Most of you know that the Beast was built with Currie Rock Jock 60 axles way back in 05. And for the most part those axle have served the Beast well. We were running 40" tires and driving daily for two years with out issue.
But then we switched to 41" Iroks. Ever since we switched to those tires, we've been going through front unit bearings like the were expensive candy. Replacing them was becoming a common occurrence that I was just getting tired of.
So as I was preparing the Beast for a big trip I checked the front wheels for play and noticed that both unit bearings were toast.
A call to Currie revealed that because mine are custom units, it would be a little while before I could get new ones.
We have been marketing Dynatrac axle's now for a while and one of the biggest reasons is because they use the old spindle and tapered bearing setup that has proven to be much more durable than the unit bearings. I put a call into my good friend Steve at Dynatrac and they had a Dynatrac free spin kit for the 1999 to 2004 Ford F250 waiting for me. Dynatrac stepped up to the plate and made it happen.
So now we are going to install this awesome free spin kit from Dynatrac onto my Currie Rock Jock axle.
Now to think this particular swap is easy or without it's issues just wouldn't be true. This kit was not really designed for this Currie Rock Jock. Even though the Currie axle is really based off of an F350 front axle, there are some custom things going on here on this axle that required some machining and fabrication. So follow along as we remove these troublesome unit bearings for good ole' American made hardware.
First of all, we need to know what we're dealing with. This axle was designed for my 02 Tacoma some 13 years ago. It was being built when I decided to sell the first gen Tacoma and get the new 2nd gen Tacoma and build it. This unit bearing was custom built by Currie Enterprises for a Toyota Bolt pattern. To do so they had to do some machining. The bolt pattern for the Ford F350, which this unit bearing was designed from, was 8 on 170mm. The bolt pattern for the new 2005 Toyota Tacoma was the tried and true 6 on 5.5 inches.
Because the F350 bolt pattern was so much wider than Toyota pattern, Currie had to machine down the outer section of the hub and also move the bolt pattern in to accommodate the Toyota pattern. So, when you purchase wheels for this pattern the opening wont fit on the larger 8 lug pattern. Because of this, when we changed over to the Dynatrac free spin kit we had to take the hubs and have them machined down so that not only would the bolt pattern fit, but the hub would also fit the center hole in the wheel.
Here in the above picture you can see the hub that has been machined down but it's still 8 on 170mm. That is because on my axle we are running 2" spacers because this axle was built for a smaller truck. So to make it a bit easier for us we just had some two piece spacers made that went from 8 lugs to six lugs.
Once all the machining was done we could start with the disassembly of the current hubs so we could install the Dyntrac setup.
First we have to take off the brakes and the rotors, and then remove the manual hubs. Although I do the strength and operation of the Yukon hubs, I have to say I'm glad they are gone. If you ever have to take this apart and put them back on you have to have a third arm to install them. Warn are probably the easiest to install, followed by the Dyantracs then a distant third are the Yukons.
Once the cover is off of the hub you'll see a spiral retaining clip. Pull that out but be careful because there is a big spring behind that which will push out so keep your free hand in front of the internal parts.
Now that the internals are out you'll need to pull the small c clip out that holds the axle shaft in. These c clip pliers work great.
The unit bearing is held on by four studs and nuts. Remove the nuts from behind the knuckle and then the unit bearing can be removed. Then pull the axle shaft out. If you haven't emptied some of the diff fluid you will have some come out as you remove the axle shaft.
Now it's time to start installing your new Dynatrac kit. It's pretty simple. Just follow the instructions supplied by Dynatrac and you should do fine.
With mine i had to do some machining of the hubs and had some adapters made to take it from an 8 lug setup to a six lug setup. Then I had to change the brake rotors and the calipers along with the front brake lines to make it all work correctly. I haven't done it yet but I'll also be installing a 2007 Tundra master cylinder and power brake booster because of the massive brakes we now have on the Beast.
First you'll need remove the two stub shafts from the inner axle shafts. I would advise you plan on changing the u joints at this point as well. We used a press to remove the old u joints. Made the job really easy.
We went with another set of Spicer u joints since the previous joints we had were Spicer and never failed in the 12 years of use.
Then we used the press and installed the joints in the axle shafts. New u joints and old u joints.
New stub shaft installed onto the inner axle shaft. This new stub shaft is 35 spline where the old on was a 30 spline. The shaft is larger as well at 1 1/2" verses the old shaft at 1 1/4"
On the left is the new stub shaft and the right is the smaller old shaft. Mo Bigger, Mo Better!!!
Install the boot seal onto the stub shaft per the instructions. I found it best to do this after I mated the two axle shafts together so I didn't damage the seal. Not shown in the picture.
Now we can install the completed assembly into the axle housing. Be sure when you install them to be careful and not damage the inner seal when you install it.