...FWD is very unruly, though I think that is just how FWD is in any bronco, my 73 was sketchy in FWD as well.
What do you mean by unruly? You should be able to safely drive it in FWD only without too much drama. Was it feeling unsafe, or just not quite normal?
If the latter, then yeah, I guess that would be "normal" for FWD.
It would slip a tire on a turn and easily in reverse.
What are you describing here?
The problem was 4wd. This was on pavement, and the binding was significant.
Yes to the binding, but no to the significant. Even though it's not exactly recommended, you should at least be able to drive it in four wheel drive for a bit without binding. We're only talking about 1 or 2 points after all. 4.11 vs 4.09 or 4.10 depending on which Dana axle.
I had myself convinced that the gear ratios were significantly off front to back, so much that I pulled the rear diff after counting driveshaft rotations and believing it to be 3.50, turned out to be 4.10 once I got it on the bench.
Not sure what we're talking about here first of all. Didn't you just rebuild these diffs? And if so, didn't you note what gear ratios were being installed? Or are these axles just put in as-is? From this thread, they should have been all apart. Doesn't sound like you changed gear ratios, so maybe you didn't think to count the teeth while they were being worked on. Is that what happened?
I believe the front to be ~4.11 doing the same test.
Rear 9" should actually be 4.11 instead. What was your tooth count?
Front 44(?) should be 4.09 (45 - 11 teeth) for the 44.
Question is, before I pull the front diff cover, how substantial is the driveline binding on pavement? Enough to slow the bronco to a stop somewhat quickly?
No. It's there, but not so substantial that it would pull you to a stop just going around the block. How far did you drive it before you felt the bind?
Of course, this is the reason it's written everywhere that you should not drive it in 4wd on dry pavement or other high-traction surfaces for extended periods where tire slip won't occur now and then. You need the slip to release the tensions. Eventually something slips or something breaks.
But I still don't think you should feel binding quickly.
I was at a stop trying to move on pavement. It felt like it could have overcome the bind, but I didn't want to risk breaking something.
Good call. Shift out of 4wd or unlock the hubs, but don't drive it in 4wd anymore. Hopefully you didn't drive it far enough to cause trouble. Probably not, but it's good you caught it anyway.
Also, when I pulled the rear diff, I found one of the caps for the rear u-joint in the driveshaft had no needle bearings in it, so I guess it wasn't a complete waste.
Definitely not! Sounds like you didn't replace the u-joints while you had it out then? How many miles on the current setup? Was it dry and rusty-powder looking inside? Glad you caught it.
Good luck. Let us know what you find in the front diff.
Paul
