waterbum

How often should trans fluids be changed? Based on hours of use, elapsed time, hard running, etc? I've got about 35 hours on mine in 12 months of usage. Mostly cruising / idleing.

Thanks,
Doug

p4-33

I change mine as part of seasonal maintenance... in the spring, I change my drive oil, grease drive splines, u-joints, change tranny fluid. Give yours the old sniff test. If it smells ok, looks bright red, then do it in the fall or spring.

There's no mistaking burnt tranny fluid; brown and smells nasty.

Brian

gripit

havoline

The Menace

Just changing over to the 1450's Kryptonite package. Will take Tom 's reccommendation.

Coolerman

Use Valvoline Type FA.

Monty

Mobil1 ATF changed every 20 hours. It's always looked cherry red, but I change it along witht he motor oil and drive lube just to keep it all synchronized and avoid confusion.

Lmarth

I wouldn't expect anyone to do what I do, but my change interval averages no more than 10 hours. Regardless of who made them, those transmissions are the weak links between big power and big drives eg. SSM's. How you run the boat makes a difference. If you're in/out of the water with big power, you're going to get a little slippage. Mine only hold a couple of quarts. For the transmissions, I use one of the drill mounted pumps. I run the small hose down the dipstick tube and the output hose to a one gallon clear plastic jug with a nipple on top. I save the two jugs and check a few days later to see what , if any crap settles out on the bottom. I fill with an identical bottle where I match up exactly what I sucked out which will vary. Checking the level after this is almost a waste of time. It literally takes minutes and a couple of bucks to do all this. Overkill? Undoubtedly. But once you smell one of those trannies when you fried it, it doesn't sound so ridiculous. I had a wounded one once, and Tom said to keep changing the fluid and do anything (flush cooler,etc) to get any particles that come off the friction plates out of the system. As I said, I wouldn't expect anyone to go to these lengths. Just telling ya what I do for what it's worth.

p4-33

That's pretty thorough, Lmarth... I like it. Good point about the cost. What's 4 qts of type F cost? 8 bucks, maybe?

I also like the idea of letting it set in a clear jug to see what settles out.

Good stuff,
Brian

Lmarth

Brian-Thanks for the feedback. Been doing this on my boat for almost five years. What you'll see after a day or two is a little black sludge on the bottom of the container. My opinion is that this is friction material that has come off the plates. Nothing to concern yourself with (in moderation), but wise to keep it out of the mechanicals. I use clean one gallon jugs that held some Kitty Litter product. You can see the residue by just holding them up and looking from the underside. Don't have to tell ya that you need four hands back there to keep fluid from splattering over anything white. I drill a hole in the bottle lid and press a barb fitting through to attach the hose to (no clamp). Having that extra 'fill' bottle allows you to refill with exactly the amount you took out which avoids a lot of screwing around later trying to get the level right. Under the best of conditions, you'll see a little sludge. As things degrade, you'll see a slight color diference between the bottles just by looking through the clear plastic. Quickly remove the lids and you can actually smell a little burnt odor, even with cherry colored fluid in one container and not on the other. For the drives. I put the fluid in a 5 gal container (from sno melt) and use my clean reversible oil changer pump/motor. The Merc catsup pump has an adaptor/hose that screws into the lower unit. I steal that and adapt it to the fittings on the reversible pump. I attach everything and sit back. I can load 8 quarts in my SSM's in 15-20 minutes while slowly turning the prop shaft to purge air. I posted this once and someone thought I might possibly damage the seals. Kinda hard to do considering the vent plug's out! It's amazing how creative you can be when you have to keep doing all this stuff yourself on hot days, in the rain,etc. Enough...Lou

p4-33

I've heard people talking about these reversible pumps that attach to a drill motor... is this a marine tool? Automotive? Where can I find one?

I've gotten spoiled with drive maintenance on my Konrads. To empty, I remove the top cap, and drain into a bucket thru the bottom drain plug. To refill, I just dump new stuff back in thru the top, and rotate the propshaft occasionally to get the air bubbles off the gears. Then I just let them sit for a half hour or so, and top off. Konrads have oil passages that you can drive a truch thru, so there's no chance of air entrapment in the drive. I wouldn't suggest this method with other manufacturers of drives, tho.

Sorry to get off-topic. I just installed new Hubers over the winter, and I'd like to have them last a while. Changing fluids in the boat isn't fun, but you've given me some good ideas. I appreciate the input.

Thanks,
Brian