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Discussion Starter #1
Thanks to anyone who can help.
I have a 1967 GTO with a 455 & a GM TH-400 Transmission.
Whene ever I start the car after it's been sitting overnight, I will hear a loud whine coming from the transmission for about 5-10 seconds. After that, it sounds OK.
I did't start hearing the noise until I recently replaced the fluid and filter.
Any ideas why it is doing this?
Is this really a problem I should be concerned about?
Could a fluid over fill cause this problem?
:crazy:
 

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If the trans is substantially overfilled the fluid will be churned-up by the gear sets causing the fluid to foam. Air in a hydraulic pump can make a noise.

Easiest way to lower the fluid level is to take loose a cooler line and run/pump it out.

expect to make a mess.

I would use Dextron II or Dex-Mercon
 

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Easiest way to remove fluid is to get a hand pump from Harbor Freight and stick the hose down the filler tube and the other end into a bucket -no mess. I do this with my Toyota rather than drop the pan.:thumbsup:
 

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How do you purge air from the pump?
You did use the correct trans fluid designed for your car? There are different makers and many types that it can become confusing.

Here's what I do anytime I change the fluid and filter. After you fill it up, start up the car, and then cycle the trans from drive to reverse a few time. Let it run to warm up, then once up to temperature, cycle the trans again, then while running & warmed-up, check the fluid level on the dip stick. It may be hard to read the level with fresh fluid in it, but you should then get a level reading. Take the car out on the road and use it, do a few good downshifts using the gas pedal to drop it down. Get the fluid flowing. Then check your fluid level again once home -car running. Then let it sit as you have been and see if you have problems.


Whining in my experience is due to a low level of fluid. Also check your power steering fluid level (if you have it) to make sure that level is full as well. A steering pump will also whine if low and can go away once it warms up. Make sure you are not hearing the steering pump and not the trans.

BUT, you may have a more serious problem. This blog on-line explains it better than I can, but have had this experience personally. "Several transmission techs on-line told me that new ATF fluid is high in detergent and new fluid may have changed the viscosity of my trans fluid as well as stripped the varnish layer on my internal parts which has caused it to start slipping. Lack of regular service allows all the "crap" to build up in the planetaries and clutch packs, and it actually does hold the transmission together, to a certain extent. Unfortunately, it also wears the plates in the clutch packs smooth.

Frequently the worst thing you can do is freshen the fluid on a tranny that old, especially if it has never been serviced, because you flush out all particles that allowed the clutch packs to mesh, and have friction. At that point, you have clean viable fluid, but nothing to mesh the clutch packs, and it slips because they are worn smooth. All they really are is a stack of metal plates."

A friend had a Ford Taurus that had trans problems which had not been serviced at all. The trans began to act up. We took it to an AAmco shop looking to have the filter/fluids changed. They were highly against it because after they test drove it, said if they do the work, the new fluid may wipe away what little friction material was still making the trans work and the car may not leave the shop under its own power as the trans will simply be slipping. They suggested just keep running it and put some additives in it until it eventually quit and needed a transmission rebuild or just schedule a rebuild before it quit. But, they did not want to touch it as they already knew what could happen -and I suspect it must be difficult explaining to a customer that their car that came in there won't move and technically it wasn't anything the did as the trans was shot.
 

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Discussion Starter #6
UPDATE... I used a hand pump and removed a little over a quart. The whine sound has practically disappeared! At the moment, according to the dip stick, I need to add back 1 pint. I checked the level with the engine at normal temp, engine running at idle in both park and neutral. I plan to add back one pint in the hopes that my transmission is just being fussy and demanding that the fluid level be at the exact perfect level. At the moment, I need to make a trip to the parts store for more fluid. I'm using valvoline dex/merc. Does anyone know if this is the right fluid type?
 

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UPDATE... I used a hand pump and removed a little over a quart. The whine sound has practically disappeared! At the moment, according to the dip stick, I need to add back 1 pint. I checked the level with the engine at normal temp, engine running at idle in both park and neutral. I plan to add back one pint in the hopes that my transmission is just being fussy and demanding that the fluid level be at the exact perfect level. At the moment, I need to make a trip to the parts store for more fluid. I'm using valvoline dex/merc. Does anyone know if this is the right fluid type?

Thanks for the update. Ask your parts store which fluid to use. There are several different types on the market because the manufacturers seem to keep changing their fluid requirements -use the wrong one and you will damage your transmission.
 

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The Dex/Merc is fine. I use the Valvoline stuff, too. I usually agree with Jim, but in the case of asking the parts store what to use, I have to say, DON'T DO IT. Parts store employees in the past 10-15 years are highly unqualified to offer automotive advice, from my experience. At least in my neck of the woods. The clerks don't even know what a valley pan is. Forget it. I have found in the past that many TH400's seem to have dipsicks that require too much fluid. I determined the actual level on mine (which is flush with the botom of the modulator hole) and marking the stick accordingly. You do not want to overfill these units.
 

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I usually agree with Jim, but in the case of asking the parts store what to use, I have to say, DON'T DO IT. Parts store employees in the past 10-15 years are highly unqualified to offer automotive advice, from my experience. At least in my neck of the woods. The clerks don't even know what a valley pan is. Forget it.
This is so sad but true. I recently went in to buy a gallon of Berryman dip to use on a carb rebuild. The clerk asked what I needed it for. When I said "to clean out a Quadrajet", he'd never heard of one.

What happened to the young guys who wrenched on their own cars taking these jobs so they could get discounts on the parts they need?
 
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