Differential lock question

GamblerAcres

Member
Oct 29, 2018
50
1
8
Ohio
The manual for my MX5200 hst states "when using the differential lock, always slow the engine down."

So what exactly does that mean? Engage and use at idle speed? Engage at idle then speed up? 1000rpms? 1500? Anything but full throttle?

Strange they don't put a number on "slow the engine down".
 

SidecarFlip

Banned

Equipment
M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
7,197
548
83
USA
Reduce the rpm to engage than increase it. Reduces shock load. My M's are the same way.

You don't want to be cooking along and engage the differential lock as the engagement shock load is high.
 

ItBmine

Well-known member

Equipment
B2620, RTV-X1100C
Jan 21, 2014
1,328
335
83
Canada
As long as you don't engage while a wheel is spinning you will be OK.
 

Rosher18

Member

Equipment
L185DT (1977)
Aug 2, 2016
113
0
16
33
Salem, Oregon
As long as you don't engage while a wheel is spinning you will be OK.
I'll second this. I haven't done it but I hear engaging your differential lock with one wheel spinning can result in a loud noise and the rapid, chaotic disassembly of the differential.

Sent from my SM-G960U using Tapatalk
 

ItBmine

Well-known member

Equipment
B2620, RTV-X1100C
Jan 21, 2014
1,328
335
83
Canada
Yes, I have heard they are not very robust. But it is the same on my class 8 trucks with 46,000 pound rear axles. You never engage the diff locks or power divider if a wheel is spinning.
 

85Hokie

Moderator
Staff member
Lifetime Member

Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
10,349
2,170
113
Bedford - VA
The manual for my MX5200 hst states "when using the differential lock, always slow the engine down."

So what exactly does that mean? Engage and use at idle speed? Engage at idle then speed up? 1000rpms? 1500? Anything but full throttle?

Strange they don't put a number on "slow the engine down".
As others have said ......you do NOT want that "pin" to slide into the hole with any great force - it will shear and the cost will be huge.

Engine rpm is really not a huge concern - the spinning of the rear end (tires) is where the problem is, and you do not want any spin at all when the pedal is pushed down.

Sometimes you do need a little forward or reward movement for the pin to lock into the hole - but this is simply a inch or two movement. On an HST - the treadle might need to be bumped to have the heal go down- on a gear, you might need to slip the clutch a smidge - once engaged, go and then stop and allow the pedal to rise back up.;)
 

SidecarFlip

Banned

Equipment
M9000HDCC3, M9000HD, Kubota GS850 Sidekick
Oct 28, 2018
7,197
548
83
USA
Both my M's have FRONT and REAR locks that are independent of each other. Don't think I've ever used the front and rarely the rear. Problem with a front lock is you cannot steer at all. She goes straight no matter what.
 

85Hokie

Moderator
Staff member
Lifetime Member

Equipment
BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
10,349
2,170
113
Bedford - VA
Both my M's have FRONT and REAR locks that are independent of each other. Don't think I've ever used the front and rarely the rear. Problem with a front lock is you cannot steer at all. She goes straight no matter what.
Ol' girl should move straight with the rears locked too!:p

Where is the front locker? near or next to the rear pedal?
 

Mister

Member
Jul 13, 2018
130
1
18
Northwest
Question is, why would you ever want to do this? Diff lock is there to get out of hairy situations at low speed. You have to keep the heel of your boot down on the lever for it to stay locked anyway, so how are you going to be driving along at higher RPM anyway?

Sent from my SM-N960U using Tapatalk
 

Rosher18

Member

Equipment
L185DT (1977)
Aug 2, 2016
113
0
16
33
Salem, Oregon
Question is, why would you ever want to do this? Diff lock is there to get out of hairy situations at low speed. You have to keep the heel of your boot down on the lever for it to stay locked anyway, so how are you going to be driving along at higher RPM anyway?

Sent from my SM-N960U using Tapatalk
Hand throttle, I'd say. I've had to stop and think several times in my L185DT, and make sure I hit the clutch before stepping on the lock lever.

Sent from my SM-G960U using Tapatalk
 

Shadetree03

Member

Equipment
L2501, King Kutter, Landscape Rake, Titan 3pt forks
Sep 20, 2017
115
12
18
Pueblo, CO
Hand throttle, I'd say. I've had to stop and think several times in my L185DT, and make sure I hit the clutch before stepping on the lock lever.

Sent from my SM-G960U using Tapatalk
Every tractor is different.... for the HST with hand throttle and treadle I need to remember to rock back to neutral on the treadle, and even pull back the cruise lever if I have it engaged. Used to be a little more intuitive with just tapping the individual brake pedal on the old Farmall...

If Im rolling with the brush hog low and one rear wheel settles into a low spot, the skid will hold the wheel up and there she spins.. maybe I can learn to tap the brakes again :)
 

D2Cat

Well-known member
Lifetime Member

Equipment
L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
13,020
4,393
113
40 miles south of Kansas City
Shadetree, maybe you're trying to mow the field too low. Set your mower up a tad and you won't need the differential lock while mowing!
 

dlundblad

Member

Equipment
G5200, L2501, ZD1211
May 16, 2009
503
10
18
IN
I always engage the diff lock before slipping. Engine speed shouldn't matter here assuming the 2 rear wheels are going the same speed.
 

Shadetree03

Member

Equipment
L2501, King Kutter, Landscape Rake, Titan 3pt forks
Sep 20, 2017
115
12
18
Pueblo, CO
Shadetree, maybe you're trying to mow the field too low. Set your mower up a tad and you won't need the differential lock while mowing!
Good Point-- much easier just to raise the mower deck and roll through, then return the 3 Pt to the preset stop where I was running. :eek:

Here in the arid west, the only time I really need a little extra traction, the front drive engage lever is probably best... especially for loader work