Join Date: Sep 2007
Location: Rhode Island
NTL1991 is offline
Truck Sounds Like it has a Jake Brake
When I am going above about 30 mph and I let my foot off the gas (and the RPMs drop to about 1100-1250) I get a sound near the middle or rear of the truck that sounds like a jake brake. When I just tap on the gas to raise the RPMs about 50 or 100, the sound goes away completely. When I go faster, like 50 or so, the RPM that will set it off gets higher, like 1300 or so.
I've also noticed that when I make a sharp left or right turn, I get a noticible THUD from the middle/rear of the truck and then when I straighten back out, another thud.
I get no thud when shifting from Park to Drive or any other gear like that. The U-Joint is new and the Pos-Trac rear end has brand new oil. The exhaust is not modified, although the catalytic converter failed the Delta-T test. The temp only increased 5 degrees rather than 100 it should have.
What could this be? At first I thought it was something stuck in my wheel well, but there isn't. Is there something wrong with my rear end or transfer case?
1997 Oldsmobile Bravada SmarTrac
4.3L V6 W-VIN w/ 145,000. Automatic Transmission.
Factory 3.73 PosiTrac; Z85 Suspension
Last edited by NTL1991; 11-03-2008 at 06:57 AM.