Superior 31sp axle shafts....can I run tapered bearings?

[mattt]

I have a set of Superior 31 spline axle shafts going into a new 9" rear axle. Since this is all new, can I run tapered roller bearings, instead of the stock Bronco roller bearings? I read a few threads here thru search, and it looks like there may be 2 different OD measurements that will dictate if you can run roller bearings only or tapered bearings. I think the #'s were 1.531"? & 1.562"?

Can someone who's BTDT give a definite answer if an aftermarket 31 spline axle can use a tapered bearing instead of a roller bearing?
Thanks in advance.

 

[DirtDonk]

No.
Well, "yes and no" would also be somewhat appropriate.

Reason I say that is that while many have done it and report no issues, the axle shafts are NOT the same diameter where the bearings press on. There is only a few thousandths of a difference, but it seems to me that this is enough to cause some trouble somewhere. I just haven't heard of anyone having it.

So take that at face value, and wait for others to chime in that have hopefully done it.
If it were me, I would just use a standard large bearing unless I was building a super rear end for a high power or large tire rig.
The BB bearings and axles hold up pretty well to minor abuse and such. And the seals are easier to replace! ;D

Having said that, and I still prefer the sealed bearings even though they're not as heavy-duty as the tapered Set-20's are, I'm going with our rear disc brake kit with axles that are special made for the tapered bearings. So I'm changing bearing type either way.

Paul

 

[DirtDonk]

Hah! Sorry mattt. I didn't even bother to read your whole post. I simply saw the part about "axles and tapered bearings" and jumped right onto the keyboard without seeing that you already knew most of what I said.

At least I got the part about waiting to hear from those that have done it right!

Paul

 

[mattt]

Thanks Paul. I'm a bit unclear on if it works based on what I read, which is why I'm hoping someone who's BTDT will pipe up. This is a complete new axle I'm putting together, Currie housing, Superior axles, ARB, 4.88's. I would prefer the tapered bearings over the sealed rollers, but if they won't work, they won't work.

 

[Quick & Dirty]

Another thing is the area where the seal rides. The tapered rollers have the seal between the bearing and flange, so that section needs to be polished and the correct diameter. Stock axles for sealed bearings are rough machined in that area.

 

[mattt]

Let me open this thread up a little...is there any Early Bronco specific 31sp axle on the market that is made to work with tapered bearings vs. the std. large or small roller bearling?

 

[DirtDonk]

Yes. Many of our "big-bearing" axles come with the Set-20's already installed.
http://www.wildhorses4x4.com/category/bronco_rear_axle
The #8602, #8604, #8606 replacements for the BB axles do.

So does our kit with axles for rear disc brakes.
http://www.wildhorses4x4.com/product/Rear_Disc_Kit_w_31spline_Axles

As mentioned, the original housing MUST be a big-bearing housing or the tapered bearings won't fit, no matter what the axle is made for.

Paul

 

[mattt]

Thank you Paul. I've got the big bearing housing covered. It's still not 100% clear after searching and reading older threads what it takes to use tapered bearings on large bearing early Bronco axles?

Is there a physical difference between..... #8602 vs. #8654/8656 or another option #8604 vs. #8658/8661......other than the bearing style that is installed? Are the axle shafts themselves the same product? If the shafts are different, where can that be discerned? Thanks again!

 

[DirtDonk]

Yes. The bearing journal diameter changes, so the ones you see listed as "Extreme" axles (like the #8602) may be the same material, length and spline count as the others, but have the different diameter to better fit the tapered bearings.
The ones listed as "Heavy Duty" replacements are sized for the standard sealed roller bearings.
So yes, there are differences and one should not be used with the other type of bearing.

As you probably figured out, the other differences, and the reason for the different part numbers in the first place, have mainly to do with wheel flange offset dimensions. So an 8602 and 8604 may use the same bearing, but fit different year brakes.

Paul

 

[mattt]

Ok, thanks for clarifying about the bearing journal differences Paul. I am aware of the different axle lengths, and brake back space differences between the 3 big bearing axles options in an Early Bronco. Ford just had to make it that complicated.....%)

I suppose it goes without saying since I saw no reference to it.....but there is not a conversion bearing on the market that is sized for original Early Bronco axles but is a tapered bearing? Thanks again.

 

[DirtDonk]

...I suppose it goes without saying since I saw no reference to it.....but there is not a conversion bearing on the market that is sized for original Early Bronco axles but is a tapered bearing?

With so many bearings available, it might very well be out there somewhere. Never heard of one, and never looked either.
Probably something fitting an Isuzu forklift, but only with the Hyundai Heavy Industries axle shafts sold exclusively in North Korea.
Or something like that!

Paul

 

[baddad457]

Just me but the bad thing about running the tapered bearings is in service they're fighting to get out of the housing. The bearing retainer needs to be a heavy duty piece and the bolts will need to be HD also and have new lock nuts to combat the tendency of the bearing to come out of the housing. I went thru this with a V8 Ranger with a narrowed 8.8 rear that was fitted with 9" bearing ends. Never again

 

[mattt]

With so many bearings available, it might very well be out there somewhere. Never heard of one, and never looked either.
Probably something fitting an Isuzu forklift, but only with the Hyundai Heavy Industries axle shafts sold exclusively in North Korea.
Or something like that!

Paul

I suspect you're correct sir