Transmission FLuid

Has anyone changed their tranny fluid?

I have a 99 and I was wondering if the gasket is re-usable or one time use only.

I was planning on using full synthetic but I will only manage to get about half out so I will most likely have a 50/50 mix.

Anyone have any words of wisdom?

I was thinking of using a pump and sucking the old fluid out of the filler tube. Has anyone ever tried this?

Anyone know why they don't put drain plugs on transmissions (in most cases)?

Thanks

Don't reuse the gasket. I beleive a new one comes with the filter anyways. It's not a clean job by any means, but if you take your time, it's not all that messy either. I wouldn't go the route of sucking it out through the filler tube. Take the time to change the filter, and don't forget to check the magnet for accumulation of particles.

The stated reason for no tranny drain plug is to be sure you remove and clean the houing during an oil change, plus change the filter. The other reason is for cost reduction. Also, unless you tow or do lots of start-stop driving, I wouldn't recommned even chaning the fluid unless the fluid is beginning to discolor.

You might as well change the Tranny gasket and filter, you can get an aftermarket transmission gasket and filter kit for under 20 dollars if you live by my area.
I would recommend a really big drain pan though coz the only way to drain the fluid is by loosening up those bolt pans and its gonna be messy.

Thanks all,

I did the fluid in my Windstar last fall and it had a reusable gasket so I had to ask. Is the filter change really nessesary? I changed my Windstar's and some people have mentioned that it really isn't required as the only "dirt" in a transmission is metal wear and tear and that gets stuck to the magnet.

I don't see the Venture's venture (lol) being much different. I had a look at the size of the pan and yah it is bigger than my oil pan.

Thanks all,

I did the fluid in my Windstar last fall and it had a reusable gasket so I had to ask. Is the filter change really nessesary? I changed my Windstar's and some people have mentioned that it really isn't required as the only "dirt" in a transmission is metal wear and tear and that gets stuck to the magnet.If the only "dirt" in a transmission is metal wear that gets stuck to the magnet, then why do they have such a small magnet and such a large filter? The magnet gets some things, but not everything. There are non-ferous particles floating around in there as well. If you really want to see what all is in your oil, spend the 20 bucks and get an oil analysis done by Blackstone Labs. You'd be suprised at how much other stuff can get into a "closed" system.

make sure to change filter and gasket do not mix the synthetic fluid with what you have in there now, and the suction idea dosent work beacause your torque convertor holds the rest of your fluid the only way to correctly put synthetic is to replace all of the fluid. also if it is brown and burnt bad do not change it just leave it alone.

Yes, the gasket is re-useable and if your carefull when you take it off and it wasn't "over torqued" when it was installed, you should be fine. I made the mistake with my 98 Venture in not knowing this and threw away the old gasket and put on an aftermarket version.(cork) It leaked like crazy. I went to the dealer and 50 bucks later had the original "re-useable" gasket.Works great and I will re-use it next time.
I wouldn't worry about going to synthetic. This is a "fluid"
not oil, and lasts alot longer. Supposedly it doesn't break down like oil just gets dirty.Regular changes will make your tranny last a long time.
I always suck the fluid out of the filler tube.I get most of the fluid out before I crack the pan and spill most of it on the ground! Much easier and cleaner.The pump was $12 and works off my drill.This also works well when you slightly over fill the tranny.I suck some out instead of cracking pan or removing transmission line at radiator.You should always change your fluid and filter together .
I've wondered why they never put a drain plug on a tranny as well!!

Kevin

also if it is brown and burnt bad do not change it just leave it alone.

Just curious - why would you recommend to NOT change it if it was burnt or brown???

You dont want to change it beacause your clutch disk material are in that fluid if you change it you flush out the material and your clutches inside of the trans will not grab if you have brown fluid just keep the fluid in it and add if you have to but do not replace, your trans is bad if the trans fluid is brown

i find that interesting. I can understand a bad tranny if it SMELLS burnt. but i dont think dirty fluid means your tranny is bad.

the fluid in my lumina needs changing, its dark red. when i check it with a white towel, it still has a redness to it. doesnt smell burnt (or even taste burnt). planned on changing it this weekend. now you got me wondering. car drives fine - perfect as a matter of fact. what would you experts do?

I have heard that theory before.

I think what dramey is trying to say is that if the fluid is brown the transmission is bad period!!!. Replacing the fluid will not prolong its life but will in fact shorten whatever time it has left.


I don't know if I agree but I have heard this even from transmission experts but of course there are many different opinions in regards to maintaining a transmission. It is quite confusing.

Even different professionals have different ways to flush them. Some use a machine that pumps in the reverse flow direction, others in the forward flow and others just start the engine and have it pump on its own. I also find that the "best" (in their opinion) way is whatever way they are equipped.

You could ask any number of mechanics or tranny experts about changing the fluid and get any number of responses - roughly half that say "Do it regularly", or "Don't do it at all if there is no problem." In the garages I have worked in it was funny to see all the different answers and reasonings behind those answers, even from guys who solely work on them for a living. As for the absence of a drain plug on the pan, it might be possible to install an aftermarket one when you have the pan off to save you the time and mess the next time you change the fluid. In the past, I have installed an aftermarket ( B&M) drain plug in the pan of a transmission I was putting a shift kit in. I haven't looked at the pan of my Venture to see if there is room to put one, you usually install it in the lowest area of the pan, providing you have access to it.

I just found an old e-mail from a few weeks ago. I use the services of Blackstone Labs for oil analysis and was sent a link to their online news letter. You can read it [url=http://www.blackstone-labs.com/newsletter.html]. This month's letter just happened to talk about ATF. These guys know oil and fluids inside in out. Feel free to take what they say as the gospel truth or a grain of sodium chloride. Just remember that they don't really have a vested intrest in your transmission working or not. Can you say the same about your mechanic?

Exerpt from the newsletter in case they change it down the road:
So why go to the trouble and expense of having your ATF analyzed?
Two reasons. Automatic transmission fluid has the multiple functions of servicing gears, running the entire hydraulics show (which replaces your having to deal with a clutch and gearshift), and lubricating all the transmission’s parts and seals. In doing all that, the oil does not have the luxury of operating in a pristine environment with steady temperatures and no humidity. It collects moisture, dirt, and other abrasive contaminants like wear metals that inhibit its ability to lubricate properly and run the hydraulics effectively. These contaminants can, if left in service for too long, damage the seals. When the seals go and the fluid level drops, you will notice shifting, hesitation, and slipping problems.

Unless you have the tranny "power flushed", you only end up changing about 50% of the fluid anyway. The remainder stays in the torque convertor.

You're correct. However that is better than not changing it.

You don't even get 50%, more like 30%. A regular fluid change refill is about 4 litres. Most vehicles hold 10 to 12 litres. A complete flush is best but not common.

There is some debate about flushing too. Some machines flush in the direction of flow and others against it there are debates about harm from pressure from external pressures. I have had one dealer tell me one way is best and not to do the other and another dealer tell me the exact opposite.

I just think you are better replacing some (I think it is close to 50%) then none at all and it you do it twice within a week or so then you have changed 75% (assuming 50 % each time).