Author Topic: Transmission Heat Warning (Read 11940 times)

RonT · « **on:** August 20, 2011, 09:47:52 AM »

Especially for those in the South: Due to the extreme heat this summer we are seeing very high lake temps. I have the first heat related transmission failure here, don't let yours become the next...what to do...
1) If lake temp is into the low 90's or above (we are currently at 95 in Louisiana)
2) Inspect & clean out seawater strainer
3) Inspect & clean out inlet of transmission oil cooler
4) Inspect & make sure trans oil levels are correct & oil was changed at the beginning of this season
5) If you operate in hot waters you may want to move up to a larger oil cooler, 4" & 5" long coolers are good to about 90deg. lake temps.

Symptoms are normal ops. until full oil temp. is reached (20-30 min of skiing) then slipping begins, when fully cooled down the trans will act normal again until heated up again & the symptom repeats itself. Each time this happens the clutch plates deteriorate until total failure occurs.

Mike Harry · « **Reply #1 on:** August 20, 2011, 06:03:51 PM »

Thanks for the heads up Ron. Water is 88 and above around here depending on lake depth.

Joel · « **Reply #2 on:** August 22, 2011, 08:58:48 AM »

Is there a thread posted someplace on how to change the tranny oil? I'm sure mine is well over due...

Mike Harry · « **Reply #3 on:** August 22, 2011, 09:10:42 AM »

Joel, everyone seems to have their own way of sucking the fluid out of the tranny, I have a electric fuel pump made up with wires and alligator clips, and hose on barbs to suck it out with. But basically that's the way.

Then fill

Search velvet drive and you'll find more info

RonT · « **Reply #4 on:** August 22, 2011, 01:48:57 PM »

When measuring the water temp what counts is the surface temp. unless using the submarine application, trans oil must be sucked up through the dipstick hole, I do alot of them so I can justify a pretty neat vacuum extractor, but if you use your wife's turkey baster be sure to rinse it out at least with gasoline before using again at Thanksgiving. In other words you may have to get creative.

Joel · « **Reply #5 on:** August 22, 2011, 05:41:49 PM »

Got R Done today... Gonna keep some ATF in the boat until I get a chance to fire her up and measure after its been warmed up a bit... and FYI... its MY turkeybaster

Thanks guys!!!

Joel · « **Reply #6 on:** August 28, 2011, 07:13:30 PM »

What type / kind of ATF is recommended for the tranny??? I replaced mine (since I hadnt yet) even though my ATF was very clear & not worn looking at all... I used top shelf synthetic. Took the boat out today - level was perfect (measured it after running for about 15 minutes). It appears to shift smoother from forward to reverse, etc, no bump, or anything...

Anybody know if using a synthetic ATF is BAD in the tranny??? If so, why? and whats the BEST ATF to use???

Thanks Joel

phil · « **Reply #7 on:** August 28, 2011, 07:49:53 PM »

Dexron Mercron III. I was under the impression that you should not use synthetic in these transmissions.

RonT · « **Reply #8 on:** August 29, 2011, 07:26:10 AM »

I've always used DEXRON as recommended by the mfg. I don't know about the synthetic AFT's for our boats, I can tell you that the vast majority of the boats on this forum have the cast iron case Borg Warner Velvet drive 1:1 which is very dependable, it's the ZF reduction gears that seem to be having troubles. I have another one in my shop with a blown trans, the customer said his last boat (a 2006 model) with the same gearbox bought his boat with 450 hrs on it & had zero time on the reman. trans, the one in my shop this week has under 800 hrs on it. Again it appears that excessive heat is the cause, & lake surface temps at 90+deg. is the key temp. to watch for.

Joel · « **Reply #9 on:** August 29, 2011, 07:37:28 PM »

I'm ALMOST positive I have the Velvet drive 1:1... Thanks guys

RonT · « **Reply #10 on:** August 29, 2011, 08:53:27 PM »

Joel, yours is not the Porsche gearbox

Joel · « **Reply #11 on:** August 30, 2011, 04:24:32 PM »

I know...

the Porsche takes gear oil - specifically 3 quarts of Redline Synthetic 75W90NS for the limited slip differential (a.k.a. positive rearend) and one quart of 75W90 so its not TOOOO slippery

I'll probably change back to the standard ATF Dexron with Mercron... whatever the hell that is...

Joel

Jed · « **Reply #12 on:** September 01, 2011, 02:44:40 PM »

Changed my trans fluid at the beginning of the summer, but have had to top it back off several times now. Guess I have a small leak somewhere. I'm thinking probably the trans cooler.

RonT · « **Reply #13 on:** September 01, 2011, 02:56:45 PM »

If your not leaking into the bilge I would also suspect the cooler, a leak into the cooler would simply be flushed out into the lake through your exhaust, remove the cooler, cap one "water end" plug a trans line, place in a vice (very gently, just to hold upright) position vertically with the open water end on top, fill the cooler with water to the top, take an air hose & pressurize the oil side & watch for bubbles in the water. If bubble appear replace the cooler & I would go with a 9" cooler vs the 5"

Jed · « **Reply #14 on:** April 06, 2012, 12:49:58 PM »

Well, tested the cooler for leaks. Checks out -OK-. Found small leak at the shift linkage on side of transmission.
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