Transfer case shifting and BTM

[thoner7]

Went off road for the first time recently. I had some trouble shifting the T case. It would grind gears when trying to shift. Park (for the trans) seemed to work for shifting into HL but not always. I took a video

m1165 T case

Trouble shifting

youtube.com

but the only time I got it into L was with the trans in N. Except for my third attempt in the video

I let the truck roll to take and pressure of the drive line etc. what am I missing?


Also for the BTM - I struggled to get it to engage. If I remember what I read - 1800 rpm and light pressure on the brakes? It’s hard to have light pressure on the brakes when you are half way up a hill! I never even got the truck to 1800 rpm in that instance.

I did get it to engage the one time I had the T case in L, but had no luck the other times. Does the Tranfser case have to be in low range for the BTM technique to work?

 

[REF]

CAUTION
• Vehicle must be stopped, engine off, and transmission shift lever
placed in “N” (Neutral), before transfer case can be shifted.
Failure to do this will result in damage to drivetrain.
• Do not place transfer case shift lever in “H/L” (high lock range) or
“L” (low range) on high traction surfaces where little or no wheel
slippage is evident, particularly when encountering sharp,
continuous turns. Failure to operate the vehicle with transfer case
in “H” (high range) on high traction surfaces, particularly when
encountering sharp, continuous turns, can damage drivetrain.

From TM9-2320-280-10 section 2-108

hope this helps

 

[TOBASH]

What he said

 

[thoner7]

Wow - truck off!? That’s surprising. Better not need to shift in a hurry lol.

What about BTM? How high do you keep rpm’s? My truck only went to about 1500 rpm with my foot on the brake.

Once the diffs lock, and you start moving - do you let off the brake? does the Diff stay locked if you do?

 

[TOBASH]

Wow - truck off!? That’s surprising. Better not need to shift in a hurry lol.

These are not shift on the fly transfer cases my friend.

 

[Mogman]

Everyone that owns a Humvee would benefit by reading the operator TM.

https://image.nsnlookup.com/equipment-intelligence/land/hmmwv/technical-manual/tm-9-2320-280-10/tm-9-2320-280-10.pdf

One more thing I love about the DuraVee, computerized shift on the fly transfer case

 

[Coug]

Wow - truck off!? That’s surprising. Better not need to shift in a hurry lol.

What about BTM? How high do you keep rpm’s? My truck only went to about 1500 rpm with my foot on the brake.

Once the diffs lock, and you start moving - do you let off the brake? does the Diff stay locked if you do?

When I'm doing it, I usually bring the RPMS up a bit, then loosen up a little on the brakes. As long as you have light pressure on the brakes, it should stay locked up. You're doing more modulating of the brakes than you are the throttle most of the time.
You do have to keep light pressure or the diffs will unlock.

 

[frauhansen]

Everyone that owns a Humvee would benefit by reading the operator TM.

https://image.nsnlookup.com/equipment-intelligence/land/hmmwv/technical-manual/tm-9-2320-280-10/tm-9-2320-280-10.pdf

I printed it out for me to read it on my 30min morning job while sitting

 

[Retiredwarhorses]

A simple trip to the dreaded -10 operators manual would have shown you that the truck needs to be off and in Neutral to shift the tcase.

 

[frauhansen]

Sorry, but I didn't understand that. Is this a joke that I, as a foreign speaker, don't get? Or does this manual really exist? Is it some kind of crash course or HMMWV for dummies? Tryed to google it, but no relevant results.

 

[frauhansen]

Ahhh, that's it. Thought you meant a different one.
I had already studied this, and others, during the long wait until my truck arrived.
It is extensive, yes. And it affects a lot of models. And I would have cut it down to half if necessary. But why is this " dreaded "?

 

[Coug]

Ahhh, that's it. Thought you meant a different one.
I had already studied this, and others, during the long wait until my truck arrived.
It is extensive, yes. And it affects a lot of models. And I would have cut it down to half if necessary. But why is this " dreaded "?

the dreaded part was sarcasm, as many people seem to dislike the idea of having to read and finding what they need to know from a manual, when they think it is easier to just ask questions (the same ones that get asked over and over, taking up a lot of forum pages)

 

[Milcommoguy]

It's NO joke. Human kind is loosing it's mind / memory. Is it just us old farts with HumV's ?? OR is it just all the good librarian's have been put out of work due to a google, an app, a forum? I'am not sure BUT I see it over and over here.

Not saying it is not OK to ask. If one doesn't know jump in here and ask away. We are born with "why and how" MOGMAN, full time ask Daddy

The TM's and a bathroom are a good place to start, LOL. Get your business done, info learned or even gleaned.... Now in memory all the other senses reinforce it, eyes, hands, ear's, even smell, the whole spectrum add up when cawing thru the problem HumV". Memory retention improved and no batteries required. Mommy....Where's the spray...Daddy has been studying again, LOL

A thumb drive is flipping thru the TM, CAMO

 

[frauhansen]

To be honest, if I hadn't read the manual, I would have handled it in exactly the same way as all the other transfer cases. Especially when I know it's an (NP)242 like everything else I've driven on Jeep, Durango, RAM.
So the idea of operating the car as it appears to you is obvious and is no reason to lose faith in the world

 

[Mainsail]

CAUTION
• Vehicle must be stopped, engine off, and transmission shift lever
placed in “N” (Neutral), before transfer case can be shifted.
Failure to do this will result in damage to drivetrain.
• Do not place transfer case shift lever in “H/L” (high lock range) or
“L” (low range) on high traction surfaces where little or no wheel
slippage is evident, particularly when encountering sharp,
continuous turns. Failure to operate the vehicle with transfer case
in “H” (high range) on high traction surfaces, particularly when
encountering sharp, continuous turns, can damage drivetrain.

From TM9-2320-280-10 section 2-108

hope this helps

Except:



I can attest that my M1165 T/C does NOT shift unless the engine is off.

 

[Mogman]

Except:

View attachment 910123

I can attest that my M1165 T/C does NOT shift unless the engine is off.

I think that is simply an omission, there are errors in some TMs

 

[thoner7]

I’m sorry if I missed the truck needing to be off in the TMs. I had tried N and P and assumed something make be broken as some of the shift linkage seemed to bind up at times.

I searched through the TM for the BTM instructions and have come up empty. Searching the document for the terms: brake throttle, brake-throttle, modulation, differential, all come up empty. That’s a common issue I’ve had with the TMs - not know what the military calls things. I’d search for switxh but the military calls it a toggle. Search for washer and the military calls it a disk spacer or something strange.

 

[Retiredwarhorses]

I’m sorry if I missed the truck needing to be off in the TMs. I had tried N and P and assumed something make be broken as some of the shift linkage seemed to bind up at times.

I searched through the TM for the BTM instructions and have come up empty. Searching the document for the terms: brake throttle, brake-throttle, modulation, differential, all come up empty. That’s a common issue I’ve had with the TMs - not know what the military calls things. I’d search for switxh but the military calls it a toggle. Search for washer and the military calls it a disk spacer or something strange.

BTM is not in the TM’s, this was taught during driver training…FYI, in the military, no one could operate any piece of rolling stock without having
been certified by a trainer, only than could the piece of equipment be added to the soldier, marine or Airman’s military Drivers License.
IIRC, the BTM portion was part of a more extensive training course for self recovery…