Hey guys,

I've been trying to replace the u-joint in my front drive shaft which has turned into a complete boondoggle. I've order two different u-joints from various places and they don't fit. The caps are too small to press in. They slide right through. Did someone replace the drive shafts in my Bronco with ones aftermarket ones at some point or something? If so, how can I find a u-joint that is the right size? Any input is much appreciated. Here are some pics:

Here's what the u-joint looks like in the drive shaft:


U-joint and drive shaft end:


Whole drive shaft for reference:

Looks like someone upgraded axles.

Stock EB axles use Dana 5-260x ujoints, bigger/later F150s and Broncos used the 5-760x ujoint. Also many aftermarket axle manufacturers used the larger ujoint.

http://www.dennysdriveshaft.com/p2207_d ... oint_.html

http://www.dennysdriveshaft.com/p1687_d ... ord_w.html

Take some measurements and compare.

Do you have F150 knuckles/disk brakes? I think the larger ujoint will not fit through the stock EB knuckles. Or maybe after a ujoint fails the damaged ujoints/axle flanges won't fit.

What gunni said.

I'm confused about what you're saying gunni. My axles are stock. I just did the u-joints in the front which were the 5-260X u-joints. Is there a correlation between drive shaft and axle u-joints?

My front axle is a Dana 30, with drums. My rear is a Ford 9 inch. The original set that came with truck as far as I can tell.

He is working on the drjveshaft, not axles, guys.

I've not seen that issue before. Unless the cross size is changed? Is the cross section too short as well or is it just the cap size that's too small?

Doh! Sorry. That is weird.

Do you have the u-joint that came out of it? About 2/3rds the way down this page are different measurments for different u-joints.

http://www.pirate4x4.com/tech/billavist ... index.html

If the 1310 joint is too small across & too small a cap, it could be a 1350.

Yes it is very strange. That's perfect! I do have the old one. I'll measure it tomorrow and check to see if it's a 1350. Thanks for the advice and info! You're a lifesaver.

So things are getting weirder. Measured the u-joint. One set of caps with a c-clip on the inside of the cap have a diameter of 1.129" or so, these are the caps that came out of the drive shaft side. The other two have no c-clip and are 1.062" in diameter. Overall length is 3.22". So the overall length and one set of caps match the 1310. The other side do not match anything in the table as far as I can tell. The 1350 caps are 1.188" in diameter which is much larger than what I measured. Not really sure what's going on with this. It seems to be some kind of adapter joint or something.



EDIT: Right after I posted this, I found table and the 1310 BC u-joint matches the specs for my mystery joint. Looks like that's what it is

1310 BC (Big cap)? I had a 1330 BC on my 79 Bronco axles. I didn't know there was a 1310 BC.

http://www.driveshaftspecialist.com/HTM ... Guide.html

EDIT: I didn't see your EDIT.

Yes there is a 1310 big cap, but I don't see anything about them being on Broncos so I'm not sure why it's on there. Never a dull moment working on the '66. Now I just need to find a replacement with the inside snap rings on the big caps and I'll be golden. Or I suppose I could try and rebuild this one. Can I do that?

If it's not damaged then you should be able to rebuild it, what do the needle bearings look like?

Needle bearings seem okay. None look damaged as far as I can tell. Could I clean the whole thing up and replace the needle bearings?

I could get a brand new one, but I can't find one with inside snap rings on the larger caps.

Alright more updates. It's not a Ford BC. I have a Borg Warner drive shaft so its an adapter between the Borg Warner shaft, which needs a bigger cap, and the normal 1310 for the diff (Mechanics 2.5r to 1310). The Spicer u-joint that would fit would be the 5-2530X, but it seems to be discontinued. The is interchangeable it looks like, so it looks like that's what I'm going to get. Just FYI for anyone else who may run into the same issue.

Wow, that's random. Good job chasing all that down. I'd be tempted to convert it back to stock just to be able to find parts more easily. I'd hate to wind up stranded in the middle of nowhere needing to order something in. Stock driveshafts are fairly easy to find, and not terribly expensive. I've got a rebuild-able spare that I'd consider selling.

Yeah it is really random. I guess the early Borg Warner drive shafts all have this adapter u-joint. Most Broncos get converted to Spicer drive shafts so you don't see it very often. I bought two new ones so I have a spare, but as this has dragged on the thought of converting to a stock Spicer drive shaft and keeping this one as a spare is enticing. The Cardan joint is probably going to need a rebuild also so it probably makes sense to swap before I do anymore work. I would be interested in buying if you have one to sell Justin.

Is this because of the 1966 production? Curious. Good work figuring that one out.

Is this on both front & rear driveshafts? Are all the joints this way?

I might have an extra driveshaft or two when I'm done with my project, but I have to see how things work out. It will be a month or so, probably (maybe/probably longer, LOL).

Keep in mind, your Bronco was among the first few hundred produced. Everything has the potential of being odd, weird, and completely off the charts.

Just wait until you have to start dealing with rust and discover the joys of the Budd body.

Yeah it's been quite an adventure already coming across unexpected bits and pieces that are irregular. It's always exciting working on the '66, even doing something as simple as drive shaft u-joints. Luckily since it spent its whole life in the dry air of the high country, it's basically rust free (minus a bot of patina here and there) with the exception of the floor panels.

You guys have been a huge help though. Would have never made it this far without your input.

Catching up on old posts. As far as I know there aren't replacement parts available for the BW driveshafts. I'd consider yourself lucky you found a U joint. When a part beyond the joint fails your best bet is to upgrade to the current Spicer setup.

That was my worst fear. And unfortunately it wasn't the u-joint at the front differential making the squeal. Looks to be coming from the double cardan joint on the other side so it looks like I'm going to be upgrading, as I don't know how easy it will be to find the parts to rebuild that.

I stand corrected. Jeff's Bronco Graveyard has Borg Warner CV heads and u-joints. I might grab a rebuild kit and stick with the BW shafts for now so I don't have to change the yokes on the transfer case.

That'd keep you running, also consider sunk costs & opportunity costs. If I remember correctly you aren't planning to make this a trail rig, so keeping the current setup will serve you well. If you are going to wheel it I'd make the investment now and go Spicer.