Help Checking Transmission Fluid Level

[noclams]

My manual suggests that my transmission fluid level will be higher when the engine is cold - doesn't the fluid expand when it's hot?

Also, I'm confused about the proper procedure for checking the level of my PCM transmission on my '94 Sport Nautique. The manual shows the dipstick resting on the 1st o-ring when checking cold. It doesn't, however, say if the dipstick should be fully inserted when the engine's hot.

Finally, my manual says hot measurements should be taken immediately after stopping the engine but several of the posts say the engine should be running. Won't the level be different with the engine off vs. engine on?

Thanks!

[Hollywood]

RE: Help Checking Transmission Fluid Level

If you're not going to follow the manual throw it away. Check it hot, engine off, 1st O-ring.

[noclams]

RE: Help Checking Transmission Fluid Level

Actually, the manual has been useless. It said to use 20 20W oil but PCM later told me that I should use Dexron III. The manual says that the dipstick is milled with "a flat side on the dipstick which extends 3/4" above the full mark on the 1.23:1 transmission." My dipstick does not have a flat side. Finally, it shows specific directions for checking the PCM cold but says to follow the "Warner" transmission checking procedure when hot. They show that the Warner dipstick is totally different from PCM's. They say it should be "merely inserted into the case until cap or plug resets on the surface surrounding oil filler hole."

You say "check it hot, engine off, 1st O-ring" but the manual says that is the directions for checking it cold (and that I should use the same "full mark." Can you now understand my confusion?

[DavidF]

RE: Help Checking Transmission Fluid Level

My understanding:

Cold = resting on o-ring (quick approximation of proper level, not fully accurate)
Hot = fully insert dipstick and check immediately after shutting off engine (for accurate fluid levels)

Personally, either way is fine and I doubt you will have tranny trouble using either method exclusively.

The reason for the level being lower when hot and immediately after shutting off engine is that the oil will occupy all the hoses and passages of the transmission before it has a chance to drain down into the sump which makes the cold level higher. You need to ensure the minimum amount of oil in the sump while in operation.

[MNSuperAir]

Re: RE: Help Checking Transmission Fluid Level

My understanding:

Cold = resting on o-ring (quick approximation of proper level, not fully accurate)
Hot = fully insert dipstick and check immediately after shutting off engine (for accurate fluid levels)

Personally, either way is fine and I doubt you will have tranny trouble using either method exclusively.

The reason for the level being lower when hot and immediately after shutting off engine is that the oil will occupy all the hoses and passages of the transmission before it has a chance to drain down into the sump which makes the cold level higher. You need to ensure the minimum amount of oil in the sump while in operation.

This is my method^^

[noclams]

RE: Re: RE: Help Checking Transmission Fluid Level

Thanks! In fact, I just got this confirmed through PCM's warranty department. It's nice to own a product with great customer service! I'm sure any mechanic worth his salt would understand the manual fine. For me, however, I thought the this section of the Nautique manual could have been written a little better.

Thanks for everyones help. Now I can get my boat out of the driveway and into the water!

[M3Fan]

RE: Re: RE: Help Checking Transmission Fluid Level

...and the newer PCM trannies have no o-ring at all on the dipstick. My dipstick plug is solid rubber.

[AirTool]

RE: Re: RE: Help Checking Transmission Fluid Level

I'm 99% sure the level should be checked with the engine RUNNING ....not off.

Also be sure to put the trans in forward and reverse at least once after starting.

I've got a good post somewhere on tranny fluid...don't have time to search now.

[WakeSlayer]

RE: Re: RE: Help Checking Transmission Fluid Level

^^ ??? ^^

I thought this was cars only. I have never checked mine running.

[AirTool]

RE: Re: RE: Help Checking Transmission Fluid Level

Snapshot from the 06 manual.