I have a 2000 Kubota L48 with 1300 hours on it. As I get older I am more noise sensitive. Although I wear ear protection it seems like my tractor is so loud! My muffler appears to be intact but I am thinking of cutting open to see if it has fiberglass packing that needs to be replaced or if I can put in more baffles. I’ve also thought of using a quiet automotive muffler as well. Anyone here have any experience dealing with this type of issue?
Your L48 is the same basic engine as our M59, but since the L48 doesn't have any emissions or computer or turbo there are lots of options open to you that don't apply to newer emissions style tractors. That's another advantage to the old ones.
The L48 beng an old style diesel, my opinion is that to do this in the best way, you could first add an basic automotive aftermarket exhaust manifold temperature gauge - and after that are free to try any configuration of exhaust pipe and muffler you want. Run the exhaust to the rear, or upright, and into/out of any muffler you want to try If the exhaust manifold temperature stays roughly the same as stock, you are good to give it a go. The engine will be fine.
BTW, I just last year went through a muffler change on our old JD. Modern replacements (Steiner) are a good fit and value, but are lighter construction than the OEM. The new lighter-wall construction means it looks identical, but passes noticibly more sound and particularly high frequency sound out to the operator - and the HF sound range is where older hearing is particularly vulnerable to damage.
So one thing you can consider would be that there is an advantage to a larger & heavier muffler. I see no reason why an older automotive type would not work perfectly well. You could mount it somewhere convenient and extend the pipe. Careful of the heat....
To muffle the JD for our older ears, we ended up using almost the same JD muffler - but went to one for the next larger displacement engine. It was close enough to look and fit fairly well so we adjusted the mounts to fit. The larger muffler lowered the frequency and reduced the amplitude.
For your L48, you might look at the Kubota M5700 to M9000 series and see if one of those will fit.
40+ years ago we converted the side exhaust on our chore tractor to a vertical stack. That worked very well. We mounted a larger muffler down low, and added an elbow with a tall exhaust pipe & rain cap. Made the upright in two sections that slid together so that hitting something like a tree limb would only knock off the top. A vertical stack is so much nicer I'm tempted to convert the M59.
rScotty
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