Get rid of massive Chevy overload leaf?

[booster]

I will answer the normal first question first (imagine that). The overload leafs weigh 25# apiece, as they are very thick steel. Taking them out saves 50# (or just under if you use spacers to reclaim the space, see below) of unsprung, rear, and gross weight, which is substantial, especially on some the Bs that are low in cargo capacity like a Roadtrek 210.

Nearly all the 2003+ Chevy class Bs sit right on the rear overload leafs, especially Roadtreks. The overload leaf is about 3/4" thick and very high spring rate, causing harshness and "pitching" on bumps of various sizes.

The most common thing done to address the issue is to add airbags in the rear, often with a spring change in the front to stay close to level (we did this over 5 years ago). A normal airbag install will get you 1/8" or so off the overload, but to get more you have to go pretty high on airbag pressure. Being that close will allow the overload leaf to still contact the springpack on moderate bumps, but will smooth out the small bumps. I had, a while ago, reached the overload to about 3/8" gap, which made it even better, but still contacted on bigger bumps with a "slap". The overload couldn't be moved further away as it was needed to pick up the weight if an airbag failed (the bags have a hard stop in them that is not designed to be driven on).

Airlift now has airbags that have a soft bump stop internally instead of the hardstop, and are now OK to drive on if failed or deflated. This makes the only function of the overload leaf go away, so they aren't needed for anything.

I decided to see how things would work out with the newer style bags and no overload leafs in place. The bag change is pretty easy at about 20 minutes per side. The removal of the overload leafs is more work at about an hour per side. The easiest way to do it is to remove the front eye bolt and rear shackle bolt and wrangle the entire spring to the rear without actually taking it out, as there is lots of stuff in the way, at least on our Roadtrek. You can get the spring just far enough back that the springpack center bolt can be removed. Once the center bolt is out, you can just slide the overload leaf out and remove it.

I had trouble deciding whether or not to cut out the center section of the overload leaf and reinstall it as a spacer, so the u-bolts and center bolt could be just as they were stock, but finally decided to do one side with the spacer and one without. Our Roadtrek has always required more pressure in the driver side airbag, which appears to be pretty common. The difference in height without the extra air pressure is just about the thickness of the overload leaf center area, so I put it in the driver side to lift it by that much, as it works just like a lift block. Passenger side no spacer, so I made some spacers for the u-bolt nut side and for the center bolt.

Driver side:



Passenger side:







Note the pix were taken before the shackle and centerbolt spacers were in place.

Doing the shim on the driver side seems to have been about right, as we sit very close to perfect level with equal pressure in both airbags.

Of concern to me was if the internal bumpstop would give similar issues to the overload leafs on larger bumps, so I wanted to try to determine when they would be contacted. Before I put them in, I collapsed them in the bench vise to try to determine when the bumpstop contacted and how firm it was. The old hard stop was at 2" of bag height, and all air support if above that. With the new bags, full height is about 5.25", the bumpstop feel like it first hits at about 4", and it goes essentially solid at 2". These heights would translate very closely to what would happen with the overload leafs in the stock position at the same van heights, so my concerns remained. The bumpstops did seem relatively easy to compress in the vise however, so they did seem to have a substantially lower spring rate than the overload leafs.

In place, with 60# in the airbags, they measure at right about 3.5", so lightly on the bumpstops. This van height is very similar to where the van sat with the old bags, and not touching the overload leafs, so the bumpstops aren't carrying much weight at that point, it appears.

We went for about a 60 mile ride and the rear did seem to be noticeably quieter and smoother, into big bumps especially. I assume this is because the transition onto the bump stops in the bags is less progressive and lower rate than the overloads were. We will know more when we get longer and more varied trips on them.

[AZ ADVenturist]

Great read, as usual. Just wish I had the technical & mechanical skills to perform & perfect some of the incredible mods you tell us about.
Thnx. R.

[Ron J. Moore]

Booster, thanks for the info. Like AZ, I only wish! As you know, I have that 210 and would love to see some resolve for raising and load carrying. Somewhere, sometime, and money available, I would love to have "your mods" done. You and all the others with the technical and mechanical knowledge really provides us with invaluable info. I wonder if any of the manufacturing firms read this from time to time, and contact you about using your modifications. Again, thanks for sharing your hard work and well thought out solutions for a nagging problem with the RT's....and maybe others. Ron

[alaskasail]

Booster: I'm back in AZ and getting ready to address the suspension issue on my 2005 190V. I'm familiar with the other suspension threads and will visit them as well, but this one covers a lot of territory. Do you have anything to add after some two years?

Thanks for your help and contributions to the forum.

[Luv2Go]

I finally bit the bullet and pulled the overload leafs out of our '06 210V. Long story short, it has DW's seal of approval!

Previously I had installed the AirLift 88205's in place of the black Sumo springs that I put on the RV four years ago. The Sumo softened the ride quite a bit but still had the big "bang" when hitting big bumps with the resulting rebound lifting you out of the back seats! The Airlift's alone actually made the ride much worse, so much so that DW wanted me to undo everything. Since I didn't really like the Sumo solution I decided to remove the overload leaf, which booster and I discussed recently in a PM. As he said I would be in uncharted territory since no one has reported doing this on a 210.

Our Roadtrek did not have any spacers commonly found in 210's so I used a 2" lift block, 1" to replace the thickness of the overload spring and 1" to replace part of the 1 1/2" spacer on other 210's. I decided this was important as it gave the airbags more height to work with before they hit the bump stop. Since others had used the airbags with the spacers in place I decided that would not break them.

At the same time I installed Moog 81004 front springs as I wanted to get the ride height at least back to normal and hopefully a little higher to accommodate the 265-75R16's I had put on. I found the springs on Amazon for $87 and figured I could cut them down if they were too high as TX-Trek did with the AC Delco's for his 210. Fortunately they were not, I'm at 37" at both fender lips which seems to be what others used to get considering my larger tires. The free height of the pair of 81004's that I received measured 17.5, a little shorter than the spec of 17.75. Maybe Moog has reduced the height due to complaints?

With 75PSI in the airbags I can match the front 37" fender lip height on both sides in the rear. I don't have the issue many reported of needing more pressure on the left side, maybe because the inverter and batteries are to the right of center.

Finally I replaced the four year old KYB shocks with the Bilstein's recommended by many on this forum.

I am lucky enough to have a 12,000lb four post lift (bought at a bargain price from a local muffler shop who was replacing one of theirs) and I used several bottle jacks, jack stands and wood blocking to make the RV safe to work under. I did buy the OTC 7045B spring compressor and would be happy to lend it out for the cost of shipping. I tried one of the "loan a tools" ones and it just didn't seem safe (practiced on the new spring) so I broke down and bought the correct one.

We took it on a test drive tonight and it passed with flying colors. No more "bang" on the big bumps and bridge transitions. I purposely hit every pothole I could find on the route. One big bridge transition bump that normally would have drawn complaints drew laughter instead from DW and DD who were sitting in the back!

Now to search for the elusive Silverado 7" rims with the correct offset. The AR wheels have caused one front wheel bearing failure and contributed to a rear axle bearing failure, and they still rub when the wheel is turned all the way because they stick out so much.

[rowiebowie]

Wow, congrats on your success!

[booster]

Fantastic results, and very good presentation of the results. Congratulations on a job well done!


I think you are absolutely correct in the way did the non airbag changes to the spring pack/spacer situation which was probably your biggest unknown going in because of being the first to try on a 210. Just as we did with ours originally, hitting the "sweet spot" of ride height to put the airbags in their optimum position seems to the be the biggest determiner of ride quality.


We don't often get this detailed of feedback on major adventures into unknown modification territory, so it is very useful for this to get into the record on the forum.


To get a glowing review from a picky pair of ride evaluators, sitting in the rear of any class b, is a major accomplishment, IMO.

[booster]

Originally Posted by alaskasail

Booster: I'm back in AZ and getting ready to address the suspension issue on my 2005 190V. I'm familiar with the other suspension threads and will visit them as well, but this one covers a lot of territory. Do you have anything to add after some two years?

Thanks for your help and contributions to the forum.

Sorry I missed this when you posted it, it appears.


Not really anything to add to it though. The no spring setup has functioned well since install without issue.

[Buc22]

Originally Posted by booster

Sorry I missed this when you posted it, it appears.


Not really anything to add to it though. The no spring setup has functioned well since install without issue.

I am as my wife calls a "lead foot" and even in my Roadtrek tend to be throttle heavy off lights, so my questions any wheel hop or axle wrap under acceleration? As I am about to install the Banks ThrottleMaster and currently pondering a 1" lift block on driver rear or remove overload spring as you did.

Thanks in advance

[booster]

Originally Posted by Buc22

I am as my wife calls a "lead foot" and even in my Roadtrek tend to be throttle heavy off lights, so my questions any wheel hop or axle wrap under acceleration? As I am about to install the Banks ThrottleMaster and currently pondering a 1" lift block on driver rear or remove overload spring as you did.

Thanks in advance

I was a bit worried that it might hop but is hasn't been an issue. We are lifted a bit compared to a stock Roadtrek but basically only up to what the stock Chevy trim height would be in an empty van. Can't speak for what it would do if it sat lower.

[Buc22]

Originally Posted by booster

I was a bit worried that it might hop but is hasn't been an issue. We are lifted a bit compared to a stock Roadtrek but basically only up to what the stock Chevy trim height would be in an empty van. Can't speak for what it would do if it sat lower.

Thanks for information

[peteco]

Originally Posted by Luv2Go

I finally bit the bullet and pulled the overload leafs out of our '06 210V. Long story short, it has DW's seal of approval!

Previously I had installed the AirLift 88205's in place of the black Sumo springs that I put on the RV four years ago. The Sumo softened the ride quite a bit but still had the big "bang" when hitting big bumps with the resulting rebound lifting you out of the back seats! The Airlift's alone actually made the ride much worse, so much so that DW wanted me to undo everything. Since I didn't really like the Sumo solution I decided to remove the overload leaf, which booster and I discussed recently in a PM. As he said I would be in uncharted territory since no one has reported doing this on a 210.

Our Roadtrek did not have any spacers commonly found in 210's so I used a 2" lift block, 1" to replace the thickness of the overload spring and 1" to replace part of the 1 1/2" spacer on other 210's. I decided this was important as it gave the airbags more height to work with before they hit the bump stop. Since others had used the airbags with the spacers in place I decided that would not break them.

At the same time I installed Moog 81004 front springs as I wanted to get the ride height at least back to normal and hopefully a little higher to accommodate the 265-75R16's I had put on. I found the springs on Amazon for $87 and figured I could cut them down if they were too high as TX-Trek did with the AC Delco's for his 210. Fortunately they were not, I'm at 37" at both fender lips which seems to be what others used to get considering my larger tires. The free height of the pair of 81004's that I received measured 17.5, a little shorter than the spec of 17.75. Maybe Moog has reduced the height due to complaints?

With 75PSI in the airbags I can match the front 37" fender lip height on both sides in the rear. I don't have the issue many reported of needing more pressure on the left side, maybe because the inverter and batteries are to the right of center.

Finally I replaced the four year old KYB shocks with the Bilstein's recommended by many on this forum.

I am lucky enough to have a 12,000lb four post lift (bought at a bargain price from a local muffler shop who was replacing one of theirs) and I used several bottle jacks, jack stands and wood blocking to make the RV safe to work under. I did buy the OTC 7045B spring compressor and would be happy to lend it out for the cost of shipping. I tried one of the "loan a tools" ones and it just didn't seem safe (practiced on the new spring) so I broke down and bought the correct one.

We took it on a test drive tonight and it passed with flying colors. No more "bang" on the big bumps and bridge transitions. I purposely hit every pothole I could find on the route. One big bridge transition bump that normally would have drawn complaints drew laughter instead from DW and DD who were sitting in the back!

Now to search for the elusive Silverado 7" rims with the correct offset. The AR wheels have caused one front wheel bearing failure and contributed to a rear axle bearing failure, and they still rub when the wheel is turned all the way because they stick out so much.

Can you provide an update on the Airlift bag performance on your 210 now that you have had them for a year? The 12 year-old Firestone bags on my 210 need replacing as they have some wear and cracking. I am thinking about changing to the airlifts to get the internal bumper. I am still debating whether to remove the overload spring though.

[Luv2Go]

Still love them. Pressure of 65PSI seems to provide the best ride. Still glad I removed the overloads also, the only time the "bang" came back was when I was experimenting with lower air pressure, at 45PSI big bumps caused the suspension to hit the bump stops and "bang".

[booster]

Originally Posted by Luv2Go

Still love them. Pressure of 65PSI seems to provide the best ride. Still glad I removed the overloads also, the only time the "bang" came back was when I was experimenting with lower air pressure, at 45PSI big bumps caused the suspension to hit the bump stops and "bang".

We also find a narrow range of best pressure with ours in the 35-45psi range, but our 190 is lighter in the rear and has less overhang. I would never put the overloads back in.

[peteco]

Originally Posted by Luv2Go

Still love them. Pressure of 65PSI seems to provide the best ride. Still glad I removed the overloads also, the only time the "bang" came back was when I was experimenting with lower air pressure, at 45PSI big bumps caused the suspension to hit the bump stops and "bang".

Have you driven with the bags at zero pressure? Just wondering how safe it would be if an air line or a bag developed a big leak while driving.

[booster]

Originally Posted by peteco

Have you driven with the bags at zero pressure? Just wondering how safe it would be if an air line or a bag developed a big leak while driving.

I have both as a test and also one time when we were in the Redwoods and I had all the air out the bags to get level. I decided not to pump them up and it was a bit wallowy but not what I would call unsafe. A 210 might be worse with it's more rear weight and overhang though.

[peteco]

Originally Posted by booster

I have both as a test and also one time when we were in the Redwoods and I had all the air out the bags to get level. I decided not to pump them up and it was a bit wallowy but not what I would call unsafe. A 210 might be worse with it's more rear weight and overhang though.

Hope to hear from Luv2Go on this but that could be a big concern on the 210. I don't like the stiffness or weight of the overload but for safety purposes I am inclined to leave it in there. I would hate to be in an accident and the integrity of my suspension called into question.

[booster]

Originally Posted by peteco

Hope to hear from Luv2Go on this but that could be a big concern on the 210. I don't like the stiffness or weight of the overload but for safety purposes I am inclined to leave it in there. I would hate to be in an accident and the integrity of my suspension called into question.

You might have and easy out of your dilemma as you have the Firestone bags in place already.



We have had both of them in the past and now on our Chevy. The Firestone bags mount to the front of the axle IIRC by way of a plate under the axle that held on by the axle u-bolts. The Airlift mount right on top of the axle on there own mounting.


It is very possible, but certainly not guaranteed, that you could have both sets in place at the same time. A simple selector valve could make it switchable pretty easily, I think.


You could leave the Firestones and minimum pressure so just along for the ride but available if needed, or the other way around.

[peteco]

Originally Posted by booster

You might have and easy out of your dilemma as you have the Firestone bags in place already.

We have had both of them in the past and now on our Chevy. The Firestone bags mount to the front of the axle IIRC by way of a plate under the axle that held on by the axle u-bolts. The Airlift mount right on top of the axle on there own mounting.

It is very possible, but certainly not guaranteed, that you could have both sets in place at the same time. A simple selector valve could make it switchable pretty easily, I think.

You could leave the Firestones and minimum pressure so just along for the ride but available if needed, or the other way around.

Not sure I see the benefit of having both airbags. I had thought about keeping the Firestones and adding a Sumospring which I think goes between the frame and axle. But the cost of the Sumos plus needing to replace the Firestone airbags it seemed to make sense to just get the Airlift with internal jounce. Overall that would be the cheaper route too.

How did the ride of the Firestones compare with the Airlifts? DId you add the Airlifts before removing the overload spring? Also, if the Airlift lifts the the springset off the overloads and keeps it off ()except in extreme bumps, wouldn't the ride be fairly smooth?

[booster]

Originally Posted by peteco

Not sure I see the benefit of having both airbags. I had thought about keeping the Firestones and adding a Sumospring which I think goes between the frame and axle. But the cost of the Sumos plus needing to replace the Firestone airbags it seemed to make sense to just get the Airlift with internal jounce. Overall that would be the cheaper route too.

How did the ride of the Firestones compare with the Airlifts? DId you add the Airlifts before removing the overload spring? Also, if the Airlift lifts the the springset off the overloads and keeps it off ()except in extreme bumps, wouldn't the ride be fairly smooth?

I was thinking of not replacing the Firestones which would likely last a long time if not carrying load. Less certain if you replace them as cost goes up.


We have had pretty much all the different setups over the years as I made continuous tweaks.



We started with Firestones only and they worked OK but needed quite high pressure to get off the overload.


When I built the rear swaybar, the Firestones where in the way of the forward arms so they got removed and the Airlift without internal jounce were installed.


With the Airlift and swaybar, I then took out the overloads and had them rearched to sit about 3/8" lower before contact, which improved the ride but still hit hard on bigger dips,


When the Airlift bags with the internal bump stops came out they solved the problem of possibly winding up running on the solid stop in the airbag so I switched to them and removed the overload leafs.


I think the Airlift bags are a better design as they put the load straight on the axle, where the Firestones try to torque the axle because off the centerline. IIRC they are also 3500# capacity vs 5000 for the Airlift so require higher pressures to support the same weight.


I think you might be able to keep the overlaod from being hit too often by bending the overload at least double what I did, but then it might not save breaking the regular springs from over flexing. Hard to tell for sure without testing that part of it. Might be OK for temp use, though, to get you to a shop to replace a popped airbag. Getting the overloads bent down was only about $30 IIRC, but I brought them to them out of the van. They can be done cold.