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Velvet Drive Overheating

"If that Shift lever doesn&#39

"If that Shift lever doesn't move fully into the FWD position, slipping is likely to happen. This will also inhibit flow oil oil to the cooler."
 
"I know it's been a while

"I know it's been a while

Took boat fishing today. Still overheating. Once it overheats if I drop back to idle (either in neutral or gear) it takes 5-10 min for the alarm to go off. If I keep it around 1200-1400 rpm the alarm goes off in about two min.
I am pretty sure it is slipping at high speed, but I am starting to think the pump might be problematic as well. I know a line pressure gauge would be a good thing to start with, but what gauge setup should I be looking for and what pressure should I find?"
 
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"All I can add is the pipe plu

"All I can add is the pipe plugs are regular NPT. Take the assortment from 1/8" to 3/8", a 200 or 300 PSI gauge, and at least a 4 foot hose.

and the guy with the red stained tee shirt said "Don't start the engine without the gauge or those pipe plugs in - tight!""
 
What was the issue that was causing your tranny to overheat? Did you ever get it fixed. I am having the same issues and would greatly appreciate the input
 
I removed it again and took it to the shop that repaired it and they said it is ready to go. At this point I have it mounted but since I had the FWC system drained and that engine was due for risers/elbows I pulled them as well. All was going fine until one of the riser studs snapped. I should have time to extract the snapped stud and re-tap the hole tomorow. From there it is a pretty quick job of getting everything back together for the bay test.
 
I am impressed with your resiliency of taking out the transmission so many times as I have done it a couple of times and it is no walk in the park. Hopefully it will pay off and correct the problem-good luck with the bay test. Please tell us what you thought the issue was and how you corrected it after the test.
 
Slightly off topic, how long does it take to remove one? I'm sure if I have one go I'll wind up at least doing the R/R myself.

I've done this on a couple of cars, these look a lot smaller and lighter. I did a swap on my wife's Audi last year, that ZF unit weighs 700 lbs.

Bob
 
Finally got everything together today and still overheating. Gonna go through the ucooler, water hoses and raw water pump again tomorrow but still at a loss of ideas as to what else to do (new water pump, ucooler, heat exchanger, trans oil lines last season and new risers/elbows yesterday).
 
Is your trans cooler installed before the rest of the hookup's? Or is it after the engine. If it is after the engine swap it so it gets the cold water first. Good luck and haave a good weekend.
 
Did the shop get a pressure reading? You should see some evidence of the pipe tap plug being disturbed. If the forward pressure is low, the forward clutch may slip, causing clutch heating and therefore, fluid overheating. The pressure could be low due to the oil pump gear wear or a bad seal in the clutch circuit. You really need to get a pressure reading, even in the boat at cruise would be a great diagnostic task.
 
U cooler is first in line for cold water. They said they checked line pressure and it was fine. I still want to get a pressure reading underway but have to get a gauge set up. I'm gonna go through the cooling system once more but am not too optimistic.
 
You can plumb the gauge in direct or with a short nipple and a coupler.

Did you ever verify the control cable gives you full control valve travel?
 
Full throw at both helms. The place that did the rebuild said to swap coolers and see if it follows. I am no ttaking the good engine apart so I have a new cooler being delivered (should be here in less than a half hour) and will try that but not too optomistic about that.
 
Rich; from what i have witnessed at even the best VD repair shops, they drive the transmission using an electric motor and measure pressures and look for output shaft rotation in neutral. I think it is fair to say that there is not a significant load test until the unit is run in the boat. So, you seem to have a situation where the VD is ok on the bench, but overheats in the boat.
I think you need to rule out that the VD is slipping in forward. To do that, what happens at WOT in gear? Is the engine turning at the rpm it did before the transmission work?
 
I have to find an optical tach and a 200 psi gauge to do some final checks. Engine is turning about the same rpm as last year and I'm still seeing 20 kts (although for only 1.5 miles before a buzzer goes off).
 
So I found a gauge. Still would have liked an optical tach but ain't gonna happen since the trans comes out AGAIN tomorrow.
Neutral -600rpm- cold shakes between 110-125 hot 80-110
Forward -600rpm cold shakes between 95-125 hot 70-90
-3000rpm- hot 140psi
-3200rpm- hot 150psi
Signs of a bad pump is what I think I am seeing, but could it be anything else?
 
The thing that I noticed was the drop when it goes into gear. That isn't "normal".

If you have been happy with the shop that did the overhaul, run your gauge data past them and take their two cents. The manual extract DD posted a while back indicates the likely area (see second Note, post #36). Could be a simple as an o-ring slipped (or worn) or a complicated as somebody didn't count the frictions and steels correctly.
 
I don't see a smoking gun. You say you can still reach cruise speed (or is it WOT speed?) with no unusual rpm changes. The forward psi, hot @ 150 is plenty to squish those forward clutch plates together. Nothing here suggest low pressure is the issue, at least to me. There is not a total, positive seal at the forward clutch circuit, since there are small pressure relief bleed holes and the fluid path involves the shaft with its own metal rotary seals. And, being hot, the oil is thinning. I think the shop will tell you this is a reasonable pressure at cruise. The next possible areas are that the reverse system is dragging (in forward) or the external oil path is somehow limiting the flow.
The prop is stationary in neutral, correct?
It might be possible that the reverse oil feed is not adequately shut off by the control valve when in FWD position, but I'm totally on a reach here. I tend to think that the external cooling is NOT the issue, since you can get overheat conditions in a just mile of travel (3 minutes?).
Get them to loan you a different transmission??

I'd call Transmission Marine in FT. Lauderdale and/or Hale Marine in the NW. They are supremely knowledgable on these.
 
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Going on Dave's theory on the pump being ok, I'd check the cooler lines to see if they are full. If they are only 'damp', I'd suspect to control valve - something being hung up inside and not letting full (normal) fluid flow into the cooler. I've never done it but wouldn't think it too challenging to tee a pressure gauge into the cooler's inlet line. I'd use the other side as a reference. More work but if it saves the R&R of the whole gear, it make be worth the effort.
 
Chris at Hale said that once the planetary in a 2.10 goes, it will overheat and there ain't much that can be done. It has to do with the design of that particular reduction so much to the point that if it is an overheat on a 2.10 he tries to avoid rebuilding them.

That being said, trans is in the back of my truck again. The shop that did the work is taking it back tomorrow and we will go from there.
 
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