1983 Sunrader 18 ft suspension help and what can go wrong

[hortonma]

Hello everyone, I love that we have a forum just for the Toyota motorhomes. This is my first post on here. I acquired my 1983 sunrader (4-speed manual, no power steering, fake dual axle sadly ) a few weeks ago as a means of traveling from Virginia to Oregon with the intention to live in it for a couple of years. Before I left, I put a new set of 8ply tires on it, changed the transmission and differential oil as well as changing the engine oil a couple of times until it was running clean oil. The previous owner could've been better about keeping up with oil changes but it wasn't horrible. 

 

I made the first leg of my journey from Central Virginia to the Upper Peninsula of Michigan about two weeks ago. The engine is running fine. Getting out of first gear is okay, but with that 22r, it definitely could be easier than it is. All seems to be fine with the sunrader except for the suspension. The ride was bumpy as hell to say the least. Some of the highways through Indiana were so bad that i pulled off and took some sideroads because it felt as if something was going to go wrong. Well, somewhere in Wisconsin, we hit standstill traffic and once we came to a stop, the engine stalled. I was able to start it up, inch up for a while then it cut off again and wouldn't get going. It was a busy chunk of highway on a 95 degree day, no fun. A kind person stopped and gave us a tow off of the highway to a neighborhood. I eventually came to the conclusion that I had vapor lock because we had been running for 9 hours straight on a hot day. We let it rest for about 5 hours and it started up. We drove to the first stop light and it stalled. I floored the gas and popped it into 1st, engined was roaring but i was able to get going. I came to the conclusion that I just couldnt come to a stop. There were 6 more stoplights to make it through before I made it back to the highway. Some high RPMS, engine braking and a bit of luck, i never had to fully stop through those lights. I made it another 200 miles then pulled off to go to bed. Once I actually came to a stop, it shut off again.

 

In the morning, I started trying to figure out what was going wrong because vapor lock didn't seem to fit the bill anymore, at least not the full bill. After pulling the gas line to the carb and starting the engine, I saw that the pull was still sending gas. I poked around some more and saw that the nut holding the throttle linkage on the carb had fallen off. This caused the spring on the idle control to come off. This was the issue. I luckily had some steel wire and duct tape with me and that was enough to finish the journey. The ride was so rough that it caused this to come loose. I am not saying vapor lock was not any part of the problem, but this bolt coming off certainly was the main culprit.

 

So on to the suspension help. I need to get this suspension upgraded and it seems like there are some options, but I wanted to see what you all thought. From what I can tell, everything is original. Should I just go ahead and replace all of the shocks, leaf springs and add one of those air lift suspension helpers? I would like to not have to do everything, but I don't want to just do one of these and it not have much positive effect. If anyone has any specific parts they would recommend for 1983 models, that would be greatly appreciated. I am all ears. Thank you

[extech]

i bet you torsion bars are shot. that makes the front end bang on bumps.  new shocks all the way around would help alot too

[fred heath]

Before spending cash on suspension upgrades, you should consider what you’re going to do about your foolie axle.

 

At the very least, you should replace the axle shafts and rear bearings. Ideally, upgrade to the 6 lug ff axle.

 

Suspension upgrades won’t repair a broken axle.

[hortonma]

5 hours ago, fred heath said:

Before spending cash on suspension upgrades, you should consider what you’re going to do about your foolie axle.

 

At the very least, you should replace the axle shafts and rear bearings. Ideally, upgrade to the 6 lug ff axle.

 

Suspension upgrades won’t repair a broken axle.

Yeah, it has had me worried since I read about it. I saw conflicting information for the 18-foot sunrader. Some had said that these shorter sunraders were not affected by the recall, and others had said all of the foolies were an issue. Regardless, it has me worried, especially with how rough the ride is. I have to imagine that every time I bottom out, it causes an immense amount of stress on that axle. At the very least, every bump made me remember the constant potential for axle failure.

 

Do you know of any resources on good ways to approach an axle swap? When I had looked previously, there weren't many direct options. Some people had luck with their local shops, others had gone to scrap yards and found an axle that worked.

 

I really don't know anything about axle shafts and bearings but I will look into it. Are you suggesting that they can reduce stress or strengthen the axle?

 

Thanks for getting back.

[hortonma]

Thanks, Ill look into the torsion bars. It is 40 years old so I have to imagine that there is a lot that could be replaced in regard to these kind of parts.

[fred heath]

11 hours ago, hortonma said:

Yeah, it has had me worried since I read about it. I saw conflicting information for the 18-foot sunrader. Some had said that these shorter sunraders were not affected by the recall, and others had said all of the foolies were an issue. Regardless, it has me worried, especially with how rough the ride is. I have to imagine that every time I bottom out, it causes an immense amount of stress on that axle. At the very least, every bump made me remember the constant potential for axle failure.

 

Do you know of any resources on good ways to approach an axle swap? When I had looked previously, there weren't many direct options. Some people had luck with their local shops, others had gone to scrap yards and found an axle that worked.

 

I really don't know anything about axle shafts and bearings but I will look into it. Are you suggesting that they can reduce stress or strengthen the axle?

 

Thanks for getting back.

First thing to do is have your rig weighed. The crucial weight is that over the rear axle. If your rear axle weight is 4K or less, you can switch to single wheels. This will eliminate the stress placed on the factory semi float axle shafts.

 

With a semi float axle the entire weight over that axle is carried by the axle shafts themselves. On a full float the axle assembly carries the full weight. The axle shafts only need to turn the wheels.

 

The factory Toyota 5 lug semi float axle (GO82) is plenty strong when used with single wheels as intended with the weight centered over the bearing assembly.

 

To carry additional weight most motorhome manufacturers added a second wheel to the axle. This caused the center of gravity to move to the outside of the bearing hub. Over time the constant flexing of the axle shafts caused them to break. When this happens the wheel assembly will completely detach from the vehicle. Not good if you’re traveling at highway speed.

 

A good parallel to draw is if you’ve ever watched a weightlifting match. With regular weights close to center  the bar stays relatively straight. When heavier weights are added to the outside the bar will actually droop down when lifted. This is the same principle as your foolie axle.

 

Switching to single rear wheels is a good first step. Replacing your existing axle shafts and bearings will essentially give you a factory fresh rear axle.

 

If your rear axle weight is over 4K then you’ll need a full float axle.

Edited September 6, 2023 by fred heath

[hortonma]

4 hours ago, fred heath said:

First thing to do is have your rig weighed. The crucial weight is that over the rear axle. If your rear axle weight is 4K or less, you can switch to single wheels. This will eliminate the stress placed on the factory semi float axle shafts.

 

With a semi float axle the entire weight over that axle is carried by the axle shafts themselves. On a full float the axle assembly carries the full weight. The axle shafts only need to turn the wheels.

 

The factory Toyota 5 lug semi float axle (GO82) is plenty strong when used with single wheels as intended with the weight centered over the bearing assembly.

 

To carry additional weight most motorhome manufacturers added a second wheel to the axle. This caused the center of gravity to move to the outside of the bearing hub. Over time the constant flexing of the axle shafts caused them to break. When this happens the wheel assembly will completely detach from the vehicle. Not good if you’re traveling at highway speed.

 

A good parallel to draw is if you’ve ever watched a weightlifting match. With regular weights close to center  the bar stays relatively straight. When heavier weights are added to the outside the bar will actually droop down when lifted. This is the same principle as your foolie axle.

 

Switching to single rear wheels is a good first step. Replacing your existing axle shafts and bearings will essentially give you a factory fresh rear axle.

 

If your rear axle weight is over 4K then you’ll need a full float axle.

Thank you for the thought out response. This really clears it up for me. So, for weighing it, should I just drive half of the vehicle on the scale with the rear wheels resting on the scale?

As for bearings and axle shafts, would I just get ones made for a 1983 toyota 2wd pickup? 

[fred heath]

4 hours ago, hortonma said:

Thank you for the thought out response. This really clears it up for me. So, for weighing it, should I just drive half of the vehicle on the scale with the rear wheels resting on the scale?

As for bearings and axle shafts, would I just get ones made for a 1983 toyota 2wd pickup? 

Yes to weight. No to axle shafts. The GO82 (3/4 ton) axle shafts up until recently we’re not available anywhere. These are the only shafts that will work for you.

 

Linda s found a source. Get the specifics from her. Bearings should be standard size.

 

I’m guessing you have the GO82 rear axle. Most of the motorhomes use this one. You might want to check your build plate under the hood just to be sure before ordering. I’ve attached my plate so you know what to look for.

Edited September 6, 2023 by fred heath

[linda s]

Here are all axle related parts for your truck. All factory OEM.

https://www.toyotapartsdeal.com/parts-list/1983-toyota-pickup/power_train_chassis/rear_axle_shaft_hub.html?filter=(d=USA;1=22R;5=MTM;6=4F;7=HVY;9=IV)

Linda S 

[IdahoDoug]

You started this thread regarding a rough ride.  I'd like to address that, while not derailing the axle concerns.

 

Any 40 year old vehicle needs shock absorbers replaced unless you know that they are in good shape.  Worn shocks will produce a terrible, harsh ride on a heavy vehicle. Especially if you are complaining about it at freeway speeds, this is likely the/an issue for your vehicle and the cheapest first step. Replace all 4 and see how you've improved it and if that makes it OK.  Based on mine, these Sunraders do not ride well - others may chime in regarding the ride quality they've been able to achieve.  It may simply be you've never owned a leaf sprung dually vehicle - not a good combination for ride and why many civilian vehicles switched away from leaf springs to coils to get less complaints on ride and handling.

 

You didn't mention what tire inflation you were at, but proper levels will produce ride quality X and overinflated tires (common from tire shops who install them as it reduces their liability) will deteriorate ride quality below X significantly.  So be sure to check that before anything.

 

Don't replace your torsion springs pursuing a better ride.  They don't deteriorate in a way that causes poor ride - actually the opposite.  IF (I mean IF) they show ageing, it will be a slight sagging and all you have to do is rotate their adjusters to bring ride height back up to the factory level.  This is a common feature on VERY heavy trucks and a proven design, so don't look here for a solution.  Adjusting these is very simple but I suggest you bring it to a heavy truck mechanic and research/provide the proper ride height for them to target.

 

Best.

[WME]

Sorry, sometimes reality sucks. No matter what upgrades you do to your toy it's going to be a grossly over loaded 40 year old 1/2 ton pickup truck. Many of the improvements result in a safer ride, not necessarily more comfortable ride. 

[linda s]

Don't be discouraged by negative comments. It's a 3/4 ton ,slightly overweight vehicle that just needs service same as any other vehicle. 

Do take one thing at a time though and shocks are the right thing to start with. 

Linda S

[hortonma]

On 9/6/2023 at 7:47 AM, fred heath said:

First thing to do is have your rig weighed. The crucial weight is that over the rear axle. If your rear axle weight is 4K or less, you can switch to single wheels. This will eliminate the stress placed on the factory semi float axle shafts.

 

With a semi float axle the entire weight over that axle is carried by the axle shafts themselves. On a full float the axle assembly carries the full weight. The axle shafts only need to turn the wheels.

 

The factory Toyota 5 lug semi float axle (GO82) is plenty strong when used with single wheels as intended with the weight centered over the bearing assembly.

 

To carry additional weight most motorhome manufacturers added a second wheel to the axle. This caused the center of gravity to move to the outside of the bearing hub. Over time the constant flexing of the axle shafts caused them to break. When this happens the wheel assembly will completely detach from the vehicle. Not good if you’re traveling at highway speed.

 

A good parallel to draw is if you’ve ever watched a weightlifting match. With regular weights close to center  the bar stays relatively straight. When heavier weights are added to the outside the bar will actually droop down when lifted. This is the same principle as your foolie axle.

 

Switching to single rear wheels is a good first step. Replacing your existing axle shafts and bearings will essentially give you a factory fresh rear axle.

 

If your rear axle weight is over 4K then you’ll need a full float axle.

So I was able to get my rig weighed. The total weight came out to 5300 lbs with a rear weight of 3800lbs. Does that seem correct? I just drove the front wheels off of the scale to make this measurement. if the total weight is 5300, it seems like the rear should actually be slightly less. That idea isn't based off anything else but what seems logical to me.

If I do switch to the one-wheel set up, would I always have to maintain less than 4k? Is that 4k what the axle shafts are rated for, or is it what those tires could support with only one? what if I have some extra supplies with me on the storage rack up top, or I am sitting in the back with another person? how sensitive is this number? Has anyone in this forum actually done this?

 

Thank you

[hortonma]

@linda s @IdahoDoug@fred heath

 

Thank you for the help! I love this thing and am hoping to get a lot of life out of the sunrader. I just need to get these improvements done!

[fred heath]

2 hours ago, hortonma said:

So I was able to get my rig weighed. The total weight came out to 5300 lbs with a rear weight of 3800lbs. Does that seem correct? I just drove the front wheels off of the scale to make this measurement. if the total weight is 5300, it seems like the rear should actually be slightly less. That idea isn't based off anything else but what seems logical to me.

If I do switch to the one-wheel set up, would I always have to maintain less than 4k? Is that 4k what the axle shafts are rated for, or is it what those tires could support with only one? what if I have some extra supplies with me on the storage rack up top, or I am sitting in the back with another person? how sensitive is this number? Has anyone in this forum actually done this?

 

Thank you

The 4K number is usually the maximum safe weight for 2 tire axle withC or D rated tires. Some tires might be rated slightly higher but you want to leave a little “fudge factor “ for

things like luggage or even bumps and potholes.

 

I would guess you’re very near the cutoff line for singles. 3800 can be done. Did you fill the gas tank and fresh water tank before weighing? If not, do that and then weigh again.

[hortonma]

5 minutes ago, fred heath said:

The 4K number is usually the maximum safe weight for 2 tire axle withC or D rated tires. Some tires might be rated slightly higher but you want to leave a little “fudge factor “ for

things like luggage or even bumps and potholes.

 

I would guess you’re very near the cutoff line for singles. 3800 can be done. Did you fill the gas tank and fresh water tank before weighing? If not, do that and then weigh again.

The tires I was looking at getting for this setup are apparently rated for 2800 lbs. They are FREE COUNTRY Premium Trailer Tires ST225/75R15 10PR.

 

would this allow me to stretch it a little farther? 

 

 The water tank was definitely not full and the gas tank was a little over 3/4 full. 

[fred heath]

23 minutes ago, hortonma said:

The tires I was looking at getting for this setup are apparently rated for 2800 lbs. They are FREE COUNTRY Premium Trailer Tires ST225/75R15 10PR.

 

would this allow me to stretch it a little farther? 

 

 The water tank was definitely not full and the gas tank was a little over 3/4 full. 

No trailer tires …….

 

 

Edited October 4, 2023 by fred heath

[hortonma]

12 minutes ago, fred heath said:

No trailer tires …….

What would be the difference if they are the same size for the rims? I think I got these numbers from another part of the forum

 

Edit: Okay, a quick google solved that one. Let's say I do find tires that are rated to hold more than 4k combined, would that allow me more breathing room going with the one wheel set up?

Edited October 4, 2023 by hortonma
new info

[Ctgriffi]

10 minutes ago, hortonma said:

What would be the difference if they are the same size for the rims? I think I got these numbers from another part of the forum

Trailer tires are a no-go. They’re not manufactured to put power to the ground, just to be “passively” pulled along. 

[fred heath]

Did you do any preventative maintenance before embarking on a 1200 mile road trip ?

 

And more importantly, are you running duals on a foolie axle?

[hortonma]

27 minutes ago, fred heath said:

Did you do any preventative maintenance before embarking on a 1200 mile road trip ?

 

And more importantly, are you running duals on a foolie axle?

I took it to my mechanic and he said it all looked fine. I put a new set of 8ply tires on it, changed the oil, changed the differential oil, transmission oil, new spark plugs, new wires, new rotor and cap. 

 

Yes, I am running duals on the foolie. I thought that was the discussion we were having. I am confused now

[linda s]

You need to get it weighed somewhere else. My Sunrader with the full float, heavier than a semi float, AC 100 lbs ,plus a generator, 120 lbs Came in at 5260 fully loaded with weeks worth of camping gear. No way yours weighs more than mine. Have you already switched to 15 inch tires. let me know and I will find the tires

Linda S

Oh I see you just put tires on it. Doesn't make sense to me if you were considering the change to single wheels but it's your rig

[fred heath]

6 minutes ago, hortonma said:

I took it to my mechanic and he said it all looked fine. I put a new set of 8ply tires on it, changed the oil, changed the differential oil, transmission oil, new spark plugs, new wires, new rotor and cap. 

 

Yes, I am running duals on the foolie. I thought that was the discussion we were having. I am confused now

Why do you want to switch to single rear wheels? Or did you make that decision after starting your trip.

Edited October 4, 2023 by fred heath

[linda s]

If you do decide to ever switch to a single tire in the back here is a list of suitable commercial van type tires that will hold almost 5000lbs in the rear. 2469 per tire

225/70R15 Tires | Shop at Priority Tire

Linda S

[hortonma]

On 10/5/2023 at 2:27 PM, linda s said:

If you do decide to ever switch to a single tire in the back here is a list of suitable commercial van type tires that will hold almost 5000lbs in the rear. 2469 per tire

225/70R15 Tires | Shop at Priority Tire

Linda S

Thank you Linda! I will definitely be going with these.

 

I am unsure what happened with weighing the camper. I used a scale for a recycling facility that municipal trucks use. In any case, I'll see about weighing the camper. I learned about the single-wheel option after already putting tires on, which obviously is a bummer. Just to be clear, if i do this single wheel option and keep my rear load under 5k with these tires, I should be okay with my axle ( assuming my axle bearing hasn't taken too much damage already)? 

 

Also, since I have you here, I want to replace my suspension. It seems that 83 models and earlier are harder to find some parts for. I'm going to get bilstein shocks for the rear and gas a just for the front (softer ride is what I am thinking in the front). As for the leaf springs, do you think i need to replace them or could i just go for a helper spring or an air lift? 

 

thank you for all of the help you do on this forum! 

[linda s]

I don't think the weight is off by tons but even a few hundred pounds is your wiggle room. Nobody drives around with an empty motorhome so you do need the ability to put things in it.

Don't know how bad your springs are. Are they completely flat?

Shocks sound good. I think the main thing you need when switching to single wheels is a sway bar. I have a factory one and dual wheels but when that sway bar came loose my camper was swaying all over the road. With the narrower track of single wheels it's a must for stability. 

You're on the right path for sure

Linda S

[fred heath]

83 ranger posted a link to a good source of 6lug ff axle. Vehicle is in CA.

[hortonma]

On 10/7/2023 at 1:48 PM, linda s said:

I don't think the weight is off by tons but even a few hundred pounds is your wiggle room. Nobody drives around with an empty motorhome so you do need the ability to put things in it.

Don't know how bad your springs are. Are they completely flat?

Shocks sound good. I think the main thing you need when switching to single wheels is a sway bar. I have a factory one and dual wheels but when that sway bar came loose my camper was swaying all over the road. With the narrower track of single wheels it's a must for stability. 

You're on the right path for sure

Linda S

They seem to be completely flat. I dont even have my water tank filled either.

 

Do you know of any sway bars that would fit a 1983. I can find some for later models but not for this one

 

[extech]

take one shock loose at the bottom and see how far it can be depressed. this will tell if you are bottoming out

[linda s]

Here's a sway bar but completely flat springs should be addressed too. 

1979-1983 Toyota Pickup 2wd & 4wd - Addco 334 Rear Sway Bar (3/4 Diameter) [334] | $146.63 | SD Truck Springs | Leaf Springs, Helper Springs and Suspension Parts

Linda S

[hortonma]

3 hours ago, linda s said:

Here's a sway bar but completely flat springs should be addressed too. 

1979-1983 Toyota Pickup 2wd & 4wd - Addco 334 Rear Sway Bar (3/4 Diameter) [334] | $146.63 | SD Truck Springs | Leaf Springs, Helper Springs and Suspension Parts

Linda S

Wonderful, how are you so good at finding everything for everyone…

 

I must enlist you for one final item. I can’t seem to find wheels for those tires. All of the wheels that seem to fit are trailer wheels and I’m guessing that won’t work. 
 

my final piece to all of this I guess will be deciding to go with helper springs or air lift after getting new leaf springs. I was able to find leaf springs for the 2wd set for $150 a piece without the bushings. Once I get new leads springs, I want to still be able to support all of this extra weight. I’ve read that you have the air lift. Is there a significant benefit? Can I even find a system that would work for the 83? 
 

the helper springs I’ve found are supposed to add 1500lbs which sounds like it could be enough. They are hellwigz i believe. The 4wd version is about half the cost of the 2wd for some reason.

 

so new shocks, new leaf springs, helper springs, sway bar, and single wheels… I should be in good shape after that..

[fred heath]

Your wheels are standard 15” with a 5x4.5 bolt pattern. Many aftermarket wheels that fit are available. White wagon style wheels are very reasonable and come in different widths and offsets. Summit Racing has a great selection.

 

Wagon style wheels have a large center bore, so no problem with fitment. Any 15” hubcap will also fit.

 

I’m running 14” fronts and 15” rears. Bought two separate sets of same style ABS hubcaps off Amazon. One in 14” and one 15”. Hard to tell by looking that I have two different diameter wheels.

 

 I can’t seem to find wheels for those tires. All of the wheels that seem to fit are trailer wheels and I’m guessing that won’t work. 

[linda s]

Some 2wd Tacoma's came with 5 lugs. These aren't too expensive and look pretty nice

2005-2014 Toyota Tacoma Wheel - Action Crash STL69457U20 - - PartsGeek.com

Linda S

Went through eBay too. These were the nicest by far

Or maybe these. The offset would keep the center of the wheel closer to your bearings and the tire out farther for stability.

1 New Vision 15X7 5x4.5 5x114.3 -6 Gloss Black D Window Wheel/Rim | eBay

Pretty sure trailer wheels would work too. They are made to carry a lot of weight.