Mechanics

ANY IDEAS WHAT IS CAUSING THE WHINING NOISE IN MY ENGINE IN FIRST AND SECOND GEAR?

2007 Chevrolet Suburban • 93,500 miles

I have a 2007 Chevrolet Suburban 1500 LT. I bought this truck brand new in Sept 2006. I have approximately 93K miles on the truck. I have just noticed a whining noise when I start to excelerate from a complete stop in first and second gear. As I increase speed, the noise goes away. I took the Suburban to my local service dealership and they suggested it could be the bearings. However, in order to confirm, I would have to pay $1250 to tear down the transmission. There would be no guarantee that the problem could be fixed. If it is not the bearings, the transmission would need to be replaced. Since I have owned the vehicle over 5 years (9/2011), the transmission would not be covered. They suggested a rebuilt transmission for $2700. Any ideas what is causing the whining noise so I can narrow down the problem without having to spend tons of money trying to find out? Thank you!
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Fabiocomes
May 15, 2012.




Is this an automatic or manual transmission? I have never had very good luck identifying a noisy bearing by holding it and playing with it so disassembling the transmission to inspect it is relatively ineffective. A noisy bearing could very easily be overlooked so it's best to just replace them.

There aren't many ball or roller bearings in an automatic transmission. It's mostly sleeves with oil in between similar to engine crankshaft bearings. Those don't make whining noises. If the fluid level is low, air can get sucked up. THAT will make a whining noise.

The best way to identify the cause is to listen to it while it's under load and the conditions are met necessary to make the noise occur. A dandy tool for that is called the "Chassis Ear". That is a set of six microphones, a switch box, and head phones. You clip the microphones to suspect points, then switch between them while listening during a test drive. Be aware that many mechanics have never seen or even heard of this tool but it's used by suspension and alignment mechanics to find clunks and rattles. Auto parts stores that rent or borrow tools may have it. I recently found out you can find it on Amazon. Com for one third of the normal price.

Caradiodoc
May 15, 2012.


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