Hurth V-Drives

[SeaBuzz]

I have a 1997 40ft SD400 with hurth v-drives. Question: Can synthetic trans fluid be used in the Hurth V-Drives ?

[gonzo]

Yes, it can.

[kapnD]

Buzz, Why do you want to change to synthetic? If you're having problems with trannys, changing the oil is no substitute for fixing them, and if they still work well, I'd hesitate to monkey with the specifications. Stick with the manufacturers recommendations and change oil frequently. If it aint broke, dont fix it!

[SeaBuzz]

Nothing worng, just thinking if it would be better with syn. All is fine. Buy I think your right.

Buzz

[Black Swan]

My experience with using syn's instead of dino stock tranny fluid leads me to choose the syn's every time. The spec's are exactly the same as far as "weight", viscosity, lubricity, etc., but the syn's will stand up longer without breaking down under extreme temperature conditions. That's not to say that you should operate your trannys under extreme conditions or with inadequate cooling, but that you may have a little more latitude in operational conditions. I think of it as a cheap investment for a little more peace of mind. My BW velvet drive veedrives seem to like the syn's, average operating temperature is about 10 to 20 degrees lower with syn's, and I have yet to have a "boilout". (ugly)

Just my 2 cents worth.

[Corpus Skipper]

Go synthetic!!! I changed the break in oil in both my engines and went synthetic and I had to LOWER the idle because it jumped up 200 RPM!!! Easier starting and smoother idling to boot. Those big ZFs ain't cheap, so the extra bucks for syn. is well worth it for the added insurance.

[LADYLOVE]

Hey Black Swan, how long have you been using synthetic oil. I assumed you are also using syn in your engines too. Also curious why (and if your engine manufacturer reference such)? The pros and cons are driving me to drink more than usual (while docked).

[Black Swan]

I've been using synthetic tranny fluid for 2 years now. However, I'm sill using dino oil in my Volvo TAMD 40's. (Diesels) I haven't even thought about syn's for the volvo's, no idea why, but probably because there hasn't been an oil issue with the engines,whereas there was an issue with the veedrives, overheating, eating bearings, and puking dino into the bilge. Larger coolers helped a little, but going to syn's helped a LOT. Boiling point on the syn's MUCH higher.

BTW I recently had a freshly rebuilt 350 long block installed in my 1984 GMC van. The rebuild shop and my mechanic both recommended against syn's or any exotic additive treatments for at LEAST 10000 miles. Something about some syn's being formulated with teflon and that the teflon in a fresh engine "could" create some kind of problem with rings seating or something. There's an extensive discussion of synthetic oils on a forum called the "Escapees Discussion Forum". It's old guys with RV's (big expensive RV's) and they get into it pretty heavy, lots of links, lots of info. Good luck!

[gonzo]

There is no teflon in syntetic oil. It is a modified petroleum product. They use heat, pressure and a catalyst to make longer molecules which have enhanced lubricity. The problem with using syntetic with a new engine is that the rings won't seat properly.

[FAST FRED]

The problem with using Synthetic in most boat engines is lack of corrosion resistance in the oil.

For auto , truck engines or trannys synthetic is tops.

For sitting UNUSED as so many boats seem to do synthetic is NOT recomended ,
a it is very poor at preventing internal rust .

FAST FRED

[kapnD]

Interesting, Fred, I just worked on a two year old engine that was pretty ugly on the inside, though it only had 300 hours on it. Now I understand why. The owner was a "syn-head", put it in everything. My opinion has always been that if synthetics and miracle additives were really all they were cracked up to be, the manufacturers would spec them and the oil companies would buy up the patents. Neither one of these enteties seems to get excited about it.

Ok. Some of the very large air compressor companies switched over to SYN. because of the brutal operating conditions they must operate in. Now they warn against NOT using SYN. May go back to the CONTINIOUS duty, 100%, they operate in. Oil changes every 300 to 500 hrs. Little or no wear after 2 years 24 hr/ day. Air compressors easely reach 220F in the summer. I am using KAESER as a reference.

Only place SYN has a place is in a race boat where the oil is changed every few runs or couple of days. Than back to real oil long term.

[FAST FRED]

Only place SYN has a place is in a race boat where the oil is changed every few runs or couple of days. Than back to real oil long term.

If your willing to go to all that expense , the old standby CASTOR OIL is still the best for racing.

Just as solder gets sucked to the hot part when joining copper tubing , The Castor bean oil goes TO the heat .

Have no idea why .

The aroma of a racing bike on vegatible castor bean oil is far better than the stench from dead dinasours oil.

FAST FRED

[LADYLOVE]

Really hooked up on the use or non-use of syn in my engines and trans. Anybody know of any reviews published? Have not "yet" got a response from the Crusader (8.1) and Hurth (630v) people.