94 Southwind suspension question

[RVTOM]

30' Southwind, Chevy. Newbie bought bad handling espescially in wind. Took advice from a couple of post on here and took it in to chassis shop. Spent the bucks for new Koni shocks, upper and lower ball joints, new Super Steer bell cranks and new front sway bar bushings. Wanted a safety steer but the wrong one was sent to them and they couldn't find the right one in time before we took our trip. Also did not have time for a front wheel alignment so they told me to take it in when we got back.

Went North (200 miles each way) and it seems to still steer a little loose and when it got windy comming home it was blowing all over the place and was pretty nerve racking to say the least.

My question is will safety steer correct this and by not getting a wheel alignment did that make it worse handling also. Would like some feedback before I call the chassis shop. Thanks Tom

[offthewall]

Originally Posted by RVTOM

30' Southwind, Chevy. Newbie bought bad handling espescially in wind. Took advice from a couple of post on here and took it in to chassis shop. Spent the bucks for new Koni shocks, upper and lower ball joints, new Super Steer bell cranks and new front sway bar bushings. Wanted a safety steer but the wrong one was sent to them and they couldn't find the right one in time before we took our trip. Also did not have time for a front wheel alignment so they told me to take it in when we got back.

Went North (200 miles each way) and it seems to still steer a little loose and when it got windy comming home it was blowing all over the place and was pretty nerve racking to say the least.

My question is will safety steer correct this and by not getting a wheel alignment did that make it worse handling also. Would like some feedback before I call the chassis shop. Thanks Tom

I can't believe they changed upper and lower ball joints and let you take it without an alignment! I doubt anything about your alignment was right.

[RVTOM]

Thanks for the insight. Will the alignment shop be able to get it right?

[offthewall]

Originally Posted by RVTOM

Thanks for the insight. Will the alignment shop be able to get it right?

I couldn't speak to their abilities

But an alignment is required after you take upper and lower ball joints off.

[targaboat]

Not with you have described so far. Get a new shop. And talk with them about how they are going set you alignment parameters. Possibly more caster is in order. PM me if you to here more. Find a shop you can work with and who speaks the language on handling and just say they will set up to the specs.

[RVTOM]

Thanks. Had the work done at Cummins Bridgeway who seemed very reputable. They don't do their own allignments but send them out. They gave me the name of where to take it and it's a full service truck center. I'll give them a call tomorrow and explain the situation and go from there. I'll call Cummins too and see what they have to say.

[Gary RVRoamer]

Are the front air bags pressurized correctly? Somewhere between 50 and 90 psi, depending on the front axle weight rating and your preference for ride vs handling.

I don't think a safety steer device will do anything at all for wandering steer. It helps keep the steering centered, but you are already doing that with your hands. Your problem is that the chassis is wandering despite that.

Another part of the problem may be driver inexperience. You have driven passenger cars for years, but this vehicle handless differently and your "muscle memory" is not tuned to it yet. New drivers tend to over correct on their steering input and also tend to focus too close to the front end, trying to stay between the lines. Relax a little and look far down the road, maybe 50-75 yards away. You will drive straighter. Pick a reference point on the dash where the line at the center of the road passes when you are properly in your lane. Glance at that rather than continually checking the road in fornt or the mirrors for lane position. That allows you to focus further ahead and avoids choppy wheel input.

[RVTOM]

Thanks Gary. I think you're right on all points. Made appointment for alignment on Monday. Will let you know what they have to say.

[targaboat]

Originally Posted by targaboat

Not with you have described so far. Get a new shop. And talk with them about how they are going set you alignment parameters. Possibly more caster is in order. PM me if you to here more. Find a shop you can work with and who speaks the language on handling and not just say they will set up to the specs.

Note the above. Tell the shop about your handling problems. You will have to use your feelings relative to their response to determine they know what they are doing. There are lots of alignment mills out that will not do you much good. I would be looking to them tell me that possibly an increase in caster to the high side of the specs and possibly a little higher.

[RVTOM]

Thanks Targa. Could you school me a little on caster if you can. Will setting it higher help with the wind gust or just better handling overall? Also had air bags set at 60 psi and the passenger bag will leak out over time. Hate spending more cash but should I replace both front bags. Rear bags seem ok and had them set at 60 also. Plan on getting coach weighed for tire pressure because even with new Koni's it still bangs pretty hard on rough surface streets.
Thanks again Tom

[Topflite51]

Often overlooked: Have you weighed your rig, if not 4 corners if possible. Set tire pressure to tire manufacturer's specs, keeping pressure on each tire on same axle the same. As far as caster goes, an extra + 1/2 or 1 degree over spec will reduce the tendency to follow the ruts in the road. Won't do much for wind or truck passing push, may need a rear track bar for that. If you or a friend are handy and can weld, there are pictures of homemade ones on OEM tech's website. Would be considerably cheaper than those made by the aftermarket companies, and every bit as good.

As per usual forgot to add his website:
http://oemys-performance.com/diytracbar.htm

[targaboat]

Originally Posted by RVTOM

Thanks Targa. Could you school me a little on caster if you can. Will setting it higher help with the wind gust or just better handling overall? Also had air bags set at 60 psi and the passenger bag will leak out over time. Hate spending more cash but should I replace both front bags. Rear bags seem ok and had them set at 60 also. Plan on getting coach weighed for tire pressure because even with new Koni's it still bangs pretty hard on rough surface streets.
Thanks again Tom

First, of all I am convinced that one must involved in our service work as compared to just leaving it at a place telling them to fix it. This will work if you absolutely know the shop, but otherwise you never know what you are getting for your money. I apply this to everything I have done, including medical things. However, this presents a problem if you are not schooled in the area that is involved in the service work. You are absolutely correct in working at learning about the dynamics of vehicle motion. However, you need only a small amount and with tactful probing you can likely make a good judgement of the shop doing then work.

Now back to caster. Beside this forum, you can do a Google on caster and obtain a wealth of information. But to start, toe and caster are critical to how a vehicle will handle in unsteady conditions such in wind custs. Toe must be slightly in and is very easy to adjust by the shop. Caster must be positive and in our top heavy box on wheels it must be to the high end of the spec or even slightly larger than the spec which is an average from the manufacturer and considered good for all vehicles. Our RVs perform better toward the higher end. I can not go into the detail reasons for this in this relatively short note. But, the major issue here is that caster is hard and time consuming for the shop to change on our truck chassis. Basically, shims must be obtained from the manufacturer and installed in the front end mechanisms. This is counter to the slam bang for a fixed fee methods that most shop operate under. The customer base is also responsible in wanting to get the best price for the work. So if the shop measure that the the caster is within spec they consider that they have full filled the contract they have with the customer. They will not guarantee the vehicle will perform better, only that the alignment parameters are to the manufacturer specs.

There can also be a liability issue encouraging the shop to operate withing the specs. This has become an important issue in recent years. The lack of knowledge in the shop people on the affects of alignment on vehicle dynamics can also be an issue.

I suggest that you discuss caster settings with the shop and react according to your instincts.

As for the technical details, if you have a problem with finding helpful information in Google, please PM me and I will send you links to the articles that I believe is the most relevant. I might point out as well that some of the articles are not technically accurate as to the reason for the higher caster settings. However, all the ones that I recently reviewed agreed that a higher reading is necessary. The down side could be at the higher settings the steering could become too stable sort of like feeling as if you are driving in sand while going down the hi way. So I lean toward wanting the caster at the high side or over if that is as close as you can get with standard shims. After the inital measurement the shop can extrapolate fairly close as to where they will be with the larger standard shims.

[targaboat]

I agree with the weight balance and other issues in the previous post. The front end needs a percent of the total weight for proper handling. Also the box needs to be fixed to the axles and not be allowed to wag back and forth sideways(lateral motion) interdependent of the axles. Also tire pressure can not be too low. Too high does not cause handling issues, just a rough ride. But many times these things have been fixed and the handling is still bad. Then the caster issue must be addressed. This is before ones spends money on all the other fixes such as the steering dampers.

[RVTOM]

Many thanks Targa. Found some info at this site


http://www.offroadtoybox.com/RV/P-Ch...entProcess.pdf