I am in the process of building a pulling truck right now and have a question on the strength of the divorced transfer case set up on the 77 and earlier trucks and the mated setup on the 78 and 79 trucks. I have 2 trucks to piece together for the project one is a 77 250 4x4 with the divorced setup but the frame is in bad shape the other is a 78 250 4x4 with the mated setup and the frame is in good shape both trucks will be running a np435 manual hooked to a 460 that will be putting out around 600hp. Which setup mated or divorced is stronger and does either have any benifits? Thanks for any replies.

 

Far better driveline angles with divorced case. If you upgrade the divorced case with 1350 or 1410 yokes and get a beefed driveline you won't be breaking anything. The mated cases are fine with a double cardin front driveline, but if you think you'll have the power to break the front driveline, double cardin CV shafts aren't cheap. Both mated and divorced T-cases are 32 spline and pretty darn bulletproof. The biggest upgrades are big yokes and the later style NP205 output shaft that has drilled oil holes instead of slotted style.

If you're gonna be pushing 600 ponies I think it's pretty safe to say you won't be rock crawling and there won't be much to catch on the t-case or front driveline. I prefer divorced, but both work just peachy really.

 

No there wont be any rock crawling here just for truck pulling only. The rear will be blocked and ladder bars installed and the front will also be blocked with ladder bars. I forgot to mention that the mated set up also has a high pinion front dana 44 so the angles actualy look less severe than the divorced set up. I appreciate the info and if anyone else has an opinion let me know.

 

I'd agree with averagef250 on this, equal strength. Divorced will give you better driveline angles if you're gonna be running much lift. If the front end is staying low the angles won't be much of an issue but it is a little pricey to have a front shaft made with a STRONG CV joint. The only thing I don't like about the divorced cases is the intermediate driveline. I've always feared that being a weak point BUT I know of several pulling trucks with divorced cases and they've never had an issue with it. I think if that shaft is built strong enough with heavy duty yokes at the tranny and t-case it won't be an issue. If you go with a divorced unit be sure to add plenty of support to it. That's a LOT of torque on the case itself and you don't want to snap a mount and have it spin on you.

Oh, one last plus with a divorced case is if you need to pull or work on the tranny you don't have to fiddle with dropping the t-case too.

 

Thanks for all the input It looks like I will be pulling the Divorced set up out of the 77 and putting it in the 78. I'll probably swap out that high pinion 44 and the dana 60hd out of the 77 this high pinion has alot smaller outer hubs and the 60HD outer houseing looks like it is beefed up more than the standard 60 in the 78. I know that these are not the axles of choice for my application but we have a couple of guys running them and as long as you keep the wheels spinning and eliminate the bounce they held up pretty good. Long term is 60 front and rebuilding a dana 70 that I have with a broken pinion.

 

The fact you can easily run any tranny in front of a divorced case really is a big benefit I forgot to mention. Most mid 70's highboys that I see had the factory t-case strut rod. I recommend urathane t-case mounts and a urathane shock absorber bushing for the end of the strut rod. When you put big loads through a divorced case they want to jerk front to back. You don't want it rigid mounted, but you want to make it so it can't move much.

I think the smaller factory center drivelines are a pretty big weak point in the divorced case design. I've seen alot of center driveline and yoke failures with stock parts behind big power. I think that small center driveline acts like a spring when you put a big shock load through it like dumping the clutch hard and it can't take it. If the center driveline is adequately sized with 1350 or bigger joints it should easily handle anything you can throw at it. The stock 4 speed highboy center driveline U-joint angles are only 3 degrees and 4 degrees with a C6 or NV4500.

I also tend to steer away from CV driveshafts because they're expensive and unlike a standard driveline you can't really farm shorten or lengthen them with good results.

The high pinion front and divorced case with a 4" or taller lift makes for a pretty nice front driveline and the stock length front driveline fits perfectly with a high pinion axle and a 4" lift.

 

Thanks for the info does anyone know how much work the swap will be from a mated to a divorced setup like I said I have the complete donor 77 250 for the parts but I'm guessing that it won't be a bolt on scenerio since the frames have different widths. Hopefully nothing a welder and a plasma cutter can't take care of.

 

How bad is the 77 Frame? There are alot of critical drivetrain angles to consider when changing from mated to divorced. Sure would be alot easier to keep the divorced frame or find another junker highboy for the frame.

 

Can sombody please post some pictures of there divorced set up? I am about to do the same on my truck...https://www.ford-trucks.com/forums/9...vorced-tc.html

 

I have a pic of my 1972 Power Wagon with Factory Divorced setup and brownie if you're interested. This means 4 shafts. I had to move the divorced np205 back 3 inches after swapping the auto for a 5 speed.

 

I am sure anything will help. I never did this before and it looks like iam going to winde up with a custom set up and Iam going to have to fab up a lot of stuff so any pics will help.

Thanks

 

run both mated and devorced i did what a hoot