How hard is this piece to replace? DP290 shift mechanism

[erikgreen]

I got a call today from the guy resealing my 290DP lower unit. He finished it and reassembled it, the pressure test went ok, but he noticed that the O ring that seals the shift mechanism is extruding out due to some corrosion of the cover that holds the shift mechanism (this is part 3855785, it's the squarish part with the round hole in the center that has the eccentric piston mounted in it).

Now, I'd like to have him replace it and be done with it, but from the looks of Volvo's catalog it's going to cost about $150 for the part, plus he'll have additional labor charges (he probably shouldn't, since he just replaced the eccentric piston, but whatever).

I'm wondering how hard it would be for me to replace it later? It's possible for me to weld or fill the cover and turn it true on a lathe so the O ring sits correctly, or I could run it as-is. As I said, the drive has held pressure for 24 hours, but that O-ring....

Or is this something that is critical or tricky enough that I should have a professional do it now, and pay the extra $250 or so?

Opinions welcome. This is an expensive process, I'm just trying to control the cost if I can.

Erik

 

[Don S]

Re: How hard is this piece to replace? DP290 shift mechanism

Here's a link to the OEM manual for that drive. http://www.4shared.com/file/48536730/fa3b3311/280_to_DP-C_Drive_manual.html

Starting on page 64 of the manual is how to repair the shift mechanism. It's not really that hard, but you do have to remove the upper gear box in order to shim under the bolt on the eccentric.

 

[erikgreen]

Re: How hard is this piece to replace? DP290 shift mechanism

Thanks, Don.

I'll see what price he quotes me for the work... if he only wants a hundred or so I'll let him do it.. otherwise I can. He's done most of the hard work on the drive seals anyway, I can probably handle the rest since I'm going to doing most minor work on this thing going forward.

Erik

 

[erikgreen]

Re: How hard is this piece to replace? DP290 shift mechanism

Ugh... well, he says Volvo wants $215 for the part and he'd charge me $90 labor... so I'm looking around to see if I can find a used part.

I also think I could probably repair the problem well enough in my shop to get by.. it's basically that the edge of the casing between the O-ring groove and the outside is chipped and missing. I'm thinking the housing is aluminum so I could weld it or grind it out a bit and patch with marine-tex gray.

The O-ring groove isn't a problem either, I can recreate that easily on a mill.

Does anyone know if this part is standard for DP290s? Are there different versions I could run across looking at used parts, or will any shift mechanism housing that looks the same work?

Thanks for any info, I'm trying to keep this rework bill as low as I can

Erik

 

[erikgreen]

Re: How hard is this piece to replace? DP290 shift mechanism

In case anyone knows, it's part # 3855785, and I'd have to replace the seal and o ring too.

Looking at it I might try a repair with a little marine-tex (see the pic, the O-ring is poking out below the fill vent screw in the upper right a little).

Erik

 

[captmello]

Re: How hard is this piece to replace? DP290 shift mechanism

I'm normally one to do things right, having tried doing things "good enough" for most of my life. In this case however, I might be prone to trying some 4200 to seal it up. Once its sealed, you shouldn't have to worry about it again for many years. You can start saving for the part now, and in 5 years It'll cost $500!!! lol

I think its your call...

 

[erikgreen]

Re: How hard is this piece to replace? DP290 shift mechanism

I found the part cheaper on an online site than the mechanic could find, so he agreed to price match and he'll order it from there. Saved about $45 or so. He'll do the install, and assuming nothing else is found wrong, the complete reseal of the drive with a couple parts replaced will come to about $1400.

So not cheap, but a lot cheaper than a new drive, and better quality than a Mercruiser.

Erik