Hello,
I seem to be going thru serpentine belts and curious if anyone has a suggestion as to why. New engine with belt and after roughly 4000 miles, the exiting one broke. I replaced it but it jumped off after 10 miles.
I haven't done a bunch of checking, but curious what I should be looking for. This ismy first forray into serpentine belts. Thanks

Ken

_________________
2006 CRD
2.5 Frankenlift,ARB front bumper with internal winch.snorkel soon to have rock lizard bumper, sliders and roof rails, 2nd gen filter head
GDE eco tune-need trans upgrade and new TC
Beaverton Oregon

Several possible causes but they all boil down to something is not spinning freely or something is not aligned correctly so. Pop the plastic engine cover so you can see down in there and grab a bright light to shine into the dark down there and
1. with the engine off see if the belt lines up along its edge and that the belt teeth fully engage the "teeth" on the applicable pulleys if not the fix if so then
2. in park with brake on crank up, step out to the side of the left front wheel and observe the belt. Is is jumping around and/or is the serp belt idler jumping around as opposed to barely twitching. If so fix. Most likely reason is a bad alternator decoupler pulley but other causes can relate to the viscous heater clutch, AC clutch, or misaligned (e.g. shot) serp belt tensioner.

_________________
Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

THANKS!! I know it's not the alternator pulley or atleast I don't think it is as its new. However, the belt tensioner is one thing I will give some attention to.i assume these are not difficult to replace? atleast, it doesn't look to be difficult..thanks again!!

Ken

_________________
2006 CRD
2.5 Frankenlift,ARB front bumper with internal winch.snorkel soon to have rock lizard bumper, sliders and roof rails, 2nd gen filter head
GDE eco tune-need trans upgrade and new TC
Beaverton Oregon

Ken - understanding that the alternator pulley is new I feel an urge to ask if it is an OEM or equivalent decoupler pulley. If it's a) solid pulley or b) a simple one-way clutch pulley then it's not the same. The CRD alternator pulley is a Overrunning Alternator Decoupler (OAD) pulley; see http://www.decouplerpulley.com/ for the difference. Use of an incorrect pulley can stress/destroy the tensioner and throw belts.

Regardless of the cause it needs to be identified and fixed ASAP as there has been at least one report of the serp belt coming off in such a manner as to cause the system to jam up enough to throw the timing belt off with attendant rocker/lifter damage. Unlikely but not impossible

_________________
Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

Thanks again. I replaced the alternator and the pull at the same time and I believe it was OEM but can't swear to that. I guess I have more research to do.

_________________
2006 CRD
2.5 Frankenlift,ARB front bumper with internal winch.snorkel soon to have rock lizard bumper, sliders and roof rails, 2nd gen filter head
GDE eco tune-need trans upgrade and new TC
Beaverton Oregon

This May be a dumb question, but how would I know the type of pulley that I currently have??

_________________
2006 CRD
2.5 Frankenlift,ARB front bumper with internal winch.snorkel soon to have rock lizard bumper, sliders and roof rails, 2nd gen filter head
GDE eco tune-need trans upgrade and new TC
Beaverton Oregon

Best I can say is look at the pics at http://idparts.com/catalog/index.php?cP ... 2d61d06b41

I think there is a way to manually check, serp belt off, by hand but I do not know how.

_________________
Sold to LOST member my 05 Ltd, GDE Stg II turbo + TCM tune, SunCoast TC w. Transgo kit, Steiger window regulators, Samcos, Fumoto valve, 2nd gen filter head with Lub. Spec. bleeder, Hayden clutch & 11 blade fan, inverted spare, P-1 battery, BF Goodrich Long Trail TAs, Etecno1 glow plugs, timing belt at 50K miles/8 yrs

Found the problem!! it was the tensioner pulley. It was totally hosed and just didn't pay enough attention I guess. It doesn't look like it damaged the second belt and its a bit quieter when running!
Thank you for all of your advice!!

Ken

_________________
2006 CRD
2.5 Frankenlift,ARB front bumper with internal winch.snorkel soon to have rock lizard bumper, sliders and roof rails, 2nd gen filter head
GDE eco tune-need trans upgrade and new TC
Beaverton Oregon