.

Can someone verify this? Basically, sounds a lot like cutting and turning front axle knuckles with the added step of shortening the tube-correct?

Originally Posted by Lil'John

But the only thing you need to do to "not have ABS" is not wire the ABS sensor in.

Finally a job up to my mechanical skills!!!!