Noise that starts at 40 MPH

[TacoJon]

Hey all,
Myself and a few other people have noticed something on our Roxors. I do not think it is anything to worry about but I am mainly more curious than anything. At almost 40 MPH exacty, regardless of gear (3rd, 4th or 5th), then engine goes from it's normal sound (revs + turbo) to a distinct almost percussive cladder. It basically gets much ladder and pronounced. I kind of want to get a tune soon, so I wanna be sure I know what this is before I do that. Has anyone else experienced this?

Thanks!

 

[Boomer]

Hey all,
Myself and a few other people have noticed something on our Roxors. I do not think it is anything to worry about but I am mainly more curious than anything. At almost 40 MPH exacty, regardless of gear (3rd, 4th or 5th), then engine goes from it's normal sound (revs + turbo) to a distinct almost percussive cladder. It basically gets much ladder and pronounced. I kind of want to get a tune soon, so I wanna be sure I know what this is before I do that. Has anyone else experienced this?

Thanks!

Dealer tells me that they all do it but no one seems to explain what going on they are trying to get something from rotor but have no answers yet sure don't sound good hope they can tell us what causes it

 

[MikeT]

Is it what these guys are discussing here?
70 miles on the Odometer and a Couple weird things - Team ROXOR Forum - Unofficial Mahindra ROXOR Off-road Community!

 

[Campyman]

Mine still does it.

 

[TacoJon]

Here is the sound. Let me know if yours is the same. Starts almost exactly at 40mph. It is MUCH more pronounced in real life compared to a video but if you turn it up, you can hear the sound at 40 MPH. Doesn't matter if I am in 3rd, 4th or 5th. It still does it. Have spoken to a few others with the same sound.

 

[Bister]

A friend drove mine and said it’s injector/fuel system noise. He said their farm tractors do the same thing at certain RPM’s and load. Mine does it in different gears depending how you step on it, but it has to be under some load.

 

[RCF]

Diesel engines have a inherent low rpm vibration which could feed back to transmission,I’m thinking the noise could be transmission chatter , doesn’t do it when clutch is pushed in and throttle is used to keep rpms up while coasting at 45 . I’ve seen this in other vehicles some companies helical cut there gears to eliminate this but straight cut gears are stronger.most modern diesels have spring set up in flywheel to help this issue and that’s expensive .Roxor is kind of bare bones and I doubt they use them should be no reliability issues. I’m trying to get trans parts diagrams to see how trans is built.

 

[sandyx]

I’m trying to get trans parts diagrams to see how trans is built.

Look up BA10/5 dias. NGT520 is BA10 in cast iron casing with may be some internal mods.

 

[RCF]

I just watched a video on ngt520 trans and it has all helical cut gears which should quiet down trans chatter depending on manufacture tolerance ,so noise above 40 still unsolved issue . I only experience the noise in 3 4 and 5 gear I realize u can’t reach 40 in 1 and 2 gear but u still have all the mechanical motions in play that happen in upper gears

 

[txroadkill]

T Case gears?

 

[Buckpasser]

Anyone ever crack this case?