Long cable coming out top left rear of transfer case, what is it?

[Bulldogger]

I was under my HMMWV last evening looking for the source of the intermittent grumbling/rattle (I feared it was from the transfer case due to the position and this pained me to think about). Underneath the beast I spotted what looked like a long black sheathed cable coming out of the top left rear of the transfer case. Messing with this cable gave me the noise I had been hearing. It is looped all over under there, and in going over the fuel tank it rubs on the underside of the tunnel. I could see a rubbed spot where it has been contacting the tunnel for quite some time by the look of the paint (or lack of paint now). I assumed it was a shift cable, since it looked like one, but in reading the TM I see that the transfer shift mechanism is supposed to be controlled by a steel arm linkage. I didn't know this yesterday, so I didn't look for that arm. I will tonight.

I can't find anything in the TM about a cable coming off the transfer case. The cooling and vent lines are there, this is not them. This sheathed cable, whatever it is, seems to definitely NOT be original equipment, since it is looped all around under the tunnel. It immediately struck me as looking just like an automatic transmission shift cable. Maybe it is?

I can take a picture tonight. Does anyone know what I'm looking at? Is it stock? What is it?

Many thanks,
Bulldogger

 

[joeberg]

Could it be an antenna cable? I have never seen one run like that but many have them run from the front of the cab to the rear antenna mounts. It's would be a black sheathed cable.

Sent from my SM-N900V using Tapatalk

 

[BLK HMMWV]

There is a lot of 1/4" hard plastic black vent lines that run all over under the truck most end up eventually running up the right frame rail. It's part of the fording system.
maybe your talking about that.
That's about the only thing I can think of that would come off the transfer case.
The speedo cable is kind of like your describing but it goes to trans .
Yes pictures would help.
Also what transfer case is it.

 

[Gunzy]

Sounds like you are describing the speedometer cable.

 

[Bulldogger]

joeberg, definitely not an antenna. All my antenna and radio power cables have been cut and this cable enters the transfer case.

BLK HMMWV, definitely not a vent line, I found those.

Gunzy, I didn't think of that. I'll look at the TM again, or just walk the cable forward. It could be that. But why so looooooooong, I wonder, if so.

I'll look harder and report back.

Thanks to all!

Bulldogger

 

[BLK HMMWV]

If it's the speedo cable it goes into the trans and should have a 90 degree fitting at the trans end.

 

[Bulldogger]

Thanks BLK HMMWV, I thought speedos generally went into the transmission. This is definitely in the transfer case.

I will trace the line and also get a picture of it tonight.

Bulldogger

 

[Action]

there will be a 90 degree elbow between the speedo cable and the transfer case. That cable should run towards the front of the vehicle and into the back of the speedo. I don't know how it can run all over under there and over the gas tank...

 

[Gunzy]

The speedo cable goes into the transfer case on all 4wd vehicles I have ever worked on. They need to read the output rotation at final drive. As most transfer cases are 2 speed the reading needs to come from the output of the transfer case. Does your speedometer work? Disconnect the cable, if the noise is gone and the speedo no longer works you'll know what it is for.

 

[Bulldogger]

Well BLK HMMWV wins. I traced it to the speedometer. Why that cable needs to be two and a half feet longer than needed I don't know. Rather than remove and lube it as planned, I'll probably just replace it with a more correctly sized one.
Bulldogger

 

[Retiredwarhorses]

Well BLK HMMWV wins. I traced it to the speedometer. Why that cable needs to be two and a half feet longer than needed I don't know. Rather than remove and lube it as planned, I'll probably just replace it with a more correctly sized one.
Bulldogger

There are 2 versions of speedo cables...the old style is short, the new is long, the excess actually should be up in the engine area and it routes differently then the old short one. The new routing actually has the cable making less abrupt turn and lessens kinks....

 

[Lawdog734]

RWH - are the cables specific to certain speedometers (65mph versus 80mph) or do they work with either/or?

 

[Retiredwarhorses]

RWH - are the cables specific to certain speedometers (65mph versus 80mph) or do they work with either/or?

The 80mph speedo is electronic, so it's not mechanical...the longer cables enters from the front of the drivers footwell, the short one enters from the side.

 

[86humv]

All work the same, unless you go electronic.

 

[Bulldogger]

Thanks for that added detail retiredwarhorses. I did some searching and bought an NOS cable off the auction site. Listed as 85". Is that the new or old style? If new, I'd appreciate a description of how it is supposed to be run, as my long later cable is definitely not run correctly.
Bulldogger

 

[Bulldogger]

I was able to source an 85" cable off the auction site and it fit perfectly. I couldn't find anything readily that said whether 85" is the older shorter cable or the newer longer cable. Well, I can tell anyone who is curious that 85" is the older shorter version. The cable I pulled off is a few FEET longer than the one I put on.

Went in without any issues and I'm very happy with it.

Bulldogger