Outfitting Your Land Yacht -A Guide to Building a Strong, Full Size-¾ -1 Ton, Domestic Rig-

[Dilldog]

The thing to remember with the GM factory locker is it uses fly weights to engage the locking elements. This allows it to work like an open diff in most street driving, but does make it more prone to failure. They are a cool design and worth looking into on depth if you have a sleepless night. Something like a Detroit uses springs and gear plates to lock up. They don't allow any differential action under power and tend to be noisy when coasting around corners but are very stout.

 

[M Rose]

Attached from frame rail to frame rail they were not made from a thick steel. Mine when I bought it had a upward curve (bend) in the middle where it did it's job protecting the trucks NP 203 (208?) aluminum transfer case. After a few years I took it off, and straightened it with a hammer. Better to have one than not (skid plate), as some protection is better than none. Aluminum is not cast iron!

208, not a 203... 203 is a full time Gear driven transfer case with a cast iron housing. The 208 is the weaker aluminum housing and chain drive. The 203 was used in 1978-79 Bronco’s and 1974-79 F150’s. The 208 was used from 1980-1986 in Ford F-150 and Broncos.

As for the skid plate...they updated them on the 1987-97 F250’s and will swap right in to the earlier 1980-1996 F-150 and Bronco.

 

[Desert Runner]

208, not a 203... 203 is a full time Gear driven transfer case with a cast iron housing. The 208 is the weaker aluminum housing and chain drive. The 203 was used in 1978-79 Bronco’s and 1974-79 F150’s. The 208 was used from 1980-1986 in Ford F-150 and Broncos.

As for the skid plate...they updated them on the 1987-97 F250’s and will swap right in to the earlier 1980-1996 F-150 and Bronco.

Thx, I was not sure. A buddy of mine had a 77 Chevy C10 (full-time auto),....a 203, that he put s electable hubs into, in an attempt to wring a extra mpg or 2 out of. I did like the H-...H lock......L.....L lock transfer case he had in it for real sloppy conditions when needed.

PS),,,,,,,,,,,,,,,,,,He was never happy with the MPG he got, but he liked his truck anyway. I definitely had a aluminum case 208.
PS2),,,,,,,,,,,,,,Update: Was a 1985 F-150, standard cab/ 4 speed manual/ 6 cylinder. Last year of Carb's on engine. Had a Lock-Rite, lunch box locker rear, 8.8, a Detroit True- Trac L/S front, with upgraded Warn premium Hubs, as the stock OEM's had a tendency to unlock on their own. This was the truck I put that dual battery set-up in.

 

[Dilldog]

208, not a 203... 203 is a full time Gear driven transfer case with a cast iron housing. The 208 is the weaker aluminum housing and chain drive. The 203 was used in 1978-79 Bronco’s and 1974-79 F150’s. The 208 was used from 1980-1986 in Ford F-150 and Broncos.

As for the skid plate...they updated them on the 1987-97 F250’s and will swap right in to the earlier 1980-1996 F-150 and Bronco.

I thought the drop housing of the 203 was aluminum and chain drive. I know the range box is cast iron.

 

[M Rose]

I thought the drop housing of the 203 was aluminum and chain drive. I know the range box is cast iron.

Nope, the whole thing is CI... or at least on early fords... and your right it’s a chain driven case.