the old way is to get the exhaust hot by running it hard and spraying the packs with a cold water hose, dont know if it actually works but i have heard ppl doing it, or maybe just a hammer and beat the hell out of the outside of the pack, its not actually glass but im not sure what material it is.
'Confucius says,"Those who do not use a jack stand shall become a jack stand."'
"9 out of 10 men prefer a woman with big breasts, the 10th prefers the 9 guys"
"Im just kinda retarded like that"
1989 F-150 L.W.B. Reg. Cab 5.0 (ole red, the tank)
The material used is fiberglass hence the glass term.....Running the **** outta the truck then spraying it down with cold water helps a little bit but not too much. Your best bet will be to drive it. I used to have glasspacks on my truck...that got old fast. Do yourself a favor, if you do any kind of constant highway driving, take the glasspacks off, the drone is pretty unbearable after awhile.
Burt- 1989 Ford F250 7.3 NA, Zf, 3.5" Straight Pipe Exhaust, 2001 SuperDuty Axles With 3.73 Gears, 5" Lift Using All Factory Parts, Captain's Chairs, G31 Batteries, NorthStar NS3000 CB With RK56 Mic & 102" SS Whip, Aircraft Landing Lights & 102dB Backup Beeper.
without the glass packs the truck is louder. i like how it use to be but it will cost like 75 dollars to remove them . im just sick of throwing money into the exhaust. the cab in my truck is so quiet you cant hear much.