Really bad tranny whine (Video)

**Thundare** · 10-22-2009, 06:27 PM

So, on my tahoe i have a bad tranny whine and i want to know what u guys think it is. I think it is the pump starving for fluid cuz of a clogged filter.

[ame="http://www.youtube.com/watch?v=7MQFFjg55nc"]YouTube - Really bad transmission whine[/ame]

Thx

**Jimmiee** · 10-22-2009, 08:06 PM

If it's the pump it will whine sitting still. If it makes the noise only while moving then it's probably a gear whine. When exactly does this noise happen?

**Thundare** · 10-22-2009, 09:10 PM

you saw the video, it starts when i but in gear.

**Jimmiee** · 10-23-2009, 04:24 PM

If it won't make the noise in drive or reverse, stopped with your foot on the brake, then it's a gear train noise like a planetary going bad or something in the transfer case. Put the transfer case in neutral and the transmission in drive. This will spin up the gear train and may help you pinpoint the problem.

**Thundare** · 10-23-2009, 10:11 PM

The noise happens when it is gear, forward and reverse while driving and with my foot on the break. i dont know how gears would make this kind of noise. my stearing pump ran out of fluid and it makes the same exact noise as my tranny so thats why i think its the pump.

**Jimmiee** · 10-24-2009, 11:51 AM

Like I said if it makes the noise in gear with the truck stopped it could very well be the pump starving for oil. How does the fluid look? Smell burned? Why don't you pull the pan and have a look. I will tell you this, if the filter is plugged with debris, the transmission is toast.

**Thundare** · 10-25-2009, 12:55 AM

Does the tranny pump operate with in park or neutral?

**Jimmiee** · 10-25-2009, 11:12 AM

Originally Posted by Thundare

Does the tranny pump operate with in park or neutral?

The pump is turning with the engine so it's always pumping fluid. In park and neutral there is no demand so a cavitating pump will make noise but it will be louder in gear.

When diagnosing transmission noise it's important to first establish if you have a pump noise, converter noise, or gear train noise.

A pump noise can be heard in park and neutral and usually gets louder with RPM increase. It will get even louder in gear however.

A converter noise will be very quiet to non existent in park and neutral and loud in gear. It will get louder as you stall it out and it will go away cruising down the road.

It is difficult to sometimes tell the difference between a pump noise and a converter noise.

A gear train noise will be non existent in park and neutral and when the vehicle is stopped. It will get louder as the vehicle speed incerases and change tone with each gear change. Also a gear noise will be most quiet in 3rd gear and get louder in overdrive.

Listening to your video it looks like it makes the noise as soon as you select drive. If so it's probably the pump. How does the fluid look?

**Thundare** · 10-25-2009, 07:44 PM

i looked at the ATF and it looks like it has no SOUL!!! serious compared it to some new stuff it was like

Anyway i took it for a very short drive and kept it in first gear, well when the engine RPM got to about 2,000 RPM the sound went way down. Maybe it got enough pressure at 2,000 to force the fluid through the clogged filter. i can also make a video of this if you wish.

**Jimmiee** · 10-26-2009, 10:20 AM

I would just pull the pan and check it out. If the filter is plugged up driving it like this will just do more damage as the clutches are slipping and lube is reduced. If the filter is plugged up then the trans is not going to last very long anyway. You can change the filter and get a little more life out of it or at least have time to decide how you want to replace or rebuild the transmission.