2004 M1123 6.5L - Serpentine Belt

[Mills]

2004 M1123 6.5L

Has anyone experienced a serpentine belt (Dayco 5081260) snapping for no apparent reason (twice in 3 weeks). Could a failing belt tensioner cause this?

~Chris

 

[simp5782]

Tensioner or idler

 

[Retiredwarhorses]

Wrong belt and too tight?

 

[avman]

What length are you using with ac I think the belt is 110”

 

[porkysplace]

2004 M1123 6.5L

Has anyone experienced a serpentine belt (Dayco 5081260) snapping for no apparent reason (twice in 3 weeks). Could a failing belt tensioner cause this?

~Chris

What length are you using with ac I think the belt is 110”

The belt # he posted is a 126 inch belt.
Dayco 5081260

http://www.daycoproducts.com/part?c...e=&model=611&description=&part_number=5081260

 

[Mills]

What length are you using with ac I think the belt is 110”

126" Dayco 5081260 Serpentine Belt

 

[Mills]

I've replaced the original belt with the identical belt (3) times - 126" Dayco 5081260 Serpentine Belt. I've had no issues with the original belt until the last 6 weeks or so.

 

[Retiredwarhorses]

There are 2 lengths, it’s based on your serial number range....or basically what version of serp setup you have.
but I can tell you there is no 126in....it’s 98 or 114in.

 

[Mills]

There are 2 lengths, it’s based on your serial number range....or basically what version of serp setup you have.
but I can tell you there is no 126in....it’s 98 or 114in.

The serp belt is a Dayco 5081260, 126" in length. That's what came on the truck. Serial Number 219504.

 

[Retiredwarhorses]

Well, then I’m wrong...the TM is wrong. But that’s not the case....check the TM, your SN is above 196xxx

https://www.hummerpartsguy.com/search.asp?keyword=20-9646&search=

 

[86humv]

He has a redot AC system, thats why its longer.

 

[Retiredwarhorses]

The SN range makes it a Cast serp system....thus you can only use pancake compressor. The cast serp setup already allows for the addition or subtraction of a compressor via the delete pulley that goes on AC bracket.
And the OP makes no statement of AC in the truck....

 

[86humv]

Heres a snap of the video he sent :

 

[Retiredwarhorses]

Heres a snap of the video he sent :
View attachment 749246

i figure if the OP wants it fixed, he can post some pics of the setup he has....from my experience with shredding belts on a serp truck with Red dot AC, it’s been alignment issues....

 

[Mills]

Serpentine Belt 6.5l NA M1123

There are 2 lengths, it’s based on your serial number range....or basically what version of serp setup you have.
but I can tell you there is no 126in....it’s 98 or 114in.

Would the 98in. be without the AC compressor and the 114in. with? Also, for some odd reason I have an additional guide roller (x out in blue below) which is NOT on the belt routing diagram on the air intake. The original diagram is on the right below.

 

[Steveo22]

Mills- I'm having the same issue. I have the additional pulley as well. I removed the Red dot system and installed a pulley (from Hummer Parts Guy) to fill the void where the compressor was. I cannot get the 114" belt to go on. Seems like I need a 116" or bypass a pulley and got with the 98". You figure anything out?

 

[Steveo22]

Mills- I'm having the same issue. I have the additional pulley as well. I removed the Red dot system and installed a pulley (from Hummer Parts Guy) to fill the void where the compressor was. I cannot get the 114" belt to go on. Seems like I need a 116" or bypass a pulley and got with the 98". You figure anything out?