leveling a fifthwheel - Diesel Forum

landis_rogers · 03-25-2008, 07:13 PM

I am trying to level my new fifthwheel to my truck. I have a b&w companion hitch. I hooked up the trailer and made a few measurements. I have 6" of clearance between the bottom of the fifthwheel and the bed rails on the truck. When I measure the front of the trailer to the ground minus the back of the trailer to the ground I get a difference of 7". So the front of the trailer is 7" higher than rear of the trailer. So I need to change the trailer in some way. I have airlift spring installed with an autoleveling compressor set up (really cool). I have the air bags set so when the trailer is on the truck that there is about 3/4" between the helper and leaf spring. The trailer has triple axles with a mor/ryde "IRE" suspension. So the only height adjustment on the suspension is the plates that bolt the suspension to the trailer. There are three holes in the plate to all you to change the height of each plate. There are no instruction about how to level the trailer in the owners manual. So what should I do. The dealer said I should lower the bed of the truck by moving the airbag height down. I don't really want to engage the helpers with just the trailer weight, I would be afraid of bottoming the truck out. So does anyone know how to adjust the mor/ryde "IRE" suspension or should I just do it by letting more air out of the air bags? Some other measurements. Bed rail height at the rear axle 54". Hitch plate above the bed 16" and the bed rail height above the bed 20".

gmoore · 03-26-2008, 12:37 AM

I had a similar problem with my 34' Alpenlite. First thing I did was replaced the 4" axle blocks on the rear of my truck with 2" blocks from an F250. Since I had been towing with the overload spring touching on one end and 1/2" off the perch on the other (could feel the spring slapping when hitting bumps), I removed the overload springs. I added Firestone air bags. A major improvement in ride while towing.

I then lowered the mounting points (the three holes you mentioned) for the trailer suspension. I only went down one hole from the factory setting.

From you information, you stated your were approx 7" high in the front. For every inch you drop in the front, you will have a similar (probably a little less depending on axle centering) rise in the rear (think tetter toter). So in theory you need to drop the front 3.5" - 4" in the front.

Block change - 2"
lowering suspension attachment points 1 1/2"- 2"

You should be in the ball park. Buy the way, with the air bags at 30# towing is very nice and comfortable. Airing the bags to 35#'s keeps the head lights aimed correctly for night time towing. By the way, I don't miss the overload springs at all, even when hauling 4k of stone or hardwoods.

Good luck

landis_rogers · 03-26-2008, 09:47 AM

Can anyone pick out the part for the blocks from this diagram or know the part numbers of the shorter blocks? I would like to get them on order

Powerstrokeshop.com

gmoore · 03-27-2008, 01:12 AM

It's part #11, plus you'll probably need part #3, new U bolts. Check, you may have enough threads on yours, but you'll need to cut them down to their new shorter length.

Good luck

gmoore · 03-27-2008, 01:16 AM

On second thought, I notice you have the Tow Boss option, that usually means Dually. Most 4x4 duallys come with only 2" blocks already. You may want to crawl under and measure before ordering.