1986 bronco ford 9 inch axle gap

[angrymeat]

so long story short I had an ear on my slip yoke break which offset the driveshaft by about 10 degrees going 80. Needless to say, the pinion and all associated bearings needed replacing as well as the yoke. So I have installed a new ring and pinion (3.50) I have that all dialed in and to spec and reinstalled on the bronco. While I had the axels out I noticed the seals had been leaking so I replace them as well with Timken set20 combo. When I slide the axles in I work them until they slide in and are engaging the diff. once I put in the bolts and try to put the drum back on I notice there is about a half to 1-inch gap between the back of the drum and the backing plate. I pulled one of the axels back out and checked the bearing and ring they are both fully seated (seated them using a 20-ton press). I have tried putting them back in and working them around a bit to see if I wasn't fully seated or something and every time I end up with the same gap. Any ideas where I should look from here?

 

[Broncobowsher]

I don't know if there is anything special about an '86. This site is really for the '66-77 first gen Broncos. Some of us know a little about the 3rd gen you have. A better source would be www.fullsizebroncos.com (I hope I typed that right). If there is anything different about being an '86 they would better know it.

 

[thegreatjustino]

Axle bearing offset needs to match the rear brakes. On the first generation Broncos we discuss here, there were three different rear brake setups - each with the corresponding axles with correct bearing offsets. They are not interchangeable. If you use the incorrect axle and brake combo, the drum will either bottom out on the backing plate or have a gap like you're experiencing.

I have no idea if there were different brakes and corresponding axles on an '86 Bronco but that would be my first thought based on the different brake setups the first generation used.

 

[DirtDonk]

Agree with the full size sites, such as the one listed and also Ford-Trucks forums.
But out of curiosity, you're managing to get the retainer plates pulled up tight against the axle housing ends, and the brake backing plates are bolted fully down? Just that the drum is not able to set back due to the axle flange itself being too far out?

That's a strange one for sure. Once you've pulled the retainers up against the housing ends, you're 99.9% there.
If those had not seated I would have asked if you had a limited-slip differential and had not engaged the second set of splines down inside. Happens a lot with that type of diff.
But the shaft sticking out too far is odd for sure.

Good luck.

Paul

 

[angrymeat]

Thanks honestly I didn't notice the 66-77 when I first posted sorry about that.
I will answer though I am snug against the axle flanges with the backing plate. These were the same axels and brakes that were on this all along so nothing there has changed. It is an open diff I beginning to think its the retaining ring on the bearing. The original one was somewhat tapered and about 1/4" smaller which is right about how big my gap is.

 

[PaveBronco]

Not knowing much about the 86, I checked Bronco Graveyard, they do full size also, and the set you specified said its for after market axles and used on 78 and prior 31 spline..so maybe you got the wrong parts.

https://shop.broncograveyard.com/Ford-9-Set-20-Timken-Wheel-Bearing/productinfo/12388/

there does seem to be several different bearings for that year..

https://www.rockauto.com/en/moreinfo.php?pk=5566119&cc=1105861&jsn=717

 

[Justafordguy]

I agree, Sounds like you got the wrong bearings. I'd double check with the supplier.

 

[TonyPDX]

If you switched from the OEM style bearings to Set-20 you need to pull the inner seal...

 

[DirtDonk]

His '86 should have come from the factory with the Set 20's.

Paul

 

[DirtDonk]

...It is an open diff I beginning to think its the retaining ring on the bearing. The original one was somewhat tapered and about 1/4" smaller which is right about how big my gap is.

What's tapered on the retainer? Smaller is somewhat unusual too, but the factory ones were often not the same as the aftermarket.
But most Set-20 bearings come with a monster thick bearing retainer ring when compared to what we're used to seeing on our older rigs with sealed ball bearings.

But a difference is a difference, and something to be questioned in this case.
I would take them out again (if you haven't already that is) and look at where the bearing seats up against the inner flange of the axle shaft and see if that gap exists. Seems it should have pulled up hard against the wide section of the axle.

If you've been on the other sites yet, I'd bet we're all curious what you find out from them too.;D

Paul

 

[angrymeat]

Oddly this is the only site that has replied .
The retainer ring on the original bearing was about 1/4 thinner I am digging for my calipers to see if the current one will clear the opening.

 

[angrymeat]

I know this is still the wrong place but I figured it couldn't hurt to ask here since I am sure you all work with a lot of ford 9's so I'm out of ideas picked up a new bearing and took one of the new ones off to take a look to see if there is anything causing a gap. this is what i found below though it looks like it should be there to me it looks like that is where the seal seats but thought maybe other more experienced eyes could help.

https://drive.google.com/open?id=1-Rof0wyA4i56JecmhqNF9kcwg4fTH7o-

 

[angrymeat]

Ok ignore the crazy man from the 80s. That ring was in face the inner race from a national a20 once i got that all I am good to go but nothing can fix my pride

 

[DirtDonk]

Haha! Yeah, no problem with us knowing what you just went through. I'm sure many have been there and done the same thing.
But I think that does tell you at least one thing that was wrong with your setup. While the outer race and seal will easily separate from the assembly once it's got a few miles on it, that inner one is part of the bearing and should never separate!
Seems you had some serious issues waiting to rear their ugly heads. Glad you found it, even though it meant a big hassle, before finding out the hard way.

Thanks for posting up the pic too, so others will know what to look for.

Paul

 

[nvrstuk]

...and here lies another reason why this is why FORD's pressed on axle brg/retainer to hold the axle in place is potentially a major safety issue. Bearing failure usually means you roll your Bronco because you are missing a rear tire/wheel combo...

Glad you found the issue and actually glad the driveline yoke caused this scenario as the wheel brg would have failed and probably let your tire/wheel/axle combo walk out of the housing and caused an accident.

Good luck with your '86

 

[angrymeat]

yeah, I picked this up from a meth head nearby for 1,500 with a 9-inch lift on it so far everything I have seen that he touched was ....... special. we won't talk about the cv joint on the rear drive shaft that had the ball backwards and the grease hole widened with I'm assuming a Dremel and a half size u joint. So far I have replaced all of the joints in the truck. the ring and pinion, all of the wheel bearings and the spindle bearings, entire front suspension and drums/rotors all around. But I have to say I have owned several muscle cars new and old but this giant redneck caricature of a truck is by far my favourite one to drive.