Suzuki DF70 Driveshaft Housing Service

[zelazknee]

A few months ago while preparing myself for a fishing trip I decided to check my lower unit and found out that I had a leak in my lower unit. After the gearcase oil was drained I pressure checked the gearcase with a small bike pump and it would start to leak at 9 psi from the driveshaft housing.

I removed the driveshaft housing and replaced the seals and o ring with factory parts. When reinstalling I did the following to help with the installation.

• cleaned housing and looked for defects
• Gasket sealer on the outside rims of the seal
• marine grease on the inside lips
• covered the splines with a ziploc bag to attempt to protect the seals from damage.
• Both seals are installed with the lips facing the same direction. Lips facing upwards towards the water pump

All of this seemed to work out for me and I was holding pressure at 14 psi. After a short outing in the boat (20 minutes) I came back home and unfortunately the leak returned at the driveshaft seal. Didn't think that was going to be a tough one to fix and now looking for guidance. Driveshaft itself looks okay to me, not feeling any nicks or gouges that would tear the seals.

[Murray]

How did you ascertain the driveshaft seals where leaking the second time? I went through a similar situation with an old mid 70’s Mercury and it wasn’t until I dunked the lower unit into a bucket of water(under air pressure) did I realize my water ingress from from the vent screw.

[zelazknee]

Hey Murray, I emptied the gearcase oil and reran my pressure check. I could hear the air escaping from the lower unit and when disassembled a bottle of soap and water was giving me bubbles where the driveshaft meets the housing

[Murray]

I checked my service manual(2009-2012 DF70A-DF90A) and it appears you got the seals in correctly. Don’t know what else your issue could be.
3C6B1813-D9C0-4E15-8765-3F2BEC9AEE1B.png

[Murray]

Sorry about the blurry picture. Can’t seem to figure out how to get a clear screenshot uploaded to this forum. Can email it to you if you want

[zelazknee]

Appreciate it and here is some info from the Seloc Service Manual for this outboard. Helpful tip for your Screenshots: They will be a bit clearer if you save them to your desktop as a JPEG instead of PNG. To do this on a windows PC open the screenshot with microsoft paint, and when you choose "save as" change the "save as type" from PNG to JPEG.

Driveshaft Housing.jpgPressure.jpg

I'll trade you PC knowledge for outboard knowledge anytime.

Thanks,
Matt

[Murray]

E57F4A25-DA13-4C8F-90B3-0CBCF11284E5.jpeg
Thanks. I’m using an IPad but I got the idea.

[Murray]

You don’t mention the year of your engine, if it’s old enough you might be able to pick up a genuine Suzuki Service Manual for $13USD in pdf. Check out s e l f f i x e r d o t c o m (all one word) I’ve purchased a couple of manuals from them and no funky Visa charges. I’ve heard numerous complaints out missing data, wrong information or information just not there with aftermarket manuals. Just a thought.

[slayray]

Did you have water in your oil when you drained it? Or did you just want to check the seal

[zelazknee]

I think I figured out what the problem could have been since I got the boat out yesterday.

Either I was applying just a tad too much pressure to the seals when I was pressure testing. (bike pump is really not that accurate) or I did notice a very sharp edge where the impeller key sits.

I filed that down and installed a new set of seals and after a 6 mile route yesterday am not seeing any water in the lower unit.