I'm getting ready for a long trip in the coming months, and I want Stinky tip-top. I'm working on shakes, rattles, and rolls in another thread - which means my ears are perked up like a mouse listening for a snake slither. I heard something in the transmission that I never noticed before, and it just might be perfectly normal - I am a total transmission newb.

When we put the transmission in gear, are we supposed to hear the torque converter? It sounds like a wet hiss, a garbled scrape (it doesn't pulse), or something I find difficult to describe. It's not loud mind you, it's barely perceptible from the cab... but I caught it. I'm thinking of exploring this the next time I get a chance, but I figured it was a good question to ask here first.

 

I've never been able to hear the torque converter. How do you know it's the torque converter making the sound?

 

Maybe what stinki needs a nee heater core. I have heard those do a swashing sound before, something to consider.

 

I put the truck in gear with my foot on the brake and I heard the noise. Once I discovered this, I tinkered with Park, Reverse, Neutral, and Drive. I also tinkered with the brakes without putting the truck in gear. The power steering pump is not making the noise - I hear it directly under the truck only when I put it in gear. I know too little about transmissions... is there a pump in there, or is the TC the pumping action?

Now I want to take a video if it - but I doubt the engine noise in the microphone will let anybody else hear it. I have a plan to catch the sound, but I need my wife to help (for safety).

 

There is a pump right behind the torque converter.

 

Should I be able to hear that in the cab? Again - it's very subtle. It sounds similar to a power steering pump when it's straining. I just reached the time where I'm due for the 30K mile transmission service.

 

What do your trans temps look like? When my tc went south it sounded like marbles in a metal coffee can lol

 

If you're having a transmission noise you can hear over a diesel engine it's probably not a good thing. My former bosses dad had an 04 5.4 F250 and you could hear the torque converter locking up because it was so quiet. If you can hear the transmission on diesel you have a problem.

 

Some would say my biggest problem is too sensitive of hearing, or too much attention to minutia.

 

Assuming you have checked the fluid levels, the only time I have ever heard a trans is when the front seal went and it was spraying fluid all over the TC.

Keep putting fluid in it, drove it for another 1500 miles adding 3-5 qts a day before putting a new trans in it.

 

Rich I am sure you do have a keen sense of hearing and that you know all of Stinkie's sounds. I doubt anything is wrong since you have no temp or shifting issues. And the only thing I could think of as far as hearing something in the trans/TC would be the front lube/ coverter drainback valve. The only time I have ever heard of them going bad is after running HOT. But if I recall correctly when this valve fails it allows the TC to drain back to the pan. I would think you could check this by checking the dip stick before cold start up and then check ATF level is correct running. Lastly turn the truck off and check ATF dip stick and see if it is the same as before cold start up. That is the only reason I would think it to be possible to hear trans fuild and TC.
Personally if you have no heat or shifting issues I won't worry about it.

Now I am not sure what drain back valve they used in the HD4R100? But here is a photo from my trans build of a stock drainback valve which is plastic and a Sonnax valve that is aluminum.

Here is a link to Sonnax and a better photo of part
Front Lube/Drainback Valve Kit - 36425-01K - Sonnax

 

I have never seen my transmission go over 195, but I don't monitor that much when empty.

As for shifts - under the right conditions, I can get a big delay in the 3-4 shift, but that may be nothing more than a tune tweak for an obscure scenario.

When I first fire up, it takes about 5 seconds before I can roll. I've done the ol' fire and shift in the morning, and Stinky's all "Yeah, yeah, yeah. Don't even give a guy a chance to wipe the sleep from his eyes."

 

That sounds like the pump is compromised. But Mark will chime in.

 

Yeah... the more I research, the more it points to the transmission as a suspect. At this point, I should share a symptom I have been chasing in another thread.

The truck "pulses" with the torque converter locked, and I feel it's in lock-step with the RPMs - not the driveline speed. I have confirmed there is no torque converter slip with the TC locked. I am at the 60,000 mile mark on the transmission maintenance schedule (30,000 since last shop maintenance). The pulsing feels like a partial injector miss when the torque converter is locked, but I can find nothing wrong with the engine or the injectors.

If I shift into neutral while rolling down the highway, the ride is smooth at idle, but rev it up and I get the tiniest of pulses with the RPMs. I can't duplicate this in the driveway - only when rolling down the road.

The pulse may be a separate issue - or not. I just figured that since the crank and the transmission are mechanically connected, I should provide that possible troubleshooting clue.

 

He'll likely ask if you can measure the pressure the pump is making. I'm just spitballing here, I have really no experience other than changing filter/fluid in these things.