HMMWV M1123 Serpentine Belt Question

[Blizken]

Hey Fellas,

Im out to replace the serpentine on my M1123-6.5L Non Turbo.

Should I be threading the belt over the fan to start? And if so-there is a hydraulic hose in the way and I am assuming I am disconnecting this to get over the fan...

Or am I going about this like a moron??

Looking for some thoughts.

Thanks all.

 

[GuntherRommel]

The hose has a quick disconnect in front of the fan, You probably should also replace the belt tensioner while its is off

 

[Mogman]

You do not need to remove the hydraulic hose on a serpentine belt, the backside of the belt drives the water pump, it goes from the bottom of the crank pulley around the pump then on to the PS pump/alt then across and down to the ac comp, then to the tensioner and then to the crank pulley.
Passing through a few idlers along the way.
There are some differences between models but not too hard to figure out.
It does NOT need to be passed over the fan blade

 

[Blizken]

The hose has a quick disconnect in front of the fan, You probably should also replace the belt tensioner while its is off

Thanks much

 

[Maxjeep1]

I have put 2 belts on my m1123 and I don’t recall the fan being an issue

 

[Mogman]

You start by making a loop big enough to go over the crank pulley, reach in between the tensioner and the water pump and loop it around the crank pulley, then pass the backside of the belt around he water pump and the rest is easy pleasy!

 

[gentech]

Hey Fellas,

Im out to replace the serpentine on my M1123-6.5L Non Turbo.

Should I be threading the belt over the fan to start? And if so-there is a hydraulic hose in the way and I am assuming I am disconnecting this to get over the fan...

Or am I going about this like a moron??

Looking for some thoughts.

Thanks all.

The older model need the belt to go over the fan. Disconnect the hydraulic line, feed the belt then reconnect it. you wont lose any oil from there.

 

[Coug]

The older model need the belt to go over the fan. Disconnect the hydraulic line, feed the belt then reconnect it. you wont lose any oil from there.

Only A0/A1 series trucks should have V-belts that require the hydraulic line be disconnected..
M1123 is A2 series, so all of them should have serpentine.

 

[Blizken]

I kind of figured this out in reverse.

My 1123 calls for-- HM-955 | Serpentine Belt 114" inch Flat Belt A2 Series HMMWV.

It is too short. Looked at the old belt and it is an RD-5-11792-0 which seems to be about 125".

USMC added AC to the truck when they did their refit and that is probably where the belt discrepancy came from.

Anyway. End of the mystery. Thanks guys.

 

[Coug]

 

[Thumper580]

I kind of figured this out in reverse.

My 1123 calls for-- HM-955 | Serpentine Belt 114" inch Flat Belt A2 Series HMMWV.

It is too short. Looked at the old belt and it is an RD-5-11792-0 which seems to be about 125".

USMC added AC to the truck when they did their refit and that is probably where the belt discrepancy came from.

Anyway. End of the mystery. Thanks guys.

So without AC it's the HM-955?

 

[Blizken]

So without AC it's the HM-955?

That is correct. I have a new one if you need it.

 

[Thumper580]

That is correct. I have a new one if you need it.

Send me a PM to discuss. My belt is showing some signs of wear.

 

[Archangel_Hk]

So, I am glad I found this post. I just recently got a m1123, 6.5L detroit, non turbo. (And no A/C unfortunately), but my serpentine belt needs replacing and I am unsure which one to get. One place says the 98 inch, and the next says 114. Any thoughts?

 

[Coug]

So, I am glad I found this post. I just recently got a m1123, 6.5L detroit, non turbo. (And no A/C unfortunately), but my serpentine belt needs replacing and I am unsure which one to get. One place says the 98 inch, and the next says 114. Any thoughts?

it's divided by serial number. Pre 196900 uses shorter belt, after 196900 serial number uses longer belt.
Easiest visual cues are the remote power steering reservoir on top of the engine, and an idler pulley between the alternator and power steering pump. Remote reservoir and extra idler are the post 196900 setup with longer belt.

The serial number break is not absolute; they did sometimes put rebuilt engines with the longer belt in the earlier trucks during reset.

 

[Archangel_Hk]

it's divided by serial number. Pre 196900 uses shorter belt, after 196900 serial number uses longer belt.
Easiest visual cues are the remote power steering reservoir on top of the engine, and an idler pulley between the alternator and power steering pump. Remote reservoir and extra idler are the post 196900 setup with longer belt.

The serial number break is not absolute; they did sometimes put rebuilt engines with the longer belt in the earlier trucks during reset.

Mine is 184869, so I guess I will try the 98. Thank you.

 

[DREDnot]

For a better chance to get the correct one take a piece of string and run it along side of the belt around the pulleys. Measure the string for the close approximation. You can actually decipher/order belts as the civilian part numbers usually correspond to the number of ribs and overall length of the belt.

 

[Archangel_Hk]

Thanks for the info

 

[SmartDrug]

Mine is 184869, so I guess I will try the 98. Thank you.

I'm a very close SN and need to replace mine as well, but won't have access to it for a few months, post up with your results, please!

 

[Thunderbirds]

I found an aftermarket belt for roughly $17, vs the $45 original... Here are the specs:

Bando 8PK2490

Mine is 184869, so I guess I will try the 98. Thank you.

I have installed a Bando 8PK2490 belt for $17 on my 1999 M1123, perfect fit.