2019 Massimo T-Boss 410 How To Unlock Differential

[Locking Diff]

I just purchased a new 2019 Massimo T-Boss 410 March 2020. I haven't figured out how to unlock the differential?  There isn't a switch?

[T-boss 410]

I asked the same question to a Massimo tech. He advised that the differential only locks when the 4 wheel drive is engaged. 

Hope this helps!

[Locking Diff]

Thanks, I'll see if it is still locked.

[T-boss 410]

So, what was the verdict?

[Locking Diff]

It's been nasty weather and I haven't had it out. So I don't know if it's still locked or not? Thanks, I'll let you know in a few days.

[T-boss 410]

OK, thanks!

[Locking Diff]

Just got off of the phone with guy from the factory and he said that it's always locked. That just can't be right. The big boss wasn't there today but I have his Ph# 972-893-3180 his name is David Stontz?. I'll try to call him tomorrow and let you know what he says.

[T-boss 410]

Are we talking about the front or rear differential? The front diff is the one that locks when the 4X4 is engaged. At least, that's what the tech said. I don't know about the rear diff. I have downloaded both the owner's manual and the parts manual, but I don't remember seeing anything about the rear diff. 

[T-boss 410]

Did you ever get in touch with the big boss? Just curious about the answer, since I have a T-boss, also. 

[Locking Diff]

  They have told me that the rear differential is always locked and it's the front one that locks when put in 4wd. It sure makes it hard to turn on wet grass, gravel or concrete.  Not a good design, you have to give plenty of gas to get it to go while turning  going slow. Other than that it seems like a well constructed unit,, it does what I need. It could use power point to plug in my sprayer.

[T-boss 410]

So, unlike a limited slip differential such as in the automotive industry,  it's locked always? Yeah, I can see how that would make it more difficult to turn. You would think the engineers would have taken that into consideration during the design phase. I have used mine for some yard work, and I can see what you mean. It doesn't have a very tight turning radius. Great for straight line traction, though. 

[Dan B]

I'm running the risk of telling you stuff you already know.  Your Massimo (made by Hisun) and the Bennche have similar 4WD/Lock systems.  In 2WD, the rear diff can't be locked (shouldn't be unless there's a problem with the actuator).  You can select 2WD or 4WD unlocked differentials.  There's a lever that covers your lock/unlock select switch.  You rotate if you're in 4WD to uncover the lock/unlock selector.  This switch locks both front and rear differentials; not independently selectable.  Apparently, you can't lock just the rear diff or just the front diff.  If you can, jack up the rear of your machine and select 2WD, neutral transmission.  Turn one of the rear wheels; the other wheel should rotate in the opposite direction if unlocked; same direction if locked.

It doesn't make sense to have a differential locked when driving on hard surfaces.  Puts too much stress on the internal differential parts and tires.

[Rocket]

Here is the dirt on the Massimo T boss 410 UTV side by side differential. It doesn't have one in either the front or rear. It’s simply a ring and pinon gear set. Therefor it can not be unlocked. It’s always, permanently locked! I asked Massimo if there is a locking differential option for this model, NO. Is there an after market locking differential available for the 410 side by side? So far google has not found one.

[Joe Breaux]

On 4/10/2020 at 9:23 PM, Dan B said:

I'm running the risk of telling you stuff you already know.  Your Massimo (made by Hisun) and the Bennche have similar 4WD/Lock systems.  In 2WD, the rear diff can't be locked (shouldn't be unless there's a problem with the actuator).  You can select 2WD or 4WD unlocked differentials.  There's a lever that covers your lock/unlock select switch.  You rotate if you're in 4WD to uncover the lock/unlock selector.  This switch locks both front and rear differentials; not independently selectable.  Apparently, you can't lock just the rear diff or just the front diff.  If you can, jack up the rear of your machine and select 2WD, neutral transmission.  Turn one of the rear wheels; the other wheel should rotate in the opposite direction if unlocked; same direction if locked.

It doesn't make sense to have a differential locked when driving on hard surfaces.  Puts too much stress on the internal differential parts and tires.

My MSU 500 is the same.. rear is not locked under 2wd position and front axles free wheel . you select 4wd, then slide cover and press LOCK .. it is much harder to steer in lock position .. warning sticker  next to selector .. DO NOT EXCEDE 18 MPH in LOCKED position.. 

[Mackc]

About whether there is a "locking differential" on their UTV??????   There is so much misinformation appearing here from folks that don't have any idea what they are posting, check it out for yourself rather than jumping on the smart phone or computer and asking questions.

[dmit]

very few atv's or utv's have an unlockable rear differential, in fact the majority have no rear differential, the few that do actively promote them as having "turf mode".

atv's and utv's are not designed to be driven on hard surfaces

[Mackc]

On 3/20/2020 at 9:27 PM, T-boss 410 said:

Are we talking about the front or rear differential? The front diff is the one that locks when the 4X4 is engaged. At least, that's what the tech said. I don't know about the rear diff. I have downloaded both the owner's manual and the parts manual, but I don't remember seeing anything about the rear diff. 

Sorry to disappoint you about the rear "differential" There is NO DIFFERENTIAL in the rear! The rear end is just a ring gear and pinion, If you doubt what I am saying jack up both rear wheels and with the shifter in neutral and the parking brake off, spin one wheel, if the opposite wheel turns the same direction as the one you are spinning there is no differential when you turn,  the wheels slide around the corner, both at the same speed

[Joe Breaux]

so ,only the front axles lock and unlock ?...... then why does my MSU 500 have controls to engage 2wd or 4wd and then seperate control to engage 4wd LOCK along with indictors on dash to show whats engaged ?  just fake? 

[T-boss 410]

3 hours ago, Mackc said:

Sorry to disappoint you about the rear "differential" There is NO DIFFERENTIAL in the rear! The rear end is just a ring gear and pinion, If you doubt what I am saying jack up both rear wheels and with the shifter in neutral and the parking brake off, spin one wheel, if the opposite wheel turns the same direction as the one you are spinning there is no differential when you turn,  the wheels slide around the corner, both at the same speed

Hey, I'm just passing along some information I got from a Massimo tech. 

[Mackc]

Massimo Tech? could that be an oxymoron term for a person that bolts wheels onto a Chinese crate job?