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Growl when lifting off the accelerator pedal - whatzit?
by
TylerDurden
on 08 Jun, 2013 14:46
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Sounds a bit like a wheel bearing, but it only happens when there is no load on the drivetrain - it goes away under acceleration or with engine drag.
Does not change when loading one side or the other, so it ain't likely a wheel bearing.
Much louder when going >75mph and gently letting up on the pedal, barely noticeable <50mph.
I have more info, but would like initial reactions & thoughts.
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#1
by
ORCoaster
on 08 Jun, 2013 20:24
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Axles tight to the flanges? Loose timing belt cover? Loose IP pump from stripped out bolt? Sounds like a bracket or holder loose. Engine mount on one side loose? Fan Shroud?
That's all the brain can produce right now.
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#2
by
CRSMP5
on 08 Jun, 2013 20:29
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what trans?? on/off power like that is like a pinion/diff bearing.. the diff load changes and the mesh in the ring/pinion makes the hum..
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#3
by
TylerDurden
on 08 Jun, 2013 20:43
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AGS, (5 speed).
There seems to be a fair amount of R&P lash - I get under and turn both axles forward/backward ~10 degrees between engagement.
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#4
by
CRSMP5
on 08 Jun, 2013 21:34
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well time to open it up..
main shaft, would have same growel in same rpm.. even netural as the clutch is connected..
pinion shaft is the one speedo runs off of.. they like a wheel bearing as noise comes in and may get more quiet with speed.. but no noise change when left/right like wheel bearing...
diff bearings are the ones your hearing... if you have that much slop.. id worry the diff rivit abt to poke a hole... but holding both wheels you have to figure in the diff spyder gears..
what your looking for is up/down/side-side flange wobble... basically the diff is twisting in the trans case... then you hear the whirl of on/off power in the ring/pinion teeth
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#5
by
TylerDurden
on 12 Jun, 2013 06:38
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Yeah, I was afraid that might be the case.
I pulled the inner CVs to inspect and one was pretty galled, with flakes of the inner race floating in the grease. Maybe unrelated. Replaced it, noise was still there (not as loud).
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#6
by
bbob203
on 12 Jun, 2013 09:25
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Yeah, I was afraid that might be the case.
Quite the pun!
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#7
by
bbob203
on 12 Jun, 2013 09:26
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This sounds like same problem im having with my asf trans in my eco.
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#8
by
CRSMP5
on 12 Jun, 2013 10:50
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nope bbob.. if you look at my other post w/descriptions.. your pinion shaft brng.. aka speedo gear one...
if yours is doing his noise now bbob.. stop driving it as your bout to have 100% non able to be fixed.. when you bbob get the on off whine noise.. and it started as a 20s ford noise.. the whole shaft is moving so muuch the gear sets, especially 5th bout to be done bbob...
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#9
by
air-cooled or diesel
on 12 Jul, 2013 06:59
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make sure trans fluid is topped off or change. all cv joints are greased, boots are good, and all bolts on inner are some over-tight(I think the book calls for 25lbft., i put them at 33-35lbsft.), outer axle nut is over 200ftlbs.
you should also lift or put front end on stands and i check all suspension bolts/nuts. stay at book torque for bigger bolts, and add some tightness to smaller nuts/bolts. snug calipers.
the axles are the main concern, and trans fluid level. suspension is secondary, but can be a problem, but not as likely.
if all else or you just want to do anyway; you can tighten all points on trans (not too tight its aluminum), and trans engine bell housing. you also will want to torque engine mounts, including small nuts/or bolts that hold in trans mount. maybe its time to replace mounts?.
it could be your clutch assembly, also.
swapping out both axles or all 4 cv joints sounds like a good bet too. the complete axles aren't too expensive, i found them a good investment and about the same price as all 4 cv joints.
your lash is not a good sign, and an easy cause of such noise, its probable you have/are wearing the gears, possibly the rear (unhardened side) of the gears. it doesn't matter which side, cause after a while the gap/lash can become too great and trans will wear on its self. one thing you can do is to get something magnetic, like a drain plug, something bigger will be better and use it to catch metal particles. clean every so often. the trans can last for sometime like this, i'd say change fluid, and use a magnetic piece that you can access to clean off(installed in bottom of trans).
you lose some fuel mileage, trans gears will drag some.
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#10
by
the caveman
on 13 Jul, 2013 09:44
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Over a few years, even if you try not to, chunks of the reverse gear break off and get lodged between the differential housing and ring gear. Possible that your diff is on it's way.