Well, here's how I see stock Toyota front axles (rears are excellent): the birfield design is good in theory. CVs don't bind like ujoints at full lock. Maintenance, however, SUCKS. The knuckles on my Toyota trucks and Dad's FJ40s all leaked. Sure, they stopped after you replaced the felt gaskets....for awhile. Within 6 months, they were leaking again.
Then there's the breakage problem with the birfs. On the mini-truck axles with stock birfs anything deemed "hardcore" with a front locker and a 35" tire, and you start breaking....a LOT.
When I converted my IFS 91 Toy to SFA, I used a front axle from an 85 Toyota truck b/c I'd been
misled to believe it was as strong as a D44. After breaking 2 front marfields, (the first attempts at upgrading birfields) destroying one housing, and dealing with what can only be described as an "unbelieveable mess" for a trailside repair, I decided to go D44.
I ran for over 5 years with the D44 with larger tires (38s vs. 35s) on much tougher trails, and broke 1 axle on the trail (it broke off in the carrier where it necked down to the splines)....I must admit, I have a little trick to make stock Spicer shafts and ujoints live, but even still....the purchase price alone of Dana components is so affordable that I can pretty much wipe my ass with them once a year and toss them in the garbage. Add to that: relatively easy and quick availability. Plus....no leaking knuckles or messy trail repairs.
Then, when you get into the D60, things get even better. Strengthwise, there's no comparison and housing failures are uncommon from broken axles with kingpin style axles. Parts are only slightly more expensive (once you get past initial purchase).
Other problems are that the mini-trucks use the 7.8" ring gear. I'm pretty sure all the electric lockers in Tacomas and 4Runners also use this size....but am unsure about the LC. The other ring gear size for open diffs is 8.2"
This generally isn't a problem, but lets say I go FZJ80 with stock open diffs (guessing it's at least an 8.2", maybe an 8.875" like the older Fj40s, but hopefully bigger). I then lock the diffs with ARBs, put in Longfields and run 5.29s to go with the 37" tires. What's my new weak link? Most guys that did this in the minitrucks found out it was their R&P...even the ones running the reverse cut FJ80 thirdmembers (albeit with the electric locker and hence the 7.8" RG). Not a good weak link.
From what I understand, the FJ80s have bigger birfs than the minitruck axles and are generally pretty good to 35" tires with lockers on hard trails. 37's is where things start breaking often. Let me be clear, I'm talking about really binding the axles up while climbing up boulders that are easily 4 ft tall or bigger. That's the kind of obstacles I like to drive and want this vehicle capable of handling. I really hope that last part doesn't sound like bragging.....I'm trying to explain the use b/c invariably someone with 37s will show up and say, "Ya, I run Martinez Canyon in my 80 a few times a year and I never break anything". I'm sure that's true, but when I run Martinez, I run lines that most people don't...not cause I'm a badass (I'm not)....I just enjoy very technical wheeling.
As for the D60s....it also makes sense from a support vehicle stand point. If I were to build it with 60s....I will make them exactly the same as what I'm running in the buggy. That way if one breaks an axle, I've already got a spare set. And....if I'm going to definitely get rid of the front axle, there's no point in keeping the rear b/c then I'd end up with a custom width front housing.
Speaking of: anyone know stock wheel mount flange to WMF width on an 80 (front and/or rear)? Generally, I've found the added width of a fullwidth axle like a 60 to be of great benefit in reducing body damage while increasing stability. Downside is: big gay mudflaps if you drive on the street. ;p
Can a triangulated upper link be made to work in the rear or does it get into the gas tank?
Sean
***EDIT*** Oh, and thanks for the links. Good stuff.
I'd guess the Toyota is their standard 1.31" (1 5/16") 30 spline or larger but would be interested to know.
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