Transmission Dipstick Washer

Mike McDonald · October 10, 2012, 08:03:59 AM

Does anyone know what type / size washer should be used on the Hurth transmission on a 1987 C-34? I changed my transmission fluid for the first time and filled to the top for winter storage as suggested. The washer on the dipstick looks like a standard rubber hose washer, and appears to leak. Can't find reference to the washer in the manual. Thanks.
Mike.....

Stu Jackson · October 10, 2012, 08:42:08 AM

http://www.c34.org/manuals/Hurth_HB_Transmission_Manual.pdf

Page 14, Fig. 6, no washer.

Mike McDonald · October 10, 2012, 09:33:11 AM

Thanks Stu. Seems odd, but I'll give it a try without the washer.
Mike....

Ed Shankle · October 10, 2012, 10:07:08 AM

Mine has a washer, but it's metal. don't know the size off hand.

Ed

tonywright · October 10, 2012, 01:01:24 PM

Check the engine manual, tranmission section (Page 36 in mine). Filling up the transmission to the top with fluid is only required if you are laying up for 12 months or more. (Even in Canada the winters don't last that long!)

Conversely, the Hurth Transmission manual specifically warns about overfilling: this can cause leakage at the shaft seals or transmission breather, and also cause the transmission to overheat if operated while overfilled. (I for one would probably forget to lower the level in the spring and quickly be in trouble).

On balance, I leave mine at normal levels during winter - seems a lower risk proposition.

Ron Hill · October 10, 2012, 03:58:02 PM

Mike : There should be an Aluminum crush washer on the dipstick, which is the same washer that is on the drain plug.

Don't have my parts book handy, but it IS listed.

A thought

SailingJerry · October 10, 2012, 06:02:32 PM

Topping off the transmission for the winter is low on my list of fun jobs. Does anyone else NOT fill the tranny to the top? Have you had any problems due to not filling it? I am thorough when winterizing, but don't need overkill.
Jerry

Ron Hill · October 10, 2012, 06:26:27 PM

Jerry : The manufacturer recommends that the transmission be filled. This is done to keep the seals moist.
Look at the angle it is mounted at and you tell me how that fwd seal is going to stay moist if you don't add transmission fluid ??

Ask your PO if your transmission was filled or not during storage, and then you might have your answer??

As Stu says "your boat your choice" !!!!

tonywright · October 11, 2012, 03:50:00 PM

I have seen a couple of references to "manufacturer's recommendation", but not sure where folks are finding this. Please give us the reference, rather than suggesting that those of us who do follow the manual are not maintaining our boats properly.

Attached is the relevant section from my manual. You will note that it says (twice) that (a) filling the transmission is only required for storage over 12 months, and (b) that the main purpose is to prevent corrosion. I will be happy to provide the other passage if required that warns why you should not use the transmission while filled like that.

Now there are of course a few other suggestions here, like uncoupling the prop shaft flange before removing the boat from the water. Raise hands all who do that, while the haulout crew is waiting!

Roc · October 12, 2012, 04:11:10 AM

Tony,
I think the reason for uncoupling the shaft is becaues when the boat is on the hard, the hull is not resting in a normal fashion as it is in the water, so the hull might twist or flex somewhat. That twisted position puts pressure on the shaft and could bend things, thus causing vibration.

Ron Hill · October 12, 2012, 05:16:34 PM

Tony : I'd put little credence in uncoupling the drive shaft.
I have not done that in 25 seasons and don't know of anyone that has!!! A thought

Jim Hardesty · October 13, 2012, 03:44:43 AM

I'm with Ron. If you are flexing the hull of a C34 that much, you are doing something very wrong. Other brands...could happen.
Jim

Ron Hill · October 13, 2012, 06:01:58 PM

Tony and Guys : You have a M35BC engine with a ZF10 transmission and Mike (if you haven't noticed ) has an M25XP with a Hurth 50 transmission.

I see that the recommended lay up for up to 12 months or more is to fill your ZF10 transmission to the top with fluid. I don't have the M25XP manuals anymore, but I always erred on the safe side especially with layup which usually lasted more than 6 months.

For those of you that don't check you engine and transmission oil in the spring and periodically, I'd recommend that your do nothing. That way you don't have to worry about being overfilled.

As Stu says, "your boat your choice".