Alternator decoupler... not a rehash... my problem

05infernoCRDL · **Posted:** Tue Jan 20, 2009 10:49 pm

so when i first bought my truck 13 months ago.. i noticed it shaking more than what i thought it should..
posted my Q's about the shaking on here many siggested motor mounts (which was a really good suggestion)
not mine though... then i thought TC/front pump... again not so...

I knew my alternator decoupler was chirping but didn't think much of it and knew it should be replaced... i finally got around to it tonight. squeeking is gone and the rough running...

the decoupler (old) would not move at all when i took it off... and the intresting thing it was the 50XXXXXXXAE the newest revision...

so if you have an odd shakey shakey, mainly at idle that kinda goes away when in N check the alternator decoupler.

javert · **Posted:** Thu Jan 22, 2009 4:13 pm

How many miles does your CRD have on it? Do you spend quite a bit of time idling?

just wondering,

Javert

05infernoCRDL · **Posted:** Fri Jan 23, 2009 12:58 pm

51600.... i don't spend a lot of time idling... just noticed it at stop lights compared to the other 3 CRD's i have driven in addition to mine

gmctd · **Posted:** Fri Jan 23, 2009 1:28 pm

FYI: While engine rpm seldom increases\decreases between Park-Neutral and any gear range (that's the miracle of ECM-managed idle speed, varying the fuel-rate to maintain specific rpm range), the additional loading of the torque convertor results in more fuel injected, meaning more powerful combustion and power-stroke, which increases the forces that damage the decoupler - traffic conditions engender idle periods (Does the term 'stop-lites' ring any bells? How 'bout 'traffic jams'?) - the higher the accumulated vehicle mileage, the greater the number of idle-periods = decoupler failure

gmctd · **Posted:** Wed Feb 04, 2009 5:39 pm

Just rec'd mine and installed it - sure quiets down the mechanical anguish noise - the original was very stiff, but still workable - the new one is smooth as butter, one-way's easily - sure a lot of hassle to get the alternator off the engine, tho - also, hadda use a air impact wrench to break the rusted hub\shaft threads - yep, hub was missing the cover\seal................

05infernoCRDL · **Posted:** Thu Feb 05, 2009 1:58 am

gmctd wrote:

Just rec'd mine and installed it - sure quiets down the mechanical anguish noise - the original was very stiff, but still workable - the new one is smooth as butter, one-way's easily - sure a lot of hassle to get the alternator off the engine, tho - also, hadda use a air impact wrench to break the rusted hub\shaft threads - yep, hub was missing the cover\seal................

mine wasn't hard to get off the engine... took maybe 10 mins... same deal with the pulley though..

my old one did not move at all...

RTStabler51 · **Posted:** Thu Feb 05, 2009 9:47 am

did you guys use the special tool?

gmctd · **Posted:** Thu Feb 05, 2009 11:51 am

Broke the hex collar of the special tool!!! - however, a good 1/2" drive air impact wrench and 1" socket on the hex part of the tool broke the rust and popped the hub right off - fortunately the rotor shaft is huge and overall rotor mass is great, allowing the impact wrench to work it's magic - still amazed at the work required to separate that alternator from the engine - and, those extreme length bolts :shock:

................

FYI - the internal-hex collar is weak due to wall thickness and the retaining holes, is meant for a girly-man with a kiddie 1/2" drive bar - just pop the tapered pin outta the 1/2" drive shaft to remove the collar - the collar prevents full insertion and correct mating of the hex-bit to the hub's internal hex - then use the large hex-bit in the sheave hub with the impact wrench

05infernoCRDL · **Posted:** Thu Feb 05, 2009 1:36 pm

RTStabler51 wrote:

did you guys use the special tool?

i used my H17 hex bit on my 1/2 inch impact wrench... no problems

ChesterCRD · **Posted:** Mon Feb 16, 2009 7:29 pm

05infernoCRDL wrote:

i used my H17 hex bit on my 1/2 inch impact wrench... no problems

Same here...impact wrench makes this an easy swap. I switched directions a couple times and it came right off.

Alternator decoupler... not a rehash... my problem

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