How I Installed a CatStrap on a 2019 Ford F-53 V10 Motorhome Chassis

[NXR]

Originally Posted by RN_EMT-P

The battery compartment is open to the undercarriage so it seems to actually focus the sound at the converter. It is ear splitting (as I found out by accident). Plus a thief would not be able to access the box to disable it.
I just hope to never get it tested in real life.

I thought about putting mine in the same place for the same reasons but was not sure how it would affect the sound.

They still could cut the sensor and that will stop the alarm with the recip saw. I think the alarm needs to go for about 15 seconds after movement ceases instead of stopping when movement ceases but whatever.

Ray

[Graydude]

Excellent write up! Thanks. I assume these were taken before the strap adhered to the exhaust? How well does the strap adhere?

[NXR]

Originally Posted by Graydude

Excellent write up! Thanks. I assume these were taken before the strap adhered to the exhaust? How well does the strap adhere?

The pics were taken after idling the engine in the driveway for two hours. But the first time we drove it, wow, that thing produced a lot of smoke and smell for the first several miles. I wasn't sure if it was us or someone else so we pulled over in a parking lot and it was us.

Kind of a light gray smoke, not black, so not scary. The smell was an overheat smell, not a "something is on fire" smell. The strap discolored in some areas from the heat on that first trip of 90 miles and has not changed in the next 1,500 miles.

The main purpose of the adhesive is to keep someone from getting a saw blade between the strap and the exhaust. After idling it, I could not move the strap or tug it away between the straps.

Ray

[SJ-Chris]

Originally Posted by freestyle_freddy

I've been wondering lately if the catalytic converters under the high ground clearance trucks used by many rvers, makes them more susceptible to theft than with most low ground clearance cars. That high ground clearance makes it much easier to slip under the truck & work quickly to cut it off. Does anyone know if trucks are experiencing more frequent theft of cat coverters than cars? And, does painting the converters with a bright red, high heat paint function well as a theft deterrent?

Yes, the higher clearance makes them easier to get under and thus easier to steal. I had one stolen while parked for just one night in front of my home in a regular family neighborhood. Strangely, while parked in the nearby storage yard which is much less secure they have not been stolen (I have 3 RVs). Insurance covered it, but it was a pain and put that RV out of commission for 5-6 weeks.


Here's what I did: (a poor man's Cat Strap...lol)

https://www.irv2.com/forums/f84/move...ef-592759.html


Nothing against the Cat Strap. I have 3 RVs and found a less expensive solution that satisfied my wants/needs.


-Chris

[SJ-Chris]

Originally Posted by NXR

Great question and I cover that in the doc in Notes. That actually is a very valid concern. When you first place the CatStrap you use the 4" exhaust clamp right up against the catalytic converter, it's "neck".

Then you pull the strap tight and do the same with the other clamp.

If you do not have the exhaust clamps right up against the catalytic converter the strap could be angled slightly away from the catalytic converter and a blade can be slipped between the strap and the catalytic converter.

If you have both exhaust clamps in the correct position there is no gap. Then you run the engine or drive the vehicle. The catalytic converter heats up and melts the high-temperature adhesive on the bottom of the CatStrap. That binds the CatStrap solidly to the catalytic converter so you cannot get a blade in the middle.

Can someone just remove the exhaust clamps? Sure but then they're still dealing with the bonded strap. And if you do something to the exhaust clamp threads, loctite, weld them, smash the threads, whatever, then the exhaust clamp is not coming loose.

Hope this helps,

Ray

Great write-up and install OP! The goal in all of this is to simply try to encourage all but the most determined thieves to simply move on to an easier target and leave yours alone. I think you have achieved this goal.


Question about the Cat Strap....I wasn't aware of the heat-bonding that happens. What happens if for some reason you need to replace your CC in the future? How hard will it be for the shop to remove the existing Cat Strap? (...and then I guess you'd have to buy another??).


Stay safe!
Chris

[NXR]

Originally Posted by SJ-Chris

Question about the Cat Strap....I wasn't aware of the heat-bonding that happens. What happens if for some reason you need to replace your CC in the future? How hard will it be for the shop to remove the existing Cat Strap? (...and then I guess you'd have to buy another??).

I imagine if they wanted to be nice and neat they could reheat the adhesive to loosen it by driving the motorhome or with a torch. More likely they'll use a torch and just cut right through the CatStrap.

Correct, it's like the old "A bear is chasing you and a friend." joke. You don't have to run faster than the bear or shoot the bear. You run faster than your friend or you trip or shoot your friend.

Ray

[Mike Finnerty]

Good write-up on installing the Catstrap. I installed two 7 foot Catstraps instead of the 12 foot version. One modification I made was to install stainless steel hose clamps in place of the straps that were provided as I wasn't able to get them as tight as I wanted. For the converter I put two hose clamps together to fit around the converter.



Regarding comments about noise, have never heard any attributable to the straps, hard to tell with all the other road noises the MH has going down the road.