C5 Automatic Transmission Fuild Change

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Jul 23, 2019 | 11:01 AM

Hyecorvette

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C5 Automatic Transmission Fuild Change

I have a 2003 C5 A/T with 25K miles and plan on going Bowling Green for the 25th anniversary.
According to the dealer, the recommended A/T fluid change is 100K.
My concern is the age of the fluid and the fact I'll be driving about 5,000 miles .
Should I have the dealer flush the fluid or don't worry about it?

Jul 23, 2019 | 12:16 PM

mstromquist

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No way, no how would I ever let anyone flush my transmission. I'd probably change the fluid that's in the pan and the filter and leave it at that. I've heard tons of horror stories of people having them flushed.

Jul 23, 2019 | 01:09 PM

JR-01

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Quote:

Originally Posted by mstromquist

After 80K miles and 17 years I had my trans flushed and fluid changed. The GM Corvette tech said a filter change only replaces less than half of the fluid and recommended the flush and change. 5K miles later and no problem. With only 25K miles on it, I would leave it alone.

Quote:

When not to flush your transmission

Before draining or flushing you should pull the dip stick and look at the fluid. If it is dark, burnt smelling, and you see little flakes or speck in it, DO NOT FLUSH IT. The fluid and transmission possibly has hard part damage, but the transmission just has not figured out it should die yet. If you flush a transmission in this condition it could fail right away. Real strange, but that is what seems to happen. If your transmission is in this condition just drive it while you save for a replacement transmission. There is no way of telling when it will fail. It might be today, next week, or next year, but it is doomed.

The goal here is to flush the transmission BEFORE the fluid gets contaminated. What you are taking out should look like what you are putting in. Do not wait for a color or smell change. Most manufacturers calls for transmission fluid change at 30,000 mile intervals. The industry standard is two years or 24,000 miles whichever comes first. It is your vehicle, you decide what is best for you.

Last edited by JR-01; Jul 23, 2019 at 05:49 PM.

Jul 23, 2019 | 01:18 PM

Brunello

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I wouldn’t flush it but rather change the fluid. If you trans is solid, would probably be OK but why chance it? I likely had a problem with my DD (10 Toyota Camry) trans and a flush turned a likely issue into a $3600 issue. Toyota drivetrains have always been bulletproof for me to 200k so this was an eye opener. No need to put that type of pressure in a system based on my research. Your only asking for problems.

Jul 23, 2019 | 05:14 PM

jim993

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It sounds like you would have the dealer perform the fluid and filter change. In my view, with 13 years on the car, it is prudent to change fluid and filter using the Factory service Manual procedure, which would not include a flush. A flush should not cause any problem, but there are posts where a flush was performed and later problems arose, perhaps related, perhaps not.

At 25K miles, there should not be anything of concern in the transmission pan. If you are having the dealer do the change, request confirmation of this.

If you would do the change yourself, I'll post my procedure. If so, it would be an opportunity to use full synthetic ATF.

Keep in mind that a FSM fluid and filter change actually removes and replaces about half the fluid. The rest is in the torque converter and transmission works.

Jul 23, 2019 | 06:40 PM

Vetteman Jack

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If it were my car, I would do a fluid/filter change and skip the flush procedure.

Jul 23, 2019 | 09:53 PM

Ed Ramberger

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I bought my car with 85000 on it and changed the fluid & filter at 100000. It was pristine. I found a receipt for a fluid change at 35k from PO. I wouldn't worry about it before the trip. It's not hard and I know it was done correctly by doing it myself. Don't do the flush - changing the fluid in the pan and filter is fine. Also, you will most likely end up leaving the filter seal in the trans and reusing it. Read up on that before getting into it.

Last edited by Ed Ramberger; Jul 23, 2019 at 09:58 PM.

Jul 24, 2019 | 03:06 PM

c5arlen

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Just change the your transmission now for a brand new one... for about 3-4 thousand dollars.. and save having to do it later when your present transmission that some inexperienced 25 year old "wrench" screwed up when he assembled it on a Monday after a weekend of hard partying at some rock concert.... Just think of the consequences man!.. It's like jumping out of a perfectly good airplane at 30 thousand feet!.. Ask me how I know.