Well about 4 weeks ago I saw an 8.8” axle, without gears, for sale on e-bay. The starting price was only $50. I was curious and e-mailed the seller and found out that it was a 31 spline axle that had been removed from an FX4. That the guy selling it didn’t live very far from me (under 100 miles) was a definite plus, no shipping charges! With a starting price of only $50, I figured what the heck and put in a bid for it.
Well, I bit my nails waiting the three days for the end of the auction. When it ended I had been the only bidder! I immediately contacted the seller and made arrangements to pick it up the next day. I wanted to get hold of it before he figured out what the heck he had.
I spoke to the seller when I picked it up and found out that he was really a Dodge lover and had nearly a dozen different ones, in various stages of disassembly, around his house. I also found out that even though he worked in a large Ford dealer as a mechanic, he had no idea of the usefulness of this particular axle. When I asked why the axle had been taken out, he told me a tale of Ford having to recall a lot of the FX4’s. It seems that people were taking them off road and blowing up the Torsen diff’s. Imagine that people actually tried to drive their trucks off road, what a concept.
With that little tidbit of information in hand I did some research on the web and found an article about it. It stated that Ford had recalled a little over 1000 of them. And I guess in the usual corporate save a buck effort to save on the labor costs. They just swapped out the entire axle assembly, drum to drum. The one I got from him had, according to him, come from a 2002 truck that had never left the dealers lot before getting the rear replaced. I believed him, the brakes were brand new, heck the emergency brake cables were perfect and the drums still had the black factory paint on them!
While it was essentially a new rear there was a couple of things it needed before I could actually use it. First there were no gears or diff inside, he had removed the diff and gears. The original 4.10 gears were used for a friends truck and he just never bothered to put the Torsen diff back in. But he did give it to me. I think he just wanted to get rid of it. I wanted it to see if it really was a bad one. If it proved to be bad, I figured I could at least use the tone ring off it for whatever I replaced it with. Ford dealers want about $40 for the ring and they were the only source that I could find.
I e-mailed Zexel, the diff’s maker, with the “lot” number on the side of the unit and was told that it was indeed one of the “suspect” units. But they did say if I used it in a car or truck with an automatic transmission it would probably be OK. Probably OK? I didn’t like the sound of that and I have a standard and didn’t want to have to baby it all the time. So I started shopping around for a new LS unit and a set of gears.
I eventually chose to replace it with a Detroit Truetrac, another gear based LS as well as a new set of 3.73 gears. I also picked up a pair of wheel cylinders because the rear had been left outside for some time and the wheel cylinders had not been sealed off. Knowing the affinity of brake fluid for water I figured that they were probably junk at this point, and it would be well worth the replacement cost just for my own peace of mind.
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