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05+ unit bearing strength vs 1 ton spindle

Fordx4Offroad

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Sep 12, 2023
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This isn't covered already :flipoff2:
My truck is going to roll the trails around 10k lbs, and I'm building a 40 spline dana 80 rear.
What is the consensus on the 05 unit bearing strength vs a east coast gear supply 40 spline spindle and hub?

Ecgs claims 80,000 lb yield on the assembly, but I am having a tough time finding comparable data for the 05 unit hub.

The front axle is a dana 80 35 spline with 05 UBs so keeping a spare hub or 2 on long wheeling trips would be easy.

Strength/lifespan

Serviceability and finding parts the 05 ub wins, but I'm looking for Strength comparison.
 
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Curious of the strength as well. Hands down the unit bearing ans a weld on cup wins for serviceability. A bent / swollen spindle from an axle failure or crash would result in a lengthy weld repair and the burden of sourcing another 40 spline spindle. Were a unit could be replaced.

I would think a double splined axle and drive flange would be stronger than a traditional axle with flange.
Regardless, what it would take to fail either the splines or the flange in something I can not even imagine.
 
Unit bearings make great spare tire mounts too. That way your spare is not dead weight.
 
Fordx4Offroad said:
What os the consensus on the 05 unit bearing strength vs a east coast gear supply 40 spline spindle and hub?

Ecgs claims 80,000 lb yield on the assembly, but I am having a tough time finding comparable data for the 05 unit hub.
Click to expand...

I'd like to know this too.
 
Im going 05 UB is way stronger, never had one but i have had a 40 spl 60 spindle and that shit gets thin. In fact i got a couple bent spindles when i got the car.
 
bunk said:
Im going 05 UB is way stronger, never had one but i have had a 40 spl 60 spindle and that shit gets thin. In fact i got a couple bent spindles when i got the car.
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I would agree on stock bored out spindles or anything that uses stock machined hubs I can imagine is pushing it.

The east coast gear supply 40 spline spindle kit us supposedly way stronger than a stock spindle. But nobody has compared much to the 05 ub in a rear application in a hard core wheeling application.
Uphill obstacle weight transfer/ bouncing
 
RustyC said:
Unit bearings make great spare tire mounts too. That way your spare is not dead weight.
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That seems like a good way to trash a bearing, especially if you have a heavy wheel and tire combo. Roller bearings are not designed to be dynamically loaded in a static position.

I am also not sure why everyone seems to think carrying around a spare unit bearing is such a great idea. If you do something bad enough to damage your unit bearing, odds are you need to fix a lot more than just a unit bearing.

Fordx4Offroad said:
I would agree on stock bored out spindles or anything that uses stock machined hubs I can imagine is pushing it.

The east coast gear supply 40 spline spindle kit us supposedly way stronger than a stock spindle. But nobody has compared much to the 05 ub in a rear application in a hard core wheeling application.
Uphill obstacle weight transfer/ bouncing
Click to expand...

In your application, the East Coast Gear 40 spline kit is the way to go in my opinion. You get oil bath bearings which is a much better design for a big heavy truck like yours. My gut feeling is that it is probably a lot stronger too, but no real data to base that on.

It would be cool if someone cut apart a unit bearing to get some dimensions to make a comparison, but the GAWR for a Superduty 60 is listed at 5,990 Lbs. for an F350, and 7,500 Lbs. for an F450/550 (Same bearings I believe?).

Some People seem like they aren't familiar with the ECGS 40 spline builder kit, so here's a video to see what the OP is talking about. Significantly bigger than 14 Bolt stuff. They claim a 4x stronger spindle (80K Lbs. yield vs. 20K Lbs.) with a wheel hub to match and 40% greater bearing capacity. As best I can tell from a quick google search, a 14 Bolt has a GAWR of up to 8,600 Lbs. So maybe good for a GAWR up to 12,000 Lbs. based on bearing capacity? Quite a bit more than the 7,500 Lbs. max listed for a Super 60.
 
Fordx4Offroad said:
I would agree on stock bored out spindles or anything that uses stock machined hubs I can imagine is pushing it.

The east coast gear supply 40 spline spindle kit us supposedly way stronger than a stock spindle. But nobody has compared much to the 05 ub in a rear application in a hard core wheeling application.
Uphill obstacle weight transfer/ bouncing
Click to expand...
Im pretty sure all 40 spl spindles start out as 40 spl, cause if you bore a stock spindle to accept 40 spl the area where the small bearing sits would be paper thin. Thus having to use a different bearing for 40 spl applications. fwiw im talking steering applications
 
bunk said:
Im going 05 UB is way stronger, never had one but i have had a 40 spl 60 spindle and that shit gets thin. In fact i got a couple bent spindles when i got the car.
Click to expand...

Who's spindles were they?

I have the Solid Axle 40 spline spindles/hubs F&R and have to say they are beef, just like what that ECGS video showed. Much bigger bearings, bigger spindle nut, forged hubs. Only difference I saw between the Solid and ECGS in that video, was that the Solid hubs are set up for double splined shafts and drive slugs.
I did notice ECGS said they widened the bearing spacing (wish they gave some numbers), I don't know where the Solid stuff falls on that issue. Guess I'll have to measure one of mine just to have that info.
 
gt1guy said:
Who's spindles were they?

I have the Solid Axle 40 spline spindles/hubs F&R and have to say they are beef, just like what that ECGS video showed. Much bigger bearings, bigger spindle nut, forged hubs. Only difference I saw between the Solid and ECGS in that video, was that the Solid hubs are set up for double splined shafts and drive slugs.
I did notice ECGS said they widened the bearing spacing (wish they gave some numbers), I don't know where the Solid stuff falls on that issue. Guess I'll have to measure one of mine just to have that info.
Click to expand...
Solid axle co. Full transparency, they came off a U4 car that tumbled down a few hills.
 
I'm going with the unit bearing being stronger than even the aftermarket spindles/hubs because of leverage.

A UB hub doesn't have the leverage a spindle does, so in my mind the spindle would bend or break first. Snapping a spindle off has been done and documented a million times but I don't hear any story's of guys snapping the wheel mounting flanges off their UB hubs.....
 
SLOWPOKE693 said:
I'm going with the unit bearing being stronger than even the aftermarket spindles/hubs because of leverage.

A UB hub doesn't have the leverage a spindle does, so in my mind the spindle would bend or break first. Snapping a spindle off has been done and documented a million times but I don't hear any story's of guys snapping the wheel mounting flanges off their UB hubs.....
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You sure about that?

The wms is still in the middle of the bearings, just because the hub is longer doesn't mean there is more leverage.

I'd actually betting a ub has more leverage over the bearings being the wms is more inline with the outter bearing.
 
YotaAtieToo said:
You sure about that?

The wms is still in the middle of the bearings, just because the hub is longer doesn't mean there is more leverage.

I'd actually betting a ub has more leverage over the bearings being the wms is more inline with the outter bearing.
Click to expand...

I'm not talking leverage on the bearings. Leverage on the spindle only. A UB doesn't have a "spindle".....
 
SLOWPOKE693 said:
I'm not talking leverage on the bearings. Leverage on the spindle only. A UB doesn't have a "spindle".....
Click to expand...

What I'm saying is the spindle being longer, doesn't mean anything if the wms is still roughly in the same spot. The

I can't find the same diagram for the ub, but here is a good one of a kingpin hub, spindle, ect.

image012.jpg
 
'84 Bronco II said:
In your application, the East Coast Gear 40 spline kit is the way to go in my opinion. You get oil bath bearings which is a much better design for a big heavy truck like yours. My gut feeling is that it is probably a lot stronger too, but no real data to base that on.

It would be cool if someone cut apart a unit bearing to get some dimensions to make a comparison, but the GAWR for a Superduty 60 is listed at 5,990 Lbs. for an F350, and 7,500 Lbs. for an F450/550 (Same bearings I believe?).

Some People seem like they aren't familiar with the ECGS 40 spline builder kit, so here's a video to see what the OP is talking about. Significantly bigger than 14 Bolt stuff. They claim a 4x stronger spindle (80K Lbs. yield vs. 20K Lbs.) with a wheel hub to match and 40% greater bearing capacity. As best I can tell from a quick google search, a 14 Bolt has a GAWR of up to 8,600 Lbs. So maybe good for a GAWR up to 12,000 Lbs. based on bearing capacity? Quite a bit more than the 7,500 Lbs. max listed for a Super 60.
Click to expand...




I would also like to factor in the large difference in just the design of the two assemblies into the mix. the UB vs an oil bath bearing spindle and OE gawr.


How much heat build up is factored into the 100% duty cycle of an oil bath hub assembly's axle weight capacity? Is that a thing?

Absolutely if you are MAX GVWR rolling down the highway in your dually whatever that has a 12,000 lb gawr. your rear hubs are subject to a much more prolonged period of heat, and an oil bath hub can dissipate the heat better??


A fully isolated, sealed, greased unit bearing I'm certain would build up a lott of heat.
Especially adding braking heat into the equation that a 1 ton truck might see down a steep grade fully loaded. Maybe braking heat isn't that big of a deal in the rear.


Bc the front axle of that same truck with a Chevy kingpin dana 60 solid front axle still has a similar spindle that all these hubs are built around, but it's not rated for 12,000 Lbs.

How much of that 12,000 lb gawr is from 4 rear wheels and tires? Bc a srw rear axle can only be rated for the wheels and tires it is sold with, no?
 
I think the UB was a way for the auto makers to simplify assembly and save a few bucks. How many factory stock work trucks from the big 3 had problems with spindles bending?
 
'84 Bronco II said:
the GAWR for a Superduty 60 is listed at 5,990 Lbs. for an F350, and 7,500 Lbs. for an F450/550 (Same bearings I believe?).
Click to expand...
By the same logic, spindle might be stronger if they step up/back to a spindle for the 650 applications?

384C61CA-CFB4-4BB7-A8EE-F75614E5C43B.jpeg

 
Little different when the spindle is solid vs the limited space in a kingpin spindle with a 40 spline shaft going through.

If we're arguing the oem application point. Dana upsizes the spindle, bearings and hubs on the D80 when going from 35 to 37 spline axles.

Also, I belive the dynatrac D80 uses a proprietary hub, being that it has 12? Bolts on the flange. Would be interesting to see if they use a larger spindle and different bearings.
 
I know there has been talk about the 05 up UB having the actual bearings closer together than the 99-04 stuff, and even more so than spindle/bearing setups. That is definitely something that would work against the UB, especially in a heavy big tired rig I would think.
 
Big4x4ride said:
I know there has been talk about the 05 up UB having the actual bearings closer together than the 99-04 stuff, and even more so than spindle/bearing setups. That is definitely something that would work against the UB, especially in a heavy big tired rig I would think.
Click to expand...

Bearing spread = more stable hub
 
EXTREMETOWNIE said:
I can confirm 6 month old 05+Timken unit bearing can break at the inner race, in a bouncer type usage.
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Is it ever fair to call them bouncers anymore? I havnt watched any madram stuff in years, watched a vid the other day. Jimeny christmas they are at a different level now.
 
SLOWPOKE693 said:
A UB doesn't have a "spindle".....
Click to expand...

What do you think is inside a Unit Bearing? :homer:

This is a '99-'04 Unit bearing on the left, I imagine an '05+ bearing is very similar, just bigger. They make up for the shitty bearing spacing by using bigger bearings. On the right is a Dynatrac "Free Spin"conversion for comparison.
Old-New-3.jpg


Fordx4Offroad said:
Maybe braking heat isn't that big of a deal in the rear.
Click to expand...

When loaded heavily, or with a lot of tongue weight, the rear axle can actually end up doing the majority of the braking.

Fordx4Offroad said:
How much of that 12,000 lb gawr is from 4 rear wheels and tires? Bc a srw rear axle can only be rated for the wheels and tires it is sold with, no?
Click to expand...

GAWR depends on whatever the weakest link is. It could be the tires and wheels, or it could be the housing, bearings, or ring and pinion. For example, the old 2WD Superduties had 235/85R16 tires that were rated at 3,040 Lbs. max load, and the rear GAWR was 6,080 Lbs. on those trucks, but the 4x4 versions had 265/75R16 tires with a max load rating of 3,415 Lbs. but the rear GAWR was 6,100 on those trucks (as much as any Sterling was ever rated I believe).
 
'84 Bronco II said:
What do you think is inside a Unit Bearing? :homer:

This is a '99-'04 Unit bearing on the left, I imagine an '05+ bearing is very similar, just bigger. They make up for the shitty bearing spacing by using bigger bearings. On the right is a Dynatrac "Free Spin"conversion for comparison.
Old-New-3.jpg




When loaded heavily, or with a lot of tongue weight, the rear axle can actually end up doing the majority of the braking.



GAWR depends on whatever the weakest link is. It could be the tires and wheels, or it could be the housing, bearings, or ring and pinion. For example, the old 2WD Superduties had 235/85R16 tires that were rated at 3,040 Lbs. max load, and the rear GAWR was 6,080 Lbs. on those trucks, but the 4x4 versions had 265/75R16 tires with a max load rating of 3,415 Lbs. but the rear GAWR was 6,100 on those trucks (as much as any Sterling was ever rated I believe).
Click to expand...

Then show me a unit bearing that's bent at the stub and not the wheel mounting flange. :flipoff2:
 
I'd bet that the UB is stronger in ultimate strength because the diameter is so much larger but I'd also bet that the traditional spindle wears out much more gracefully due to the wider bearing spacing, especially with the BGMT tires OP is probably putting on the thing.
 
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