Question for Ujoint Chris??
- Thread starter dsw4x4
- Start date
ujoint
Supporting Sponsor
I've done one, and we're still working on a solid solution to keep everything happy. The van drives fine, just has a waring on the dash about the RSC system. I'll have a complete axle upgrade to make everything plug n play. It won't be cheap, but it's a solution.
Should have final word in a few weeks.....
Should have final word in a few weeks.....
dsw4x4
Adventurer
Ya i am going through the same thing I have a customer that lifted a 2wd van and the RSC alarm and light keeps going off. It has nothing to do with the front axle it is just changing the center of gravity by lifting it that throws off the control module cog. There has to be a way around it because the 4wd conversion companies have to be doing it. I will see if I can find out some more info on the issue.
LeadDoggy
Observer
Who's lift kit does your customer have?
I have a lift on my 07 E350 and been having problems with the RSC. Talked with an Engineer from FabTek at a show and he said that as long as you keep the turning ratio the same you will not have any problems. It has nothing to do the the height of the body, it's all in the turning ratio.
With that said, my observations has shown me that the drop pitman arm that was used with the lift has a longer reach than the stock arm, thus causing the wheels to turn more with less steering wheel input, therefore causing the RSC system to think that the vehicle is going into a slide of some sort.
Presently working on a solution.
dsw4x4
Adventurer
I do not have the van here at the shop so I am not sure but next time I can get my eyes on the van I will check it out. He lifted the van himself which makes me believe he is running the stock pitman arm however I am not positive. He has just asked me about the problem and I would like to find a solution for him, because I want to be able to do fourwheel drive conversions on vans equipped with RSC with out any surprises. Keep us posted on what works and what does not. My little brain is rattling around the logistics of how the van would be able to tell it is sliding from the steering ratio being changed. I do not have a RSC equipped van here to look at so I am just trying to grasp how it does what it does and with what sensors. If there is a sensor that reads steering position then it would seem to reason that something else would need to give feed back to tell the ecm the van is sliding, maybe speed sensors in the wheels?? At a certain percentage of the turn dfront will spin x% slower than Pfront if those numbers do not chime RSC kicks on and does its job?? I don't know just speculating! It would be nice to figure this out. Especially for the do it yourself crowd. I will ask some questions tomorrow and maybe even get down to look at the van and see what I can find out.
Derek
Derek
LeadDoggy
Observer
DSW 4x4,
Yes, there is a sensor the reads the steering wheel input. It is located on the steering shaft behind the plastic panel below the steering wheel. If the pitman arm is longer than stock, the front wheels will turn more with a given amount of steering wheel turn and the WAN sensor will pick that up. Most of the problems I have are when I have turned the wheel more than 1/4 turn. It's less of a problem the faster I go, so it is also speed sensetive.
Yes, there is a sensor the reads the steering wheel input. It is located on the steering shaft behind the plastic panel below the steering wheel. If the pitman arm is longer than stock, the front wheels will turn more with a given amount of steering wheel turn and the WAN sensor will pick that up. Most of the problems I have are when I have turned the wheel more than 1/4 turn. It's less of a problem the faster I go, so it is also speed sensetive.
There is a black box under the driver seat, it is referred to as the "Gyro" in the service manual, however I think it works based on a harmonic frequency, it monitors pitch, roll, and yawl. When the steering wheel is turned, a signal is sent from the "steering wheel position senor" (located on the steering column) to the ECM, the "Gyro" sends the signal of the change in the vans position(yawl in the case). If the new pitman arm is longer, then the front wheels would turn more with the same steering wheel input thus the ECM thinks the van is sliding sideways because the "Gyro" and the steering wheel position sensor don't agree.
The pitman arm that came with my lift kit is 1-3/4" longer from center of steering box to center of the outer hole in the pitman arm. I am curious if putting the stock pitman arm back on would correct the RSC problem. That might cause bumpsteer but at least we would confirm the fix for the RSC.
dsw4x4
Adventurer
Regist1,
Welcome to the portal from my old back yard!! I grew up on the Meremac River on the edge of the Ozark mountains spending my child hood wheeling, camping and paddling all over Missouri Oklahoma and Arkansas. I am always looking for people from that area on the portal and it is few and far between. Anyway, I am agreeing with you 100%. I am assuming your van is 2wd with a lift. My research from the last couple of days have taught me that the distance from the center of the knuckle (spindle) to the tie rod mount needs to always have the same relation with the pitman arm (for reasons you explained). So if you use a longer arm you must use a newer axle knuckle to match it. Or a high steer arm to match the length of the new pitman arm. Also you must use the correct wheel speed sensor with the axle you put in the van. I.E. if you put a 2010 axle in your 2002 van the wheels speed sensors will not read properly with your ecm causing the rsc to whack out, so you must use the correct sensors however the stock van ones will not fit in the new axle so you have to find the correct superduty sensors that will fit in that axle to read correctly with your van. This involves some research because it all depends on what year axle and van you are using as to what will work and what won't. You changing out your pitman arm will confirm what i am suspecting. I have a 4wd Quigly here at the house that equipped with rsc and there appears to be nothing special done to it other than the correct abs sensors and matching axle to pitman arm and it never acts up. The only cure I can think of for a 2wd van is to go back to a stock pitman arm like you said and see if the bump steer is tolerable. I do not have 2wd to look at so I can't really give any good ideas at this time.
Welcome to the portal from my old back yard!! I grew up on the Meremac River on the edge of the Ozark mountains spending my child hood wheeling, camping and paddling all over Missouri Oklahoma and Arkansas. I am always looking for people from that area on the portal and it is few and far between. Anyway, I am agreeing with you 100%. I am assuming your van is 2wd with a lift. My research from the last couple of days have taught me that the distance from the center of the knuckle (spindle) to the tie rod mount needs to always have the same relation with the pitman arm (for reasons you explained). So if you use a longer arm you must use a newer axle knuckle to match it. Or a high steer arm to match the length of the new pitman arm. Also you must use the correct wheel speed sensor with the axle you put in the van. I.E. if you put a 2010 axle in your 2002 van the wheels speed sensors will not read properly with your ecm causing the rsc to whack out, so you must use the correct sensors however the stock van ones will not fit in the new axle so you have to find the correct superduty sensors that will fit in that axle to read correctly with your van. This involves some research because it all depends on what year axle and van you are using as to what will work and what won't. You changing out your pitman arm will confirm what i am suspecting. I have a 4wd Quigly here at the house that equipped with rsc and there appears to be nothing special done to it other than the correct abs sensors and matching axle to pitman arm and it never acts up. The only cure I can think of for a 2wd van is to go back to a stock pitman arm like you said and see if the bump steer is tolerable. I do not have 2wd to look at so I can't really give any good ideas at this time.