Alright this is my first post. Ive been using this sight for about 6 months without asking any questions and I've learned alot about my 78 from everyone here. My problem now is what i think is my transfer case grinding and clanking while in 2hi going down the highway today at about 55-60. After about 15 min i shifted into 4hi without locking the hubs and it went away. Any ideas? 1978 f150 351m np205 3.50 gears. Stock truck

 

the 205's generally go forever , but anything can wear out. I would check your U joints really good. and I'd drain the T case oil and see what it looks like.

 

I checked my fluid this evening. A little dark but fluid came out when I removed the plug

 

Yikes, may want to drain it and remove that back cover to the front out put shaft and see if you have metal in the oil and any obvious mechanical damage. Seen a few good write-ups on rebuilding the 205, unfortunately there aren't as many for my 203.

 

I was thinking more about metal in it. it will show if you're eating a bearing.

The shifting on these is a little funky too, if you were were shifted a little wonky and it was bumping another gear it could cause what you're talking about. and shifting into 4 high would cure it.

 

And then again it might not be the transfer case. I'm not 100% sure. I have the np435 transmission which I haven't had any problems with. The grinding sounded like it was coming from one of the 2. I could feel it through the floor shifter.

 

I'll drain the fluid tomorrow and see what i can find. Hopefully no metal. I'll drive it in the morning in 2hi and see if I possibly had the shifter misaligned before draining the fluid. Probably best to drain and refill anyways. I appreciate your advice

 

I would dang sure rather pull a 205 than a 203

 

If it does it again play with the shifter and see what it does. the shifting on these has always been a little troublesome that's why some guys put the twin sticks on.

 

tried the shifter this morning and its still doing it. Once i hit about 40-45mph it starts grinding. I guess I'll drain the fluid next