Hurth 630 trans- is Dexron VI approved?

[Jim Gandee]

Fleet,
I'm servicing my Hurth 630 transmissions. I've sucked out the old ATF, ( looked nice and red ), cleaned the filters and am preparing to refill. The Hurth maintenance manual was written back in 1989 and advises Dexron III. Fast forward to now and Dexron VI, full synthetic, is the current rage. Anyone know if that would be appropriate for my 630's?

 

[FF]

WHY ?

If the existing ATF has worked well, why go looking for leaks with synthetic?

Engines can get 1/2% better fuel mileage with synthetic as it drains with less effort from the oil scraper ring.

Not a tranny plus.

 

[wyoboater]

I agree with FF...if it ain't broken, don't fix it! A lot of ATF "upgrades" include new detergents/additives. The seals in your older tranny may not react well to the new stuff.

 

[psneeld]

Actually if the tranny ever runs hot, synthetic will withstand heat better.


But there are a lot of reasons not to mix types of tranny fluid....unless a direct replacement.


Check with manufacturer or extremely reputable repair facility...if they say OK...I don't see a problem and possibly a small benefit.

 

[Jim Gandee]

While I certainly understand the mantra "if it ain't broke...." The fact is that over the last 25 years dramatic improvements have been made in fluids and lubricants and I was hoping to take advantage of that. However, I'm not willing to experiment nor argue with success. I'm attempting get an answer from the manufacturer and if I do I'll post back. Thanks guys!

 

[psneeld]

While I certainly understand the mantra "if it ain't broke...." The fact is that over the last 25 years dramatic improvements have been made in fluids and lubricants and I was hoping to take advantage of that. However, I'm not willing to experiment nor argue with success. I'm attempting get an answer from the manufacturer and if I do I'll post back. Thanks guys!

 

[jleonard]

While I certainly understand the mantra "if it ain't broke...." The fact is that over the last 25 years dramatic improvements have been made in fluids and lubricants and I was hoping to take advantage of that. However, I'm not willing to experiment nor argue with success. I'm attempting get an answer from the manufacturer and if I do I'll post back. Thanks guys!

Yes that is exactly why I changed to synthetic when I did a rebuild on my BW Velvet Drive.

 

[RT Firefly]

Greetings,
Mr JG. "...25 years dramatic improvements..." I fully agree but one would like to think that if one used a Dexron III compatible fluid for your refill, one may experience fewer problems. I am assuming the basic formula/chemistry remains the same WITH some of the newer improvements added.
In preparation for OUR tranny fluid changed I specifically bought a fluid that said "compatible" with Dexron II as that what was recommended for our Velvet Drives.

 

[River Cruiser]

I have Hurth HBW450 gears and I switched to synthetic because it runs much cooler and cooler is better for longer life. My boat is a 1987 with 1632 hours and has no tranny leaks using synthetic. Good luck

 

[Jim Gandee]

River Cruiser,

Thank you for sharing. What type of synthetic fluid are you using? Have you noticed any difference at all?

P.S. Nice boat you've got there!

 

[River Cruiser]

I get it at car Quest auto parts it's their store brand, I've seen no difference in operation and like I said no leaks. A Hurth dealer had information on their website recommending synthetic because it runs much cooler, they said it was like having a extra quart of capacity. I've been using it since 2010 when I bought the boat.