Rear Axle maintenance

[theSane]

I want to lift the rear end of my F53 chassis, but am struggling with the proper method.

My inclination is to drive the rear tires onto ramps, place 6-8" of leveling blocks under the leveling jacks, use them to lift the rear end and set it back down on jack stands. Then use a bottle jack to lift the axle enough to get the tires off as needed, and let the axle hang free as needed for maintenance.

I look forward to reading your thoughts and wisdom.

[ThomB]

It's my understanding that using the jacks to lift both of the rear wheels off the ground at the same time is not a good thing. The emergency brake is no longer able to keep the rv from rolling when that happens. When I had tires balanced they did have me lift one side at a time to get to the tires.

[theSane]

Originally Posted by ThomB

It's my understanding that using the jacks to lift both of the rear wheels off the ground at the same time is not a good thing. The emergency brake is no longer able to keep the rv from rolling when that happens. When I had tires balanced they did have me lift one side at a time to get to the tires.

I do have good rubber chocks on the front tires. I do not know if I need to lift the tires off the ground with the built-in jacks, just extend the suspension enough so they are nearly off the ground and set on jack stands. I could then use a bottle jack to lift the axle on side I am working on to create the clearance to remove the tires on that side, and lower the axle back down to to give me space to work. That is my thought anyway.

[tderonne]

Originally Posted by ThomB

It's my understanding that using the jacks to lift both of the rear wheels off the ground at the same time is not a good thing. The emergency brake is no longer able to keep the rv from rolling when that happens. When I had tires balanced they did have me lift one side at a time to get to the tires.

With a driveline parking brake, lifting one wheel will let it roll.

Wheel chocks are the real answer. As the OP intends to do.

[Wyatt]

Originally Posted by tderonne

With a driveline parking brake, lifting one wheel will let it roll.

Wheel chocks are the real answer. As the OP intends to do.

So do the Ford F53 chassis use the driveline method for a parking brake, instead of the typical parking brake at both rear wheels?

And how does the driveline work, if you know? Locks the drive shaft? Isn’t that what putting it in Park does? Thanks!

[tderonne]

"Heavier" F53s have a driveline parking brake. Some of the lighter duty ones use a traditional parking brake setup. It was on the rear of the transmission until about 2016 when some where mounted at the differential.

The trans mounted ones were made by ZF. A search of "ZF parking brake" will bring up a lot of info too. You'll also find folks talking about adding oil to them. Without oil, they burn up the bearings inside. Not sure of the details on the differential mounted ones.

Here's video I found of a 2016 differential mounted brake. They look a little easier to service than the trans mounted version, that has to be removed and disassembled to get at the brake shoes, a potentially dangerous situation.

https://www.youtube.com/watch?v=JMaYXRZpqqI

I mention it here as when you set a driveline parking brake, it only holds the driveshaft. If you raise one side of the rear axle off the ground, the motorhome can roll.

[Goodspike]

Originally Posted by Wyatt

And how does the driveline work, if you know? Locks the drive shaft? Isn’t that what putting it in Park does? Thanks!

I've not run into this issue myself, but my guess is it would be effectively like putting it into park as long as you had both wheels on the ground. But the claim is being made that with an open differential that drive line parking brake won't hold the vehicle in place if one wheel is raised. Makes sense given how open differentials work in the snow, but not something I've run into or tested.

[tderonne]

Originally Posted by Goodspike

I've not run into this issue myself, but my guess is it would be effectively like putting it into park as long as you had both wheels on the ground. But the claim is being made that with an open differential that drive line parking brake won't hold the vehicle in place if one wheel is raised. Makes sense given how open differentials work in the snow, but not something I've run into or tested.

Exactly. Just a "be careful" message here. OP mentioned lifting one wheel. Someone else mentioned setting the parking brake. Just making sure everyone knows that may not work in certain situations.

[theSane]

The Ford owners manual calls out to block the front wheel opposite the rear wheel to be lifted. I have enough chocks to do them both, so that is what I am planning on doing.

[NeilV]

You service it like any other 10 to 20 ton truck or bus. Chock both front wheels and use a service jack and jack stands. You really do not want to use the levelers for this except for in an emergency situation since if the coach shifts you can damage the levelers so they will give you trouble retracting them. Slides should be in and nobody should be inside the coach. The coach should obviously be on a thick concrete pad when doing this type of maintenance. The routine axle service though should not require the wheels to be removed since there is plenty of room to crawl under to check the differential fluid level. Brake and tire service will be when you will be removing the wheels however the wheels do not need to be removed in order to flush and replace the brake fluid which should be done a minimum of every 2 years. Personally I tend to leave the tires on whenever I need to crawl under to coach and only remove them when servicing the brakes pads or lubing the caliper guides since that will be done without crawling under the coach.


What particular service are you trying to perform?

[theSane]

Installing sumo springs. I have to drill a few holes through the frame and the tires need to be removed for tool clearance. At least that is what the installation video from the manufacturer shows.

[Wyatt]

Originally Posted by theSane

Installing sumo springs. I have to drill a few holes through the frame and the tires need to be removed for tool clearance. At least that is what the installation video from the manufacturer shows.

Exactly. That’s why I never did those...

[YGoHom]

It's very easy. I had to remove them, one side at a time, to install air bags in the rear. And then removed them again to remove the airbags 2 weeks later!

Trans in Park. Emergency brake. 20 ton bottle jack, a block of wood and a chunk of plate steel.
Position the jack under the axle, directly below the leaf springs, and put the block of wood between the u bolts, and the steel between the jack and the wood to prevent the wood from splitting apart.
My DeWalt cordless impact easily removed the lug nuts. When finished, check the lugs with a torque wrench. It's a lot of torque and I was lucky to have a good wrench available.

The wheels are very heavy, but you won't be lifting them, so it's easy. Lift the rear just enough to wiggle the tire out and roll them aside.
Pay attention to the valve stems when you put them back so the inner one doesn't get wedged. Yup, it happened.

-Robb

[rvbud]

You'll be happy with the Sumos. I installed Sumo Maxims on my 2008 18K (front and rear) a couple of years ago, along with a Henderson rear track bar and Roadmaster second sway bar. Yes, removing the rear tires will help in drilling the bracket holes. Be sure the mounts are positioned so that the upper and lower bracket are true vertical; not angled toward front or rear. Use caution on the driver's side...you may have fuel line or electrical that run along the frame channel. Also, use nothing less than Grade 8 hardware. Don't drill the holes too oversized; the brackets can "work" under load. I used Grade 5 (I think) and after a trip to Alaska, the lower bolts of the upper bracket on both sides sheared. Torque bolts evenly and use Loctite 242 or 262 thread locker.

[jbrattain]

I've done this many times for different reasons.
Here's my procedure:
1. Park on level ground, preferably on a concrete paved surface. (If ground
is level, jacks won't be damaged by side-load stress.)
2. Set parking brake.
3. Securely place chocks in front and behind both front tires.
4. Place jack pads or blocks under both rear leveling jacks.
5. Deploy rear jacks together at the same time to lift rear end sufficiently off
the ground. If your controller won't deploy both jacks at the same time,
do not lift one side or the other more than an inch or so
at a time to avoid excessive twisting of the chassis and/or coach body.
If wheels don't leave the ground, retract jacks and add sufficient
pads or blocks and deploy jacks again.
6. Place adequately rated jack stands or suitable cribbing blocks under axle
on each side. (If not on concrete pavement, put heavy wood blocks or
bricks under jack stands to avoid sinking into ground or asphalt
pavement.)
7. Slowly retract leveling jacks until axle settles on jack stands or cribbing.
8. Double check that axles are safely resting on jack stands or cribbing.

After finishing project:
1. Check to make sure any items placed under the motorhome while doing your project are removed.
2. Deploy leveling jacks until axle is clear of jack stands or cribbing.
3. Remove jack stands and/or cribbing from under motor home.
4. Retract leveling jacks and remove jack pads.
5. Remove chocks.

[Wyatt]

Originally Posted by YGoHom

It's very easy. I had to remove them, one side at a time, to install air bags in the rear. And then removed them again to remove the airbags 2 weeks later!

-Robb

Hi Robb, Why’d you want to put them on, and why did you remove them?. Curious...

[YGoHom]

Short story...they didn't work.

I wanted them to lift the rear when fully loaded, back to stock height and help create a forward rake to shift the momentum forward to make the steering less floaty.
At max PSI they didn't lift the rear more than 1/2". This was a specific kit recommended by the manufacturer. After many pictures and conversations, the company said that I needed 2" spacers. So I bought and put them in. I did a long trip north pulling my Jeep and had to fix airlines 4 or 5 times because they blew out. Complete waste of time.
In the end they had no explanation, even though they said the same kit is used on 22k chassis just fine.
I sent everything back for a full refund.
Same with Bilstein shocks. The stock shocks on the INTENT are much better. It's not heavy enough to make the Bilstein work properly. They were unbelievably harsh on the smallest bumps! Took them off and sent them back for a full refund.

[theSane]

@YGoHom

I thought the stock shocks were Bilsteins?

Have you tried the KONI shocks? I heard they were softer.

[YGoHom]

Bilsteins are factory on some, but not the INTENT. We have standard oil filled shocks.

I spoke with a KONI rep and explained my experience with the Bilsteins. He gave me a speech of how different KONI’s are, but in the end he said that they would probably yield a similar result due to the light weight chassis.

Here’s the problem...both brands only make ONE shock for all the F53 chassis, regardless of weight. They may work well on a 20k chassis, but too soft on a 24k. That means too harsh on a 16k.

[Wyatt]

Originally Posted by YGoHom

Bilsteins are factory on some, but not the INTENT. We have standard oil filled shocks.

I spoke with a KONI rep and explained my experience with the Bilsteins. He gave me a speech of how different KONI’s are, but in the end he said that they would probably yield a similar result due to the light weight chassis.

Here’s the problem...both brands only make ONE shock for all the F53 chassis, regardless of weight. They may work well on a 20k chassis, but too soft on a 24k. That means too harsh on a 16k.

Hmm. I really like the Koni shocks. They will adjust the ride according to demand (self adjusting). Along with stopping all the oven, front dash, compartment noises and suspension stabilizers, to me this thing is a dream to drive now, as compared to all of the RV’s we’ve rented over the years, and a huge improvement from when we first got it. Seriously.

Here’s their description:
“ KONI frequency selective dampers. We have combined the benefits of performance and comfort into one shock absorber. FSD is firm for control over large bumps and corners, but soft for comfort over expansion joints and rough roads. While KONI is known to reduce bouncing in motorhomes, our FSD shocks include a special valve that filters out annoying vibrations before they enter the coach. The result is an incredibly smooth ride, with plenty of shock left to control pitching and swaying.”