Tranny filter change

[fs98sim]

Hi guys im new to the Caddy family. I have a 2002 STS and was wondering if the main tranny filter could be replaced without having to lower the engine or tranny. I dont have the service manuals yet.

Thanks Mario.

[Ranger]

The "filter" is deep in the tranny and only gets replaced during a major tear down. When you drop the pan, there are two screens that you remove, clean and replace. The gasket is also reusable. There is also a "hidden plug" up there. I think it is between the two screens, or at least very close to them. It is directly under the side cover and it drains the side cover. Don't forget to pull it and drain the side cover.

[tjtjwdad]

fs98sim Posted on Nov 27 2005, 07:46 AM

Hi guys im new to the Caddy family. I have a 2002 STS and was wondering if the main tranny filter could be replaced without having to lower the engine or tranny. I dont have the service manuals yet.

Just curious, but I've always believed that the transmission fluid is good for the life of the car as long as no towing or any activities that would cause it to heat up and/or over heat.

Jim

[Ranger]

Technically true Jim. I do mine at 100K anyway. Error on the safe side and old habits die hard.

[Devin O'Conor]

Just curious, but I've always believed that the transmission fluid is good for the life of the car as long as no towing or any activities that would cause it to heat up and/or over heat.

Jim

I wouldn't say it is good for the life of the car but maybe good for the life of the transmission. If you don't change the transmission fluid, it will shorten the life of your transmission. I recently changed the trans fluid in a Sunfire that was supposedly "filled for life". The car was shifting very poorly and after a fluid change, it shifts like new. The fluid was a dark brown color and had a very bad odor. Have you ever looked at transmission fluid that has been in the trans for 100k? It will be brown and have visible soot and clutch material regardless of how the car is driven.

[JasonA]

Have you ever looked at transmission fluid that has been in the trans for 100k?  It will be brown and have visible soot and clutch material regardless of how the car is driven.

Have a look at mine. It has 148k miles on it and if you drove it, you'd swear you just drove it off the showroom floor (original spark plugs too). The fluid isn't blood red, no, but it's not burnt brown either. It all depends on how the car was driven during its life. It sounds like that Sunfire you encountered had severely burned fluid that required a change. Going by a simple mileage number isn't appropriate for estimating the life of transmission fluid, just as it's not appropriate for estimating the life of engine oil.

Just as these cars have engine oil life monitors indicating when it's time to change the oil, they have transmission oil life monitors. If the transmission fluid is overheated or stressed, the car WILL tell you to change the transmission fluid. Else, it's generally good for the life of the car. If you do drive it under "severe service" as indicated by the manual, you may be instructed to change it sooner.

So far, the "change transmission fluid" message has never appeared on my car, and the fluid in mine still appears satisfactory. Having said that, I would like to change it soon, but it's not all that high on my priority list.

[Devin O'Conor]

My point is....why wait until the fluid is completely filthy and burned up? Trans fluid is cheap and when the pan is dropped on a 4T80E, only about 4 quarts come out...maybe a quart or two more after removing the side cover drain plug. It's cheap insurance to replace 5-6 quarts every 30-40k.

Never changing the trans fluid to me is like waiting to see metallic flakes on the dipstick before changing the oil.

[Ranger]

My point is....why wait until the fluid is completely filthy and burned up? Trans fluid is cheap and when the pan is dropped on a 4T80E, only about 4 quarts come out...maybe a quart or two more after removing the side cover drain plug. It's cheap insurance to replace 5-6 quarts every 30-40k.

When I did my '97 Deville last summer, I got 12 - 13 qts out of it. Most of it came out of the pan.

[BodybyFisher]

I am with you Devin, a lot of guys here like to run up to 100,000 miles and hey that may be ok according to the maintenance schedule. Me, I like to get the old fluid out, clean out the pan, clean off the magnets.

At 50,000 miles the scheduled maintenance says:

Change automatic transaxle fluid and filter if the vehicle is mainly driven under one or more of these conditions:

1) in heavy traffic where the outside temp regularly reached 90 degrees or higher.

2) In hilly or mountainous terrain

3) When doing frequent trailer towing

4) Uses such as high performance operations

If the vehicle is not used under any of there conditions, the fluid and filter do not require changing.

My entire summer is spent in bumper to bumper traffic and I do WOT's at least once a week. Why should I let it go until 100,000 miles and why should I allow sediment to collect on the bottom of the pan? Clutches wear and fine clutch material sits on the bottom.

What I don't agree with is, while it may be OK for a car in the warranty period to go 100,000 miles with no fluid change, my 1996 is now 10 model years old, I think a fluid change is good for the seals and its good to get the sediment off the bottom and to clean the filter and screens. Not only that, while I know the gasket is 'reuseable' mine is leaking and I think its good to replace it to stop the leaking.

But as many know here I am Mr. Safety, and I keep my pants up with a belt and suspenders just to be safe...changing the fluid is cheap

[JasonA]

Of course -- if your vehicle is driven in NYC in stop and go all the time, follow the severe maintenance schedule! If my vehicle sees a relatively easy live in semi-rural NC, why should I change the transmission fluid every 50k? It's way overkill. Why not also change the engine oil every 500 miles to be on the safe side? It's all about using the full life of the lubricant, whether we're talking about engine oil or transmission fluid.

I don't understand why so many of us have bought off on the engine oil life monitor concept, but have yet to accept the fact that under the right conditions, as the owners manual says, transmission fluid can go SO MUCH LONGER than used to be the norm (replacing it every 50k miles no matter what). If you drive your car in severe conditions, by all means change the tranny fluid like the owner's manual says. But if not, why waste the fluid? Just like engine oil...if you don't need to change it every 3000 miles, why waste the fluid?

[BodybyFisher]

Jason, you are overlooking my tranny fluid monitor, which has never come on. Some have said if the tranny fluid monitor does not say to change the fluid you are ok. I just think that its prudent to change it. What I am saying may be old CW and new CW (conventional wisdom) may be to go by the tranny fluid monitor. If you look at the list of reasons to change your fluid, I really don't fit into any either with only three months out of the year being in traffic say twice a week. I just think that age has something to do with it also.

The oil life monitor is doing what we were unable to do years ago, where the manual said change your oil between 3,000 and 7,500 based on driving style. The computer is determining that driving style for us now, plus the oil has gotten better.

While I agree that the tranny fluid monitor is great during the warranty period (3 years?) if you reach 100,000 miles, if I reach 100,000 miles 10 years later (I am at 77,000 miles now at 10 years), I just think its a good practice to change it, to get sediment out of the pan, refresh the pan gaskets and refresh the fluid to protect the seals.

By the way I am not posting up against you, I am just saying what I do, old habits die hard. If you look at oldgamer's recent problem, after it was over, he said he would have changed the fluid sooner had he thought about it.

[Regis]

I can see both sides of the discussion here. While I subscribe to the "Leave it alone if it ain't broke" side, I also can fully appreciate the value of preventative maintenance with certain fluids. I swap coolant out every 2 years. And I'm currently on my 4th transmission fluid swap. Although the tranny fluid change last week was definitely unscheduled (busted cooler line) as well as last years (almost to the date). I would have had the tranny fluid drained and filled this year anyway. Once it gets that funny smell and off color it's time to go.

Tranny fluid is very inexpensive and comparing the waste aspect to that of oil is hardly in the same category.....even with the amount of swaps I've made. That's like comparing an individual relieving himself out in the woods and comparing that to the amount of raw sewage that's dumped into the Atlantic via the lower Hudson River (New York Bight). Not even close.

Now this will be interesting for some that are interested in knowing or just dead set against changing the tranny fluid. When I blew the cooling line and lost 8 qts of tranny fluid, I noticed a measureable difference when I fixed the break and topped off the lost 8 qts with fresh fluid. Big difference. I could barely feel the gear changes. It still feels that way a week later. I check the fluid level every 2 weeks and it's always been the same. So why the difference? Why the sudden pillow/ marshmellow like shifting? You decide for yourselves.

This really seems to boil down to personal priorities. Some like to invest their car money in the latest greatest waxes, some on wheels and rims, some on fancy aftermarket brakes and rotors, some on exterior lighting, some on lowering components, some on tint, some on ground effects and wings, some on exhaust, and some on engine and performance tuning. Did I miss anyone? I dedicate my car money to simply preserving what is already there and helping it to last. That includes certain fluids. Every original accessory still works on my 94 except for the power antenna which is not practical in regions where heavy layers of ice often cover the mast opening so it can't go up. That has been replaced with an internal antenna. Don't get me wrong, I would love to have shiney chrome rims, have Bronson lower my car, have Jason wax it, have Scotty replace all of its bushings with polys, and have Mark tune the snot out of it. But those things are just not a priority for me. But what is important to me may not be for others. Each to his/her own. I just may not feel as safe riding with some of you.

[Webmast84]

I want to replace my tranny fluid soon. I just got this car in September so I have no clue when it was last changed. It doesn't shift hard or anything. I just want to know that I changed and when.

[jschunke]

I'll have to agree that transmissions seem

to shift smoother after a good pan-off cleaning

and refill. Not sure how much of it is psychological

persuasion though.