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Discussion Starter #1
Hey guys,

since i have my Saratoga, you can hear a whine or buzz noise, only in reverse, maybe coming from the torque converter. But only if the transmission hasn´t reached full operating temperature. It sounds like a bad power steering pump and is only noticable if you accelerate a bit, just touching the accelerator is enough to start the noise.

Of course, fluid and fluid level is OK, only used Mopar ATF+4 the whole life of the car. I also let the car run for at least 30 seconds (in warm condition), to let the TC run full of oil, pointless, i know.

But until the trans hasn´t been driven for arround 20 minutes, the buzz noise will appear every time.

A new TCU is on it´s way (as you already know ;) ), but i can´t imagine why the noise just appears in Reverse.
 

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Dees the buzz vary with speed, or is it a constant buzzing regardless of how fast the car is moving? You could just be hearing gear noise.
 

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After it buzzes for about 10 minutes, pull the dipstick and look for foam or air bubbles in the ATF on the dipstick. If the front pump sucks air with the fluid, it will aeralate and make the buzz noise going through the front pump.
This can occur with a missing or not sealing o-ring between the filter and valve body, loose valve body bolts or some other internal leakage.
Higher pressures are required in reverse compared to other gear ranges.
Warmer fluid will rise in level and be easier to pull through the filter to the suction side of the pump, maybe reducing the mixing with air.
 

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Discussion Starter #4
The buzz just appears for a few seconds, going away after a few ones.....it appears even in almost still-standing condition.

There was a topic about a year ago, i think by Oklahomawolf, not 100 sure, cause of the valve body bolt torque specifications, i checked them on my last oil change (about 25 000 KM ago), everything fine.
Also filter and O ring was replaced, everything´s sitting fine.

So the problem appeared when i buyed the car (2009), then i flushed the trans, replaced all cooler hoses and also the radiator.

Now where you said it.....there´s only a chance for an internal leak and / or air sucking into the flow, i just have some bubbles on the dipstick in warm condition, but not really foamy, just a few ones. I´ll check that tomorrow after the noise appears and try to get a video where you can hear the buzz
 

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Yeah, unfortunately that transmission is no longer in the Imperial, just to give you an idea how things turned out with it. It still works for the most part, but the torque converter isn't much good any more after I overfilled the tranny by accident. About the only thing I ever did that actually helped any was rebuilding the solenoid pack.

I don't remember it buzzing in reverse like that... not even when it started having trouble engaging reverse. Then again, the Imperial has extra soundproofing compared to most other cars I've had, and uses the 3.8 instead of the 3.0. Interesting thing is, my 1991 rebuilt transmission makes more gear noise than the old one did, even though it's in flawless working order. I believe there were changes to the gearing in 1992 to quiet them down some, and then more changes in 1993 or so.
 

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Discussion Starter #6
Hmm....interesting...

One thing i forgot...my trans runs with Code 38 saved, TCC is shot i believe, one last harsh, or lets say out from Heck, rumble of the TCC engaging, then Code 38 saved. Flushed it, checked for any mechanical trouble outside, temp. sensor replaced, thermostat replaced, cleaned out every connector to the trans, no chance. So you all can imagine how curious i´m ´bout using my new TCU....

Cause you said gear noise.....i can´t even hear the Saratoga´s transmission, just a loud solenoid block cause of a missing sound shield (i believe they replaced it years ago).
But the Voyager is almost loud......OK, shorter gear ratio, but pretty noise gear sound, but not damaged.
 

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That's definitely not gear noise...
Does the buzz change with RPM? I would think that if the pump is sucking air, you would be able to change the frequency of the noise by changing the speed of the pump.
 

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It doesn't sound like front pump either. The pump is more of a 'whine' that changes with engine speed (like a power steering pump).
I thought that I heard the engine rev and that there was no change in the pitch of the buzz. It certainly sounds hydraulic and may be a shuttle valve oscillating against its spring inside the valve body.
Is the noise the only symptom and it shifts/drives OK otherwise? Does the condition of the rest of the 20 year old car warrant putting a replacement valve body in? If you replace the torque converter, you may want to replace the front pump at the same time as well.
See page 66 in the following link under the Service Information note. A 3rd design valve body (part # 4659044 or later) addressed the buzz in the 1992 A-604.

http://oskin.ru/pub/chrysler-dodge/manuals/ATSG_Transmission_Repair/ATSG_A604_Part4.pdf
 

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Discussion Starter #10
Yep, noise doesn´t change with rpm´s.....

Shifting quality is not the best any more, lets say it´s OK, like i said, i´m curious if the new TCM changes anything.
1 - 2 is OK, 2-3 also, 3-4 is a bit harsh, or lets say delayed, 3000 rpm + on the freeway, a 3 - 4 upshift is pretty hard.

The car itself is in great condition, 100 % rust free, paint looks great, i replaced all bushings on the chassis, all joints and the rear wheel bearings. OK, normal service things.
Now the Mitsubishi comes thru, so there are some NOS Valve stem seals, head gasket / bolts, cam / crank seals wating to be used. Next spring i guess.


And the Link.....now everything makes sense....at arround 70 Km/h, where the TCC normally engages, Code 38 saved, like i said, you can hear one solenoid working....but it´s not able to engage the TCC any more....so if that solenoid is burned out or worn, could it be the bad boy in my valve body causing Code 38? I´ve never heard from that change in 1992, thank you very much!
 
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