2006 F-150 XLT 4wd 4R75E rebuild
 

Owner of this truck complained the transmission lost overdrive. I towed the truck to my shop. This truck has 309000 miles in the odometer, the transmission fluid and Transfer case fluid were black. The yellow dipstick plug was present when I pulled the pan. The magnet in pan has moderate metal contamination.


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Everything in the transmission is coated with a black film. Originally, I expected to find the OD servo snap ring broken and debris from the snap ring lodged in the valves in the valve body, this wasn't the case. Once I got the transmission removed from the truck and taken apart, I found the internal splines on the direct clutch hub snout were stripped. This means this transmission had no 3rd gear or 4th gear. I have heard of high horsepower cars either stripping the splines on this drum or breaking the stub shaft, but I have never seen a stock vehicle do this.


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The foward clutch material was dark and starting to pit, the OD band was glazed and the reverse band was worn.


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For the rebuild, the direct drum was replaced, the OD band is updated to latest black high carbon material and because this is a truck, the reverse clutch is updated from 3 clutches to 4


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Normal for 300kmi or no?

like I said, this was the first stock transmission I had seen that stripped the splines on the direct drum.

I would NOT consider this normal

So they basically drove the hell out of it and burned the fluid and stripped the drum

The person that owned the truck did own a construction company, so I sure he was towing trailers and hauling stuff in the bed.... you know, "truck" stuff.

Oh. So it's normal but it's not... this is too confusing for me. I guess the point is you're rebuilding it and that's all that matters

well, its NOT normal for the splines to strip in the drum. usually the intermediate shaft will break first.