Toyota Axle Parts In A Jeep?Posted in How To: Transmission Drivetrain on September 1, 2012 0) (
Call us what you want—turncoat, heathen, apostate, betrayer, snake, double- crosser—chances are that we have been called all of this and worse by our mom. Yep, she is harsh but honest. Love ya, mom! We are running a Toyota axle in our TJ. The fact is that we have pulled plenty of parts from non-U.S. vehicles, and millions of Jeeps on the road or trails in the U.S and abroad are littered with foreign-made parts right from the factory. Ever heard of an Aisin’s AX15, AW4, AX5? How ’bout the Peugeot BA-10? Yep, all of those are foreign-built transmissions and hell, two of the four are pretty darn good. So why not turn to other parts from Toyota 4x4s (which share some Aisin parts with some Jeeps). The fact is that our misguided fellow four wheelers who either intentionally or reluctantly find themselves behind the wheel of Toyota 4x4s have been using and downright abusing Toyota axles with rather large (35-38-inch) tires for years. Okay, so you say that these guys running toy axles are only making 115 horsepower or so. Yep, you are right, but they do usually use stacked and low-geared transfer cases where stress and strain are compounded. Also, our little SE TJ (“3-Day TJ for $3K ,” April ’12) makes similar power numbers with its 2.5L AMC-designed four-banger, and we don’t have dual- or triple-stacked T-cases with comically low gearing. So yeah, we admit it, we wanted to check out some of these Japanese parts for ourselves when we came across the perfect parts rig at our local pick-your-part junkyard. A wrecked ’97 V-6 2WD Toyota Tacoma—we could not resist.
A couple of hours and $125 later we had the object of our interest—a Toyota rear axle for our TJ. This axle is unofficially known as a Toyota 8.4 (Sometimes 8.25), or T100/Tundra/Tacoma axle, and shares many similarities and improvements from the original V-6/Turbo Toyota truck 8-inch axle. The axle has an 8-inch ring gear (the name is misleading, huh?), 30-spline shafts, 30-spline pinion, V-6 carrier bearings, larger pinion bearings, and reportedly a stronger third member casting than the ’86-’95 V-6/Turbo differentials. The 2WD Tacoma V-6 we want you to look for also shares the 5-on-4.5-inch (5-on-114.3-mm in metric land) wheel bolt pattern of ’87-’06 Wranglers, ’84-’01 XJs, ’86-’91 MJs, and ’93-’98 ZJs. Plus, it has a (roughly) 59-inch WMS-WMS width. It’s a near-perfect swap for several late-model Jeeps and is way stronger than any beefed-up Dana 35. The similarities in strength approach, if not exceed, that of a Dana 44 rear axle with 30-spline axles. The best part for us and our underpowered TJ is that this Toyota axle offers a similar weight and a touch more ground clearance than that of the weak stock Dana 35. Okay, so this may not be the most common axle in the junkyard, but hell, we found one, and have noticed it under every newer ’05- present 2WD Tacoma we’ve had a chance to peek under. (Although we are not sure that these newer Toyota trucks share the WMS-to-WMS width of the earlier ’941⁄2-’04 Tacoma axle we have.) Follow along as we set up, test, and beat on this Toy axle with help from JTS Justdifferentials, Nitro Axle & Gear, ARB Air Locker, Rusty’s Off Road, and Tom Wood’s Custom Driveshafts. Yo!
Why’d We Choose That?
We chose ARB Air Lockers for our ’97 TJ because we wanted the ability to turn the lockers off and wheel our Jeep with open differentials. Why, you ask? Well, in our opinion, driving a rig with big tires, spools or auto lockers can make you a lazy off-road driver. We like the challenge of driving an open diff’d, small tire’d Jeep off-road sometimes.
Getting the pre-built Toyota third member from JTS Justdifferentials was a no brainer. The company knows all about these axles and was happy to help us figure out what third member we needed. Also, it has more experience setting up a ring-and-pinion properly, which is a key to long life of the gears. Sometimes it’s worth the cash to have someone else with more experience handle tougher upgrades.
We also filled our TJ’s Dana 30 with an ARB Air Locker (PN RD100) 4.88:1 Nitro Axle and Gear gears, new bearings, and a master install kit from JTS Justdifferentials. Installation of the locker and gearset is relatively easy with lots of expensive specialized tools, knowledge of the process, and experience. Lack those things? Get a professional to set up the axle.