Roadmaster Active Suspension-RAS the lowdown

torx · March 4, 2006

Product Name: Roadmaster Active Suspension-RAS MKII XXF #2541

Manufacturer: Roadmaster Active Suspension

Purchased at:www.summitracing.com

Cost: 291.95 + 9.50 handling fee+ free shipping UPS Ground

Skill Level: Easy

Overall Rating: 9.5

Roadmaster Active Suspension-RAS instead of rear swaybar

This might seem long-winded but all the answers to the questions I wanted instead of just freakin' awesome, works great, or noticeable difference. Hope this answers the questions people have about them.

I have a 2005 Sierra 1500 2wd rc/lb. It rolled in the turns and I have the driveline clunk when jumping on the throttle. Here in VA, the exits off the interstate are tight circles that vary from 55mph all the way down to 15mph. The state used to go with the good ol'boy system. It wasn't until a few years ago you had to be an certified engineer before you could design the roadways. After reading all the reviews I decided on the RAS because it seems to have more benefits than just a swaybar, traction bars, or overload springs. The RAS does all three of these to prevent excessive roll, axle wrap, wheel hop, and works as overload springs for heavy loads/towing. The swaybar might block the differential, if you use an aftermarket differential cover the swaybar might not work/fit correctly or if you have a 4x4 and want the ground clearance instead of a swaybar. You could install traction bars to avoid the axle wrap/wheel hop but I think most would be happier with the swaybar unless your at the dragstrip. It works as overload springs also. I like that each wheel works independent of the other too instead of the swaybar acting on the whole axle but I'll need more time to evaluate this. I still have the OEM shocks but you could always just go to edelbrock ias or bilstiens to try to fix the problems we are talking about. When the OEM's useful life has ended I plan on switching to bilstein hd shocks but the RAS is an addition mod not an upgrade/replacement type of modification. You don't just pull of ok parts to trash and put on new better ones. You compliment the parts you have with the RAS until the OEM or regular ones wear out and then upgrade. I contacted the maker to find out the difference between the regular model and the HD model. I ended up going with the MKII XXF #2451 which is the HD model designed mainly for the 3/4 and 1 ton trucks. I don't tow usually but when I do I will max it out. I wanted all the capability I could get. They said it's only 20.00 more for the HD model and there was no ride difference just stronger for the 3/4 or 1 ton pickups.

You need to check to see if you have overload springs also. Some people might not know what these are. Do I have them or don't I. Make sure you find out. To install the RAS you have to remove the overload springs if your truck already has them. They are installed on some HD or the larger pickups as standard equipment. They are the same as the over load spring you can find online. They float above the leaf spring assembly that is bolted to the axle. They are attached to the leaf spring with shackles usually and when the regular leaf spring deforms enough the overload spring goes to work. I didn't have them so I really didn't know what exactly they were talking about and had to do a little research.

You also want to make sure you are ordering the 2nd generation RAS system. There are great deals/discounts on the internet for the 1st gen ones. Don't do it. There were problems with the 1st gen models breaking. 1st gen. tension spring used to just connect directly to the axle anchor bracket which was a simple "L" bracket with just the cap screw. This was the fail point. The cap screw would shear from excessive vertical loads from what I was able to decipher from all the information I read. No one said directly what failed just the broke, several times and wouldn't recommend them. The 2nd generation has a beefier axle bracket attachment for the cap screw. Instead of a plain "L" bracket it has two forks that bend over and around a solid metal cylinder that the cap screw goes through to connect to the tension spring. The cylinder rotates and the cap screw keeps it centered in the axle anchor bracket. It allows for vertical travel and is quite an improvement over just the plain cap screw which should keep it from shearing. When you look at different pictures you should be able to tell the difference by looking at the axle anchor bracket.

The kit comes completely preassembled and lubed in the heavy cardboard box which is approximately 24 x 4.5 x 4, with two hd plastic straps to keep it closed. It weighs about 30 lbs so look for a deal with free shipping or only a set handling fee.

Here's the install instructions for the 1st generation model. 2nd generation instructions are almost exactly the same. http://www.roadmasterok.com/Installation%20MKII%20XF.PDF

They say 60 minutes to install but I like to take my time and be very thorough and not just slap stuff on. If you've done a lot of them or have a lift that might be the case. I would say 2-3 hours for a single person to take your time and double check everything using a floor jack, jack stands, and deep sockets. It's an easy bolt on. It would take longer using the bottle jack for the emergency spare, cribbing/cinder blocks, and regular wrenches but can be done. LOL

I would highly recommend getting a deep socket for the nuts on the u-bolts that hold the springs to the axle. It makes the job a lot faster. For my vehicle I believe it was a 21mm deep socket. The regular socket won't reach far enough down the u-bolt to touch the nut.

Take the tires off and put the axle on jack stands.

Unassemble the RAS tension spring from the axle bracket.

Install the axle anchor bracket. You have to loosen (more like take off) the ubolts holding the leaf springs to the axle. Locktite might be a good idea when reinstalling the nuts to the ubolts. You can use a regular wrench. I did one using this method just to see how it would work. The deep socket is worth it's cost to justify the time savings and aggrevation factor. You need to do both axle anchor brackets instead of trying to completely install one side and then switch to the other side.

Now that the axle anchor brackets are attached. You need to jack the vehicle back up and support the vehicle from the frame not the axle. The RAS has to be installed with the leaf springs hanging free. That's the reason you install both axle anchor brackets at that time. To get my leaf springs to hang free and the rear differential to extend to the end of it's limt downward I had to place pieces of 2x10's under the jack stands. The jack stands weren't tall enough to get the differential to hang free by themselves supporting it from the frame.

Once the leaf springs are hanging free, Slip the eye bracket over the rear eye of the leaf spring and connect tension spring to the axle anchor bracket. The cap screw uses a 12mm socket. The cap screw has a 12mm female hex or allen head. They have inserted a 1/2in long steel hex piece (male) into the female hex head. They have used some sort of plastic epoxy to keep it in the head of the screw. It seems they have done this so you can use a 12mm socket to tighten the screw down. When you tighten down the cap screw with a 12mm socket it breaks the epoxy that keeps the 1/2in male adapter and it falls out. At least they didn't require special tools but I prefer to have my own tools to make adjustments in the future. A 12mm hex/allen head socket is hard to find. Most places, including Sears only carries up to 10mm sockets. Sears does have a 12mm hex key but not a socket in stock ususally. I found a set of 12mm, 17mm, and 19mm OEM brand sockets at Advanced Auto. You don't need to buy a 12mm hex socket but just make sure you save the male adapter or pull one out so they don't fall out later and you can't adjust them yourself down the road without buying a 12mm hex socket.

Adjust the spring tension and keep the eye bracket centered.

Lock everything down.

Jack the axle back up, put the tires back on and your finished.

Your truck will sit with a little bit more rake towards the front. Maybe an inch or so.

It works as advertised. The truck was designed to be more car like and it looser and more sloppy in the suspension than they used to be to be softer. Driving has gone from nice to very pleasurable after the install. There is no roll in the corners. Corners I used to have to slow to 15mph I can now take a 35-40 safely, confidently. Truck feels tighter and the rear tracks like it's on rails for a truck. LOL Light bumps I used to feel are gone but on the bigger bumps feel a little bit harder since the whole truck feels tighter. I feel the bigger bumps in the front not the rear. The rear bounces a little but soaks them all up. With the rear end tightend up you feel the play/slop in the front now. Where before the play/slop in the rear was so bad you didn't notice the front. New hd or performance shocks should take care of the play in the front. Since RAS is on each spring I would think it should provide better performance on uneven terrain than a sway bar. I would think the sway bar would probably give a little bit better performance than the RAS on flat surfaces since it ties the load to both sides of the axle but the RAS overall compromise for what it does is worth it to me. The RAS has stopped axle wrap, wheel hop, and the clunk when drive train is put under sudden load. It just hooks up and launches. No pause from the drive train. I haven't pushed it hard enough to break the tires free before or after the install. It's my baby. I try to save it for when I really need it. I haven't towed anything yet but my impressions are that the RAS would counter act the strain from the load being towed and absorb the force rather than throwing the rear end of the truck around.

Hope this helps those of you trying to decide on whether this is the mod for you.

They seem to be worth the money. I'm a satisfied user so far

torx · March 4, 2006

before installation, hard stops the nose would dive and it could get to feel almost uncontrollable, after install truck is neutral with no lunge forward and feel very safe. Did not test to make sure but seems like it stops faster, shorter distances but that might just be perception.