Q: Allison trans in 2001 gmc 2500hd will sometimes "whistle" when put in reverse

asked by on August 09, 2017

When trans is hot and shifted into reverse (when stopped) it sometimes emits a "whistle" sound very much like a "backup warning" on a garbage truck. It is intermittant and does not seem to effect performance. Smooth shifts, trans temps getween 150f and 175f. New filter abd fluid in last 1500 miles

My car has 65000 miles.
My car has an automatic transmission.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing


Experienced Mechanic?

Earn up to $70/hr

What others are asking

Check Engine light repeatedly lights up no matter what
There is an original equipment manufacturer (OEM) campaign 14515b that is calling for the chassis control module. The module has a problem that it has corrosion internally causing random check engine lights and possible engine stall or fail to start....
How do I use the air conditioning?
Turning on the air conditioning couldn’t be easier. Simply press the A/C button, which you’ll find in the climate control cluster on the center console. A light will illuminate on the button confirming that the air conditioning has turned on....
How do I adjust the rearview mirror?
The rearview mirror is an important safety feature that provides you with visibility out your rear window. Before driving, you should always adjust your rearview mirror so that you have maximum visibility. To adjust the mirror, manually move it up,...
Truck does not start
Hi. If the engine cranks normally but doesn't start, most likely the engine is not getting fuel or spark. Just because you have fuel pressure from the pump doesn't mean that fuel is getting to the engine. In modern vehicle,...
Engine dies after Battery Light came on
My diagnosis would depend on whether the Battery Light illuminated before the engine died, or if the engine died before the Battery Light illuminated. If the Battery Light illuminated before the engine died, then you most likely have an issue...
My engine light keeps coming on. We have replaced the air/fuel ratio sensor four times.
Hey there. As you may know, this may be caused by a few different things, one of which is a faulty sensor (which you have already replaced). This may also be caused by an intake air leak, leaking or dirty...
Car overheats
VSC refers to vehicle stability control and any fault there can be diagnosed and repaired after the overheating and oil warning light are resolved. If the oil light you are seeing is the low oil pressure warning light, oil pressure...
My 03 745 li is over heating I changed thermostat and thermostat housing my car idols for five minutes and message comes on overhe
There may be trapped air in the cooling system. Air can get trapped if you drain coolant and then refill the system without purging. Trapped air can cause overheating by blocking coolant flow and can also faulty heater operation. Other...
Wiring Diagram on the Blower motor resistor
Hi Chanel. Since we can't attach images or files on this platform, your best resource is going to be purchasing a service and repair manual for your 2010 Chevrolet Malibu to review the detailed wiring schematic for each mechanical system....

Related articles

A Buyer’s Guide to the 2012 GMC Acadia
When When it comes to finding the right SUV for your family, it seems like there are always a lot of compromises to be made. One vehicle is so performance and off-road oriented that you can’t imagine taking your kids...
2012 Chevrolet Equinox vs. 2012 GMC Terrain: Which One Should I Buy?
The mid-size crossover SUV category offers the comfort and size of an SUV, but on the platform of a car, giving it the look and feel of a large hatchback. The unibody construction typical of passenger vehicles is used instead...
How to Get Buick Dealership Certified
GM/Buick car dealerships offer automotive technician jobs to mechanics who are certified through the Universal Technical Institute (UTI) and GM.