Any body know how to synchronize these boxes to get equal steering results ? Brad Metzger
I do not think there are two many units on this forum that has that system. You might want to call James T. and ask him.
The heavier front suspensions (18k and up) require two steering gears to handle the extra load. The one connected to the steering wheel shaft is referred to as the "master" and the other the "slave". All the units I have seen do have a linkage connecting both wheels but it's not so obvious on an IFS. There will likely be several linkages connecting the two together and not a simple straight bar like you would see on a solid axle. One issue Country Coach was concerned about was if the driver would have the strength to steer the coach if you ever had the engine shut down while still rolling down the road. I think there is a design trade-off between having a low steering ratio for driver comfort and a large enough ratio so the driver has enough mechanical advantage to steer in a power-loss condition. We actually talked about a backup system for the steering: electric hydraulic pump, hydraulic accumulator or even a driveshaft driven backup pump. Nothing more than talk took place as the company was starting to grind to a halt back then in 2008.
I spent some time on a creeper , had a long look . Noticed a solid sliding bar approximate size 7/8 inch by 4 inch , maybe 4 foot long , that move left and right through a heavy metal framework . Each end has several heavy steel linkage bars all hooked to the wheels. Complex kinda thing , but very sturdy looking . My first post , I was expecting a big sturdy round connecting rod . I can see how the hydraulic hoses come from the steering shaft and then tee off one going to each gear box and back on another hose . The coach steers very good , does not wonder around at all . Brad Metzger
Brad,
Do you know who the maker is of your IFS?
I remember Dana and Reyco-Granning at CC. I understand ZF makes one too. I'm curious what FT used.
It took awhile but finally got needed info from Foretravel . The IFS is "Rayco Cranning " Don't know if this is good , ok or bad . What is your take on this . Brad Metzger
Rayco Granning: Reyco Granning » Suspensions » Independent Front Suspension (http://reycogranning.com/suspensions-cat/independent-front-suspension/)
I think the Reyco-Granning is a good unit. If I remember correctly that's what CC used on their high end (Magna and Affinity) lines which were at 18,000 lbs. in 2008 and moving towards 20,000 lbs. on the front axle. The only complaints I recall were some owners (small minority) thought the shocks needed to be stiffer even though the largest shocks were already standard equipment. The downside to any IFS is there are many more moving pieces and each usually has some kind of rubbers bushing that will eventually dry out, crack and need replacing as well as pins, bearings and such. I'm not sure but even the brake rotors might be unique on some IFS systems. I do remember an issue on some older (model year 2000) units (most likely Dana-Kirkstall) where the repair shops didn't know where to get parts or what the part numbers were. I was tasked with going through all the engineering manuals to look for information for them. Apparently in those years when IFS was a new thing, the IFS manufactures were making a lot of changes to the models which makes finding the right parts even harder.
And that brings up a good point: There are very few of these on the road and each manufacture can have different methods and procedures for doing an alignment which might vary from one IFS model to the other. Along with eccentric bolts, they may use unique shims that can only be purchased from the manufacturers. All of this can be very puzzling and overwhelming for an alignment shop unless they happened to be very familiar with your particular brand and model of IFS. Foretravel, Country Coach Service (Junction City, OR), or Oregon Motor Coach Center(Eugene, OR) are your best bets (that I know of) for getting an alignment/service done without fuss. Maybe there are other brands out there that used this same IFS, but I don't know of them. My recollection is Prevost and Newell us a ZF (European) IFS.
I see no reason to have IFS on a big truck, bus, or RV. The minimal improvements don't justify the massive increase in complications.
My first three Foretravel's had the solid axle . Liked them just fine . Present coach #6527 is my first anything heavy vehicle with IFS . Do I like it --yes . Could I go back to a coach with a solid front axle -- yes . Will I do that no . Once you get used to something newer and improved , why step backwards . What I notice is this -#1 turns a lot sharper which is noticed in camp grounds and parking lots . #2 the ride is better since the trauma from tire / wheel is not transferred to the other .# 3 none of this comes back to the steering wheel. Yes it has more grease fittings , I see six on each side . Brad Metzger
On my first post on this item , I said gear boxes . Well , yes , it has two steering gear boxes , one on each wheel . This is all pretty new for me , but am starting to get a hold on things . What motivated me to buy this coach in the first place was , 650 HP , two potty rooms , seat in the shower and DW's blessing , as she likes the floor plan layout . It had a few issues when new like most coaches have . Foretravel took good care of me and all is well .I have 66,000 + miles on it already with plans to run the wheels off it . My quote is " I didn't buy this thing to park it " Brad Metzger
On the motorcade tour in Alaska, I helped park the coaches in an RV park in Anchorage. Most of the parking spots were "back in" slots with just enough room between slots for slides and a parking space for a car. The streets were not wide. I saw the advantage of the sharper turning radius of IFS when long coaches were able to back into the slots in one pass (under the control of a good driver).
Some explanation of how Sheppard hooks together master/slave steering gears is here: Videos (http://www.rhsheppard.com/videos.htm)
Brett,
I've heard conflicting reports about whether the M-100 steering gear boxes can be adjusted to increase the gear mesh (slight play in the steering wheel). Apparently much older models had two adjustments? I wonder if my 2002 has that. Who might you suggest to to rebuild or adjust the box?
Jim
Jim,
Most large cities have at least one shop that overhauls gear boxes. In ATL there are 2 shops within 5 miles of each other. They both have 1 man who does nothing but re u old gearboxes.
These units are used on a lot of equipment. Look up hyd. Shop and call and ask if they overhaul Sheppard gears. There is no mystery to these, very few parts. Most shops around ATL charge in the 350 range if you pull the gear.
Jim,
I would give Red Head a call: Red-Head Steering Gears - Custom Rebuilt Steering Gear Boxes in USA (http://www.redheadsteeringgears.com/)
I started a section re Sheppard steering boxes a week ago and got a lot of good information from several members. (look on page 3)
My box is going to Red Head in Auburn, WA next week, and their telephone numbers are: 800-808-1148, ot, 206-364-3333. I am having a local shop remove, and refit it.
I will post with my experience/results.
Brian.
Don't know if it applies, but we just heard this week that steering gears may wear in the straight ahead position, from turning the steering wheel back and forth to keep the vehicle going straight down the road. But the rest of the gear has no wear away from the center part, as the gears only touch on full turns. If the gear box is adjustable, moving the gears closer to remove center slack often causes the non-worn part to be a little tight which can prevent the steering wheel from returning to center.
Great set of instructional videos! Wish all the components had that much clear information.