Community Forums

rjproctor · 04-01-2014, 11:21 AM

I have a 38FT DSDP year 2000. My problem is that motor home rear end digs into concrete drive when entering or backing out of drive. I currently have some wooden pads which I put under the rear tires just before the rear end touches. They are constructed from 3 three high and two across 2x8's giving a total lift of about 4.5 inches. I have to keep the rear wheels on these lifts for about 16 feet in order to get past the point where the rear end drags. The solution of correcting the slope of the driveway is right at $10,000. I as wondering if there is an alternative to repouring the driveway. i.e. can air bags in the rear give me 4.5 inches of lift. My current air lift lifts both the front and back together. Any ideas would be appreciated.

FlyingDiver · 04-01-2014, 11:58 AM

I would contact the maker of your air suspension system (HWH or Hadley, most likely) and ask them if there's some modification of the system that can do what you need.

PDR John · 04-01-2014, 12:13 PM

I'll second what FlyingDiver said.

To my understanding, there only around 3" of lift when the bags are maxed. That will give or take dependent upon each coach.

wracinti · 04-01-2014, 02:11 PM

rjproctor,
I feel your pain! Every time I switch motorhomes I am sweating it if I will get up my inclined driveway without dragging something into my stamped concrete. So far so good, but I neeed a formula for future coaches, like distance from back wheel to end of coach and height from ground to lowest point at the rearend.

rjproctor · 04-02-2014, 11:12 AM

Thanks for the replies. I contacted HWH which has the system currently installed on my coach and they said they could do nothing more. I suppose I am stuck with moving my wooden ramps around as needed or convincing myself it is worth $10,000 not to do it. I am sure I can live with the ramps. Thanks again.

millerj · 04-02-2014, 11:39 AM

Does it make any difference if you back in?

terry735001 · 04-02-2014, 11:41 AM

your current air lift lifts both the front and back can be setup to not work at the same time

if you add a valve where the front well be the only one going down it well give more then 4in in the back

you just have to take some time in backing out and 1/2 out the drive way you need to add air again to the front or it could drag

had a friend do it its a under $100 mod

rjproctor · 04-02-2014, 12:14 PM

Quote:

Originally Posted by millerj

Does it make any difference if you back in?

Don't see how that would change anything but possibly where I drag, but perhaps it is worth a shot.

rjproctor · 04-02-2014, 12:15 PM

Quote:

Originally Posted by terry735001

your current air lift lifts both the front and back can be setup to not work at the same time

if you add a valve where the front well be the only one going down it well give more then 4in in the back

you just have to take some time in backing out and 1/2 out the drive way you need to add air again to the front or it could drag

had a friend do it its a under $100 mod

I will check into the valve. For $100 it is definitely worth a shot.

Tony Lee · 04-02-2014, 12:36 PM

Assuming you have the normal airbag suspension, it isn't a big job to install a manual or electric valve to bypass the automatic height valve and so extend the rear airbags to full height. If you can get three inches extra on the rear airbags, that would give you closer to 4" right at the back.
Depending on the overall geometry, you could add a similar system to the front to drop those air bags to the minimum and that would get you a little bit extra lift on the rear.

Obviously you would be interfering with approved vehicle systems so any manual overrides would need to comply with any relevant regulations.

wb7auk · 04-02-2014, 04:26 PM

Keep in mind changing the ride height also effects the drive line/ U-joint alignment and major damage can result if driven that way.

TRAILERKING · 04-02-2014, 05:13 PM

I've seen a picture on one of the truck conversion sites. You can build an adjustable linkage/rod for your ride height valve. It can be air operated with solenoid valve and a toggle switch. When you want to raise it hit the switch and it changes the length of your rod. When done what you're doing hit the switch and it changes back to original length via spring return.
***However got to be careful you're not put your driveshaft into a binding situation*** Use only at a slow crawl

DutchStar38 · 04-02-2014, 06:48 PM

If you deflate the front then you can't steer because the tires will scrape the body. If you bypass the height then you will have to take extreme care not to damage the airbags.
Wouldn't it be cheaper to have some metal ramps made to cover the driveway dip? Seems any local metal shop could do this for you rather than spending $10k for cement.

TRAILERKING · 04-02-2014, 10:12 PM

Quote:

Originally Posted by TRAILERKING

I've seen a picture on one of the truck conversion sites. You can build an adjustable linkage/rod for your ride height valve. It can be air operated with solenoid valve and a toggle switch. When you want to raise it hit the switch and it changes the length of your rod. When done what you're doing hit the switch and it changes back to original length via spring return.
***However got to be careful you're not put your driveshaft into a binding situation*** Use only at a slow crawl

By the way on this method you do not "By-Pass" the height valve. You momentarily alter the length of the linkage. It will only raise as high as you let it. You could really have one on the rear to override to raise and simultaneously one on the front to lower slightly. That thing will slide up your driveway like a Rocket Launcher.
Just be lined up straight with your driveway, change your ride heights, and drive up slowly. Again just don't forget to change back to normal height so don't damage driveline.
This can be made with an air actuator or an electric actuator. Very simple. You just have to experiment on the required length you will need to get out of the actuator.