F53 ride and handling

[Oldcarnut]

I've read so many threads on these topics that I'm getting cross-eyed! I've read about the chf, track bars, Sumo Springs, steering stabilizers and everything else. I consider myself mechanically inclined but I will have to admit to being a bit confused at this point. I know I need a steering stabilizer. That should take care of the road wander. The coach does suffer from some body roll but that is to be expected. I'm not sure if it would be considered excessive. Other than the wandering, the biggest problem is the ride quality. I always say it rides like a buck board. Very harsh ride, especially in the front. I'm probably going to install a set of Bilstein shocks but beyond that I'm at a loss. I've considered the chf but I understand that can make the ride worse. There is no point in doing everything to it if it isn't necessary because none of these items are cheap. I realize its not a DP with air ride and it never will be. However, there has to be a way to make it better than it is now.
Help!

[EdInArk]

Originally Posted by Oldcarnut

I've read so many threads on these topics that I'm getting cross-eyed! I've read about the chf, track bars, Sumo Springs, steering stabilizers and everything else. I consider myself mechanically inclined but I will have to admit to being a bit confused at this point. I know I need a steering stabilizer. That should take care of the road wander. The coach does suffer from some body roll but that is to be expected. I'm not sure if it would be considered excessive. Other than the wandering, the biggest problem is the ride quality. I always say it rides like a buck board. Very harsh ride, especially in the front. I'm probably going to install a set of Bilstein shocks but beyond that I'm at a loss. I've considered the chf but I understand that can make the ride worse. There is no point in doing everything to it if it isn't necessary because none of these items are cheap. I realize its not a DP with air ride and it never will be. However, there has to be a way to make it better than it is now.
Help!

I'm not clear what you want here that you haven't already found

But I put a Trac Bar on ours. It felt like the wandering was coming from the rear on our, and I addressed that by putting the Trac Bar at the rear. The change was very noticeable.

I did the CHF first. Big change in swaying but the wind or passing semis still affected it enough that my wife fought it and would get it weaving.

Second the Trac Bar. Another big change. The wind didn't affect it much at all any more. Passing semis are barely noticeable.

But there was still a bit of wandering which a front end alignment fixed.

[phil-t]

Originally Posted by Oldcarnut

I've read so many threads on these topics that I'm getting cross-eyed! I've read about the chf, track bars, Sumo Springs, steering stabilizers and everything else.
Help!

Have you had your rig thoroughly inspected for chassis wear? Front end alignment? Tire pressures set according to actual weight of rig (ready to travel)? The CHF is free! Don't believe it has, or can, add to any ride harshness.
For the alignment, be sure to find a shop that has lots for Ford F53 chassis experience and talk to them about your ride and the settings they might, or will, make.

[wildtoad]

Here’s my list of items that have helped mine.

1) Did the CHF.
2) Used the Goodyear tire chart for my unit/weight, lowered pressure by 10-12 lbs.
3) Travel with full fuel, full water.
4) Replaced Ford spec’d Bilsteins with aftermarket Bilsteins.
5) Slowed down to the 62-65 mph range.

Net is a better ride, more enjoyable drive.

[Wally61]

Wild toad does the my need to be level to do chf

[jharrell]

A vehicles suspension system is a trade off, soft ride is at odds with sway control and firm handling. If you you stiffen the suspension to control sway it will be less compliant over bumps.

Sway bars are the best solution to sway without getting into active computer controlled suspension, that's why nearly every car has them now days. They are just a spring but attached in such a way to only engage when the axle moves unevenly. This reduces body roll because the spring stiffens the suspension during a lean but has no effect when the axle moves evenly up and down such as over a expansion joint. The CHF moves the link attachment point closer to the bar reducing leverage increasing stiffness of the torsion spring therefore reducing sway. There is a cost in ride harshness for uneven bumps such as pot holes. Motorhomes have a high center of gravity and tend to have a lot of sway, most people seem to prefer the trade-off of a stiffer sway bar. With adjustable links or brackets you can adjust the stiffness and the trade-off in a more fine grained way. You can also change the bars out for thicker ones or add secondary ones to increase stiffness.

Wandering can be addressed to a large degree without stiffening the suspension, adjusting toe in easy easy and can be done yourself if inclined, the more toe in the straighter the vehicle will track at the expense of tire wear, again another trade-off, a small amount of toe-in is recommended, Ford specs 3/32" toe-in max which I adjusted to and made a big difference on wander with no sign of tire wear.

Caster also helps wander and tracking, increasing it to around 6 degrees seems to be the recommendation. On a F53 Caster must be done with shims between axle and leaf so not easy to do yourself but has no effect on tire wear.

A steering stabilizer can help wander too, its basically a shock attached to the steering to dampen movement reducing outside forces from pushing the steering around as quickly, this has a side effect of giving better control in the event of a blow-out. Many for RV use have a spring system that tries to keep the steering centered, so beyond the dampening will also help keep the RV tracking straight if aligned properly.

A trackbar can help wander and sway. It locates the axle more firmly than the leaf springs, reducing side to side movement. Small amounts of side to side movement can be amplified needing steering correction. Secondary to that a track bar can change the roll center of the vehicle, most rear trackbar designs for the F53 raise the roll center closer to the vehicles center of gravity, this reduces the leverage of the COG to roll the vehicle decreasing sway. Trackbars only trade-off is the axle will move slightly side to side as the suspension travels up and down due to it following an arc created by the bars pivot. Longer bars minimize this effect. The F53 comes with a front track bar stock in later years but no rear.

Harshness is more difficult to solve because it is at odds with firm non-wandering handling. The springs and shocks in motor-home isolate the axle from the frame the tires isolate the road from the axle, its actually two suspension systems stacked. Lowering tire pressure, changing springs to softer ones and changing shocks to ones with less dampening will reduce harshness, so long as you don't bottom out due to them being too soft.

Tire pressure is an easy one, you can lookup the minimum tire pressure for your axle weights and start there, it will soften the ride but now you may get more wander and sway due to side wall flex. You can then increase pressure to trade off between softness and handling. Tires are basically a air spring suspension.

Softening the leafs are a bigger job but can be done, you have to swap them out. If they are too soft however you may bottom out over bigger bumps hitting bumps stops which will be very unpleasant. The idea is to have the softess springs that prevent bottoming out with the normal weight on the axle. This is the big reason why air suspension is used, it will have ride height valves that adjust air pressure to exactly the minimum pressure needed to get proper ride height and no more.

Shocks are relatively easy to change out but as always a trade off. A shock with more dampening will be stiffer and dissipate more energy more quickly this reduces sway and can help prevent bottoming, but this also means a harsher ride otherwise. So again you want the minimum dampening you can while preventing bottoming and keeping sway minimized. Koni FSD shocks attempt to have "smart" dampening that increases on slow movements like sway while having less on faster movements like bumps, reviews are mixed.

Sumos and helper air bags are placed in parallel with your leafs springs, this causes them to add spring rate to the leafs increasing stiffness. This will reduce sway like a sway bar but they don't disengage like a sway bar, they are always contributing spring rate. Normally these are used to boost weak springs to prevent sag and bottoming out. The only way they can soften the ride is by preventing bottoming otherwise they are stiffening the ride all the time. Normally in a pickup truck you inflate helper bags when carrying a load and deflate them to minimum when not to return to factory softness.

More expensive solutions to harshness involve more extensive changes to the F53 suspension such as Kelderman air. This does more radical changes to the suspension to make it similar to a true air ride, with ride height valves and ping tanks and softer leafs and detached rear leaf shackles.

[Sweetbriar]

Before doing anything check your tire pressures. Over inflating, such as using the tire sidewall pressure will cause a harsh ride AND lane wonder. As a default until you can get the coach on a scale use either the Ford or the house builder pressure numbers which should be the same. If adding extra helps you sleep at night I wouldn't go much more than five or so pounds over recommended.

Next try the Cheap Handling Fix. Considering the change costs you're out nothing other than the time spent under the coach and if you don't feel the change was of any help then put everything back to original configuration.

Next let's work on ride quality. Getting the coach weight check will also help here particularly if you can get the weight of each tire. The goal is to, as best you can, balance your load. You want to try and load the axles to the same percentage of maximum. You could be heavy but under the axle limit up front which could result in the suspension hitting the limits of movement on poor roads. Something as simple as moving your tool kit and a case of water from the front storage to the rear can have a several hundred pound effect even though you only moved 50 pounds.

And speaking of suspension movement limits get under the coach and check the suspension bumpers. My front bumpers deteriorated and basically fell apart. Easy to replace. Also look around at any visible rubber bushings (actually you should do this during the CHF change). Rubber bushings have a service life particular the rear sway bar bushings which will more or less start to melt the day after the warranty expires.

For shocks consider Koni rather than Bilstein. Koni shocks are somewhat softer to the initial suspension movement but will attenuate the rebound about the same as Bilstein. With the Bilstein shock having a gas charge they are a bit stiffer and can cause a somewhat harsher ride particularly during the first hit of a pot hole or other road deformity.

At this point you will be moving into the world of bolt on devices and escalating costs. What to do next is dependant on what you are trying to effect. Do the low cost stuff first although shock can be expensive they are somewhat of a wear item. Evaluate the coach ride and handling over the course of several outings. If you're happy with the set up congratulations and go camping. If you're looking for something more you'll need to be specific concerning the effect you want when asking for guidance.

[jharrell]

Originally Posted by wildtoad

3) Travel with full fuel, full water.

I think this is a somewhat forgotten adjustment. I typically run full water and gas too.

Softening your leafs springs is involved and expensive, but adding ballast weight is cheap and easy and has a similar effect, it just cost in gas to carry around and increased braking distance.

The lower the weight in the MH the better, low enough can actually improve sway acting as a counter weight.

Either way its softens the suspension, but too much and you bottom out. you can tune your ballast weight to your load and place it to effect front or rear or both.

I have heard of some attaching steel ballast to the front bumper on the F53 to soften the front and improve handling.

To do it right you will need to weigh axles or even 4 corner to make sure your not exceeding the axle specs and that its balanced side to side.

[Waiter21]

I've considered the chf but I understand that can make the ride worse.

Trust me, The CHF will significantly improve the sway and handling, and have minimal effect on ride.




My recommendations:

1) CHF - both front and rear. You didn't mention year, but if 2006 or newer, verify the rear torsion bar bolts are tight. I'd recommend removing the bolts, inspect the mounts, then re-install the bolts with blue locktite and torque to 65 ft-lbs.


Do NOT spend any money on aftermarket suspension components until you do the CHF firrst, then re-evaluate it. Most find that the CHF satisifies their needs.


2) Verify front end alignment - have shop set at max toe in and if they are shimming the axle, have them shim for max caster.


3) If older than about 10 years, consider replacing shocks, as they ar probably worn out. I used standard ole Monroe shocks. Big improvement over worn out shocks.

[jharrell]

Originally Posted by Waiter21

Trust me, The CHF will significantly improve the sway and handling, and have minimal effect on ride.




My recommendations:

1) CHF - both front and rear. You didn't mention year, but if 2006 or newer, verify the rear torsion bar bolts are tight. I'd recommend removing the bolts, inspect the mounts, then re-install the bolts with blue locktite and torque to 65 ft-lbs.


Do NOT spend any money on aftermarket suspension components until you do the CHF firrst, then re-evaluate it. Most find that the CHF satisifies their needs.


2) Verify front end alignment - have shop set at max toe in and if they are shimming the axle, have them shim for max caster.


3) If older than about 10 years, consider replacing shocks, as they ar probably worn out. I used standard ole Monroe shocks. Big improvement over worn out shocks.

Good advice, the CHF cost nothing and can be easily undone. Alignment should be done at the factory but we have to instead, max toe max caster, get a good tire balance an index while there if you have any noticeable vibration.

Shocks, well I wish I had enough time and money to try them all and do some experiments because reviews are all over the place and not much info on the actual valving. Actually I wish someone would make and adjustable shock for the F53 then it could be dialed in, keep wondering if an offroad adjustable shock could be put to use on a MH.

[jharrell]

Originally Posted by Wally61

Wild toad does the my need to be level to do chf

If the axle is not level with the frame when doing the CHF the sway bar will be under load and difficult to deal with. Use jacks to level them and the sway bar will be under no load and be easier to disconnect links and realign with secondary holes.

[Harvard]

POPULAR MECHANICS MAY 1973:
START QUOTE:
If too little caster exists, the car will wander and weave,
thus necessitating constant corrections in steering.
END QUOTE:

[jharrell]

Originally Posted by Harvard

POPULAR MECHANICS MAY 1973:
START QUOTE:
If too little caster exists, the car will wander and weave,
thus necessitating constant corrections in steering.
END QUOTE:

Same with toe, same with sway, same with axle locating, these all contribute to wander:

In a rear wheel drive vehicle, increased front toe in provides greater straight-line stability at the cost of some sluggishness of turning response. Performance vehicles may run zero front toe or even some toe out for a better response to steering inputs. The wear on the tires is marginally increased as the tires are under slight side slip conditions when the steering is set straight ahead. On front wheel drive vehicles, the situation is more complex. Rear toe in provides better stability during cornering.

https://en.wikipedia.org/wiki/Toe_(automotive)

[kenandterry]

Originally Posted by Waiter21

Trust me, The CHF will significantly improve the sway and handling, and have minimal effect on ride.




My recommendations:

1) CHF - both front and rear. You didn't mention year, but if 2006 or newer, verify the rear torsion bar bolts are tight. I'd recommend removing the bolts, inspect the mounts, then re-install the bolts with blue locktite and torque to 65 ft-lbs.


Do NOT spend any money on aftermarket suspension components until you do the CHF firrst, then re-evaluate it. Most find that the CHF satisifies their needs.


2) Verify front end alignment - have shop set at max toe in and if they are shimming the axle, have them shim for max caster.


3) If older than about 10 years, consider replacing shocks, as they ar probably worn out. I used standard ole Monroe shocks. Big improvement over worn out shocks.

I used to drive school buses. My Georgetown drives and handles nicer than any of them and all I did was the CHF. Tire pressure 92psi, cruising speed 62mph, take curves with consideration of the posted speeds, and don’t try to be in a hurry.

I’ll save the money of upgrades to make it handle like a diesel pusher and enjoy more campsite adventures.