We have a A30C that shifts into reverse on start up. When you turn the key off, but do not kill the engine it relaxes back into neutral. Because of this we believe it to be an electrical issue. It will still operate normally, i.e. shift into forward gears. We found a bad solenoid in the transmission, but it still does it. We bypassed the ECU and it stops. After replacing the ECU it still does it. We have gone through all the harnesses & connections, we check the shifter. We have gone through every test in the repair manual. We just picked it up from Volvo after 2 months. They rebuilt 1 harness ordered a ECU from Sweden and exhausted all their options. Their next step was a $ 40,000.00 trans. We are at a brick wall and hoping some one has some advice. PLEASE!?!?
Hi GYB, i would suggest you need to work backwoods here and see what pressures are at the clutch stations For reverse to engage you need clutch K2 engaged and either brake B4 or B5 engaged depending whether in high or low. install gages in the ports shown and start machine, if there is pressure in K2 you have an hydraulic or electrical issue if you have no pressure and reverse still engages you probably have warped clutch plates in K2 What was in the filters ? what was the lead up to the problem? Mark
Thanks for the response, Mark250. We will definitely try your suggestion. As far as the filters and the trans. (internal), everything was clean (very, very little metal, no more than normal wear and tear). The problem pretty much just happened over night. One day it was fine and the next it was trying to run in two gears. Thanks again.
I had the same problem with the same machine in the end one of the clutch packs welded itself together. We did harnesses solenoids ECM the same stuff you have done and in the end it was the transmission needed a rebuild.
Hello, If you guys ever need any help with these transmissions give us a call we will be able to get you fixed up. www.centranz.com [email protected]