Crowd Sourcing Transmission Advice

Greetings everyone, I'm back for my second post. Some of you may remember me asking for help a couple/few months back with my '68 Correct Craft Mustang with a 289 Ford Interceptor engine in it. Well, with all your help, particularly the help of Keno, I got all the correct parts, and, after trying to do the plugs and wires myself, brought it in for a tune-up. We just got it back two weeks ago. Read on for what I need advice on.

So, I already privately messaged Keno, and I'm not doubting his advice, it's just that I don't want him to have to take the time to address every little follow-up question I may have so by posting I can let him reply if he has the time and will :) Thanks for everything Keno!!!

Anyway...

    Two days after getting the boat in the water, the transmission is slipping. My nephew, who's 20 and thinks he knows everything, is blaming me for ruining it because I put the wrong fluid in it saying aslso that the mechanics at the repair shop didn't correctly determine if the level was correct. I used Dexron 3 fluid just like you all advised, and the mechanic said he checked the level after the engine ran in the shop so it was warm. My Nephew was spouting some stuff about having to check it multiple times at different points in the process and in neutral and blah blah blah I have no idea what he was really saying. The mechanic smiled and said that cars and boats aren't the same and he is confident it was good. Before I brought it to the shop, I pumped out the old fluid and put in a quart of brand new Dexron 3. It was so light pink that I had a really difficult time seeing the specific level on dip stick. However, the shop said it was good. I'm going with the fact that the level of fluid in the transmission was probably good. Thoughts?   How much wiggle room does one have in over or under filling transmission fluid? Would any issue with either yield a different problem or the same? I know it had a quart in there which is exactly what I pumped out. I just put in what I pulled out.

Other than old age, is there any reason the transmission would slip after 48 years the very week we get it back from a tune up? My brother said it slipped first while waking boarding, but then my nephew towed three tubes behind it the next day. Regardless, I guess I'm just wondering what experienced folks opinions are on this matter.

I just checked the transmission and it's a 1:1 velvet drive as1-70C. I can't tell if there is fluid in the bilge because it's so light pink and the lake water in there now is a light tan anyway.

None of this really matters, I guess, except I'd love to know if there's a way to narrow down the reason it's bad now so I can tell my nephew to F off or eat crow. Regardless, the path is the same, get it pulled out and repaired. Thankfully, there's a marine transmission company right here in Kalamazoo.

If in doubt add more fluid...

JoeinNY wrote: If in doubt add more fluid...

Hi Dave

Like Joe said above

If you pumped out a quart and put back in a quart you have 2 things that could have been the case.

It holds 2 quarts so if you only had one quart in it to begin with and you pumped it out and put one in then you were a quart low.

If you had 2 quarts in it and pumped out one and put one back in, then it was full.

Sounds like your boat mechanic said it was good.

A quart low probably wouldn't make it slip under normal conditions but 3 tubes aren't normal conditions.

If it was original and never rebuilt, it's time was coming anyways and the load from the tubes made that time come a little earlier.

Maybe your brother should have checked things out at the first slip when wakeboarding and things might still be OK.

Thanks all. You're awesome. And thanks Ken and Gary. You two are awesome specifically.

Thanks for making a noob feel a little more in the know. Looks like I'll plunk down the coin to get 'er going. The strange this is, I thought my dad told me before he died that everything in life always works perfectly all the time and never ever costs you money ...if I heard him right that is. I was a teenager at the time