Hurricane Advice: HMMWV will not move!

[FlameRed]

Once again I need the advice of the collective as I might be seeing something HMMWV specific.

Back in July, my batteries failed and I had to have the M998 towed home. Since the batteries were replaced, it has been sitting unmoved.

Fast forward and now I wanted to make sure it was in shape to handle any hurricane duties. Engine started right up. I felt the transmission shift between Neutral and drive and into reverse. Released the parking brake, and the brake light went out as expected.

Problem is the wheels won't turn and the M998 won't move! I hear the engine rev. I can feel it shift.

I turn off the motor and changed the transfer case "clicked" into the other positions. Shift lever feels normal, not like it is disconnected. Restart and still won't move in any transfer case position.

First thought, stuck parking brake? On other cars, if the parking brake is stuck, you can usually feel it "trying", but I don't feel that sensation on the M998. I would try pushing it to see if the brakes are stuck but it is on an incline and I cannot move it as it has no room to go down the incline. I would have to push it "up" the incline which would need a a dozen guys!

Any known issues for a M998 stuck after sitting months? Stuck parking brake? Broken transfer case? Something damaged during the tow?

Thank you in advance!

 

[Mogman]

Does the engine "rev" or can you feel it "load up" you should be able to feel the difference, Also how much of an incline? if the tranny is low on fluid it may make a difference.
Probably the best is to find something to try and pull it.
I have never had the parking brake set so tight that I could not overcome it but I have never had a "stuck" brake ether.

 

[Bulldogger]

Double check the linkages for the shift lever and transfer case lever, but those would not have spontaneously disconnected most likely. The parking brake on a 998 is very mousy, there's no way it would hold against power applied. It just wouldn't feel right (slowed movement, but YES movement).
It sure sounds like something else is wrong.

How far did you tow it and what speeds was is towed at? HMMWV are not rated for long distance towing or towing above slow speeds without disconnecting the drive shafts (also called propellors).

If it was towed a long way, even with the transmission and transfer case in neutral, yes something bad could have happened, though it varies by situation and circumstances. If one differential is bad, I believe it will still move if the transfer case is in Lock (Low or HL). I've heard it can depend on the transfer case sometimes.

Best of luck,
Bulldogger

 

[FlameRed]

Yes, the engine revs. No, I do not feel it load up. But I can definitely feel the tranny shift between N to D and N to R. That seems normal. But I did not want to go over 1500 RPM fearing I might break it worse.

I should have stated that the M998 was flat bedded, not towed with the wheels on the ground.

I agree, if the parking brake was on, the M998 would move slightly. I do have another car where I have to make sure after I wash the car I do not apply the parking brake as the barking brake pads can actually stick to the calipers if they are wet and it won't move an inch, but I hear the engine load up and if I give that car enough power, it brakes free eventually.

I have a winch on it and I am relucatant to use it as the only thing I have to anchor it is a palm tree and they have no roots and I might end up pulling the palm out trying to pull it up the hill with all the rain we are getting.

Maybe I should go out there an gun the engine and see if it brakes free. I have a new 4L80 and gearbox sitting here for eventual installation anyway.

 

[98G]

Is it acting like the tcase is in neutral?

 

[NY Tom]

Check the trans fluid level first as MOGMAN suggests above in case you missed it.

 

[NDT]

Sounds like a CV joint is broken. Put it in gear and look for shafts spinning at all 4 corners.

 

[FlameRed]

Is it acting like the tcase is in neutral?

Yeah, kind of. I don't feel the engine load up, but I do feel the tranny shift. Guess I could disconnect the gearbox linkage and just manually move the lever on the gearbox and try it again.

Check the trans fluid level first as MOGMAN suggests above in case you missed it.

Hard to do while it is sitting on a fair incline. I don't want to overfill it. I got to figure a way of getting off the incline and then I can check it.

 

[Mogman]

Are you kidding me? have you ever tried to push over a palm tree??
I have one that died in the freeze two years ago that was only about 8 feet tall, even after a year I could not push it over with my JD backhoe, I had to dig it out.

 

[Coug]

have you crawled under it yet to make sure that all of the half shafts and drive shafts are still connected? It's unlikely you had 2 half shafts fail or 2 drive shafts didconnected or some combination of the two (which would have to happen if it won't move in either HL or L), but not impossible.

it does sound more likely to be a transmission or transfer case issue.


As for palm trees, those things are designed to withstand hurricanes, so if you can pull it out of the ground with just a winch and a couple thousand pounds of force, then it wasn't going to survive the coming storm to begin with. Just hook the line up as low as you can to the ground and you should be okay.

 

[Mainsail]

I felt the transmission shift between Neutral and drive and into reverse. Released the parking brake, and the brake light went out as expected.

I can feel it shift.

If you can feel the transmission shifting through the gears, then you have power to at least the transmission output shaft.

Start there.

Maybe disconnect the driveshafts from the transfer case and see if the output shafts are rotating with the motor running and the transmission in gear.

 

[Mogman]

You need to get it moved off of the incline before you go crawling under it and disconnect anything, one of our members figured that out the hard way just recently, if it was running and driving before the batteries went dead and it was transported on a flatbed it is very doubtful it is anything like a broken half shaft or a bad transfer case.

 

[simp5782]

With an unprepared vehicle just leave it in the garage before it strands you somewhere.

 

[Bulldogger]

It does sound like the transfer case is stuck in neutral. Are you sure it is shifting? Might crawl under it and confirm the TC linkage is intact. The linkage rods are only held on with cotter pins, and they sometimes fail/fall.
BDGR

 

[FlameRed]

Thank you for all the advice!

Post storm, I went outside and accessed the damage. Mostly minor thankfully. Others not so lucky here.

I started it up and tried putting it in drive and it moved perfectly. Self healing

Took it for a short drive as they closed all the roads and all good.

I will investigate further after the rain stops.

Generator started and beer is chilling so life will be good!

Thank you all!

 

[Mogman]

Thank you for all the advice!

Post storm, I went outside and accessed the damage. Mostly minor thankfully. Others not so lucky here.

I started it up and tried putting it in drive and it moved perfectly. Self healing

Took it for a short drive as they closed all the roads and all good.

I will investigate further after the rain stops.

Generator started and beer is chilling so life will be good!

Thank you all!

Good deal on surviving the storm a cat 4 is no picnic, the wife is visiting her sister in Greensboro NC, it looks like a plentiful amount of rain headed their way.

 

[juanprado]

simple. the low barometric pressure of the storm affected the flux capacitor.

Glad you are ok.

We are hoping here in the Big Easy to avoid one of those wind storm things this year. We typically prefer our hurricanes at Pat O Briens in the quarter.

 

[Dieselmeister]

simple. the low barometric pressure of the storm affected the flux capacitor.

You mean this thing?

Flux Capacitor - Great Scott! | O'Reilly Auto Parts (oreillyauto.com)

 

[juanprado]

You mean this thing?

Flux Capacitor - Great Scott! | O'Reilly Auto Parts (oreillyauto.com)

I love it. My son is a manager there and says it makes the rounds there occasionally of customers finding it.

 

[Mullaney]

You mean this thing?

Flux Capacitor - Great Scott! | O'Reilly Auto Parts (oreillyauto.com)

.
I Love It!!

Somebody in that outfit has a sense of humor...
That is hard to find these days.