I am the second owner of this Boat with 1985 Universal M12 and Hurth HBW 50 tranmission. 600 engine hours perhaps, but was not sure when trans oil was changed so did the job this past week myself. It's a bear to get to the drain plug so I pumped from the top, getting about 250 ml out that way (fill is 300 ml). Then filled with same amount of Chevron Dexron III ATF. Bottle perhaps 15 years old but never opened. Checked fill level to ring. Took the boat out Thusday and noted a surprising increase in vibration at all rpms. I am not talking about major shaking here, but noticeably different than before the oil change. Ran about 5-6 hours, no improvement. You would have thought I put water in there instead of ATF. Anyone got a clue on this or have I likely got something else going on?
Vibration after tranny oil change - what the heck???
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Does the oil that you removed feel and look of the same viscosity as the replacement oil? It is possible that there is a difference in oils for a multitude of reasons. Other than that I can't think of another cause.
Heavier oil is an old trick in the automotive world where it helps cover-up noisy gearboxes or increase oil pressure in worn engines.
Ray
Heavier oil is an old trick in the automotive world where it helps cover-up noisy gearboxes or increase oil pressure in worn engines.
Ray
I wouldn't discount some other little nasty boat gremlin that just happened to show up at that time.
Check the trans oil when its warm to see if it is over full.
I recently had a hard shifting problem on my car that was remedied by removing some of the trans fluid. (It was about 100ml over full.) It dosn't seem like a lot but it fixed my car.
I recently had a hard shifting problem on my car that was remedied by removing some of the trans fluid. (It was about 100ml over full.) It dosn't seem like a lot but it fixed my car.
Could under-fill also be a problem? Apparently not from the description that you replaced the amount you removed.
When we drain our SailDrive, we must manually rotate the prop to be able to refill the amount of fluid removed.
When we drain our SailDrive, we must manually rotate the prop to be able to refill the amount of fluid removed.
The manual calls for Dextron II. Dextron III is for
electronic transmissions. The manual warns against interchanging fluids.
electronic transmissions. The manual warns against interchanging fluids.
Thanks to all who posted for your ideas! Not a prop issue, as boat was at dock and vibration started from the git go. Did dive to have a look/feel at it anyway. All good. Dip stick is fine, but there is certainly a mix of new and old oil in there. And the old stuff was very black whereas new is red. I think I will start by doing a full drain out of the bottom hole, i.e. a 100% clean out and fill with the exact 300 ml of new fliud.
Are you sure your trans uses ATF fluid? It may be to thin my boats trans calls for 30 weight engine oil.
Yes, that much i think I got right. Hurth HBW 50's need ATF Type A, Dexron II according to owner's manual.
Odayokay, in your opening of the thread you said
Dextron III. That would be different than Dextron II.
Dextron III. That would be different than Dextron II.
So now I have about 90% Dexron III in there and 10% unknown. Are you suggesting, I need to get some Dexron II, i.e. that the vibes are coming from either the wrong spec fluid or the mix of unknown and III????
Dextron III is not a superceeding replacement for
Dextron II. Given the problems that you are experiencing I'd be hoping that that is the problem and that you could remedy it by putting in the proper oil.
Years ago I learned the hard way about trannies. I had a Nissan with a manual trans that had a drain plug. I drained it and filled it with standard 90 weight gear lube as that was the standard for many years before. Immediately it shifted poorly. Fortunately there a wholesale lubrication distributor just down the street from me. Note, he was a wholesaler and did not sell me anything He informed me that there is a GL rating for gear oil and that I should use one with the rating of GL-6. The rating of the stuff that I put in was GL-4. I got the GL-6 rated oil and my problems were over. the same man told me that some manual trannies use automatic transmission fluid as their gear lube. Ever since I have been VERY sure that any lube oil is the proper type. Gear oil can damage gears if it is too thick as it can literally hydroform the gears.
If it were me I'd immediately refill it with Dextron II and hope that it works.
What Ray Bowles says is true. I ever knew of an unscrupulous mechanic who put oat meal in sick trannies to sell them. I would suggest though that you make sure that the error was not yours and change it.
Dextron II. Given the problems that you are experiencing I'd be hoping that that is the problem and that you could remedy it by putting in the proper oil.
Years ago I learned the hard way about trannies. I had a Nissan with a manual trans that had a drain plug. I drained it and filled it with standard 90 weight gear lube as that was the standard for many years before. Immediately it shifted poorly. Fortunately there a wholesale lubrication distributor just down the street from me. Note, he was a wholesaler and did not sell me anything He informed me that there is a GL rating for gear oil and that I should use one with the rating of GL-6. The rating of the stuff that I put in was GL-4. I got the GL-6 rated oil and my problems were over. the same man told me that some manual trannies use automatic transmission fluid as their gear lube. Ever since I have been VERY sure that any lube oil is the proper type. Gear oil can damage gears if it is too thick as it can literally hydroform the gears.
If it were me I'd immediately refill it with Dextron II and hope that it works.
What Ray Bowles says is true. I ever knew of an unscrupulous mechanic who put oat meal in sick trannies to sell them. I would suggest though that you make sure that the error was not yours and change it.
Thanks for the warning, but this siutation may be a bit different. I called a reliable yard. When the spec is for II (which is way old like my engine), it should be fine to use III and they are very skeptical that this is causing a vibration. Having said that, since ATF was not changed for so many years, pumping it out again and refilling is not a bad thing, which I will do. I don't think one could fine any Dexron II anymore anyway.
I would find some Dextron II or a suitable
replacement. Dextron III is not a replacement for Dextron II. It's possible that the vibration will not be helped but why risk doing it wrong ? Check with a good auto parts store. There has got to be a way people with classic cars deal with getting Dextron II.
replacement. Dextron III is not a replacement for Dextron II. It's possible that the vibration will not be helped but why risk doing it wrong ? Check with a good auto parts store. There has got to be a way people with classic cars deal with getting Dextron II.
Does this happen in reverse too?
Does the vibration increase in frequency linear to the engine RPM?
Is it a harmonic vibration or lower period shaking?
Play in the cutlass bearing?
Maybe the transmission was somewhat slipping before and now that you have changed the oil it is under increased load which has pulled you system further out of alignment.
Don't get into a narrow mind of thinking... it must have something directly do with the oil change.
Does the vibration increase in frequency linear to the engine RPM?
Is it a harmonic vibration or lower period shaking?
Play in the cutlass bearing?
Maybe the transmission was somewhat slipping before and now that you have changed the oil it is under increased load which has pulled you system further out of alignment.
Don't get into a narrow mind of thinking... it must have something directly do with the oil change.
Thanks, I will look into that. A second experienced Universal Engine mechanic has now weighed in and he does not think that is what is going on. Has used plenty of the DIII in these 80's engines. Won't cost much to check out your theory however. I did do the second change last night. The fluid was nearly black again after only 6-7 hours of running with the first change, so that was probably a good thing to do.
Those all seem like smart questions and I appreciate. Was only in reverse for a few seconds backing away from dock so will have to check that out. No the vibration does not get worse with RPM change, with the exception that at extremely low RPM it is not manifested. But no difference between say 50%, 65%, 80% of throttle (no tach so this is estimate). Harmonic or lower period? No sure what you mean, but it does not feel like a shake, really. Slippage theory sounds plausible. I did spin the shaft and gave it a good shake up and down, right and left. No play whatsoever. Will be out this weekend and will do some more assessing to better answer your questions.
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