Hey guys! It's been a while since I've been here last. Anyway, here's my trouble: I've got a '78 F-250 with Full-time 4x4. When my truck is under load I hear a deep clunking coming from the T-case and I can feel the motion trough the drive train. Is this transfer case chain driven???
If it is I've got a hunch that the chain is jumping the gears, and my T-case is shot.
I do know a friend who may be parting out a '77 F-250 with a gear driven divorced transfer case. I haven't looked at it yet, but would a divorced T-case work in place of a transmission mounted one??

Please help!

-Dan

 

> Hey guys! It's been a while since I've been here last.
>Anyway, here's my trouble: I've got a '78 F-250 with
>Full-time 4x4. When my truck is under load I hear a deep
>clunking coming from the T-case and I can feel the motion
>trough the drive train. Is this transfer case chain
>driven???
> If it is I've got a hunch that the chain is jumping the
>gears, and my T-case is shot.
> I do know a friend who may be parting out a '77 F-250
>with a gear driven divorced transfer case. I haven't looked
>at it yet, but would a divorced T-case work in place of a
>transmission mounted one??
>
> Please help!
>
> -Dan

Dan, in your case, no. Not without some serious Afro-American engineering. You need to find a married NP-205 to bolt up to your tranny. If you want to make this guys t-case work, you will need to change trannies, and add a crossmember to hang t-case on. It will be simpler to use a married case in my opinion. If your truck is full time 4x4, and you convert to a gear driven case, you might have to convert to part time hubs as well. The easiest way to tell what kind of case you have is to look for the sheetmetal I.D. sticker that is on the case, usually on the front. If you cant find a tag, you can look at the back of the case. If it is gear driven case, you will see a small circular disc about 2" in diameter with 3 bolts in it in the lower center. If this is not there, it is a chain driven case.

Before you go blaming your transfer case, you should look at your entire driveline to make sure that it is the problem. Check your u-joints, rearend, brakes, etc etc. I am not sayin I know whats wrong with your truck, but you should check out everything before youstart tearing stuff apart.


Tony

'77 F250, 4X4 460 transplantee, "Flamer"
'74 F250. 460, "beater" now "1 dead ford"
'73 F250, "midnight auto" now a trailer for the flamer

 

-Sorry about the delay. About the Divorced T-Case, I'm no stranger to doing difficult modifications. The donor truck would be junked out so I could grab the crossmember and the trannny from it for cheap, but I don't know if the frame widths on '77 and '78 4x4s are the same. By the way, my transfer case is an NP 203. So it is chain driven? Hmmmmm. I have checked just about everything else in the drivetrain and the hubs have been changed, so I fear it is the T-case. BTW, I can get these parts for cheaper than my junkyard wants for a gear driven NP 205.

-Dan