Alternator Screaching!!!

For the last couple of weeks my alternator just starts screaming when I start up the jeep. It goes away after a couple miles, but starts up again each day. When it is screaching my volts drop down around 9 and when it stops they go back up to normal. I took it to Auto Zone to have it tested and it tested out fine. They told me it could be the bearings??? Maybe the bearings are freeezing up and my belt is sliding over the pulley??? Can you rebuild these, or is my alternator toast? My jeep is a '96 with 131K miles. I DO NOT know if the alternator has been changed out, but probably NOT.

Anyone run into this?

Thanks.

yes...I ran into it once...

Install a new alternator! Perfect time to upgrade.

Perfect opportunity for the ZJ 136A alternator upgrade

reelbigdundy87 said:

yes...I ran into it once...

Install a new alternator! Perfect time to upgrade.

Click to expand...

Fastdemise said:

Perfect opportunity for the ZJ 136A alternator upgrade

Click to expand...

x 2 for both the above. my alts bearings went out on my 95- it threw the bearing and split the case. i took the opportunity to upgrade instead of just replacing. if you can replace your alt, you can upgrade to a zj alt with a tiny bit more work.

Thanks for the reply guys. Looks like a trip to the junk yard is in store for me.

its too bad ur not a 99+, theres a 160A swap with a 03 Durango w/ 5.9l alt...

For that 160A alternator should I expect even more grinding? I have the 136A right now.

Fastdemise said:

For that 160A alternator should I expect even more grinding? I have the 136A right now.

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I don't think so but i've never done the 136 amp swap. We compared the size of the cases though and they are the same size.

ARGHH!

Just did a little more searching and found out it is not the alternator at all. IT IS THE A/C COMPRESSOR SCREAMING. What can I do? Rebuild? Replace?

most of the time its the AC comp that is causing the squealing. but the solution is almost never to replace the AC compressor. Try this- when you start your rig up and the squealing occurs, turn the AC off. this will usually stop the ear killing sound.

the noise is caused by the belt itself not the compressor. with the ac on it adds a lot of extra load to the belt. some times it causes the belt to slip a little bit with that extra load until the belt warms up a little bit. then the noise stops.

the most common causes of serp belt squealing is improper tension (usually the belt is loose) or the belt is getting worn out. our XJs have the tensioner on the power steering pump bracket that allows us to set the tension. for other vehicles that have an automatic tensioner (spring loaded tensioning arm) the spring may be wearing out (it is in my dodge ram)

the quickest, easiest and cheapest of the solutions is to check/adjust the tension of the belt. you can also inspect your belt. you will most likely see the smooth side is a little glazed or somewhat shinny. there may even be some cracking or deterioration on either side. check for excessive wear over the entire belt- its easiest to do with the belt off as you can bend the belt both directions looking for cracking. a small amount of cracking on the ribbed side is normal and occurs as the belt starts to wear down, but be sure there are not cracks running with the ribs as this can lead to the belt failing lengthwise with the ribs. small cracks on the smooth side can be normal as well. also check for areas where the belt may have slipped when going over any of the pulleys. you may find a build up of material on a/some pulleys either ribbed or smooth. clean the build up off the smooth pulleys with a scotch bright pad.

now you can either reinstall the old belt, or you can get a new belt and install it- a new one wont be any more difficult to do than reinstalling the old one- and use the old one as a trail spare. yes, in fact i have used my trail spare belt before after the one on it broke on the interstate.

but either way you choose, i suggest trying the cheaper items first before you replace the ac compressor.

hth
stewie

Thanks for the info Stewie. I just had the belt changed when they recharged my A/C, so maybe they didn't get it tight enough. Maybe I will take it back and have them tighten it up a bit.

I need alternator help to, i flooded my jeep the other day and fried my alternator and i was wondering what i can do to keep this from happening again. I heard a couple things but dont know if they will work or not

-Putting vasoline on the connections
-moving the alternator to the top of the engine capartment
-putting a switch on the alt when im in the mud

there must be some tip or trick to help me out

ivegots0u1 said:

I need alternator help to, i flooded my jeep the other day and fried my alternator and i was wondering what i can do to keep this from happening again. I heard a couple things but dont know if they will work or not

-Putting vasoline on the connections
-moving the alternator to the top of the engine capartment
-putting a switch on the alt when im in the mud

there must be some tip or trick to help me out

Click to expand...

its called dont play in the water or mud unless you like messing up your alt.

Tightened up the old serp. belt and guess what? No more screaching. Hope it was the only problem. I was just about to buy a new A/C compressor. Thanks Stewie, saved me a buck fitty.