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New owner here! 1981 Sunrader


Dgillies

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4 hours ago, Dgillies said:

Sorry, i meant will my load capacity increase after the swap?

and, do you not mind carrying two different spares?

Can you load your rig up with thousands more pounds no, but now you can run a little over GVWR cause all of these rigs are overweight and the ones with the good axle seem to do fine. I don't carry 2 different spares. If I get a flat in the back I drive somewhere as is, but slowly, and get it fixed. Funny I've had flats multiple times in the rear but only once in the front. Never had a problem getting to a service station to get the tire fixed or switch the spare to the dually wheel. I don't know what the big deal is with the need 2 spares thing. You buy a new car today and you get a wimpy little donut spare that your lucky to go 10 miles on.

Linda S

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10 hours ago, Dgillies said:

Just talked to the guy! 

questions:

1. what is a "safe" weight for the foolies?

2. How much weight will this "upgrade" add?

3. This new axle is safe because it has dual bearings that wont go dry and break?

4. Is this the beefiest option for an acle swap?

5. How would i go about getting the fromt axle swap?

"Safe" as far as a full-floater rear goes has nothing to do with the bearings.  The big plus is NO weight is carried on the drive-axles at all.   With a semi-floater - ALL the weight is on the drive axles.   Subsequently, with a full-floater - if you break an axle right off - the wheel on that side stays attached.  If you break an axle with a semi-floater - the wheel falls off along with a piece of the axle.

The little full-floater that Toyota uses came from a Japanese school bus.  Just calculating by the mass of the bearings and stubs they mount on, along with the 3 1/8" axle-tubes - it likely has a 5000 lb. rating.  That is just the axle assembly and not what it provides when mounted in a little Toyota pickup chassis. There are many other limiting factors.

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You don't change the axles up front because, well, there really isn't an axle, just a spindle. There are two ways to go. There is a spaacer kit that takes the existing spindle from 5 to 6 lugs or you could get the whole thing from a donor one ton truck. This is more work, but I do believe it gives you better brakes.

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the main thing is no matter what lose the foolies. they are the issue. cheapest safe ride would be losing the foolies and swapping into better load range rears while you get your axle or go full monte and get r done but be without use for a while. in no way is the foolie safe unless of course you dont mind driving and having your wheels AND brakes come off if it fails...

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To change from 5 lug to 6 lug - using OEM parts - the spindles do not get changed.  Just the hubs.  As far as brakes go?  OEM dually front brakes are 1/2" wider then what a 1981 has.  So I assume if you want the dually front brakes on a 1981, you  need different calipers and mounting brackets.

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The GM full float I installed is rated for 7500#'s. No way I'll ever get that much weight over the rear axle.

Any difference in the actual weight of the replacement axle will have no bearing on the carry capacity. Maybe a little on total vehicle weight.

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On September 2, 2016 at 6:32 AM, Totem said:

the main thing is no matter what lose the foolies. they are the issue. cheapest safe ride would be losing the foolies and swapping into better load range rears while you get your axle or go full monte and get r done but be without use for a while. in no way is the foolie safe unless of course you dont mind driving and having your wheels AND brakes come off if it fails...

Well my rear dualies are load range D yokohama 195/75r14 so thats good

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23 hours ago, fred heath said:

The GM full float I installed is rated for 7500#'s. No way I'll ever get that much weight over the rear axle.

Any difference in the actual weight of the replacement axle will have no bearing on the carry capacity. Maybe a little on total vehicle weight.

Yea i meant to ask how will my weight carrying capacity increase...

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1 hour ago, Dgillies said:

Yea i meant to ask how will my weight carrying capacity increase...

The advantage to a ff axle over your current axle is on a ff axle there is no weight resting on the axle shafts themselves. With a ff axle you can load as much weight as the axle is rated for.

Your current "foolie" is carrying the weight on the axle shafts themselves. You could go to single wheels on the back. You would be fine from a weight standpoint. The disadvantage is you have no way to determine if your axle shafts have been compromised by years of foolie use. The metal could be fatigued, and not obvious to the naked eye. Replacing the bearings and seals is a must. If you could find a machine shop that does magnaflux or MPI, the axle shafts themselves should be tested.

The only disadvantage to single wheels on your current axle is a reduced rear track which could be a stability problem as your coach has a high center of gravity. Other than that, your only limited by the load range of your single tires.

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He mentions lots of suspension upgrades and heavier leaf springs. I really think 2 wheels in the back at least for right now is the answer. Wider might be better but I already posted 205r14 tires that are commercial van type tires and some wheels that would work that also look super. A way cheaper and simple fix for a little Sunrader.

Linda S

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11 minutes ago, linda s said:

He mentions lots of suspension upgrades and heavier leaf springs. I really think 2 wheels in the back at least for right now is the answer. Wider might be better but I already posted 205r14 tires that are commercial van type tires and some wheels that would work that also look super. A way cheaper and simple fix for a little Sunrader.

Linda S

I agree. I wasn't trying to suggest an upgrade to a ff axle. The current axle is fine, I was just suggesting some preventative measures he can take to ensure he has no problems in the future.

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On 2016-08-31 at 7:32 PM, Dgillies said:

I weighed it today, its 4880.

And the weight on the rear axle? Most who have weighed their homes seem to have ~2/3 of the weight on the rear. 2/3 of 4880 is ~3250lb. The rear axle is rated at 3300lb (per JD). A 195/75R14 LR C tire is rated at 1710lb # 65psig, so 3420lb/pair. Does 4880lb include all your 'stuff' ready to travel? I hope so, because you're already bumping your head on the ceiling and over the GVRW.

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A good case for an MPI inspection of the axle shafts in the semi-float axle.

If you look closely at pictures #2 and #3 on JD,s post, you will see brown discoloration in the center and sides of the "snapped" axle shaft. This is caused by metal fatigue and moisture getting into the shaft. A clean break should be all "shiny" metal. This axle shaft was already on its way out.

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The tires I posted are 205r14. They have a weight rating of 2500 lbs. More than enough for his rig plus some. No size problems with a single tire

https://www.tires-easy.com/205-14/thunderer-tires/ranger-r101/tirecode/TH0309

Linda S

I was not recommending he continue to use the same tires in the back. Still far cheaper to buy a couple of tires and wheels to match than install a whole new axle

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Remember that when the MFG sets the GVWR part of the calculation they also look at shocks and brakes. So having a 7500 lb axle does not mean you can have a 7500 lb Toyota.

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3 minutes ago, WME said:

Remember that when the MFG sets the GVWR part of the calculation they also look at shocks and brakes. So having a 7500 lb axle does not mean you can have a 7500 lb Toyota.

GVWR is a product of the limitations of also the engine, the transmission, the frame, final-drive-ratio, etc.  That being said - the 5 lug semi-floating rear is rated as high as 3700 lbs. in some of the USA Toyota cab & chassis trucks and 4400 lbs. for the full-floating duallies.  The 5 lug semi-floater when used overseas is rated as high as 3900 lbs.

 

 

 

 

 

 

 

 

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11 hours ago, Derek up North said:

3700lb? Hmmm. That's the last time I quote someone without fact checking! :)

Toyota used the same 5 lug rear axle (as far as load cap goes) from 1975 to the 2000s in the USA and still does in other parts of the world with the Hilux.  When used in the 1978 cab & chassis - it is only rated for 2900 max lbs. Same in 1981.  Then it climbs up - I suspect since the frame and other parts got higher ratings.

1978.jpg

1981.jpg

1985.jpg

1988.jpg

1990.jpg

2004.jpg

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Yes Derek they are all overweight. So weird that so many of them are still driving around all these years later. On the other hand when they went to the 6 lug in 86 they didn't change the GVWR. That seems funny to me too. So since none of this makes much sense, yes I think he would be fine with 2 wheels in back like the ones I suggested. I know a few 4x4 Sunrader owners who just switched to single wheels in the back and haven't had a wheel fall off. Also the V6 Odyssey 4x4's only had single wheels in the back and they are way heavier than a Sunrader. Heard a lot about the coaches falling apart but never an axle problem. Give the guy a break already

Linda S

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I've no idea what the gawr is for a 4x4 rear axle. Or what the rear track (width) is compared to a 2wd. But I do know that quite a few 4x4 Sunraders have had rear axles changed to FF, converted to FF or another make HD axle with rims with larger diameter and offsets. I don't remember anyone being the pioneer of the 2wd SRW Sunrader.

Give him a break? I'm just passing on what I think and what I think I know. That's what Forums are for. I think. :)

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The actual load-carrying capacity of the axles and bearings is the same from the  1960s up through 2000s.  No matter if 2WD or 4WD.  What changed as far as weight-bearing capacity is when Toyota enlarged the housing-tubes from 2 1/2" to 3 1/8" OD.  I don't remember exactly what year that happened but I think if was 1982 or 1983.  The wheel bearings themselves and the diameter of the actual axles remained unchanged.  The weight-bearing capacity is just one factor though when it comes to gross-axle-rating.  Another is how much torque the ring & pinion can handle and that is determined by things like ring-gear size, or amount of differential-pinions, etc. That's why most V6s and turbo 4s have four-pinion rears instead of 2 pinion rears.

I think it was around 2010 when Toyota finally increased the diameter of the axles and wheel bearings for the Tacoma and Tundra.  Before that - a 1970 Toyota pickup has the same axle diameters as something like a 2006 V8 Tundra or Tacoma.

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The GO82 axle which was standard on my mh came with an 8" ring gear. The standard Toyota 2wd trucks came with the 7.5 ring gear. The axle shafts were beefier on the 8" than the 7.5. (JD will have the specs.)

My concern with using 30 year old axle shafts, even with single tires, is metal fatigue from the stress of being used overweight for so long.

Even the SUV in JD's pictures, never having had a second wheel attached, broke from excessive stress caused most likely by off road driving.

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1 hour ago, Dgillies said:

So what is considered the max weight capacity for the current axle and foolies?

What everyone here has been trying to tell you is there is no safe weight for "foolies".

 

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On ‎8‎/‎27‎/‎2016 at 1:08 PM, Dgillies said:

the guy i bought it from is convinced its not a deal with the small rader. he thinks its better and cheaper to just open and inspect the bearings every so often

With your axle you can not just "open it up and check the bearings". To access the bearing means destroying the seal. To replace the seal you have to drive off the pressed on bearing, which destroys it. So now your doing new bearing(s) and seal(s).

The guy you bought it from was looking to sell it.

At this point, your going to do what you want. But should something bad happen, you can't say you weren't warned.

Edited by fred heath
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Judging from the literature posted above, the 1981 axle is only rated for <3000lbs. 

I would not feel comfortable recommending anyone drive it like that. 

Get the full floating axle, load up the gear and don't worry about it. 

Ok my 1984 sunrader I have 5 lug wheels up front and it's fine. However, I'm not sure but I think the axle swap could change your gearing. I think mine changed and doesn't pull as well because the rpms are lower. 

 

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^ that's correct the axle will have a gear ratio; the ratio of turns the wheel spins to its driveshaft. the seller of the axle should know the ratio. different ratios will have different performances under different power.

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On 9/1/2016 at 0:15 PM, Derek up North said:

If you ask a junkyard for the axle from a 1-Ton pickup, they will be quite correct in selling you a 5-lug rear axle.

BX0238.jpg

OTOH, if you ask for the axle from a 1-Ton C&C, you've got a better chance of getting what you need. :)

This is the 'kit' (NLA) that Toyota put together for the axle recall:-

m70

 

looking at the 'kit', is appears the FF axle was 'dressed' with backing plates. the pictured wheel cylinders suggest they were intended to be swapped-out during the axle change-out process. odd that the axle would have to be dis-assembled to change/upgrade the braking capacity. a parts man at my local toyota dealer was involved in the recall effort in the mid 80's. 

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  • 3 weeks later...
43 minutes ago, linda s said:

Only if it was upgraded to a full floater at some point. You need to know the difference. Plenty of information on this site and in the answers people have already give you

Linda S

I do understand the difference between the 5lug semi float foolie and the 6lug ff. The dolphin that lives next to me has 6lug axles in both front and back. Seein this led to be believe that the dolphins came equipt with a non recalled axle and may be a possible option as donats axles.....

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47 minutes ago, Dgillies said:

I do understand the difference between the 5lug semi float foolie and the 6lug ff. The dolphin that lives next to me has 6lug axles in both front and back. Seein this led to be believe that the dolphins came equipt with a non recalled axle and may be a possible option as donats axles.....

Sounds like it might be just the thing. you should have said that in the first place. Extra good thing is the spring perches and other stuff has already been altered for the older chassis. Might be a super easy change over

Linda S

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