Got home on the hook

[MKeeney]

Yesterday I had to get towed home because something went out in either the transmission or transfer case. I have a 99 F350 DRW with a 4R100 automatic. I use this truck in my firewood business but it's never really had a load that would overly task the drivetrain.

When we're in the forest I put it in 4×4 Low Range so I can tow trees up to the cutting area. Again, not really overloading anything. A couple of weeks ago the Low Range light would only come on intermittently but it did go into low range. Occasionally, I would hear a bit of gear grinding when changing back and forth but I would instantly stop. Every once in a while it would get hung up and I wouldn't be able to get it into gear and it would grind like crazy if I tried to put it into park. When that happens I would shut the truck off and put it into gear with the engine off.

Yesterday I had one of those days when it wouldn't go back into 2wd without grinding. I did like I always did and shut the motor off and got it into gear. As I was going down the road I noticed that I was doing about 30 mph in 4th gear at around 3,000 rpm. The transfer case lever was unquestionably in 2wd but I pulled over and double checked. I took off again and it was still doing the same thing. Then it just stopped working. It wouldn't go into any gear or park. Now the grinding was much quieter too.

I'm fairly sure it's the transfer case but I've never attacked such a task before. I'm a mechanical engineer so I'm not afraid of the job, but it would sure be nice to get some advice from the folks here that know more about this kind of problem than I do. I have a hunch what the problem is, but it certainly could be something else too.

Does anyone sell aftermarket transfer case parts?

[NoRalPh]

First, I have to assume it's stuck in Low Range (for that rpm/mph in hi gear).

Second, you say "lever" so you don't have the ESOF (knob on dash)?? If the lever moves into 2WD HI and your not out of Low Range, are you sure the outside linkage is OK? If so, it's gotta be a Fork or something, bent or slipped, inside.

Next, you certainly should Not be "afraid of the job" The TC is EXTREMELY simple to take out and take apart. The top bolt can be a Pain (long extensions, wobbles & universals help a lot), it splits pretty easily and there is no gasket, just RTV (you might want to get the Trans to TC paper gasket first, they can be hard to find) and the fork comes out very simply once opened.

As a warning to everyone about these forks, you want to be sure that nothing "rests" on the manual shift lever. That fork has little nylon "feet" on it that ride in the slot on the gear and if constant pressure is held on it (like from a gymbag/lunchbox/anything/ on the lever in the cab) they wear out quickly....

[MKeeney]

Your correct, it's a manual shift transfer case, definitely not on the fly. I'm going to take the TC out in the morning and get a good look. I suspect you're right about the fork, I just hope there isn't any big damage inside. There was some pretty significant grinding noises, much like the sound of putting it into park while the car is still moving. What worries me is the noise is still there, but much quieter. Hopefully it's just the fork and no serious damage anywhere else.

[MKeeney]

Does anyone have an assembly drawing of the transfer case? Also, if I have to replace parts, gears or whatever, where can I get them? I've seen some places that have a few parts, but if memory serves me correctly, it was just a shaft. I hope it's not all dealer parts.

[NoRalPh]

Somebody just posted this the other day (I grabbed it ) The TC is made by New Process so, I'm sure you can find parts in lots of places...

[MKeeney]

Thank you for that PDF. It led me to this website, : Transmission Parts Makco transmission parts online. These guys look to be the holy grail for every transmission and transfer case on the planet. A valuable resource indeed. Thank you.

[MKeeney]

Update: I got the transfer case out yesterday and split the case apart. It was definitely the transfer case that failed. Actually, it was the shift fork and syncro for the hi/low range, but there was metal everywhere. As much as I would have liked rebuilding this, mine is a work truck and I can't afford the downtime.

Here's a couple of pictures of the damage.





Fortunately, my local junkyard had a transfer case in stock for $500. Unfortunately, I don't have a shop to work on the truck. It's outside and we got a dusting of snow last night. I'm too much of a sissy to work out in that.

[99red7.3]

A few months back I had the shift fork in my TC mess up and it kept the truck from going anywhere. Anyways long story short i called everywhere parts were damn expensive i ordered from this company Transfercase parts transfer case chains good prices all they deal in is Chevy Dodge and Ford they will have what ya need for your TC!