larry perkins

Name: mack rw613 superliner (1988) Date Added: 15 April 2009 - 01:48 PM Owner: larry Short Description: straight truck,22 ft box used as a weight carrier for scale testing View Vehicle

follow up, turned out to be the tranny,slider gear was worn so bad it was comming out of gear with back pressure. i will try to get a better description ,but it was a gear with a tapper and the taper had opened up fron wear,going to have to retrain the drivers to shift again. thanks for the asssist, i did learn a lot. larry perkins lou ky

ok ,thanks for the assist. all bolts tight on bellhousing this noise happens both in hi and low range. i put a air pressure gauge on the air supply(s) of gear lever air shifter and have 69 lb, i did adjust air regulator up to 90 psi, drove with no difference then adjusted it back to 70 psi. i can walk beside truck moving in yard and noise can be heard when driver ask for power and then lets off pedal with clutch out.just a big clunk and gear noise. it was suggested by power trane of louisville to lock power divider in with air sw on dash,drive to see if problem went away, driver did for about 10 miles from job,thought we has found it, then 1/2 mile from shop in 25MPH zone he is sorta coasting and heard the noise clunk,didnt come all way out, then started pulling again and all smooth. any help appreciated. larry perkins

forum,i need help,i have a 1988 rw613 superliner with 12 speed,this thing is about to break me. when driving and when the maxibrake is engaged the tranny will come out of gear and make a terrible noise. in high fifth there is just a slight clunk that comes and goes away,but as you use the maxibrake down in the lower gears the clunk is magnified and you know the tranny came all the way out of that gear and is trying to re-engage. at that point one goes to survival mode to get the thing to netural . so far premier mack of louisville(kentuckiana mack) has replaced all the air cylinders ,valves and regulators and problem is getting worse. before i replace the tranny,would anyone have experienced a problem simular to this? its really hard for me to believe that with low miles(less than 300k) and the correct maintenance preformed that this tranny that shifts and runs so smooth could be bad. there is never a problem while under load,only when the engine is preforming the braking process. larry perkins,perkins scale corp lou ky