Hello everyone I didn't see a introduce yourself area, but I'm from RI, on my second F150 first one was a 08 which I recently traded in for a new Fiesta ST which I absolutely love. Now I'll introduce you to the issues I'm having with my truck. I just bought a 86 bullnose I6 auto 4X4 with a NP 208F t-case fresh from New Mexico.

I've always wanted a bullnose, they just look awesome. I absolutely love everything about this truck aside from the problems it's giving me. It has some dents, tons of desert patina, surface rust and has a cool worked in look, but zero rot. It looks new underneath aside from the oil that was leaking before I fixed it. I'll be fine tuning the patina look and eventually clear coating over it. I've slowly been going through it new tires, rebuilt carb, regasketing, fluid changes, etc.

I'm having a couple issues, but I think I know what they are, but would like someone more experienced with these trucks to confirm my diagnosis. The 4X4 seemed to work fine on the test drive, however stupid me I only tested 4H. I decided to retest the 4X4 in 4L this morning. I locked the hubs and I put it in 4H and got a little grind, so stupid me I put it in trans in N and tried 4L and got a loud grinding noise and it was stuck in 4L.

I checked all the linkage and it was fine. I drained the fluid and found a lot of white plastic chunks visible through the drain hole, on the bright side no metal at all. I'm guessing the plastic range fork inserts in these NP 208s failed and it shredded to smithereens. So I started to take the T-case off got about 80% there and it started pouring out. So I'll have to finish tomorrow.

Is this a common failure and likely that it was just the $8 plastic inserts that broke and everything else is all good? Or did this cause a chain reaction that caused multiple things to break? I just wanna know if it's worth fixing or should I start saving my $ for a rebuilt t-case or rebuild my current one. Sorry, I know know it'll help much more when I get the t-case down and open but I'm hoping someone else has experienced the same thing in the past and it only cost $8 to fix lol.

My other issue is the truck is shaking pretty good while in gear while stopped. Out of gear it runs like new. Driving down the road it runs like new. It shifts down the road perfectly. My only guess is maybe a misfire, but I just wanted to make sure I'm not missing something. I haven't had a chance to change the plugs and wires yet.

Anyways, I've been lurking for some time now and the excellent info on here from everyone has been extremely helpful to me. I'm hoping to contribute soon as I learn more about this truck as I fix it up. Sorry for the overly long post.

 

ATF in that case. It's likely just the plastic inserts broke, but only one way to find out.

NP208 Ford, GM, Dodge and Jeep Rebuilt Transfer Case and Parts| Midwest Transmission Center no hassle warranty

Was searching for a friend the other day and came across this website. I noticed they have 2 different part numbers for the shift forks (updated vs non-updated which does not have the inserts). You might want to call them an explain your issue. It might be possible to install the non-updated forks.

 

Thanks a lot, I saw those forks as well. Hopefully it's just the inserts so I ordered the inserts and a case adapter gasket last night since they were cheap. Unfortunately, I didn't get a chance to get the case off as it started pouring again this morning. I have the week off so I'm hoping to have this mess sorted out by Friday 'fingers crossed'. I eventually plan on just rebuilding the whole thing, but I just want to get it on the road for now and put what money I budgeted for it into finishing tuning it up and weatherproofed for winter.

 

Don't despair, these transfer cases are easy to rebuild. Most likely the chain and sprockets are fine, unless the truck was worked long and hard in 4WD. Get a good rebuild kit with bearings and gaskets. If you have opposable thumbs and some mechanical aptitude, you can do it.

I'm not sure failed shift fork inserts would stop the shift operation, though. As long as the shift fork can move the mechanism close to position, the spring-loaded detent should be able to make that last little of travel. Did you try driving a few feet in either direction to help unload the drivetrains? If you have manual hubs, unlock those. Shifting the transmission to neutral will help, too.

Back to those plastic bits you found, I wouldn't drive it very long like that. The transfer case has a low pressure oil pump that lubricates the input bearing. Pump may be too strong a word. It's just a little doohickey (driven by the output shaft) that gently persuades oil to move forward via a passage to the input bearing. If any crud collects in that passage, the input bearing will starve for oil and eventually seize up. I had that happen on a different vehicle. The input bearing heated up, expanded, and then broke the case when it seized. A postmortem found old debris clogging that passage.

 

Thank you, yeah I've heard its a pretty straight forward rebuild. For now I plan on getting all of the plastic out and replacing the inserts for now. I'll run it through the winter and rebuild it in the spring. I need to just get it back on the road for now. I need it for my boat and for transporting my big a** telescope.

After disconnecting the driveshafts and fiddling with the shifter the case does shift easily now so I guess that's a good thing. The incident occurred in my driveway so it's parked and on ramps, I haven't driven it since. Thank you for the advice on the oil 'pump' for the input bearing.

 

Welcome to the forum.
It is not good to lock the hubs & move the lever to 4x4 as you can get binding in the drive line and break the weak link. That link could be anything from U-joints & drive shafts, transfer case to front axle u-joints & hubs.


You can leave the hubs un-locked and move the lever in & out of 4x4 hi/lo to test the transfer case.
Then when on snow or dirt try locking the front hubs and try 4x4.


In the old days if running in 4x4, hi or lo range and wanted to go back to 4x2 and could not move the lever to get it out of 4x4 you would have to get on dirt and spin the tires a little to un-load the drive train from binding. Then you could move the lever.
Same goes for un-locking front hubs when they do not turn.


Good luck on an easy fix
Dave ----

 

Opened up the t-case today. Here is what I found. All the metal looked good. The fork inserts were completely gone. The annulus hub was completely baked and stripped. To be completely honest, I'm not even sure if this is the upgraded fork with no inserts or not. However I cant see metal rubbing against plastic at high RPMs being a good thing. If anyone can give me some knowledge as to if this this the fork with or the upgraded fork with no inserts or not would be most helpful.

I went ahead and ordered the full rebuild kit and will document the rebuild to help others in the future. Unfortunately the part main part that failed the annulus hub is just a plastic part that demands a $75 asking price. You can't just buy the plastic part, you have to buy the whole thing. If anyone knows where I can just get the plastic, you would be my hero right now. Anyways, here's a few pics of what I found. BTW I f**king hate needle bearings.