Hurth transmissions

jddens · Post by **jddens** » Sun Sep 30, 2007 6:29 pm

Went out on the hook this weekend in my 30 ft Searaider, while manouvering out of my slip it fast became apparent I had only one engine turning props.......after some difficulty I returned to my slip to check things out....Earlier in the week I had checked fluid in the transmissions and apparently didn't get the dip stick fully seated on the port transmission. After discovering this and seating it fully, everything shifted normal and continued to work fine the rest of the weekend.

My question is....how can this effect shifting? Is there some safety lockout that prevents shifting unless the dip stick is fully seated? The dip stick is only about 6 inchs long but the rubber seal is at least an inch thick and very difficult to put back in.

What is the proper procedure for checking fluid in a hurth transmission...

Sorry for what is probably a stupid question but I'm fairly new to this boat and am still figuring things out...thanks in advance for your input..............John

JuiceClark · Post by **JuiceClark** » Mon Oct 01, 2007 9:52 am

I've never heard of that happening...anxious to see if/what someone says who knows.

Tony
1982 F-36

jddens · Post by **jddens** » Wed Oct 03, 2007 10:53 am

Looks like nobody has input on this..........any ideas where else I could check????????

jav · Post by **jav** » Wed Oct 03, 2007 1:13 pm

shot in the dark -

these are hydraulic units I presume? If so, the shifting occurs via ported pressure from the gears selector shaft. Could your control linkage adjustment be marginal such that the failure to engage was co-incidental to the dip sticks failure to seat? OR, could internal sump pressure, in conjunction with a marginal shift sleeve engagement combine to prevent full engagement?

These are outright guesses and my first inclination is to check for full travel at the tranny actuator. If that test shows good and full gear lever travel (actuated from the controls that you used that day (upper or lower helm if you have one)), then the next reasonable test might be to try the engagement again with the dip stick loose to see if the condition recurrs repeatably. The key to understanding what happened that day will only come if the condition can be duplicated and corrected repeatably by just one variable (the dip stick tube seating).

As far as wether the dipstick should or should not impact shifting, I would that if this is a 71c series box, then it shouldn't make a difference in an otherwise healthy box. BUT, if things are worn (like o rings or seals), it's difficult to predict what could be happening inside.

jddens · Post by **jddens** » Wed Oct 03, 2007 4:42 pm

Thanks jav, many low sump pressure due to poor stick seating?? It seem when i pull the stick to check fluid there is alot of suction when it come out.....I will try to duplicate the problem this weekend. thanks again.....

etpence · Post by **etpence** » Sun Nov 11, 2007 5:00 am

pump works on vacume suction it could not creat the proper suction because of air coming around dipstick

jddens · Post by **jddens** » Sun Nov 11, 2007 7:52 pm

Thanks etpence............this had remained an unsolved mystery...........I did not try to duplicate the problem.............working great now and I didn't want to mess with it...........thanks.........John