I ave heard numerous people tell me that when you replace tranny filter, you should use most of the old tranny fluid. People say that when you replace the old fluid, the new fluid is not as thick and since there is wear and tear on all of the 30 or so clutches within the auto tranny, that you need to keep some of that "Dirty" fluid to help keep the newer tranny fluid "Thick" for the worn out tranny parts. Any validity to this madness?

i just read about this about 3 hours ago as ive been debating changing mine


you can find some interesting threads if you use the search feature
(theres 2-3 of them)

Is that for auto or shift tranny?

nemo

I ave heard numerous people tell me that when you replace tranny filter, you should use most of the old tranny fluid. People say that when you replace the old fluid, the new fluid is not as thick and since there is wear and tear on all of the 30 or so clutches within the auto tranny, that you need to keep some of that "Dirty" fluid to help keep the newer tranny fluid "Thick" for the worn out tranny parts. Any validity to this madness?

I strongly disagree with the notion that you should leave old, burned-up fluid in your transmission. That's like saying you should only replace half of your engine oil. Contaminates and broken down fluids need to be ousted. I would go on to state that you should be sure that you drain and replace the fluid in the torque converter too.

If your tranny is worn to the point that fresh, quality fluids make it operate poorly, do you want to trust it to get you out of the forest?

Do the right thing. Change the fluids properly. If it needs fixed - fix it. You be glad you did.

There's no such thing as a mechanic in a bottle.

Clean new fluided is always better.  It has detergents as well as lubricating principles in the trans fluided.

If you just replace the filter and the fluid in the pan you are only replacing about a 1/4 to a 1/3 of the the fluided in the hole trans.  To really replace the fluid you need to go to someplace that has some kind of fluid exchanger.  They will hook up to the trany coolier lines and as the fluid flows out of the trans it is replaced with new fluid.  They do this until the fluid coming out of the trans is the right color.

I have been told that if you have 100k or more on a trans and have never changed the fluid that it "might" not be a good idea to do so.  The new fluid will "clean" out the transmission to much and cause problems.

I've done it and have never had a problem.

Quote from: OHIO_ZUKI on September 13, 2008, 10:37:26 PM

I ave heard numerous people tell me that when you replace tranny filter, you should use most of the old tranny fluid. People say that when you replace the old fluid, the new fluid is not as thick and since there is wear and tear on all of the 30 or so clutches within the auto tranny, that you need to keep some of that "Dirty" fluid to help keep the newer tranny fluid "Thick" for the worn out tranny parts. Any validity to this madness?

I strongly disagree with the notion that you should leave old, burned-up fluid in your transmission. That's like saying you should only replace half of your engine oil. Contaminates and broken down fluids need to be ousted. I would go on to state that you should be sure that you drain and replace the fluid in the torque converter too.

If your tranny is worn to the point that fresh, quality fluids make it operate poorly, do you want to trust it to get you out of the forest?

Do the right thing. Change the fluids properly. If it needs fixed - fix it. You be glad you did.

There's no such thing as a mechanic in a bottle.

Ok, now who is going to tell me how to do that? Correct me if I am e\wrong, but in ordser to change the torque converter fluid, I have to drop the entire tranny right?

Ok, now who is going to tell me how to do that? Correct me if I am e\wrong, but in ordser to change the torque converter fluid, I have to drop the entire tranny right?

Like mentioned above, you can do it with a tranny flush. Not many torque converters have a drain plug.


This is a good subject. I was going to replace the tranny fluid in my 95 kick as it looks more like engine oil than tranny fluid. As it has 150K miles on it and the tranny isn't acting up I don't think I will mess with it as the new tranny fluid will probably do more harm now than good. I'll wait till it coughs it's cookies before messing with it.

Clean new fluided is always better.  It has detergents as well as lubricating principles in the trans fluided.

If you just replace the filter and the fluid in the pan you are only replacing about a 1/4 to a 1/3 of the the fluided in the hole trans.  To really replace the fluid you need to go to someplace that has some kind of fluid exchanger.  They will hook up to the trany coolier lines and as the fluid flows out of the trans it is replaced with new fluid.  They do this until the fluid coming out of the trans is the right color.

I have been told that if you have 100k or more on a trans and have never changed the fluid that it "might" not be a good idea to do so.  The new fluid will "clean" out the transmission to much and cause problems.

I've done it and have never had a problem.

Quote from: OHIO_ZUKI on September 14, 2008, 12:24:21 PM

Ok, now who is going to tell me how to do that? Correct me if I am e\wrong, but in ordser to change the torque converter fluid, I have to drop the entire tranny right?

Like mentioned above, you can do it with a tranny flush. Not many torque converters have a drain plug.


This is a good subject. I was going to replace the tranny fluid in my 95 kick as it looks more like engine oil than tranny fluid. As it has 150K miles on it and the tranny isn't acting up I don't think I will mess with it as the new tranny fluid will probably do more harm now than good. I'll wait till it coughs it's cookies before messing with it.

 I have had this problem in two S10 Blazers I have had! I did a trans service and the trans wouldn't shift properly in one case and slipped in the other. Now the one that wouldn't shift I did add Lucas trans additive to it also and that may have caused it! I also have done trans services on higher mileage cars and trucks that haven't exactly been maintained very well with discoloured fluid and have had negative results. With that said, in my opinion if you keep up with regular and filter changes i would say go for it! But if the fluid has been neglected and is fairly dirty, i would stay away!

Ok, now who is going to tell me how to do that? Correct me if I am e\wrong, but in ordser to change the torque converter fluid, I have to drop the entire tranny right?

No need to drop the tranny. Let's all stay calm!

Here's a link to help with the whole process. The answer to your question is on page two of this article.

http://www.popularmechanics.com/how_to_central/automotive/1272521.html

Enjoy!

If it is an automatic I find it easier to just pay someone to flush the transmission for me.  I've had it fix two auto tranny's that where having problems finding gears when shifting under power.  Neither where Trackers though. 

...I have been told that if you have 100k or more on a trans and have never changed the fluid that it "might" not be a good idea to do so.  The new fluid will "clean" out the transmission to much and cause problems.

I've done it and have never had a problem.

I've often heard the same thing; not to change the transmission fluid on a vehicle with over 100K if it has never been changed before. But I've done it anyhow, and never experienced any problems. In fact, I changed the tranny fluid on my X-90 at 105K and I very much doubt the previous owner's had done it before; no problems yet. Maybe this was more likely to be a problem with the automatics from 60s and 70s, and the advice has just lingered on..?

Maybe this was more likely to be a problem with the automatics from 60s and 70s, and the advice has just lingered on..?

You may be onto something. I too have changed transmission fluid in high-mileage vehicles with no ill effects. But I've never worked on a 70's or older model (mainly because I was under 10 years old!) 

When I buy a used vehicle I always change all fluids, spark plugs, etc. ASAP.
Never had trouble with a tranny after changing fluid.
Using the correct fluids and strict attention to detail are the key IMO.

Quote from: OHIO_ZUKI on September 13, 2008, 10:37:26 PM

I ave heard numerous people tell me that when you replace tranny filter, you should use most of the old tranny fluid. People say that when you replace the old fluid, the new fluid is not as thick and since there is wear and tear on all of the 30 or so clutches within the auto tranny, that you need to keep some of that "Dirty" fluid to help keep the newer tranny fluid "Thick" for the worn out tranny parts. Any validity to this madness?

I strongly disagree with the notion that you should leave old, burned-up fluid in your transmission. That's like saying you should only replace half of your engine oil. Contaminates and broken down fluids need to be ousted. I would go on to state that you should be sure that you drain and replace the fluid in the torque converter too.

If your tranny is worn to the point that fresh, quality fluids make it operate poorly, do you want to trust it to get you out of the forest?

Do the right thing. Change the fluids properly. If it needs fixed - fix it. You be glad you did.

There's no such thing as a mechanic in a bottle.

I have to agree tranny fluid and any other fluids such as oil or coolant have detergents in them that break down after so many miles or periods of time and then they tend to break down and not provide the protection they were intended to in the first place. Would you want to count on that tranny or engine to get you out of the forest that is up to you.

I don't know much about trackers but with GM in the picture I believe it will need a specific type of ATF GM style you know dexcool coolant crap the red antifreeze

I have heard that you shouldn't use a modern detergent oil in an old engine if a non-detergent oil was used before. The thinking is that with older oils sludge builds up around the engine (or tranny in this case). A detergent oil will lift it and could cause the filter or small oil passages to clog.