Volvo SX drive tilt trim drifting down problems

ron3033

Seaman
Joined
Sep 10, 2012
Messages
62
1995 Four Winns, 5 liter Ford, Volvo SX Drive runs only fresh water, and back on trailer after outing.
In about 2 days the drive had gone down about 1/4 inch maybe a bit more, in about 5 to 7 days it was down about 3 to 4 inches. (is this what is referred to as drifting??) There are no visible leaks of oil around the rod where it comes out of the cylinder.
I see there are 2 vendors on eb*y that sell rebuild kits for lift cylinders.
Any one any experience with doing rebuild and/or these kits?
1. I understand it can be done on the boat in the driveway?
2. No hydraulic lines need to be undone?
3. Bleeding is just raising and lowering the outdrive? (in my case I need to put the trailer wheels up on some board to get full down clearance for the drive)
4. An adjustable Pin Wrench (used for small angle grinders) is what is used to take the caps off the prop side of the cylinders?? THIS IS A CONCERN, AS THOSE WRENCHES ARE NOT TOO STRONG???
5. On another note my riser on the driver side of the boat is about 30 degree Fahrenheit warmer than the passenger side I point to the boss mark that is about 3 inches round on each riser. If I remember one is 167, other 124, temp on dash 160.
6. Another note trim gauge is erratic, I assume water has got to the sender on the outdrive, and it reads funny. I just go buy sound and how the boat is planning. Is this a hard fix? I read somewhere it can be done without pulling the drive of the bell housing?
I could use all the help I can get, can't afford trip to shop, too many other things spent any extra $$. The boat is showroom condition, as you see from the drive photos.. just age getting these parts??

Also I looked here but link is not opening:

14. Drive leaks down, trim system does not hold pressure.
This Service Bulletin applies to: - All DP-290 with Power Trim.- All SX, DP-S drives where the shield designation starts with ??SX-M??. Previous shields had a different type of pump and pump house.
http://forums.iboats.com/attachment....9&d=1312641139

Thanks for the long read
ron3033
 

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Fishhead-1

Petty Officer 2nd Class
Joined
Oct 10, 2003
Messages
110
eBay has kits, you can also piece it together if you take the samples to a good hydraulic shop to match up. Yes, you have to remove lines on back of cylinder before pulling rod out because vacuum won't let you pull it out, may only need to pull lines on one side for they are teed together. You can pressure test them for internal leakage,you may only have one leaking. Question do you store it with drive up? Also it's possible the valve in pump could be leaking fluid back to resivour causing drift but not as likely as cylinders.
 

Fishhead-1

Petty Officer 2nd Class
Joined
Oct 10, 2003
Messages
110
That's odd the bulletin says could raise during operation as the torque is always pushing it under. I sure would check and clean valves first. Most of those cylinders fail by leaking externally by bad rough rods or gland seals.
 

steiger23

Cadet
Joined
Nov 27, 2015
Messages
12
Had a similar experience with my SP-a drive. No sign of leak at cylinders yet would slowly drop down over the course of several hours. Took a chance and replaced pump first (found a relatively inexpensive after market pump on eBay). Problem solved. Sure glad I didn't take veryone's advise and attack the cylinders, which can be a real problem. Worked in my case.
 
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