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18' Axles *DO* Fail - Replace Yours ASAP


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Glad you're ok!

This is what I'm hoping will save me...I have a 78 Chinook. It's the bigger, "Newport" model. Single rear wheels. It might have a bit of a low rating, but its passable, right? The big problem was the "fake" duallys, right?

If there were heavy duty axle shafts and heavy duty bearings I could buy that were a direct swap, I'd definitely like to do that.

There are no Toyota axle shafts or bearings that are more HD then what you already have for your rear axle assembly. The later years did upgrade the rear axle tube OD to larger size - but not the bearings or axles. There are aftermarket kits to make your rear axle into a full floater to make it stronger. The kits cost more then just buying and swapping in a FF assembly. The kits use the bearings and stubs from the fronts of Toyota 4WD trucks and bolt them to the back to make full floaters out of them. You can also install a full floater from a Land Cruiser and have single 15" rear wheels instead of dually 14". I'm not recommending it. Just mentioning as an option.

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from what i have heard a big part was the fake duels way yours with your common load see where you are check your rear bearings for slop three two six months. i used to have a toyota corona wagen fifteen years wife three kids loaded to the gills even the roof 200,000 miles wa to whyoming and everwhere else put three sets of rear axle bearings at least. in montana some people could not bleve we all got out of that car had a 10 by 14 caben tent tied on top.

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I have never personally seen a Toyota axle actually break off but I've read stories about it happening from the "fake" duals. The claim of axle duress caused by the uneven leverage they cause makes sense to me.

I HAVE seen Toyota and Ford F150 axles come out. I.e "fall out", still in one piece and not longer attached to the vehicle. There is an aftermarket kit available to make them more secure but I doubt it's worth the expense. The standard Toyota axle is only held in place by the integrity of the ball beaing and the press-on steel ring. If the bearing goes bad and the vehicle keeps being driven, it can result of the axle "leaving home" and falling out.

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There are no Toyota axle shafts or bearings that are more HD then what you already have for your rear axle assembly. The later years did upgrade the rear axle tube OD to larger size - but not the bearings or axles. There are aftermarket kits to make your rear axle into a full floater to make it stronger. The kits cost more then just buying and swapping in a FF assembly. The kits use the bearings and stubs from the fronts of Toyota 4WD trucks and bolt them to the back to make full floaters out of them. You can also install a full floater from a Land Cruiser and have single 15" rear wheels instead of dually 14". I'm not recommending it. Just mentioning as an option.

there are however, aftermarket ones that the rock crawler guys are fans of that claim to be more HD. they are not made by toyota.

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there are however, aftermarket ones that the rock crawler guys are fans of that claim to be more HD. they are not made by toyota.

Yes they offer aftermarket axles but as I understand it . . the only added strength is in the inboard splines. No added weight bearing capacity. The same place also offers the full-floating add-on kits.

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Yeah, there are longfields and other aftermarket "stronger" axles for 4x4's, which is why I was asking. Thanks!

They are rated as being stronger at the splined ends inboard. I don't see any claims for being more durable where it counts on a motorhome. Rock-crawling machines are concerned about twisting the splines off the axles from torque and to a lesser degree -breaking them in half from weight overload or drop-shock. Stock Toyota axles are already high grade steel and heat treated. I suspect the only way to make them stronger is to make the axle larger diameter or - increase the area the bearings ride on - or totally eliminate the axle from weight bearing like the full floater does.

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pardon the question but what makes you think the axles are identical in size to the toyota ones? do you have a link to that>?

also metal alloys have far advanced since the 1980s... I believe the aftermarket ones are as such a different metal alloy.

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Longfield is even making chromoly axles now. But it mostly talks about torque, especially at sharp turns (offroading). It does talk about more weight capacity...but I don't feel like searching through all the threads right now to really find out.

I've been planning to just keep my Chinook axle stock and replace my bearings and always make sure they're in good shape, and call it good anyways. I just figured if there was an easy, not crazy-expensive upgrade, I'd look into it.

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Glad to hear no one was seriously hurt !

This has really got me thinking.....

I do have the 6 lug rear axel in my 86 Winnie , but it still has the 5 lugs on the front. It sounds like mine was upgraded , no ?

Now I am worried about the front 5 lugs. I understand these were not subject to recall , but that Toyota did make a 5 lug to 6 lug adapter for the front.

I had my Winnie weighed at a local landfill last year when I bought it , and with full water and propane (empty holding tanks and NO passengers) it weighed in at a WHOPPING 6800 lbs. !!!

Does this sound like my rig is SERIOUSLY overloaded ??

I am going to try and search for the 5 lug to 6 lug adapter , but I hear they are quite hard to come by.

Anyone know where I may find one ?

It is not a problem, actually the wheel bearings are the same size it is a pain because you have two different wheel styles and slightly smaller front brakes the load capacity is the same.

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I know the regulars chimed in on this but what failed was the fake dually wheel

The 18 foot sunrader is fine with the regular wheel and 185 14 tires.

That's within the weight limit. Its the fake dually wheel that's dangerous.

That's within the half ton payload of the regular truck. I dream about it really literally a thousand pounds less than mine.

I'm sorry for the damage to your vehicle but if I were you id literally be looking for a half ton rear end and put single wheels on it. That's the best of all worlds single wheel toyhome.

Those fake duallys were just on there to use cheap tires, they aren't a dually at all that's what killed the axle.

My 79 with fake duallys literally had a bend in the rear wheel between the wheel and axle.

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What is this "regular wheel" that you're saying is okay on the 18' Sunrader?

P.S. Glad you cleaned up your signature! :-)

The 18 foot sunrader is fine with the regular wheel and 185 14 tires.

That's within the weight limit. Its the fake dually wheel that's dangerous.

That's within the half ton payload of the regular truck.

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The problem with the 1/2 ton axles is the ability to carry the weight they break at the flange where it meets the hub just outside the bearing. The aftermarket axles have a deeper radius at the flange but are still prone to flex at the hub because the single bearing is it's only support. The fake dual wheel don't help because it actually increases the tendency to flex the axle at the hub. An after market axle will help the torque rating but not much more.

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pardon the question but what makes you think the axles are identical in size to the toyota ones? do you have a link to that>?

also metal alloys have far advanced since the 1980s... I believe the aftermarket ones are as such a different metal alloy.

Crome-moly alloys e.g. 4340 for axles has been around a long time. NOT a new-age alloy and it is pretty much the standard for truck and high performance axles.

As to increased size? How is it possible to increase size when the aftermarket axles use the same bearing? Axle OD is limited to wheel bearing ID. Toyota axle is 1.5" OD and that's as big as can be used with the RW130R ball bearing. Same size as many 70s-80s Ford F150 axles rated at 3300 lbs. I've had not seen anyone offering larger diameter axles and bigger bearings for the Toyota rear. Marin Rock Crawlers et. al. offer a full-floater add-on kit for the rear for that purpose.

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The problem with the 1/2 ton axles is the ability to carry the weight they break at the flange where it meets the hub just outside the bearing. The aftermarket axles have a deeper radius at the flange but are still prone to flex at the hub because the single bearing is it's only support. The fake dual wheel don't help because it actually increases the tendency to flex the axle at the hub. An after market axle will help the torque rating but not much more.

Yes that is one of two problems. The other is . . the sealed wheel bearing and little pressed-on steel ring is all that holds the axle in. If the bearing fails, the axle can fall out (in one piece without breaking). The older Ford F100s and F150s were set up exactly the same way and also had an "axle falling out" problem. The Toyota axle looks to me like a Ford copy. Maybe it is.

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Okay I'm still unclear about 18' Sunraders being okay with "regular" wheels... Are you saying that some Sunraders had single wheels in the back and that those are okay?

a standard 14 inch wheel

a non fake dually wheel.

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The purpose of the fake dullys was originally tire loads. the tires they used could not support the weight, Passanger car tires.

The recall specifically called out the fake dullys as the problem.

On a regular single wheel, the center of load is directly over the bearing, and the rollers in the bearing support the weight evenly. See drawings below.

The fake dullys move the center of load 6 -8 inches outboard. As the axle bends slightly, the loads on the bearing are now on one side rather than evenly across the entire surface of the roller bearing.

This can cause premature bearing failure, which will cause the axle to fail.

The Recall says that you need to increase the tire pressure on the inside tire and reduce the pressure on the outside tire. This will move the loads more to the inside tire, and help move the center of load back inboard and more directly over the bearing.

If I owned one of these, I would get the truck weighed. If its less than about 4500 lbs, I would get rid of the fake dully and just run a single wheel with a light truck tire.

JOhn Mc

88 Dolphin 4 Auto

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I would also I'm sure I said that.

The load of an 18 foot sunrader is fine for single wheel tires.

I can see that it could get overloaded with people and canoes.

If not its perfect you don't need all that useless weight.

But if there's something I never heard here about it I don't know.

I know this if you're not replacing anything today take out the fake dually wheel and put on a regular wheel with a hd truck tire its better at least. It should be safe.

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The purpose of the fake dullys was originally tire loads. the tires they used could not support the weight, Passanger car tires.

The recall specifically called out the fake dullys as the problem.

On a regular single wheel, the center of load is directly over the bearing, and the rollers in the bearing support the weight evenly. See drawings below.

The fake dullys move the center of load 6 -8 inches outboard. As the axle bends slightly, the loads on the bearing are now on one side rather than evenly across the entire surface of the roller bearing.

This can cause premature bearing failure, which will cause the axle to fail.

The Recall says that you need to increase the tire pressure on the inside tire and reduce the pressure on the outside tire. This will move the loads more to the inside tire, and help move the center of load back inboard and more directly over the bearing.

If I owned one of these, I would get the truck weighed. If its less than about 4500 lbs, I would get rid of the fake dully and just run a single wheel with a light truck tire.

JOhn Mc

88 Dolphin 4 Auto

Let's say a specific Toyota RV weighs 5000 lbs. when on a scale. At that time it is level and weight is fairly equal front to back. Considering the overhang beyond the back axle I'll guess and say 3000 lbs. in back and 2000 lbs. in front on level ground. That is not a "real world" weight reading. When the same RV climbs a hill, more weight comes off the front and transfers to the back. When you round a curve at a high speed weight transfers from one side to another. What is the safe weight capacity of a Toyota 1/2 axle? Probably around 3300 lbs when spread evenly between both sides. If run at 1000 lbs. over (4300 lbs.) it will wear prematurely. The more overweight it is, the faster it will wear but - at some degree of overload there is the "straw that broke the camel's back" and you get immediate failure. The standard rear Toyota axle is lighter then used in a Ford F150 truck and that Ford axle is rated at 3300 lbs.

So I guess it's up to the individual owner to assess what safety factor he/she wants. I certainly would not trust my well-being on what was done (and not done) during a recall. I suspect that during any automotive recall - it is partly voluntary and there are many compromises made - good and bad.

General Motors with the Chinook campers in the late 70s also had a recall due to overload. That with GM semi-floating 10 bolt rears. The result was - GM agreed to stop authorizing production of them.

My opinion is that even some small Toyota RVs e.g. a pop-up Chinook have inadequate rear axles, brakes, etc. Highway vehicles we trust our lives to are usually overbuilt and engineered with a lot of lee-way in the loading. That level of safety factor was pretty much eliminated when people starting making motorhomes out of mini-trucks and even K series Chevy Blazers and GMC Jimmys. GM agreed to not only stop authorizing them - they also agreed to put stickers in the glove compartments stating "no campers allowed."

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JD,

If the fake dully weighed 5000lbs, I believe I would start looking for a full floater. If it weighted 4,500, I would probably get rid of the dully and put on a regular single with a truck tire.

Reading and understanding why the recall was made is valuable and important, regardless if your vehicle is part of the recall or not.

John Mc

88 Dolphin Auto

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JD,

If the fake dully weighed 5000lbs, I believe I would start looking for a full floater. If it weighted 4,500, I would probably get rid of the dully and put on a regular single with a truck tire.

Reading and understanding why the recall was made is valuable and important, regardless if your vehicle is part of the recall or not.

John Mc

88 Dolphin Auto

To each is own. If my rig weighed 4000 lbs. on level ground and the axle is rated for less - I would never feel safe making long high-speed trips with it;. Axle max load ratings for light duty vehicles are assumed to be "part-time" loads. The full-time loading of Toyota RVs was not part of Toyota's engineering.

Axle max load ratings are also based on the real axle being in good condition. I assume that not everyone driving a Toyota RV has checked their rear wheel bearings and made sure they are in perfect shape. At $30 each - I would not drive one without at least putting in new bearing and then checking them once in awhile. I know for sure that some RV owners do not even know what a wheel bearing is, much less how to check it.

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Yes that is one of two problems. The other is . . the sealed wheel bearing and little pressed-on steel ring is all that holds the axle in. If the bearing fails, the axle can fall out (in one piece without breaking). The older Ford F100s and F150s were set up exactly the same way and also had an "axle falling out" problem. The Toyota axle looks to me like a Ford copy. Maybe it is.

Yes I have seen axles come out but that is usually neglect and bearing failure (except 60's-70's GM Dana's they just fell apart). The overloaded axle generally brakes off right at the radius on Eaton style rears.

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Yes I have seen axles come out but that is usually neglect and bearing failure (except 60's-70's GM Dana's they just fell apart). The overloaded axle generally brakes off right at the radius on Eaton style rears.

The GM corporate 10, 12 and 14 bolt axles used inboard C-clips to hold the axles in - unlike Ford and Toyota that use pressed on steel rings outboard. I have seen all fail under certain conditions. Just about always a combination of overload and neglect. The GM semi-floaters hoever have lubed roller bearings instead of sealed ball bearings. I just to replace a 14 bolt axle on my Suburban due to road-salt intrusion that ruined the seal-race.

Like I said earlier - I know, for sure, that some RVers are clueless mechanically and don't even know what a wheel bearing is - much less maintain it.

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I've already decided its getting new tires all around this spring. I'll get some LTs, because they're just car tires now...and make sure they're rated for a heavier vehicle.

Tires-easy has some Ds for sale at $69 each. I can't comment on how good they are but seems to be a great price. $13.50 each for shipping and not tax to NY. Don't know about the rest of the USA. http://ssl.delti.com/cgi-bin/rshop.pl?dsco=135&sowigan=&Breite=185&Quer=&Felge=14&Speed=&kategorie=6&LoadRange=&Marke=&ranzahl=4&suchen=View+tires

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