What is the interval for tranny fluid/filter change for a 98 Lesabre

[swipter]

What is the mileage interval for a tranny and filter change for a 98 Lesabre?

[avatar307]

I believe the manufactuer specification is ever 100,000 miles. Check your owners manual to be absolutely sure.

I know some people who swear by changing it ever 30,000 miles (which was the spec for pre-1995 cars). I changed mine when the transmission gasket started leaking. Right around 125,000 miles.

[buickmastermind]

It depends who you ask. You shouldn't have to change it until the fluid is a deep red color. If the fluid is turning brown, it means the clutch plates have started to strip, and no amount of new fluid can stop them from continuing to strip. After they begin to strip, it's only a matter of time before they are bare. Sometimes it takes 30,000 miles, sometimes it only takes 5,000. When the clutch went bad at 160,000 miles on mine, the fluid was still cherry red, but it was darker than new fluid.

[avatar307]

Brown fluid most often represents a burnt fluid caused by excessive clutch engagement/disengagement.

For example, when towing a trailer, especially up and down hills, the transmission will continously jump from drive to overdrive. This results in excessive wear on the transmission, brown/burnt transmission fluid, and has has been the death of many automatic transmissions.

Brown fluid can also indicate the presence of oxidation (i.e. rust) or certain transaxle damage. If transmission fluid ever turns brown, it should be changed immediately. The pan and filter should be inspected for a larger than normal amount of metal fragments, the type of fragments indicating the location and presence of damage.

A "non-transparent pink" color represents cooler damage. More specifically antifreeze leaking into the transmission by way of the transmission fluid cooler. A transmission overhaul is required.

Foam in the fluid represents contaminated fluid. Most often antifreeze, but it can also represent other contaminants. A transmission overhaul is required.

Transmission fluid should be red, and should remain red or gain a very light brown after many thousands of miles. Wiping the dip stick on a white cloth is probably the best way to determine fluid color.

[buickmastermind]

I post this ONLY in agreement with Avatar, and to also clarify some other common misconceptions about brown colored fluid that I have been asked about.


The only time tranny fluid will gain any brown color is when the clutch plates are starting to burn, or strip. Brown fluid doesn't cause the problem, it simply indicates a problem. Towing trailers over time can cause the fluid to turn brown, but only because the added wheight causes the clutch plates to slip when they shouldn't, and even putting new fluid in will not prevent slipping again, and eventually, they will never grip again.

If you change the fluid at the first hint of brown color, it doesn't prevent the further stripping of the clutch plates. It may help to slow it, but it only saves you probably about a few thousand miles at most.

The fluid, under the condition that the clutch plates remain intact and unburned, should never show a hint of brown color, but become a deeper red with age. There should never be any rust inside of the transmission, as it is aluminum, and the steel parts are coated with, you guessed it, transmission fliud, and there isn't a sufficient amount of air to cause rust inside, and it is sealed from the outside. So, if you see rust inside, time for a teardown/rebuild job as some gaskets/seals may be bad, which can cause other problems. When it gets to the point that the fluid gets dark, then it should be changed.

My dad's '84 GMC Sierra 2500 has the automatic 4-speed, and he put 230,000 miles on the tranny before he got any sign of brown in the fluid, and that was because he pulled a 8,000lbs travel trailer through the Rockies. When he got home, he checked the fluid, and found it to be slightly brown, and changed it. After that, he only got about 20,000 miles on it before he had to rebuild the tranny. He lost reverse at 233,000 miles , third at 240,000, fourth at 247,000, and second at about 250,000.

My grandfather put 470,000 miles on an oldsmobile before he had to change the fluid, and the motor died a week later, before the tranny ever came close to breaking down.

My dad also put 10,000 miles on brand new '89 Chevy Astro, which has the same tranny as his pickup does, before he pulled a boat and trailer on a 700 mile round trip (again, through the Rockies). The fluid had begun turning brown, so he changed it. The tranny died at 12,000 miles because the clutch plates completely stripped.

By the way, if you are considering buying a used car, no matter the mileage, always check the tranny fluid for a burnt rubber smell and Extremely tiny metal flakes, no matter the fluid color.
Burnt smell = dying clutchplates = 1,000-20,000 max mileage before a major rebuild job, costing an extra $700-$3000 for parts, plus labor (unless you plan on fixing it yourself).
Tiny metal flakes ~ excessive wear or broken springs ~ poor fluid flow or pressure -> clutch plates begin to slip -> Tranny breakdown after x miles, and rebuild needed. Buying a new tranny isn't any cheaper. The best you can hope for is that a car in a junkyard died with a tranny that has less than 60,000 miles on it that still works, so you can expect to get up to 60,000 more miles on it, depending on previous wear, before you should have any problems.