mchan68 Posted December 2, 2014 Share Posted December 2, 2014 I have myself an '09 F-350 Harley truck that came in on the hook with a loss of steering control. The part number for the steering box this truck calls for is STG-286-RM. I have since installed it into the truck as you can see in the first photo, but now unable to fasten the lower coupler to the input shaft of the replacement box. As you can see in the first photo, it appears the replacement box input shaft is completely different from the original box in the second picture. To illustrate this point more clearly, I have removed the lower steering column coupler for a better visual of the differences. It appears the original box to coupler mating utilizes splines and a "half moon" shape, as opposed to the "triangle" shape of the replacement. Anyone else ever run into this, or able to shed some light on this issue. Of course, another replacement box is on USA no-stock status. I've since ordered a new lower steering column coupler in for the morning, but something gives me this awful feeling that it will only be identical to the original coupler, putting me no further ahead and in a bind. Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted December 3, 2014 Share Posted December 3, 2014 I am interested to see what the new shaft looks like. My brain is telling me I've seen the half moon splined shaft on the 6.0s and the triangle non-splined shaft on the 6.4s. I know for sure I have resealed steering boxes on 6.4s (because they are on backorder) and I specifically remember the triangle shaft. Perhaps it's a running change. When you look up the box for 09 (no vin) does it show multiple choices? Quote Link to comment Share on other sites More sharing options...
mchan68 Posted December 3, 2014 Author Share Posted December 3, 2014 I am interested to see what the new shaft looks like. My brain is telling me I've seen the half moon splined shaft on the 6.0s and the triangle non-splined shaft on the 6.4s. I know for sure I have resealed steering boxes on 6.4s (because they are on backorder) and I specifically remember the triangle shaft. Perhaps it's a running change. When you look up the box for 09 (no vin) does it show multiple choices? Nada. I tried looking it up with no VIN as well, and it still comes up with that part number. Unfortunately in this case, replacement is the only repair option due to the input shaft being broken and completely separated from the box. Compunded to this, is the fact that it remains stuck on the hoist due to no way of being able to steer it, if I were to choose to push it out of the bay. Quote Link to comment Share on other sites More sharing options...
YukonTyler Posted December 3, 2014 Share Posted December 3, 2014 Not a huge help, but I can offer a bit of solidarity. We had a Super Duty in not too long ago for a steering box. We got a Motorcraft piece and found that the king spline was 180 degrees off compared to the original unit and what the pitman arm would accomodate. Ordered up a new gear and pitman arm and got the same thing. At that point my colleague opted to remove a spline by grinding in order to make a new master spline. In this case it worked out. Too bad that yours is such a big difference. Quote Link to comment Share on other sites More sharing options...
mchan68 Posted December 3, 2014 Author Share Posted December 3, 2014 Well, it turns out the lower steering coupler is in fact non-splined as you indicated Matt. Which leaves me scratching my head wondering why there isn't any mention of this in Microcat. This also means that any truck requiring either a box or steering coupler replaced will end up crossing this bridge. Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted December 3, 2014 Share Posted December 3, 2014 So the new shaft fit the new box. Good to hear. Do you think there's any chance the old box in the truck was replaced at one point? Perhaps with one from a junk yard, maybe an older model year? I know one thing. I'll be keeping an eye out from now on. Quote Link to comment Share on other sites More sharing options...
mchan68 Posted December 4, 2014 Author Share Posted December 4, 2014 So the new shaft fit the new box. Good to hear. Do you think there's any chance the old box in the truck was replaced at one point? Perhaps with one from a junk yard, maybe an older model year?I know one thing. I'll be keeping an eye out from now on. I doubt this box was ever replaced at any point in this truck's life, due to the fact they seldomly ever fail. But that still doesn't explain the splined steering coupler. Before you suggest an older truck, it's impossible due to the '07 and older trucks use a completely different shaft (and part number) from the '08 to '10 trucks. Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted December 4, 2014 Share Posted December 4, 2014 Yeah I wasn't thinking when I typed that, of course a 6.0 shaft would be different in some way, shape or form. There must be a change over from shafts and boxes in 08 or nothing like what you found would exist. I'll pick my parts guys brain tomorrow about all this. Quote Link to comment Share on other sites More sharing options...
mchan68 Posted December 5, 2014 Author Share Posted December 5, 2014 Well, I guess you don't need to. I took it upon myself to dig a little deeper into this. It turns out, all '08 F-250/F-350 trucks with a build date up to July 30th 2007 use STG-263-RM steering boxes (which by the way is the same part number for the steering box for my 2007 F-250) and 7C3Z-3B676-C steering shaft (which I'm assuming HAS TO BE the splined shaft pictured above). All F-250/F-350 trucks after that build date use STG-286-RM boxes and 9C3Z-3B676-A steering shafts. BUT, the particular truck referenced has a build date of May 2009, so how in the hell did this truck end up with an early box and shaft? Quote Link to comment Share on other sites More sharing options...
Matt Saunoras Posted December 6, 2014 Share Posted December 6, 2014 The late 6.4 boxes have been on backorder for as long as I can remember (or at least every time I needed one in the last 3 years). Given the availability I'm sure someone at one time as retrofitted an early to a late. At least now this appears to be a viable option. I can't check availability on either number because it comes from a FAD but my guess is the early box is a little more available than the later one (even used is an option given how many are out there). Quote Link to comment Share on other sites More sharing options...
Aaron Posted December 7, 2014 Share Posted December 7, 2014 Guy like jumping curbs or something that kills boxes? Lol Quote Link to comment Share on other sites More sharing options...
mchan68 Posted December 7, 2014 Author Share Posted December 7, 2014 When I first quoted this job, I had my parts manager consult PACO. It turns out that lack of availability is due to lack of available rebuildable cores on hand. This tells me they fail very seldomly. Quote Link to comment Share on other sites More sharing options...
cbriggs Posted December 8, 2014 Share Posted December 8, 2014 Or when they do they aren't buildable.... Quote Link to comment Share on other sites More sharing options...
DieselD Posted December 9, 2014 Share Posted December 9, 2014 superduty gears in general have been pretty damn good. I tend to repace them around 200-250k miles due to being sloppy but they are not undrivable Quote Link to comment Share on other sites More sharing options...
cbriggs Posted December 10, 2014 Share Posted December 10, 2014 I see a lot of 6.4 boxes shit the bed, mostly broken input shafts, a few that the adjuster nut stud came apart from the sector shaft and the sector shaft fell away from the worm gear, and a bunch of worn out sector shaft bushings, and 2 cracked housings. Quote Link to comment Share on other sites More sharing options...
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