2 Big Broncos Rocky Mountain Site
Ramp Time
This was essentially the first time the Bronc got out for anything other than pavement after the rebuild. I went down to Rockstomper's place to use his DTRTI (Dump Truck Ramp Travel Index) ramp to check for binding of the suspension, interference between parts and driveshaft length. The results were encouraging. There was actually very little interference between the tires and fenders. The right front fender had been smacked from the front before I bought the Bronc and had a slight wrinkle in it. With all the weight on the right front tire, the tire hit this wrinkle. A little hammer time will fix that problem.
Surprisingly, the short rear driveshaft turned out to be no problem. It's still too short, but I don't need to worry about losing it in the twisties. The rear springs are stiff enough that the axle doesn't seem to move away any further than it does hanging free. This is a concern in itself, but I'll deal with that another time. The loading we did from the front and the rear actually collapsed the rear shaft, or at worse, didn't change the length at all.
With a clean bill of health, it's time to hit the dirt!
Me again. I haven't figured out how to explain the lean...
The front tire is about 30" off the ground here. That translates to an 840
RTI. Since the lift kit will not improve flex by itself, this isn't surprising.
What is nice is that this flex comes with all new springs and bushings, instead
of all worn out parts. The truck has unbelievably better road manners now.
Here you can see the amount of droop in the front end. The TTB will drop
incredibly on either side. What I like about it so far is that one side can fall
completely away without affecting the other side. As Scott noticed, though, the
steering makes some pretty wild gyrations as the suspension cycles.
This picture shows the main problem with the TTB front end. Look
at the difference in length, angle and mounting locations between the swing arm
and the tie rod. Ideally, these should be the same length and parallel. One
possible solution for this is to add the Superlift Superrunner steering system.
This system is pretty expensive, so another possibility is to swap in some Chevy
steering parts that would lengthen the tie rod to the left side. Another mod I
will make pretty quickly is to switch the mounting of the tie rod ends to the
top of the knuckle arm from the bottom. This will help the parallelism
considerably, but will do nothing for difference in swing arcs.
The front driveshaft really doesn't move around too much on the TTB. I think
this has to do with the proximity of the differential to the swing arm pivot
point. Through the full suspension cycle, the differential only moves about 4
inches up and down. The problem some Fords have with front driveshaft clearance
between the 'shaft and the suspension crossmember is non-existent on The Bronc.
I have not seen it less than 1/4 inch with the shocks connected. Even with the
shocks disconnected and the swing arm forced down, there is still no contact
between the 'shaft and the crossmember.
The picture on the left shows the rear driveshaft with the truck sitting
normally. The picture on the right shows the 'shaft with the front end up. It
collapses about 3/4" or better.
This is the rear shackle angle with the rear suspension unloaded. This may be
limiting articulation, but we're not sure right now. The arch in the rear spring
actually makes the spring a hair short eye-to-eye. This warrants more
investigation.
Rockstomper (Scott Ellinger) himself
measuring for a new transfer case skidplate. The transfer case is really exposed
on The Bronc. This will be money well spent.
Another view on the ramp.
The back on the ramp. You can get a different feel for how far the TTB will drop
without too much encouragement. Driving up the ramp both forwards and backwards
would lift the other tire on the ramp axle off the ground easily. With the new
gears, could put the driveline in low-low and slide the clutch enough to make
the truck climb the ramp with only three wheels on the ground with no additional
throttle. That kind of control makes this all worthwhile.
Rear view on the ramp.
Here you can see the amount of droop available in the rear suspension. The
springs really limit articulation, I don't think it's over 6 inches or so
side-to-side. The problem is that the springs are almost fully extended with
just the weight of the truck on them. They do collapse nicely with the full
weight of the truck on them, though.
This is the unloaded side of the front suspension. Even with most of the weight
on the front, the off-camber side still droops nicely.
Remember, this is a 36" tire stuffed into this fender. The TTB has to
collapse about 8 inches to reach this point. I really don't think I could have
picked a better vehicle for a build up. It has required virtually no
modification to accomodate some rather extreme equipment.
Here is the wrinkle that the tire hits at full stuff. I do suspect that the
front fenders may require minor surgery to avoid all rubbing. Trail time will
tell.