Rockheadsson

Looking at an '80 Bronco with a 302 Jasper engine, a 6-inch lift, and 35s. How do the Broncos tend to stack up against XJs (the other vehicle I am predominately researching)?

emptypockets

The '80 Bronco came factory with a 9" rear (removable third member makes trail repairs easier) and a Dana 44 TTB (twin traction beam) front end. The transfer case will be either a NP208 (2.61:1 low range) or a BW1345 (2.72:1 low range), both of which are part time cases. You didn't mention if it was an auto or manual, so I'll skip that. You can check the gear ratio either on the axle or if the door jamb sticker is still present. A door code of two numbers is an front/rear open diff, a code with a single letter and digit is a limited slip rear, and two letters and a number indicate front and rear limited slips.

A 6" lift is kind of excessive for a TTB and I would really check out the steering angles on the linkage. They came with a Y steering setup, but using a drop pitman and tie rod flip, you can get the linkage very close to level with the beams. If you want more detail I can go into it, but I have a feeling this might get boring for some...

Wheeling a TTB is very different than wheeling a straight axle. As a straight axle goes up over an obstacle, the one side forces the other down, so you'll have more contact. On a TTB neither side has a real effect on the other. Steep hill climbs can be adventurous as the front suspension unloads and pulls the beams together...

D44 TTB with 4" lift and drop pitman:


Here you can see how the beams act independently of each other:


TTB coils are a much stiffer spring rate than straight axle coils due to the movement of the beams. However, guys have made them flexy by swapping in 78-79 lower coil buckets to the beams, raising the upper shock mounts, replacing the 80-96 coil/shock bucket combo with the individual 78-79 setup, and replacing the TTB coils with 78-79 coils. Also, the addition of extended radius arms helps the suspension to further articulate before binding.

The weak link on a TTB setup is the fact that it has three u-joints. The inner stub u-joint is the usual culprit for breaking, but you can swap in a Dana 50 TTB inner stub and upgrade to a 1350 u-joint vs. the 1310 that the D44 inner stub takes. The same side axle is held in by a c-clip, but there is a trick to eliminate it, which requires a little bit of welding and a spring.

35's are about the upper limits for the D44 TTB, so if you want to go bigger, you need to swap in another axle. Swapping in a straight axle D44 doesn't give you any strength upgrades and by the time you're done upgrading it, most guys go with a D60 swap.

Things to look for on the Bronco is rot in the rear sill and around the rear quarters. Check the hinges on the rear tailgate, because they have a tendency to rot out as well. Also check the floors front and back to see if they're solid, body mounts, and the frame.

All in all, if you can live with guys making fun of your TTB, you'll find the Bronco to be a capable wheeler. I wheel the snot out of my TTB F-150 and it has yet to let me down. I think Ford's TTB is finally getting some of the respect it deserves in recent years. They're starting to run them in events like King of Hammers, though of course they are modified. One thing you need to know though is the TTB has to be understood to make it perform it's best. Many people consider them junk, but setting one up is an art and most aren't willing to try.

Ok, my XJ knowledge is limited, so hopefully someone will chime in. You might want to mention what year of XJ you're looking for, as there are some pros and cons to the various stages of the platform. Things I like about my XJ is the 4 link front, the smaller size (I can squeeze down certain trails that my truck never could), parts interchangeability between the Jeep platforms, and I get much better gas mileage (14 mpg in my XJ vs. 8-10 mpg in my truck with a slightly warmed 302, C6, 4" lift and 35's).



Owning both, I can say they both have their pros and cons. Each takes a different approach to setup and driving style. However, I don't think I could personally choose one over the other, since they both serve a definite purpose. Hope somewhere in this novel you found some useful info...

Rockheadsson

Wow, thanks!
The XJ I am currently looking at is an '89 with a 6-inch lift on 33s.

hawkfn18

The Bronco I s a great truck, I had a 92. I agree, I wouldn't go any higher than a 6 in. lift with a TTB axle. There are kits out there that allow you to install a solid axle on a Bronco and you can go higher. My brother in law did it on his F150, a lot of welding involved. One issue I know of from experience is that the automatic locking front hubs suck. Most guys (including myself) swap em out for manual locking hubs. Broncos are very good trucks, I do miss mine, but I don't miss the gas mileage!