Short bed 4x4 owners- driveline question?

[Rembrant]

Hey Jon,

I'm probably not much help at this point, but can confirm a couple things I guess. I swapped a 1995 4x4 chassis under my 1980 Flareside, and it was a factory SWB 4x4 with dual tanks, etc.

It had a BW1356 transfer case with a tail section and slip yoke design. It had a fixed length drive shaft and a fixed u-joint at the 8.8 rear diff. Can't tell you the length of the driveshaft though as the truck is gone, but it was pretty short. I later bought a 1988-1991 BW1356 TC because I needed one with a cable speedo drive for the the Bullnose cluster, and it was identical to the 1995 BW1356 other than the speedo drive.

This 1995 swb 4x4 had dual tanks, but I don't recall any skid plates...definitely not on the rear tank. It was a heavy spec truck for a swb though...it had factory front and rear swaybars and quad front shocks.

Here's a pic of the BW1356 TC behind an M5OD 5spd and a 1986 300, just before I installed it all back in the frame.

[Nothing Special]

Ford F834 wrote

Bob that’s interesting, thank you! I assumed they were standard equipment on all 4x4 but evidently not!

A spare tire and even a rear bumper were options on my '85!  Ford liked to keep the base price down.

[Pete Whitstone]

Ford F834 wrote

Pete, I have another question for you… does your truck have as gas tank skid plate?

The frame I bought was from a 4x4 truck, and not likely a conversion. It has the wider rear springs and the hangers are on with the factory rivets. It has dual gas tanks, but both were mounted with straps, not skid plates. I’m wondering if the short box trucks didn’t get them? Thanks.

-Jonathan

My truck was not born as a 4x4 either, so it's not a good example of an original truck. I've never heard of gas tank skid plates. The 94 donor vehicle I took the 4x4 stuff from did not have them. It did have a kind of a plastic cover on one end of the sidesaddle tank. Not sure if that was designed to be protection of some kind or not.

[Ford F834]

Ah, I should have picked up on that since a 1981 would not have come with the BW1356. I’m not sure of the purpose for the plastic cap on the front of the saddle tank, but it’s there on both skid plate and non-skid plate trucks. It’s pretty caked with grease and dirt but you can see it on my 89 parts truck:



And here is the rear skid plate under my ‘81 that came from the ‘82 4x4 parts donor:

[Ford F834]

Thank you Cory! It looks like your factory set up actually WAS a slip yoke 1356. That must have been a very short rear shaft indeed… which makes me wonder about the transmission mount and position of the transfer case yoke relative to the axle yoke. If it didn’t have that much drop then I suppose short would be okay. Very interesting information thank you.

One thing that occurred to me is a fixed yoke transfer case would make the back shaft uncanny close in length to the front one. I don’t know if I would get so lucky that one would work as-is, but it might be a starting point for shortening.

[Rembrant]

Ford F834 wrote

Thank you Cory! It looks like your factory set up actually WAS a slip yoke 1356. That must have been a very short rear shaft indeed… which makes me wonder about the transmission mount and position of the transfer case yoke relative to the axle yoke. If it didn’t have that much drop then I suppose short would be okay. Very interesting information thank you.

I must have taken a thousand pictures of that truck as I built it, but I didn't get much of the driveline unfortunately. Here's the frame before I set everything back in. The rear driveshaft slip yoke sits almost directly under the cab rear mount crossmember.



Just found another pic, and the slip yoke is actually just forward of the cab rear crossmember. Man, the length of that trans and transfer case make it look like it would stick out behind the cab...



This one is with the cab back on and everything installed...sort of...lol. The rear driveshaft, as short as it was, was actually not on that sharp of an angle...at least not as steep as one might think, relative to the length of the truck!



I kinda miss that truck some days. It was a great Covid project...I probably should have kept it. I'm a sucker for a Flareside 4x4! It currently lives in a warehouse about 75 miles from here...just sitting there with a battery tender hooked up. It might have had 100 miles put on it since I sold it a few years ago.

[grumpin]

Dang Cory! That's a good looking truck!

[Nothing Special]

I used to have a '75 Jeep CJ5.  With an in-line 6 and a T-18 4-speed it wasn't a short setup, and it was in a short vehicle.  The rear driveshaft on that was about 12" long.  And that was with a fixed yoke on the transfer case, so there was a slip joint in the driveshaft.

All I'm saying is there's no such thing as a "short" driveshaft in a full size truck, no matter what cab and bed it has!

[Ford F834]

Cory, thank you for the additional pictures, these are helpful and gives me a better understanding of the slip yoke set-up. I must have had my measurements scrambled because I checked again and I think you and Pete had the same configuration and the rear shaft would be 33 3/8”. I have a solid 34” shaft on the ‘89 parts donor, so maybe shortening it 5/8” and running the 1356 is a viable option.

Cory, Pete, can either or both of you tell me what you had to do to get a bullnose 4x4 shift lever to link up to the 1356 since it came through the side of the tunnel on later models? Thanks.

Bob, I guess short driveshaft talk for pickups probably equals long driveshaft talk for Jeep owners! 😅

[Rembrant]

Ford F834 wrote

Cory, Pete, can either or both of you tell me what you had to do to get a bullnose 4x4 shift lever to link up to the 1356 since it came through the side of the tunnel on later models? Thanks.

Jon, I used the 4x4 shifter set up from the 1995 donor truck, and installed it in the 1995 factory location. When I bought this 1980 4x4, the transmission and transfer case were already gone, so I didn't have the Bullnose parts to work with. I'm pretty sure I've read that others have done what you're asking, but I did not. I had the 1995 parts and I didn't mind using them.

Here are the only pics I could find showing the 4x4 shifter (and also the 1995 tunnel cover and 5spd stick).

[Rembrant]

grumpin wrote

Dang Cory! That's a good looking truck!

Thanks man! But, I must admit that it showed better than it actually was! The bed was great...I built it brand new from scratch (I had another Flareside at the time to copy). The cab, front clip, etc was only so so. Still, it looked like a million bucks at 20/20....that is, from 20ft at 20 mph lol. I betcha I spent 100 hours welding that truck back together, and it still was never 100% finished. The 300 inline six was a nice match up with the 5spd and 3:55 diffs though, I do remember that.

[Pete Whitstone]

Ford F834 wrote

Cory, Pete, can either or both of you tell me what you had to do to get a bullnose 4x4 shift lever to link up to the 1356 since it came through the side of the tunnel on later models? Thanks.

No actual lever linkage on mine, the 94 (95? not sure which) donor vehicle has the motor on the back of the transfer case. I transplanted the switch into the cubby to the right of the column.

[Ford F834]

Thanks Pete and Cory, for sharing how you shifted the 1356.

Oddly enough I probably have my own answer, since I am running a late 1345 out of a bricknose. Everything fits and works but the transfer case lever is clocked differently which puts my shift lever in an odd position (too far forward). I meant to modify the linkage to correct this but never got around to doing so. The 1356 is likely similar if not exactly the same. I believe the connecting arm needs lengthened.

[Dabbler]

I might be a bit late on this but if it helps, my ‘84 F150 117” SB has a NP 208F with a slip yoke driveshaft at 40-¾” in length from top of yoke ears (longest points).

[Ford F834]

Thank-you! Not too late at all, and helpful as this is different than the two gentlemen who responded already (their trucks had later generation drive train). Much appreciated 🙂

[Dabbler]

Glad to help. Here are a few pics. Shows front slip shaft too.