Our '86 has an Allison four speed with Stone Bennett shifter , hydraulically activated. Started having an intermittent problem shifting from neutral to drive during a 700 mile trip Friday . Twice it also would not go into neutral from drive , so I had to manually move the lever at the trans . Problem seemed to worsen as the day got hotter .
I can't see anything obvious at the trans shifter station , and the toggle shows voltage on outputs when moved forward and back . The shifter has an accumulator which has a Schrader valve on it . I am wondering if this should have air pressure . It seems like it should , but I want to be sure before trying to add air . Trans shifts fine , no slippage .
Anyone have any info on these shifters ?
Thanks , Chris
if you do a search on the forum you will find info about it. btw, it is air operated and not hydraulic.
quite a few gurus have worked on them. there is a place in texas that rebuilds them as well.
tom
Actually there is no air going to the shifter . There is a line from the trans to the shifter via the accumulator, and another back to the sump . Tim kindly sent a manual that covers this particular shifter including the accumulator pressure , 90 psi . So far today the shifter is working , 500 or so miles to go , hopefully we can get to the barn as is . We have nitrogen in the trailer , I can fill accumulator if needed .
Thanks for the response ,
Chris
I had T H Anderson Pump Co. , Kilgore, TX Rebuild my Stone-Bennett shifter . They were great! 800-594-7867.
T. Anderson was so amazing! The man KNOWS these shifters. He was real nice & fun to talk to. He explained the process of rebuilding it myself & encouraged me to do it.
All things considered, the prices were very fair.
Good luck with your shifter!
Shifter update , checked trans fluid level yesterday morning. To my dismay and embarrassment the fluid was just touching the stick . Three qts ATF brought the level into the safe range . There were no shifting problems during the 700 mile trip home . I should note that the trans always shifts/pulls well , the shifter is actually a gear selector . When we had problems Friday ( mostly the N to D shift ) it was very hot and we got stuck for hours in a traffic snarl on I 65 N at E Town ,Ky . Perhaps heat soak compromised fluid pressure to shifter . We were also experiencing an overheating problem, about which I will post another thread .
I have found T. Anderson to be a very good outfit . Sourced information and parts from them when I went through the gear position indicator components .
Thanks for the input !
Chris