|Haunted Volvo MDB3 MS Gearbox?
Post Number: 2
|Posted on Saturday, September 20, 2014 - 10:53 pm: ||
Could this be a haunted MDB3 MS gearbox? The motor runs great, but the gearbox stopped working while under power in reverse. The prop had no torque but spun freely in both directions. I could stop prop shaft with bare hand. NEXT DAY - started the engine, fwd was the same, but reverse started working for no apparent reason. While on deck checking prop rotation in reverse, a loud CLUNK occurred, and engine stopped dead. NOW - props spins with torque in fwd no matter what gear position or clutch position EXCEPT... If shifted into reverse with drive engaged, engine stops dead with a CLUNK. (Decided to stop experimenting at that point.) Linkage seems fine. Trans oil looks new without odor, although overfull. We've owned the boat a few months. Beginning the process of pulling the gearbox. Any Suggestions?
Post Number: 139
|Posted on Saturday, September 20, 2014 - 11:44 pm: ||
Pull the tranny. You will see the problem is a broken casting. It worked in reverse (or forward) because of the way the casting broke. This will be obvious once the casting is on your workbench. Send me a photo.
Metric socket head cap screws were standard but no telling what might be in there now. Try to get them very clean before inserting the wrench. Get a firm fit and wrench them easy, you really don't want to strip the heads or break them off.