PCM 80A - Brand New Transmission Leaking

[GBoucher]

Bottom line: Is there any possible reason a transmission fluid leak apparently coming from the bellhousing would be anything other than a bad front main seal on the transmission?

Full details:
At the beginning of the season, I launched my 1997 Ski Nautique and had no transmission engagement (PCM 40A). I checked the fluid level and it was completely dry. It apparently leaked out in storage after my fluid change during winterizing. I pulled the transmission, replaced the front main seal, re-installed, and filled with fluid. Everything seemed great, boat ran fine, but the next morning there was more transmission fluid in the bilge.

I decided to completely replace the transmission and upgrade to the 80A kit, including a new damper plate, transmission cooler, and hoses. Through a series of events (like a seized coupler and propeller to the driveshaft), I also replaced the driveshaft, coupler, cutlass bearings, shaft packing and rudder packing. I also made sure to get an excellent engine alignment to within 0.0015".

I finally got the boat back in the water to test with all the new components; again, everything seems great on the test drive. The next morning, however, there is absolutely no fluid on the dipstick. It's hard to tell where exactly the leak is coming from, but there is fluid on the exterior bottom of the transmission as well as the bellhousing area where it mates to the transmission. I assume that the bellhousing is the source, since it's 'upstream' of the transmission.

Everything I've read suggests that a leak in the bellhousing area means it's the front seal; what are the chances the main seal is bad on a brand new transmission? Is there anything else it could be, before I tear apart my engine bay for a third time? In both the old trans and the new, it appears to be a very slow leak when the boat is trailered, and a much faster one if it has been recently driven. Is it just coincidence that I have almost the exact same symptoms on the old transmission and the new? What am I missing?

I've been so frustrated by this, I'm hoping someone can give me some insight.

I took this picture of the new 80A before installation. Does anything look out of place?

[GBoucher]

I meant to follow up and provide an update on this a couple weeks ago, but I'm just getting to it now.

Fingers crossed that this is just a fill issue with some residual fluid from the prior job.

I'm very relieved, and a bit embarrassed, to confirm that this was indeed the case. The fluid was not at the level it should have been in order to fill the new hoses, etc. I filled to the proper level, ran the detailed tests we talked about for set intervals of time at particular RPMs, and checked fluid level every time.

I was thrown off a bit by the dipstick. It seems there's a pretty small difference in the overall amount of fluid in the transmission whether the dipstick reads high or low on fluid. I think when I ran the boat for the first time with the new installation, the fluid level dropped just a little bit below what the dipstick could measure, which I took to mean that most of the fluid was gone, but that was not actually the case. In other words, it seems like the difference between the low and full marks on the dipstick equates to only a handful of ounces.

Thanks to everyone who helped me with this. I had been working on the original leak issue for so long now that I was prone to believe the worst.

Ended up being the case adapter gasket shown in the pictures below.

I also replaced the case adapter gasket at the same time as the front seal. Now to see if anyone wants to buy a 40A core and try to fix what I couldn't!

[NautiqueJeff]

Here's a theory:

Transmission cooler wasn't drained last year, froze, and cracked internally. Fluid came out. Transmission was replaced, but transmission cooler was reused without being fixed. Problem continued.

Thoughts?

[GBoucher]

I love the spitballing, Jeff, that's what I'm looking for. Unfortunately, no, in this case. Transmission cooler was fully drained - I always disconnect the lower hose rather than just the drain plug, and I used the new bigger cooler from the upgrade kit, so it's brand new too.

[jpwhit]

It's extremely unlikely you'd have nearly the exact same symptoms in the before and after case. It's also very unlikely the new transmission would have a seal with that significant of a leak from new. Are the hoses from the transmission to the cooler new? If not, a hose can have a hole such that the fluid sprays up onto the bottom of the transmission / bell housing.

[GBoucher]

Yes, the hoses and fittings are new too. I used Teflon tape and tightened the connections snug; I can try to see if tightening more will help but I don't want to risk breaking the fittings.

I just found this post on BallOfSpray where a brand new 80a had bad assembly from the factory. Pretty disappointing if that's happening here too.

https://www.ballofspray.com/forums/t...sion-question/

[SilentSeven]

Odd one. Here's a few questions I have.

- Did you follow the initial fill procedure to make sure the new 80A was full?
- If you are leaking that much fluid (my notes are an 80A holds 2 1/2 quarts of fluid) overnight, I would think you could find a quart or more of fluid in the bilge. How much did you find?
- After the test run, did you note if the unit was leaking or did you only discover the next day?
- Have you carefully checked the new fitting locations to make sure they are not the leakage points?
- Why do you think the fluid is draining out overnight? The trans is installed nose up and I can't really see how the front shaft seal would leak that much fluid when the boat is not running.

If it was my boat, here's what I would do to debug the issue. First, I would clean up the bilge and the trans to remove all signs of trans fluid. Then I would refill the unit using the PCM initial fill procedure. Finally, I would do a very structured test run to ID the source of the leak.

I have a bit of experience with transmissions. I had a '97 Ski that had a weeping front transmission shaft seal that passed just enough fluid to make the bilge oily. The front shaft seal is a common oil leakage point as the boats age. At 1500 hours, I pulled my trans and replaced the front seal re-using the cooler and hoses. Repair fixed my oil leak.

[GBoucher]

• I was meticulous in making sure the fluid level was right on the "full" mark of the dipstick. Other than that, I'm unaware of an official fill procedure. If it's more complex than that, can you link me to somewhere I can read about it? My searches aren't coming up with anything specific.
• The boat was stored on the trailer overnight with the drain plug out, so I'm unsure of the amount of fluid. I will keep the plug in the next time I test it so I can check.
• During the test run, I visually checked for leaks but did not reach under the trans/bell housing to check. I only discovered it the next day. I'll also check for this next time.
• Once I realized there was leakage (the morning after the test run), I felt around all the fittings. They were all dry; all the fluid was on the bottom of the trans and bell housing. I may try to snug these up more just in case.
• I did check the fluid level during testing, and it appeared correct, but the next day the fluid was all gone, so that's why I thought it was an overnight leak after everything had been warmed up. I will be sure to check immediately after the next test run.

One additional note that I didn't even think about when writing up the original post is that there was transmission fluid all over the packaging when I first opened up the box the transmission was shipped in. I was surprised they shipped it with fluid to begin with, and I assumed being jostled/packed on its side would have caused the leakage during transit. Not sure if that's relevant information to this case.

You mentioned you would do a very structured test run; what all would that involve? Running the boat for a while and checking each possible leak location at timed intervals?

I appreciate everyone's help!

[SilentSeven]

I was meticulous in making sure the fluid level was right on the "full" mark of the dipstick. Other than that, I'm unaware of an official fill procedure. If it's more complex than that, can you link me to somewhere I can read about it? My searches aren't coming up with anything specific.

OK, I may have gotten ahead of myself as I can't find a documented PCM procedure. Typically, a new tranny is filled with fluid and then gently engaged in forward and then reverse and then the level verified. This is done to ensure that any trapped air is removed from the system prior to determining the fill is complete. Did you do something like this to verify that all the air was out of the system? For my boat, I would have done this check multiple times during the initial run and then verified the level again after an extended run. You have a fair amount of new stuff that needs to filled with fluid - lines, cooler plus any air gaps in the unit itself.

The boat was stored on the trailer overnight with the drain plug out, so I'm unsure of the amount of fluid. I will keep the plug in the next time I test it so I can check.

Hmmm. OK, so there really is no way at this time to tell how much fluid the tranny lost while parked.

During the test run, I visually checked for leaks but did not reach under the trans/bell housing to check. I only discovered it the next day. I'll also check for this next time. Once I realized there was leakage (the morning after the test run), I felt around all the fittings. They were all dry; all the fluid was on the bottom of the trans and bell housing. I may try to snug these up more just in case. I did check the fluid level during testing, and it appeared correct, but the next day the fluid was all gone, so that's why I thought it was an overnight leak after everything had been warmed up. I will be sure to check immediately after the next test run.

So, when you re-installed the new transmission, would you say you had cleaned up the leaking oil from the prior trans? Here's my half baked alternate hypothesis - the new tranny was never completely filled and the oil you're finding at the bottom of the bellhousing is left over oil from the old unit.

This is where I'm going with a very deliberate test. First, clean everything really well. Like take it to the self service car wash and hot pressure wash clean the engine, tranny and bilge. Make it easy to really see what's leaking now and where it's leaking from. Then be super deliberate on your fill to make 100% sure all the trapped air is out. Finally, then do some water tests and see if indeed you are still leaking fluid and from where. I'd run the boat at different speeds for like 5 minutes at a time and verify fluid level and inspect for leaks after each run. Idle out of gear, in gear idle, 2k RPM, 3K RPM or something like that.

One additional note that I didn't even think about when writing up the original post is that there was transmission fluid all over the packaging when I first opened up the box the transmission was shipped in. I was surprised they shipped it with fluid to begin with, and I assumed being jostled/packed on its side would have caused the leakage during transit. Not sure if that's relevant information to this case.

Factory new engines and I would assume new transmissions are normally shipped without fluid. If the unit was tipped over, it may have leaked a little assembly oil but there shouldn't be that much. There is usually a great big warning tag that says to add required fluids before running. Did you see that tag? Was this a 'factory new' 80A or a 'new to you used' 80A?

Sorry for the raft of questions but asjpwhit says above....two identical failures defy the odds.

[GBoucher]

Did you do something like this to verify that all the air was out of the system?

No, I did not. That makes sense, I will be sure to do this in the future. Do the hose lines stay full of fluid when not in operation, or does it drain back to the pan?

OK, so there really is no way at this time to tell how much fluid the tranny lost while parked.

True, I will report back when I have a better idea. All I know is that the dipstick was completely dry. I didn't have any more fluid on hand to see how much more would be needed to fill it up.

So, when you re-installed the new transmission, would you say you had cleaned up the leaking oil from the prior trans?

I cleaned up the bilge but it wasn't spotless. The bell housing, however, was spotless because I removed it in order to install the new damper plate and thoroughly scrubbed it clean. So the fluid on the bell housing is not left over, but I don't necessarily know whether it's coming from inside the housing (the main seal) or outside (spraying or leaking from somewhere else).

Thanks for the guidance on the testing procedure, I'll be a lot more methodical now.

Did you see that tag? Was this a 'factory new' 80A or a 'new to you used' 80A?

I don't believe there was a tag like that. I was certainly led to believe this was a brand new transmission, I bought it directly from NautiqueParts.

No need to apologize for the amount of questions, I'm happy to provide as much info as possible to arrive at a fix. I'm grateful for everyone taking an interest.

[SilentSeven]

Good luck. Fingers crossed that this is just a fill issue with some residual fluid from the prior job. But the above approach should tell you for sure.

If you got the unit from NautiqueParts, I'm sure it's a quality new unit. You might want to call them and ask them if the units ship full or empty and if they have a recommended first fill procedure. Regardless of their answer, I'd still be super deliberate to ensure all air is out and the fluid level is stable before running your tests.

Loved my '97 ski. Such a pure tow boat with a butter wake.

[gary s]

Late to the party and not related to the 80A but 6 days before I'm supposed to drive 600 miles to meet up with friends at Norris Lake my 40A threw up into my bilge. Ended up being the case adapter gasket shown in the pictures below. Big job in a V drive but had it done in 3 days with the successful water test the 4 day and able to keep the Norris date. Absolutely no damage to the gasket I suspect the gasket shrank or relaxed and then the bolts lost tension and then leaked.

[GBoucher]

I meant to follow up and provide an update on this a couple weeks ago, but I'm just getting to it now.

Fingers crossed that this is just a fill issue with some residual fluid from the prior job.

I'm very relieved, and a bit embarrassed, to confirm that this was indeed the case. The fluid was not at the level it should have been in order to fill the new hoses, etc. I filled to the proper level, ran the detailed tests we talked about for set intervals of time at particular RPMs, and checked fluid level every time.

I was thrown off a bit by the dipstick. It seems there's a pretty small difference in the overall amount of fluid in the transmission whether the dipstick reads high or low on fluid. I think when I ran the boat for the first time with the new installation, the fluid level dropped just a little bit below what the dipstick could measure, which I took to mean that most of the fluid was gone, but that was not actually the case. In other words, it seems like the difference between the low and full marks on the dipstick equates to only a handful of ounces.

Thanks to everyone who helped me with this. I had been working on the original leak issue for so long now that I was prone to believe the worst.

Ended up being the case adapter gasket shown in the pictures below.

I also replaced the case adapter gasket at the same time as the front seal. Now to see if anyone wants to buy a 40A core and try to fix what I couldn't!