Yet Another Sumo Springs Thread

[Kxbronco]

Originally Posted by CamJam1

P32 FRONT Sumos on the rear? I think you mean REAR P-32 Sumos. I don't think they make a front Sumo for the P30/32.

In any case, I'm glad it seems to have helped. You should get a rear trac bar too if you don't already have one. That bar took care of the passing truck problem almost entirely for me.

You are correct CamJam1, it was the REAR P32 Sumos.

[Kxbronco]

Took the rig for an 800 mile jaunt with the rear P32 Sumos installed. Overall impression is very positive. Side to side movement is significantly reduced. The “push” from passing trucks is better, but still there in some cases. It’s odd how some trucks push you around and some don’t. Going through the mountains between Knoxville, TN and Asheville, NC I felt like I was in a sports car as compared to the original bump stops. The Sumos made the rig feel a lot more stable in the curves.

On the less positive side, the ride is much stiffer in the rear. Not terrible, but noticeably stiffer.

All that being said, I think I’m going to do like CamJam1 did and cut one section off the Sumos. Hopefully, I retain the positives and get a slightly less stiff ride. I’ll report back once I’ve cut them and given them a good test run.

[SmilingSam]

I wonder though if NOT using the hard firm spacer and NOT cutting the equiv length of sumo sponge would be better, as sponge is more progressive than a hard spacer/washer ??

I have just order a set of rear p30 sumo as the left-right motion in slow campground UNlevel potholey drives is a royal PIA and have had actual stuff come out of closed cabinets !! this occurred at 5mph or even LESS !!

I will use complete size of sumo and then cut if there seems to be too much rear controlling the front syndrome !!

This will be my first suspension change on my W24 it likely will help my low speed issues.

ps: my on interstate experience ref passing trucks, i do not get too much action, i do seem to push them as much as they push me !!

[yeloduster]

Originally Posted by SmilingSam

I wonder though if NOT using the hard firm spacer and NOT cutting the equiv length of sumo sponge would be better, as sponge is more progressive than a hard spacer/washer ??

I have just order a set of rear p30 sumo as the left-right motion in slow campground UNlevel potholey drives is a royal PIA and have had actual stuff come out of closed cabinets !! this occurred at 5mph or even LESS !!

I will use complete size of sumo and then cut if there seems to be too much rear controlling the front syndrome !!

This will be my first suspension change on my W24 it likely will help my low speed issues.

ps: my on interstate experience ref passing trucks, i do not get too much action, i do seem to push them as much as they push me !!

Good Morning Sam,

If you go back to the very first posting on this thread you will find that installing the P32 Sumos on the rear of my W20 WITHOUT the black spacer is exactly what I did.

For me the rear P32 Sumo induced handling problems and after a few thousand miles I cut a section and a half off of the spring. Cutting the Sumo shorter solved my handling problems.

I took the spacer that came with the springs and installed it on the front Sumos.

I hope the Sumo Springs help reduce side to side sway at slow speed. You didn't say but does your W24 have after market sway bars? High rate sway bars can contribute to slow speed side to side sway!

[Kxbronco]

SmilingSam, like yeloduster and CamJam1 I did not use the spacer with the rear Sumos. I have Sumos on the front and like the way they ride as they are so I will not be using the spacer at all. I will be cutting one section off the rear Sumos later this afternoon.

[CamJam1]

I also put my spacers on the front, but it might be a bit too much for some people. It made the ride up front slightly stiffer, but it's still soft enough not to bother me and seems to help make the handling feel a bit more secure so I've left it in place.

Some of these mods are more incremental improvements rather than drastic changes, and I find I sometimes need a little time to evaluate their worthiness.

[MrMark52]

Just wanted to update the thread and give an install idea for replacing the front Sumo’s in a Workhorse chassis.

It’s been commented here before that once the old jounces are off, getting the new ones installed is fairly easy except for starting the nuts as there is little room to get a finger reach between the frame channel and the engine mount channel.

I thought about it a bit and came up with cutting some 1 inch metal strips about 6 inches long. Then went to my local hardware store and got a couple of tinnerman spring clips with nuts that were the same thread as the stud on the Sumo jounce.

I drilled a hole in one end of the metal strip that would both allow the tinnerman clip to lock in place and for the stud on the Sumo to pass through the metal clip.

I’ve not gotten my old jounces off yet (it’s hot here in Texas right now!) but I will be doing the install in the next few days.

Pictures show metal piece and clip disassembled, assembled, and installed on Sumo as somewhat of a mock up of what it will look like once installed (less the chassis of course).

[yeloduster]

That looks like it will work really well. Good little invention!

[CamJam1]

Originally Posted by yeloduster

That looks like it will work really well. Good little invention!

Agreed. That should simplify the installation. Now if you can just get that old nylock nut off!

[MrMark52]

Got mine replaced today. ‘02 chassis, no ny-lock nut - they used a nut and lock washer.

So, the process was -

Used a double box end 15/13mm wrench and reached the 15mm end onto the nut.

At first I tried loosening the bumper using a rubber strap wrench but between the softness of the jounce and their age, the strap wrench just collapsed the jounce and slid off.
Then I tried my chain strap wrench with the same results.

If you look at the pictures, there is no “body” to the jounce for the strap wrench to squeeze against.

So I got my oscillating saw out and cut the jounce off hoping there would be a bolt head to grab on to. There wasn’t - again, looking at the pictures you’ll see a bolt stud through a larger washer that the jounce was molded to.
With the jounce now out of the way, I used a 3” pipe wrench to grab the washer the jounce was attached to and started turning.
Once loose, is completed removal turning by hand. The only restriction to turning was accumulated dirt on the threads. Once the nut was loosened I pulled my wrench out with the nut, but I could still see something semi-blocking the hole. I subsequently found when I removed the jounce on the other side that there was also a lock washer. And looking at either nut, neither were ny-lock or self-locking.

Reassembly was fairly easy with the piece I fabricated. I took care to make sure I didn’t tighten down on the 2 brakes lines that ran through the channel on the driver side.

For what it’s worth, there seems to be a depression where the original nut and lock washer are placed. That depression makes it a little harder to located the end of the fabricated piece right against the hole in the frame.
The way the tinnerman clip is made the stud on the Sumo first goes through the hole I. The MoHo chassis, through one side of the tinnerman clip, the 1/8” fabricated piece, and then the nut part of the clip. All that allows a kind of lead hole into the fabricated piece - and what you do is locate the tinnerman clip over the hood in the chassis (it may not be right against the chassis) then carefully push the staid of the Sumo up through the chassis and start turning. Give it a few turns, then let go. If the Sumo remains hanging, the threads caught and all you have to do is continuing tightening.
I tightened as hard as I could by hand - and you have a lot of leverage when tuning the 3” diameter.

Oh, and I used the large washer that came off with the old jounce. It’s only about 1/8” thick - but for me it provided a complete surface for the Sumo’s to bear against.

FWIW - sorry for the one picture showing the length of the fabricated piece - but it’s length should be about 6”” long. You could go longer if the metal was 3/4” wide, and even longer if 1/2”. Narrower would be better in order to manipulate the tinnerman clip around a little easier. There is a bolt that holds the motor mount to the frame that you have to work around.

[MrMark52]

Originally Posted by MrMark52

Got mine replaced today. ‘02 chassis, no ny-lock nut - they used a nut and lock washer.

So, the process was -

Used a double box end 15/13mm wrench and reached the 15mm end onto the nut.

At first I tried loosening the bumper using a rubber strap wrench but between the softness of the jounce and their age, the strap wrench just collapsed the jounce and slid off.
Then I tried my chain strap wrench with the same results.

If you look at the pictures, there is no “body” to the jounce for the strap wrench to squeeze against.

So I got my oscillating saw out and cut the jounce off hoping there would be a bolt head to grab on to. There wasn’t - again, looking at the pictures you’ll see a bolt stud through a larger washer that the jounce was molded to.
With the jounce now out of the way, I used a 3” pipe wrench to grab the washer the jounce was attached to and started turning.
Once loose, is completed removal turning by hand. The only restriction to turning was accumulated dirt on the threads. Once the nut was loosened I pulled my wrench out with the nut, but I could still see something semi-blocking the hole. I subsequently found when I removed the jounce on the other side that there was also a lock washer. And looking at either nut, neither were ny-lock or self-locking.

Reassembly was fairly easy with the piece I fabricated. I took care to make sure I didn’t tighten down on the 2 brakes lines that ran through the channel on the driver side.

For what it’s worth, there seems to be a depression where the original nut and lock washer are placed. That depression makes it a little harder to located the end of the fabricated piece right against the hole in the frame.
The way the tinnerman clip is made the stud on the Sumo first goes through the hole I. The MoHo chassis, through one side of the tinnerman clip, the 1/8” fabricated piece, and then the nut part of the clip. All that allows a kind of lead hole into the fabricated piece - and what you do is locate the tinnerman clip over the hood in the chassis (it may not be right against the chassis) then carefully push the staid of the Sumo up through the chassis and start turning. Give it a few turns, then let go. If the Sumo remains hanging, the threads caught and all you have to do is continuing tightening.
I tightened as hard as I could by hand - and you have a lot of leverage when tuning the 3” diameter.

Oh, and I used the large washer that came off with the old jounce. It’s only about 1/8” thick - but for me it provided a complete surface for the Sumo’s to bear against.

FWIW - sorry for the one picture showing the length of the fabricated piece - but it’s length should be about 6”” long. You could go longer if the metal was 3/4” wide, and even longer if 1/2”. Narrower would be better in order to manipulate the tinnerman clip around a little easier. There is a bolt that holds the motor mount to the frame that you have to work around.

Todays update -

Rears we’re easy -

Block front wheels.
Use rear levelers to raise the back of the coach until the rear tires just started to lift.
Place jackstand under torsion bar for side I’m working on and move to other side as I uninstall old/install new Sumo’s.
Reaching over the top of the tire and used a 15mm end wrench to loosen nut and carefully turn to allow the natural bonding of the old jounce to the frame to hold the jounce as I turn the 15mm nut. Mine had long studs on the jounce and were held with a nut and lock washer - not an elastic stop nut.

I did not use the spacer provided with the Sumo’s.

Spacer, old and new bumpers seen in picture.

[MrMark52]

UltraPower upgrade received yesterday, installed, test drive made and data sent to Brazel’s. Am awaiting their response to the data.

Observations so far - more pep and power both when first heading out out sloped driveway and on the highway. Shift points of the transmission definitely different and I like the feel - except there is a noticeable downshift to 1st.

I can definitely tell the difference in the ride with the new Sumo’s installed. I did mostly Interstate and state highway driving. Whereas before I knew when a vehicle was passing me, I was sometimes surprised as a vehicle did during my test run.

Rear trac bar arrived yesterday as well, that goes on today. Brake cable for my ReadyBrake Elite I’ll get installed today or tomorrow and tested (better tail wagging the dog control) Friday.

[Tov61]

I had the Ultra Power TCM and ECM installed on my 2003 National Dolphin Workhorse. Some Power increase, but a large improvement in the shift pattern of my Allison 5sp Tranny. Money well spent I believe. I have a trac bar on the rear and the Roadmaster steering stabilizer on the front. Upgraded shocks and front Sumo springs have all incrementally improved the steering and handling and the stability of our coach especially in high winds. I especially recommend the front steering stabilizer. Several years ago an incident happened right in front of us at freeway speed. After steering to avoid the accident in front of us I had trouble getting the motorhome steering to recorrect from the skid. I finally get it stopped but it was difficult and I am an old 18 wheel driver. When I got home from the trip I had the Roadmaster stabilizer installed and it helps the motorhome steering.

[CamJam1]

We've been putting some miles on our W-22 Dolphin since we bought it three years ago. It had 13k miles when we bought it and we're at 30k now. I've been upgrading the suspension as we go and couldn't be happier. I've done just about everything you can do, but the biggest changes I noticed were from trac bars, front sway bar and steering stabilizer. The Sumos were a nice incremental improvement as well. I used to watch the weather like a hawk to avoid breezy days, but now I don't give it a second thought unless there is a high profile vehicle warning. Passing trucks don't bother me at all either. Mine is 33'9" on a 208" wheelbase, so not the best at a 51.35% ratio. I'm sure a longer wheelbase would be even better, but I now have no complaints with how my coach drives.

I might try the Ultra Power TCM upgrade next. I just wish the coach weren't 18 years old, as it drives like a new one and I'd be happy to keep it for another 15-20 years if not for snooty RV parks that don't want to let older rigs in.