UFO Bump Stops

[UFO Pilot]

While repairing the generator exhaust on my UFO chassis today, I found both the bump stops are almost destroyed. It looks like they are $182 each from Ultra RV Parts. I wonder if there are any cheaper alternatives that might work?
https://www.workhorseparts.com/W0008...m-Front-Spring

[nvs4602]

That kind of looks like a sumo spring would work there.

https://www.suspensionconnection.com...gs/sumosprings

[yeloduster]

I think nvs4602 has a good idea. See the picture of the Sumo Spring that has replaced the bump stop on my W20. It looks like the same arrangement as your UFO.

It looks like you need a Sumo Spring that has a simple threaded stud coming out of the top. The color indicates how stiff the Sumo is. Yellow adds 2800 lbs capacity to the axle, Black adds 1500 lbs and Blue adds 1000 lbs.

To order mine I looked through the web site on the link nvs4602 sent and got the part numbers I wanted. I then ordered from Amazon because Amazon has no hassle return and free shipping.

I put the Black listed for the Workhorse W22 on the front and the Yellow listed for the Workhorse P32 on the rear. The rear Sumo's I ordered were a little too tall so I cut 'em off. The cut very easily with a bread knife, or fine tooth saw.

If you go this route, select the tallest Sumo (you can tell by the number of bulges) with the threaded stud out the top.

You will find a lot of discussion on putting Sumo Springs on the Workhorse W series and the Ford F53 chassis. The front suspension of your UFO looks similar and I suspect you will like what the Sumo Spring does for your ride and handling.

[UFO Pilot]

Looks like the Sumo's are only about $100 cheaper than the Workhorse originals. I wonder how I can find the specs on the originals? I guess I can just order the yellow ones and be safe? I should have taken a picture of the existing ones while I was under the RV. It looked like the were black on the outside but yellow inside. I guess the black exterior could be 15 years of road dust.

[yeloduster]

Originally Posted by UFO Pilot

Looks like the Sumo's are only about $100 cheaper than the Workhorse originals. I wonder how I can find the specs on the originals? I guess I can just order the yellow ones and be safe? I should have taken a picture of the existing ones while I was under the RV. It looked like the were black on the outside but yellow inside. I guess the black exterior could be 15 years of road dust.

The Sumo Spring is a SPRING. The are solid air impregnated plastic. The original bump stops are not solid, the are hollow. I think the idea on them is when the bump stop contacts the axle the hole in the bottom of the stop is plugged and it becomes an air springs for a moment!

I think you will find the original bump stop is mostly just a bump stop. The Sumo Spring is a springs that adds capacity to the axle. Looking at the specs on the UFO's it appears that you have a 9000 lb front axle. The W24 has a 9000 lb front axle. Sumo specifies the black Sumo for that axle. Perhaps that is the best choice for your UFO as well. The Yellow Sumo might give a harsh ride.

Maybe!!! You are on a path no one has gone before! I decided to put Yellow Sumo Springs from a Workhorse P32 chassis on the rear of my W20. I had to cut the length a little bit bit they have worked out well. Maybe you are the trend setter.

[Persistent]

Thanks for the report on seeing an Unidentified Flying Object bump stop. Did it bump a wall or something?

The conspiracy theorists will have a field day over this report of a siting.

Yah! I know. I am irritating. Everyone says so.

[UFO Pilot]

Originally Posted by yeloduster

The Sumo Spring is a SPRING. The are solid air impregnated plastic. The original bump stops are not solid, the are hollow. I think the idea on them is when the bump stop contacts the axle the hole in the bottom of the stop is plugged and it becomes an air springs for a moment!

I think you will find the original bump stop is mostly just a bump stop. The Sumo Spring is a springs that adds capacity to the axle. Looking at the specs on the UFO's it appears that you have a 9000 lb front axle. The W24 has a 9000 lb front axle. Sumo specifies the black Sumo for that axle. Perhaps that is the best choice for your UFO as well. The Yellow Sumo might give a harsh ride.

Maybe!!! You are on a path no one has gone before! I decided to put Yellow Sumo Springs from a Workhorse P32 chassis on the rear of my W20. I had to cut the length a little bit bit they have worked out well. Maybe you are the trend setter.

Workhorse lists them as Bumper Asm - Front Spring. I wonder if they are Sumo's? Almost everything on the Chassis came from different suppliers, I don't know how many parts were Workhorse only?

[Lash]

Hi Wayne;

Been a while but have been following your post in regards to bump stops. What originally caught my eye was the generator exhaust support. Mine has also bit the dust and will have to follow up on repair techniques.

In regards to the bump stop, I replaced mine about 18 months ago and decided to go with Sumo Springs and have not regretted that decision. I used the yellow Sumos and have found the ride to not be affected in my view. Maybe it just because I am getting ancient and feeling is gone. I really do like the ride that they give and would not go back to regular bump stops. The way the UFO frame is done requires some mods in my view for the way the bottom of the Sumo fits to the frame. There has been a post a few years back by Olskool in regards to how he made a piece to fit to his UFO. I did a similar method but not exactly. In addition it requires some trimming on the length but that is easy. Used a fine blade hacksaw and it came out great. Take care and best of luck

Ron

[UFO Pilot]

Good to hear from you. I just discovered the damage to my original so just getting started with the research. We are on a 12 day trip so will get back with more questions when we return home. This is the 3rd time I have replaced the exhaust hanger so I sorta reoriented the hanger. Hope this one lasts.

[yeloduster]

Originally Posted by UFO Pilot

Workhorse lists them as Bumper Asm - Front Spring. I wonder if they are Sumo's? Almost everything on the Chassis came from different suppliers, I don't know how many parts were Workhorse only?

When I first saw the bump stops on my W20 I thought they might be Sumo Springs. They aren't. As you have already noted, your bump stops are hollow. Sumo Springs are NOT.

I have the original bump stops I removed from my motorhome. The fronts are ≈5" tall the rears are ≈3" tall. I think they will bolt right in. You can have them if you pay shipping! Almost free to see if they work for you.

I think you will be happy with Sumo Springs regardless of the color (spring rate) you select.

[UFO Pilot]

I measured the space where the bump stop is and it is 3 1/4". The height of the sumo is 5". Can I safely cut almost 2 inches off of the sumo?

[yeloduster]

Originally Posted by UFO Pilot

I measured the space where the bump stop is and it is 3 1/4". The height of the sumo is 5". Can I safely cut almost 2 inches off of the sumo?

You can cut them easily. I used my radial arm saw but others said they used a bread knife.

My opinion is the height is not critical. I cut mine just short enough that on level ground they lacked about 1/4" touching.

I ain't got a UFO but on my W20 it works well.

[UFO Pilot]

Originally Posted by yeloduster

You can cut them easily. I used my radial arm saw but others said they used a bread knife.

My opinion is the height is not critical. I cut mine just short enough that on level ground they lacked about 1/4" touching.

I ain't got a UFO but on my W20 it works well.

I will verify the measurement so it looks like 3" would give me a 1/4" gap.


Thank you for your advice.

[UFO Pilot]

After a lot of measuring and fitting I made a mock up out of 3" ABS pipe. These are 2 pictures of what I made.






I will post pictures of the mount made out of metal in the next post.