Gassers on Ford F53 Chassis?

[Quincy]

We bought our first camper in the early eighties and lived in the Smoky Mountains for over twenty years. I had a 7/8 mile dirt road up a mountain to get to my house where I parked our 36' Pace Arrow Vision. (try stepping on the brakes real hard on a dirt road while driving 25000lbs of MH and see what happens) And yes to Colorado and the El Cajon pass. We used to travel west every year for years and return home eight or nine months later.

I have never had a flat tire or worn out a set of brakes nor boiled the fluid out of the Master Cylinder ever. And I always kept the rpms to around 3500 when on hills without needing to step on the brakes HARD or aggressively. As I said, if you have to do that then you are already going too fast.

Keeping the rpms at a lower speed by selecting a lower gear early enough so you do not have to brake hard to keep the engine at a reasonable speed is much better than picking a gear that is too high and then realizing your tach says 5 or 6 thousand rpms and have to stand on the brake to make the next turn. Moderate breaking is all that is necessary going down a hill if you are in the correct gear. If you are letting the rpms build until they approach redline and letting the transmission shift you are not operating safely and should pay attention to your trans. and motor that are trying to tell you the same.

If 6500 is redline and you are revving at 6300, do you really think that is ok just because you are a few rpms below the redline?

Reaching the redline for a few seconds is one thing, allowing the motor to steadily climb to 6 or 65 hundred rpms and maybe leave it there while you are just now standing on the brakes or waiting for it to upshift is totally another.

I have also been a motor head since I was 14 or 15 years old and removed, rebuilt and replaced quite a few motors and transmissions over the years so I have a fair understanding of what goes on inside a running motor.

I am not trying to start a war here and I respect all of your opinions, I only responded to reinforce my point and make clear that I speak from experience and what has been working for me for many years.

Why run a motor near or at redline and stand on a break pedal when it is not necessary? Nobody drives a car that way, why would you drive a motorhome like that? JMHO

[Oldcarnut]

Quincy, I agree with you 100%. Even though I have owned my class A for only 2 years, I drove a tractor and trailer for 35 years and over 4 million miles through 48 states and Canada. I, too, have done my share of mechanic work over the years. If your engine is wound to near red line, you didn't put your transmission in a low enough gear. Until you know your rig and the road you're traveling well enough, you need to slow down. You can always shift to a higher gear if you know it's safe to do so. However, if you choose too high of a gear and get all of that weight going down hill too fast, you are in big trouble! If you drive a diesel coach with an engine or exhaust brake, it's easier but you still have to be careful. If you drive a gas model, like I do, you really have to be careful. In either case, don't be over confident and slow down. It's not a race. Even if you arrive at your destination a day late and you have to forfeit a day's rent, it's better than losing your rig or maybe your life! Slow down, be safe and happy camping!

[Quincy]

Originally Posted by Oldcarnut

Quincy, I agree with you 100%. Even though I have owned my class A for only 2 years, I drove a tractor and trailer for 35 years and over 4 million miles through 48 states and Canada. I, too, have done my share of mechanic work over the years. If your engine is wound to near red line, you didn't put your transmission in a low enough gear. Until you know your rig and the road you're traveling well enough, you need to slow down. You can always shift to a higher gear if you know it's safe to do so. However, if you choose too high of a gear and get all of that weight going down hill too fast, you are in big trouble! If you drive a diesel coach with an engine or exhaust brake, it's easier but you still have to be careful. If you drive a gas model, like I do, you really have to be careful. In either case, don't be over confident and slow down. It's not a race. Even if you arrive at your destination a day late and you have to forfeit a day's rent, it's better than losing your rig or maybe your life! Slow down, be safe and happy camping!

Thanks much for the post, i am always concerned when I hear how some people operate a very heavy vehicle. I am not attacking anybody in particular, I just want to try to make it a bit safer out there.

I have nowhere near the experience you have and greatly apprecaite you offering your expertise.

[Betr2Trvl]

Sorry guys (above) maybe it’s my writing, so let me try to clarify my previous posts. In any case, it was never my intent to say to ever let your vehicle go too fast for the conditions.

The intent is to save your brakes on a downgrade, maximizing the effects of engine braking, so that the brakes are most effective to slow you when you need them. Wear on the engine due to high rpms is irrelevant when driving (significant) downgrades; modern engines / transmissions will not let you over rev the engine.

And, some of your interpretations of what I am (trying) to imply is exactly opposite of my intent (such as, I’m implying to start a downgrade in a lower gear for a given speed, which I thought was clear).

First, braking hard is not about how much speed you are trying to scrub off, but no matter how much you want to scrub off do it quickly so that your brakes build heat over the the shortest time possible while getting cool air over them as quickly as possible to cool them down.

Im sure you’ll, agree with this point: At any given speed, the lower the gear chosen the higher the rpm. Yes?

Starting down a downgrade in a low(er) gear for a given speed is going to put you into a higher rpm range, which is going to be more effective engine braking. That is the case if it’s 15mph or 35 mph.

By starting at a slow speed, and in a lower gear, at higher rpms and not being afraid of rpm gain as you naturally accelerate (while maintaining a safe speed), you’ll spend less time on your brakes, saving them for when you really need them to slow down for a corner or simply get back down to a slower safe speed that will allow gain until you need to jab the brakes again.

The reason you want to brake between 5000-5500 rpm (assuming a safe speed) on the “modern” Ford engine in tow haul mode is so that it DOES NOT shift to the next higher gear which will immediately cause you to accelerate which is exactly what you don’t want to do. If you don’t believe that, try this experiment as you approach the bottom of a grade if it is safe to accelerate at that point: shift off tow haul off and the engine will immediately upshift to a higher gear and you’ll immediately accelerate given the lower rpms / higher gearing.

A couple things I found that may more eloquently make the points I was trying to. Please see the bolded point in the 2nd note.

1)
Downgrades
There’s a limit to the amount of heat that brakes can absorb and dissipate. The highest brake temperatures occur when braking from highway speeds while on long downgrades, or from repeated use of the brakes without enough cooling time between applications. Almost all brake failures and downhill runaway crashes are caused by overdriving the ability of the brakes to deal with heat. In other words, poor speed control.

Whether in town or on a highway, you’ll usually need to descend a hill more slowly than other traffic in order to avoid overdriving your brakes. You should be in a lower gear to go down the hill than used to climb it. Never shift
to a higher gear on a downgrade unless the speed on the grade can be controlled with a retarding device or engine compression.

Select a safe speed that's not too fast for the weight of your vehicle, length, and steepness of the grade, weather, and road conditions. Use an appropriate low gear to hold that speed, and use the vehicle’s retarding device.

If this doesn’t control your speed, and speed is increasing above your chosen speed:
• apply the brakes hard enough to reduce speed by 10 to 15 km/h — the brakes are cold at this point
• downshift to a lower main gear

Continue down the grade, using engine compression, transmission gearing and your vehicle’s retarding device to control your speed. If the speed increases again, repeat this process. Be careful using this procedure on icy roads.
Keep your vehicle in gear all the way down the hill.

2)
Engine braking occurs when the retarding forces within an engine are used to slow down a motor vehicle, as opposed to using additional external braking mechanisms such as friction brakes or magnetic brakes.

The term "engine braking" refers to the braking effect that occurs in gasoline engines when the accelerator pedal is released. This results in the throttle valve that controls intake airflow closing and the air flow through the intake becoming greatly restricted (but not cut off completely). This causes a high manifold vacuum which the cylinders have to work against—sapping energy and producing the majority of the engine braking force.

While some of the braking force is produced due to friction in the drive train, this is negligible compared to the effect from the manifold vacuum caused by the air-flow restriction.

As soon as the accelerator is released enough to slow the engine, engine braking comes into effect as long as the wheels remain connected via the transmission to the engine. A slipping or disengaged clutch, or a torque converter, would disengage the wheels or absorb braking energy.

The braking force varies depending on the engine, and the gear the transmission is in. The lower the gear, the higher the braking effect due to higher rpm and the torque transferred through the transmission (higher torque is delivered from the engine in lower gears).

Engine braking avoids wear on brakes, and can help a driver maintain control of the vehicle. Active use of engine braking by shifting into a lower gear can help control speed while driving down very steep and long slopes, saving the brakes from overheating or excessive wear. If it is applied before the brakes have been used, it can leave the brakes available to make emergency stops (or slow when necessary; my edit)

Regards and drive safe.....

[macnut]

Betr2Trvl, this is the best post I’ve read on the subject. We all want to be safe on the road and this provides really practical advice. Thanks for taking the time to write it!

[twinboat]

They say you want to go down a hill in the same gear you would go up it.

With a 1999 to 2015 Ford V 10, that would be between 3800 and and 4800 RPMs.

Old V 8s and diesel engines shouldn't turn that fast, but that's a whole different engine designs. The weak link of high RPMS in gassers is valve float, with pushrod, rocker arm, engines. Not an issue in the Modular Ford OHC engines.

Diesels have long piston strokes.

[Oldcarnut]

Believe me Betr2Trvl, I am not arguing with you. In fact I agree with everything you said. I guess I'm like Quincy. I'm just trying to get inexperienced or unthinking Rv drivers to slow down and think about what they are doing. An RV weighs several times more than you car. In fact, you probably have the weight of your car added to the weight of your RV because you are towing it. An RV doesn't accelerate, stop or handle like a car and, until a person has enough experience driving an RV, they need to be extremely careful. Even then, you need to pay very close attention to what you are doing and what the vehicles around you are doing. Always be aware of the size and weight of what you are driving and give it your undivided attention. Forget you have a cell phone. And, as I said before, slow down! I know we're all in a hurry to get where we are going. Believe me, after driving a truck for so many years, I've had to make a conscious effort to slow down. Most of the time when driving a truck, they want you there yesterday so you drive in a timely manner. I still catch myself driving that way sometimes. I already knew it is safer to slow down but I have also found that you will reach your destination less tired. And you will get there about the same time anyway! It's stressful enough driving a small house in today's traffic. Don't make it harder on yourself. I promise you will enjoy your trip even more. As always, happy camping!

[Betr2Trvl]

Oldcarnut, I know it can be a challenge at times to ensure a point is clearly stated in a forum without more clarification. And sometimes things don’t necessarily read the way one intends it to.

I’ve just driven enough significant grades to know there is no way that I wouldn’t be unsafely on the brakes constantly if I was trying to stay in an arbitrary “low” rpm range, and / or try to manage to a 5mph speed gain (for instance).

In any case, I guess I’ll add one more clarifying post.

Driving significant downgrades in a “modern” Ford V10, I think you’ll quickly realize how much more effective engine braking is for a given “safe speed range” running between 3500 rpm and 5000+ rpm vs. 2000 rpm - 3500 rpm (as a simple example to illustrate my intent), which means using the brakes less......


I’m just guessing at the numbers here in this example, but I think it may help illustrate what I am trying to convey.......

Given the downgrade, curves, etc., you probably want to account for something like a 10-15mph speed gain. Start slow, very slow if / as appropriate. So if it’s 35mph safe max speed, you’ll probably want to start at 15mph or 20mph in first gear and 3500 rpm (if that’s what ties out) and as long as you are confortable with the speed gain (lets just say to 30mph) no need to brake until you get to 5000 rpm or so, and then brake hard to get it back to 15mph or 20mph if that’s what worked, and get off the brakes ASAP. Then repeat and / or adjust target speeds / gear / rpms as necessary. And if you hit and stay at a comfortable / appropriate speed at 4500 rpms (as an example) just let it spin and stay off the brakes, it’s the best case.

On higher speed grades, it’s the same principle but just adjusted for an appropriate higher gear for the speed but same rpm range.

And while tow-haul takes care of some of this for you, sometimes you really have to force a downshift by jabbing the brakes and feeling the downshifts, or manually, to get to the low(er) gear / higher rpms you want to start in.

Again, I’m NOT saying in any way to start a significant downgrade in a high(er) gear at 1200 rpm (for instance) and let it rev to 5000rpm, as the speed gain would be very unsafe, and require excessive braking.

Hope this makes sense.......

Regards

[Chris Hayes3]

One major omission in the Ford application of the 6 speed transmission, is the inability to manually select 3rd or 5th gear. Why they do that is beyond me.

Chris

[Walt Graham]

What I would like to know is why is it the MH manufacture doesn't make any adjustments on the anti way bars on the chassis to take out some of the rock and roll these motorhome ? They have the bare F53 chassis on the shop floor and it would be simple to relocated the four bolts on the ends of the sway bar and improve the handling by 90% or install a second sway bar in the rear and have at least 95% improvement. Yes I have made the sway bar adjustments (no big deal other than crawling under the coach to move the bolts), added the steering stabilizer for safety and now looking or at least thinking about adding a track bar.

[twinboat]

Originally Posted by Chris Hayes3

One major omission in the Ford application of the 6 speed transmission, is the inability to manually select 3rd or 5th gear. Why they do that is beyond me.

Chris

You can select 5th and then 3rd, with Tow/Haul on, by tapping the brakes.
Of course, you have to be at a speed where it will not over rev to down shift.

[EdInArk]

Originally Posted by blueridge-fl

Based on my experience, the weak link with the F-53 is not the V10. This is especially true with the newer 6-speed tranny configurations. The weak link is the suspension. You should plan on adding suspension mods to eliminate a white knuckle experience from wind and passing trucks. Like all trucks, F-53s ride better loaded than unloaded.

We experienced the "white knuckle" handling when ours was new. I did the Cheap Handling Fix (search this forum) and installed a Blue Ox Trac bar at the rear to settle down the tail wag. I think the rear overhang was a large part of our problem. The Trac-bar solved that. Trucks affect it very little now. I now drive it with the palm of my left hand on the crossbar with no problems.


We came from a 28' Class C on an E450 chassis, and our fuel mileage is virtually the same in the 8.2 mpg range. We pull a RAV-4 on a tow dolly.

Even though the A may be heavier than our old C, it performs better. I was surprised how much better when we got it.

[cmcconn]

I'm in a similar boat as you currently in a class C, and I've been doing research into class As for awhile.

First, Ford just announced a new gas engine, the 7.3 V8 to replace the V10. More horsepower , more torque, better fuel economy, and it comes with a 10 speed auto. More electric safety aids but I'm not sure what'll make it to the new F53. Personally I'm waiting.

I've also recently test driven some class As they rode better and were quieter. Go drive a few. They are a little slower accelerating, as you'd expect with the added weight. But the ride and handling was improved.

I'm looking at the Newmar Baystar 3014 and the Jayco Precept 31 UL. I like the heavier duty chassis, full body paint options and the availability of larger 4 door RV fridges. We boondock in the mountains under trees so I don't think a residential fridge is a good idea. We'd be running the generator a lot.

[BigDan1]

Nobody mentioned after 5 pages that the class A has the 3 valve 362 hp V10. Compared to his 2 vlave 305 hp V10 ...it makes a big difference

And please dont buy an FR3 , I know 3 owners , they all hate it !

The Jayco J ride ( both sway bars, hd gas schocks ) is quite better handling too.