Toro Dingo TX425 Muffler Bellows flex pipe keeps cracking

[PeterG]

I have 1600 hours on my Dingo which I've had since 2012. Mostly a fantastic machine. However, my maintenance records show the muffler has been replaced five times. This last time in less than a year. Toro replaced it under warranty. The muffler itself is fine. The issue is the steel corrugated looking flex bellows pipe between the Kohler gas engine and the muffler. first question is what causes this to break? The engine has just been replaced, not bad motor mounts. Idle is 1275-1320. Maybe it's just bad quality. The muffler flex pipe breaking is a known Toro problem. I would like to get a cheap better fix as the mufflers are going up over $400 now. The two pipes are 1.5" dia on each side of the bellows. I tried to insert a piece of Surebilt flexible galvanize steel exhaust pipe with hose clamps and exhaust sealant. Wasn't going to work well. Would prefer to find steel flex bellows for 1.5" dia pipe and get someone to weld it in. The fancy stainless steel Car flex pipes don't look good either. Any ideas?

 

[PeterG]

 

[PeterG]

 

[PeterG]

Here's the machine for your reference

 

[ianjoub]

Is the muffler rubber mounted? Maybe too much flex from bad mounts? Maybe not enough flex from rigid mount muffler and rubber mount engine?

 

[hosspuller]

Just a thought ... Looks like the bellows is doing duty as an elbow. That uses some of the flex. Sort of like a spring that is compressed solid. Can you use a rigid elbow and keep the bellows straight?

 

[Jonas302]

https://www.amazon.com/Exhaust-Adaptor-Durable-Stainless-Braided/dp/B08HVKLHDS

Braided flex pipe will last and give you all the movement you need lots of different ones available

 

[DDoug]

Just a thought ... Looks like the bellows is doing duty as an elbow. That uses some of the flex. Sort of like a spring that is compressed solid. Can you use a rigid elbow and keep the bellows straight?

Yes. look at ultralight air-o-plane exhaust systems, they use a ball & socket with 3 springs.

 

[PeterG]

Thanks for all the info. Yes, the muffler has no rubber mounts and the bellows is pretty much like an elbow. There is some talk of excessive exhaust heat or something (engine running lean, idle too high), engine isn't cooled off enough before the engine is shut down, but I think it is just vibration and design. Regarding the noise level, if you see slight exhaust coming out where the muffler pipe attaches to the engine header pipe, does that add to noise level? I tried some JB exhaust sealant before I put the clamp on. Is one clamp enough, or is two better?

 

[PeterG]

Update! So, for the last few years I've been using the machine with a broken flex pipe. Lately I found a Company online selling a modified super duty muffler set up with what I hope will be a better flex pipe design. The list price was a whopping $1,400.00 plus shipping!! The current pipe is 1.25" dia, but the flex pipe parts are only in 1.5" dia. This means you need a reducer and bend to connect all. However, this new unit seemed to be a simple bolt on professionally made unit. I called them several times but got all kinds of delays and strange answers on fit, design, and how well it worked. They finally sent me the name of the manufacturer for it so I could buy it directly from them!

 

[PeterG]

The Company is in Canada, and is called Catalytic Exhaust Products, LTD.
905-799-9770

For the Dingo TX425 and 427 the model is a 4SXT-105-0249 for the muffler and assembly. They sold me the purifier muffler with flex pipe for the same price as a regular muffler and flex pipe system for the Dingo since they had one in stock. This was substantially less than the price offered online. They also sell the flex extension part (You will need to cut your OEM muffler pipe by the muffler and cut out a slot, to clamp the new piece in. I ordered and extra flex pipe piece as the price was not too bad. I had to widen the dia of the Dingo mounting brackets for a touch more wiggle room, but otherwise it fits in. Only issue is the UPS shipping was like $150.00, plus UPS charges an additional import transaction Tariff fee. However, so far, I'm happy with it and will report back with an update on how it's lasting. Machine has 1855 hours on it (but with new Kohler motor in it).

 

[PeterG]

Can anyone offer advice on the clamps? I used copper anti-size on all bolts, but no pipe paste.

 

[HarleyHappy]

I tend to always use muffler cement and whenever possible I double the clamps, offset to get maximum clamping force.
I have used the wraparound band clamps and if used correctly, they rock.
Don’t really like muff clamps on hard pipes, they don’t seal well.

 

[PeterG]

I did have to modify the muffler, and engine covers a touch as the flex pipe is longer and larger in diameter. Not too big a deal though.