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Discussion Starter #1
I could take the input and output shafts on my bike, dump all the gears, spacers, snaprings, and bearings into a box and reassemble them in less than 2 hours. However, I really have no idea how automotive automatic transmissions work. I bought a 84 Chevy Nova from some girl for $300 bucks. It didnt run when I bought it, but I fixed it up to the point where it runs fine. However, I figured it would be a good idea to change the trans fluid and filter in it. I took it to a Cottman Transmission joint because I had a coupon for a $15 fluid change. They of course told me that I needed a "transmission refurbish" which would cost over $600. They told me that it would be a bad idea to even change the fluid in it because the detergents in the Dexron Mercon 3 fluid would accelerate wear to the friction plates in the transmission. In fact they said that they are borderline about changing just the fluid because they dont want to be responsible for my transmission unless they can rebuild it at the same time. Are they serious about this? I dont understand how they could say that new, fresh, fluid would accelerate wear on my transmission, especially when the service manual for the car says it should be done every 30k miles. :mad:
 

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First of all, detergent in this case means:

"important component of engine oils that helps control varnish, ring zone deposits, and rust by keeping insoluble particles in colloidal suspension and in some cases, by neutralizing acids. A detergent is usually a metallic (commonly barium, calcium, or magnesium) compound, such as sulfonate, phosphonate, thiophosphonate, phenate, or salicylate. Because of its metallic composition, a detergent leaves a slight ash when the oil is burned."

So, the detergents actually help to lift and suspend foreign substances inside the tranny. The fluid needs to be changed ever 30k or so to drain out the collected particles. I cant really see the detergents causing much wear to the friction plates, with the exception of cleaning deposits and such from the surfaces.

Unless the tranny isn't shifting properly and/or is almost completely shot, it sounds like you need a fluid and filter change. Im working in an auto parts store now, so when I go to work Monday, I'll ask one of the tranny guys what he thinks.

Local shops near here are notorious for ripping people new ones. These guys may be being honest with you, but everyone seems to be out for the almighty dollar these days :rollseyes
 

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bElla.tErra said:
First of all, detergent in this case means:

"important component of engine oils that helps control varnish, ring zone deposits, and rust by keeping insoluble particles in colloidal suspension and in some cases, by neutralizing acids. A detergent is usually a metallic (commonly barium, calcium, or magnesium) compound, such as sulfonate, phosphonate, thiophosphonate, phenate, or salicylate. Because of its metallic composition, a detergent leaves a slight ash when the oil is burned."

So, the detergents actually help to lift and suspend foreign substances inside the tranny. The fluid needs to be changed ever 30k or so to drain out the collected particles. I cant really see the detergents causing much wear to the friction plates, with the exception of cleaning deposits and such from the surfaces.
And what happens when these collected particles get flushed out of every nook and cranny start floating around the valve-body and get stuck in the shift valves, govenor, and TV valve?

Don't change the fluid unless you are ready to rebuild it. Once its gone more than ~60K miles on the same fluid its a ticking time bomb.

If its an old school RWD Nova it should have either a TH200, TH200C, TH350, or TH350C.If its a POS FWD (Citation II) it will have a TH125C or a TH440-T4) Go to your local auto parts store and look at any books they have reguarding these transmissions. You should be able to identify the transmission by the shape of the oil pan and the number of wires coming out of the connector on the driver's side (near the shift linkage).

If you can rebuild a standard transmission within 2 hours then you shouldn't have any problems rebuilding a Chevy automatic with a few books.

(I worked for AAMCO for 5 years, it really stands for "All Automatics Must Come Out") :)
 

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tranny problem

I have been working at jiffy lube for over three years and have seen all kinds of transmission colors and problems. If your trans fluid is brown or other such color, I would sugget a fluid flush and pan drop. I flush out many a car with over 100,000 miles on the trans and the customer has never flushed it out befor and I personally have not seen one come back with problems. It is cheaper by far than rebuilting a transmission. Also it another opinion on it.
 

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Discussion Starter #5
It is indeed a POS FWD Nova/Corolla 1.6 liter single barrel carb. The thing is a real turd but it does get me around and gets decent gas mileage at the same time. The transmission does slip on occasion but I am not ready to drop a few hundred bucks into the bastard. I would be far more willing to learn how to rebuild the thing by myself, or spend 300 bucks and get a junk yard tranny. I appreciate the replys.
 
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