Need help diagnosing low roaring sound only when gas pedal is engaged.

[00abellemare]

I recently notice a difference in the performance of my truck and a new roaring sound only when the gas pedal is engaged. The sound is low hum - kind of like the hum of mud tires at a high speed, but a little deeper and rigid. The sound tens to get louder as the engine gets warmer.

I have looked underneath the truck for any visible signs of damage, but did not see anything different. I had all the fluids in the transfer case and transmission, and they are good. The guy at the lube place road with me in the truck and suggested that it may be some kind of vacuum/exhaust leak.

Another sound that may be related to this is that on hills when the transmission switches gears and has to work a little harder, I will get a high pitch whistling sound.

Any help would be greatly appreciated.

 

[00abellemare]

I should mention this is an 88 fj62 automatic.

 

[Kynot62]

Fluid in the diffs OK?

Tony

 

[00abellemare]

They said they checked all my fluids underneath, but I will go back to them and ask this question specifically. I will also try and check this myself today.

 

[Michael Hanson]

Whistle sounds like exhaust leak,have a muffler shop check it out or just buy a 1/2 hose hold it to your ear and use the other end close to different places in your cruiser and check for leaks. When is the last time you seviced ALL your fluids and grease? MIke

 

[00abellemare]

Within the last two months, I had them check all the fluids at my local lube company.

 

[Michael Hanson]

Check....replace them most are 20 plus years old. Repacked the bearings, when? At least once a year. MIke