Some advice on a Chevy Suspension Upgrade

[mangomike]

Booster
It seems like what you're saying about the front makes sense, logically.
So, what I'm thinking is there we're going to do this in baby steps. I think I'll go ahead with the springs in the back. And then see what they have the say about the front. If they still don't want to mess with the front, I'll just find another shop and tell them that I'm having a problem with the front.
it just seems like it's so hard to find that understands how badly the chassis is overweight. I wonder if RT still uses the same suspension system. Or if they have gone to something more heavy duty? I guess it doesn't matter to me.
I will let y'all know what happens next
Michael

[booster]

Originally Posted by mangomike

Booster
It seems like what you're saying about the front makes sense, logically.
So, what I'm thinking is there we're going to do this in baby steps. I think I'll go ahead with the springs in the back. And then see what they have the say about the front. If they still don't want to mess with the front, I'll just find another shop and tell them that I'm having a problem with the front.
it just seems like it's so hard to find that understands how badly the chassis is overweight. I wonder if RT still uses the same suspension system. Or if they have gone to something more heavy duty? I guess it doesn't matter to me.
I will let y'all know what happens next
Michael

Roadtrek leaves whatever Chevy puts in for suspension in the vans, so no changes that we have heard about.


Good plan on the front, the only downside would be the extra cost of a two alignments instead of one, and maybe a bit more labor if it is done separately. If they raise the back much, you may be 3 or more inches out of level with the front, so bring along your leveling blocks



I have talked to at least a half dozen shops and none of them, including Bill Erb at Valley Spring, even knew where to measure the trim height, much less what it should be, so your shop is not alone on that issue, for sure.


As you say, they are dealing with normal weight vehicles, not ones that are in the very top of their capacity, and it also may be that they are scared of the very still front spring in a one ton van, as they can be scary. The good, that you could let any shop know, is that you don't need a spring compressor to put in the Moog springs, as they are the same free length as stock.

[Asphalt Addict]

mangomike, I just had my chevy done with moogs in front and air lifts in back. Very happy with it so far. I still need to adjust air lifts and I think the alignment may be off. It pulls slightly to the right.

My rear springs are no longer flat. They have a nice arch. The front is much better than stock. Better ride.

I'm still adjusting and will post a final result when I'm satisfied. One thing I can't believe is even though it only raised it a couple of inches or so it appears much higher. Even my wife thinks it is more than 2 inches.

[booster]

Originally Posted by Asphalt Addict

mangomike, I just had my chevy done with moogs in front and air lifts in back. Very happy with it so far. I still need to adjust air lifts and I think the alignment may be off. It pulls slightly to the right.

My rear springs are no longer flat. They have a nice arch. The front is much better than stock. Better ride.

I'm still adjusting and will post a final result when I'm satisfied. One thing I can't believe is even though it only raised it a couple of inches or so it appears much higher. Even my wife thinks it is more than 2 inches.

The allusion of being higher than the lift did is pretty common, I think. Probably has to do with the relatively small tire size in the wheelwells becoming more visible with added height. I have noticed that on the lifted ones with stock tires and wheels, but as much not on ours with the larger tires.

[markopolo]

Originally Posted by alaskasail

I'm curious: what is the advantage of Moog springs over stock or other brands. I'm assuming they are more robust.

It is the specifications of the spring and not the brand that matters. Years of searching for and trying different springs passed before realizing that the Moog 81004 specs would work well on 2003 & newer vans. Those specs are:

ID: 4.068
Wire Dia: 1.031
Rate/Inch: 1570
Load at rated height: 5934
Rated compressed height: 14
Free length: 17.78

I think all of these coil springs:
Moog 81004
ACDelco 45H0340
Napa 277-3435
Husky SC20468
Raybestos 585-1340

have the same specifications. Confirm that before purchasing.

Great pricing on the Moogs too - around $200 for the pair.

We had a few early posts by folks using other Moog or Napa springs but they were all slightly shorter.

I think the first forum member to post about using the 81004 springs was GroupB in this post: http://www.classbforum.com/forums/f8...html#post55023

Originally Posted by booster

............The springs themselves are the same free length as stock, but have more coils (softens a bit and makes them less progressive), and are made with 1.030" diameter wire. Stock springs are in the .94" or a bit larger on some we have heard of...............

You can see what Booster explains in the photos here: http://www.classbforum.com/forums/f8...html#post55034

The Moog spring wire diameter is thicker and has an extra coil+ when compared to the OEM spring.

[Asphalt Addict]

Hello again, I've put a few miles on my lift and lovin' the ride, and the height. Still haven't re-aligned front end but will in the next week or so. My big problem was 15-20% less mpg. What? Yep, went from an all around average of 15 to 12-12.7. A friend said it was air under carriage, which is also causing the float I'm feeling. I was going to extend the front air damper and test but first I took it in for diagnostic as I also replaced spark plugs and wires and thought maybe I goofed. Turns out I was told it is the Upstream O2 sensors. I'll have them replaced and report back.

But first, anyone know part number for Upstream O2 Sensors for a 2008 Chevy Express 3500 or where I can order? Searched net and it is kinda confusing. Thanks.

[booster]

Originally Posted by Asphalt Addict

Hello again, I've put a few miles on my lift and lovin' the ride, and the height. Still haven't re-aligned front end but will in the next week or so. My big problem was 15-20% less mpg. What? Yep, went from an all around average of 15 to 12-12.7. A friend said it was air under carriage, which is also causing the float I'm feeling. I was going to extend the front air damper and test but first I took it in for diagnostic as I also replaced spark plugs and wires and thought maybe I goofed. Turns out I was told it is the Upstream O2 sensors. I'll have them replaced and report back.

But first, anyone know part number for Upstream O2 Sensors for a 2008 Chevy Express 3500 or where I can order? Searched net and it is kinda confusing. Thanks.

The mileage thing is really unusual compared to what we have seen on the forum in the past, including our 190P. Our change was essentially within any measurement error, as have the others that I can recall mentioning mileage. We have found that the handling improvements has us driving faster and that drops the mileage very quickly.



Air underneath can cause some resistance, but the front dam is already pretty low, and the van is really only back up to stock height. On a flying brick like our vans, I don't think the the underbody air is much of a factor, especially that much change. On our van the only time I have seen airflow make any difference was when I blocked the air from going into the front wheelswells by extending the wheelwell liners in the front. I did the change to prevent wheel splash that was getting dirt into the front of the radiator area and plugging some of it. It worked for that and also seemed to settle the front a bit, probably from a bit more downforce.



Are you getting a code on the front O2 sensors? Generally, those are the ones that control mixture, so that could be messing up the mileage. Also, if the battery was disconnected and the van wasn't left idling for a while to relearn the fuel trim, that could need to be done as it takes quite a while to do while driving.

[Asphalt Addict]

Thanks for the reply booster. Yes, front O2 sensors, that's what the mechanic said, they affect mpg. Did not disconnect battery. Driving pattern has not changed enough to drop 3mpg. My overall mpg for about a year was 14.7. Haven't seen anything close to that. I got 18 mpg from Tahoe to Jackson WY keeping it at 60. I'll be going again in May. I'll recheck.

Do you, or anyone, have the Vent Shade on the side windows? Do they affect milage. I had them on a 210 RT and liked them so I just put them on my PW. I also have the hood wind deflector but haven't installed because of weather.

[booster]

Originally Posted by Asphalt Addict

Thanks for the reply booster. Yes, front O2 sensors, that's what the mechanic said, they affect mpg. Did not disconnect battery. Driving pattern has not changed enough to drop 3mpg. My overall mpg for about a year was 14.7. Haven't seen anything close to that. I got 18 mpg from Tahoe to Jackson WY keeping it at 60. I'll be going again in May. I'll recheck.

Do you, or anyone, have the Vent Shade on the side windows? Do they affect milage. I had them on a 210 RT and liked them so I just put them on my PW. I also have the hood wind deflector but haven't installed because of weather.

It will be interesting to see if the O2 sensors do the trick, but is likely they could.


The Chevies often will go heavily toed in when lifted, so that also could be an issue for mileage, so you might see an improvement with the alignment.

[Asphalt Addict]

The guys who did the lift said they also did an alignment but it pulls. They are too far away to deal with so I'll have a local do it. I read somewhere there are special specs for the chevy 3500 after lift. Do you recall? Thanks booster.

[booster]

Originally Posted by Asphalt Addict

The guys who did the lift said they also did an alignment but it pulls. They are too far away to deal with so I'll have a local do it. I read somewhere there are special specs for the chevy 3500 after lift. Do you recall? Thanks booster.

With the "standard" lift of Moog 81004 in the front and bags in the rear you will end up just about right at the stock 3500 factory ride height spec, so nothing really special needed, but I do recommend narrowing the the range of the factory settings as they are way too wide IMO. The biggest problem lately is getting a shop that actually knows how to get to specific settings as many of us have had huge issues with that and crappy results. You also probably are "in the green" on settings but not handling well. There are several threads that talk about all the issues with alignments lately with the current machines and techs both being issues.



I like as much caster as you can get on right front and .3-.5 less on the left front.


Camber at + 1/8 to 1/4* both sides. No negative, especially if only negative on one side.



Toe at 1/16" to 1/8" in, which I think is about .08*


Front tires at 65psi, rears at 80psi for stock 245-75-16 size

[Asphalt Addict]

Thanks again booster. 65psi for fronts?
I ran 60 and then read on this forum, I think, to run 55psi for this set up.
Just want to be sure it is not a typo.

[booster]

Originally Posted by Asphalt Addict

Thanks again booster. 65psi for fronts?
I ran 60 and then read on this forum, I think, to run 55psi for this set up.
Just want to be sure it is not a typo.

I have also seen a couple of 55psi recommendations, but the largest amount of users are using 65 in the front of the 2003+ Chevies, from what I have seen. Higher front pressure will increase front traction and reduce the inherent understeer in our heavy rear vans. It is also a free thing to try. I think some people may like a lot of understeer to and are used to the large motions needed on the steering wheel to stay straight.



This is with stock size tires of 245-75-16, though. With the larger 265-75-16 that we run, I have been able to reduce the pressure slightly, running 63 front and 76 rear because of the higher load capacity of the bigger tires. Note that the front to rear ratio is still about the same and that is what has the biggest effect on handling.

[mangomike]

Well, I'm back ... to report on our final
I had been asking about sunpen for my RT210
We finally got the van to where we are happy with it. I'll remind all that our judgement has very little expertise to draw from. So, thanks everyone for their advice.
We replaced the existing 5 leaf rears with a nine leaf springs and new HD shocks and shocks only in the front. And, did an alignment,,,, this gives us a little rake in the rear but once we load 2 bikes ,,,,,one electric ,,,,heavy,,,, and one reg. beach cruiser. We also added a Rochymount Backstage swing away platform bike rack (heavy) . With that weight on the far rear it seems to flatten the van out pretty well. And seems to handle and track well.
I noticed a recent post on MPG. we get between 12 and 14 MPG ,,, is that about right?
Thanks everyone for the help
Michael

[booster]

Originally Posted by mangomike

Well, I'm back ... to report on our final
I had been asking about sunpen for my RT210
We finally got the van to where we are happy with it. I'll remind all that our judgement has very little expertise to draw from. So, thanks everyone for their advice.
We replaced the existing 5 leaf rears with a nine leaf springs and new HD shocks and shocks only in the front. And, did an alignment,,,, this gives us a little rake in the rear but once we load 2 bikes ,,,,,one electric ,,,,heavy,,,, and one reg. beach cruiser. We also added a Rochymount Backstage swing away platform bike rack (heavy) . With that weight on the far rear it seems to flatten the van out pretty well. And seems to handle and track well.
I noticed a recent post on MPG. we get between 12 and 14 MPG ,,, is that about right?
Thanks everyone for the help
Michael

That mileage is not horrible with a 210, but on the low side by a bit based on most of what we see. Speed is a huge factor as is wind, so hard to tell. Our 190 Chevy will vary from 17mpg at 50mph to low 14's at 72-74mph.


You have a lot hanging off the back for a big overhang 210. If you haven't already been there, I think a trip to the scales when fully loaded would be a good idea for you, as 210s are very easy to get overweight in the rear. The rear rating is 6080# and that is also the rating on tires if they are the stock E rated 245-75-16 size.

[Asphalt Addict]

Yes, free to try and I will. I just bought stock size. I wanted to go to the 265s like I did on my older PW but Costco said they wouldn't do it because they wouldn't fit. I do remember on my Dodge they would rub making a tight turn. How about your 190?

[booster]

Originally Posted by Asphalt Addict

Yes, free to try and I will. I just bought stock size. I wanted to go to the 265s like I did on my older PW but Costco said they wouldn't do it because they wouldn't fit. I do remember on my Dodge they would rub making a tight turn. How about your 190?

Ours fit well, close on the front but don't hit anything. There are actually getting to be more of the oversize being used lately with good success.


I don't know if you have read about wheel offset issue with Roadtreks or not, so here is a quick version. The stock steel wheels from Chevy that Roadtrek leaves on are too narrow for the 265-75-16 tires so can't be used. The aluminum wheels they use are either zero on the early ones or 66mm on the later ones, compared to the +28mm that the stock Chevy wheels are. This moves the tires out about 1 3/8" per side and makes them move more forward and back as they turn. It also messes up the scrub radius which will effect handling. They are wider wheels though and will take the wider tires but you might have some touching at the front or rear wheel lips on the front or maybe even the wheelwell back.


For stock size tires there are Chevy pickup truck aluminum wheels or the stock Chevy steel wheels to get the right offset, but in wider wheels AFAIK there is only one wheel available that is wider and has more capacity like the tires, and that is a steel wheel from a Chevy pickup. I think someone did come up with another stock capacity wheel that was close, in aluminum, though but I don't recall the specs, so perhaps they will jump in if they are still on the forum.


We didn't have the issue of application being wrong because I just took the wheels in to have tires put on so as long as they were wide enough no problem. If they had questioned, I could just show the wheels were for the pickup the came stock on from Chevy with the 265 tires.

[cruising7388]

Originally Posted by Asphalt Addict

Yes, free to try and I will. I just bougt stock size. I wanted to go to the 265s like I did on my older PW but Costco said they wouldn't do it because they wouldn't fit. I do remember on my Dodge they would rub making a tight turn. How about your 190?

The 265 tire will fit on a 210 Chevy. We're using them. It's more likely that the increase in tire diameter exceeds the 3% threshhold policy that the Costco tire shop has. So it can be done. But you have to go to a 7 1/2 inch rim. We opted for Chevy OEM steel wheels in order to get the proper wheel offset. The 265 won't fit well in the Continental spare assembly which didn't concern us because we put the spare underneath the rear seat.

[booster]

Originally Posted by cruising7388

The 265 tire will fit on a 210 Chevy. We're using them. It's more likely that the increase in tire diameter exceeds the 3% threshhold policy that the Costco tire shop has. So it can be done. But you have to go to a 7 1/2 inch rim. We opted for Chevy OEM steel wheels in order to get the proper wheel offset. The 265 won't fit well in the Continental spare assembly which didn't concern us because we put the spare underneath the rear seat.

Here is a link to a post with some pix of the various wheels that we had found at the time, there may be another aluminum one by now but unconfirmed, for stock size tires. The Silverado wheels that are used for the 265 tires are actually only 7.0" wide, which is right on the low end of recommended for that tire size.


http://www.classbforum.com/forums/f8...html#post10407

[markopolo]

Originally Posted by mangomike

..................
I noticed a recent post on MPG. we get between 12 and 14 MPG ,,, is that about right?......................

Your 210 most likely has the 4:10 rear axle ratio. I had a 190 with the 4:10 rear (4 speed) and remember the mpg being similar to your numbers.