shayden69

Hello everyone. I have a 1989 vette with 60k miles. It is an automatic transmission, and it shifts very very well. The fluid is a slightly brown, and im not sure if the fluid has ever been changed. My question is should I change the fluid, and filter? Ive heard that changing the fluid can dislodge debris from the friction plates causing it to malfunction.

Cjunkie

Change the fluid and filter. Get 6 qts, you'll use 5.5.

Joe C

(my 2-cents, FWIW) -- brown fluid - not a good sign. the fluid change causing (transmission) malfunction - ??? - most of it is urban legend and old wives' tale. try to find documented proof of fluid change causing a transmission failure. I think all you'll find a lot of on-line hearsay. seems, in most cases, when folks have transmission issues after a full fluid flush, there were already transmission problems. they change the fluid, the transmission goes bang - at fault, the fluid change - thus birth of the legend.

I service my 85's 700R4 with a fluid and filter every 36-50K miles, complete flush (and filter) at 100K miles. i'm at 161K on my original transmission - still has good firm shifts, and as I recall, as good as when I bought the car with 33K on the clock. i'd say my 700R4 is pretty healthy, and that's an early unit that's supposed to be somewhat problematic.

what concerns me, is you said the fluid is slightly brown. well "slightly" is somewhat subjective, and dependent on personal observation. have you had, or do know of, any transmission over-heating issues with the 89? 60K is not a lot of miles. since you say, the transmission shifts very, very well, well, that's a good sign. my opinion, and w/ Cjunkie - fluid and filter change - and keep a close eye on things - maybe a second fluid and filter in a year or two. one thing I might add is to go with an AC Delco service replacement filter kit. I've tried several different types, and they just don't seem to stack up to OE. you'll pay a couple dollars more, but you're dealing with a fairly expensive piece of hardware. IMO, a transmission is no place to save a buck. besides, delco filters are still made in the U.S.A. -



this is the standard delco service replacement - 82-93 700R4 transmission filter service kit (P/N 8657926). amazon or rockauto will give you the best pricing.

finally, stay away from dealers, or service centers that have these machines the "reverse flow suck" the fluid from the transmission without dropping the pan or changing the filter. this is one job, I recommend doing old school - drop the pan, fresh filter and gasket, torque hardware to spec, and add fluid to correct operating level.

good luck - hopefully everything is good.


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confab

It is technically possible to wash some debris loose with the new fluid and stick the controls, but it usually isn't a problem if your transmission is healthy. Huge amounts of "plaque" aren't something you find in a transmission with 60k.

I would just change it, but some people siphon out a quart every week or so and replace it, thereby slowly effecting a fluid change, till they have clean fluid and then do the whole fluid and filter swap.

I think it'll be fine to just do the fluid and filter. It is an overblown concern.

shayden69

Thanks for the responses to everyone I greatly appreciate the help. I will most likely change the fluid and filter soon. And Joe C. sorry for not being specific enough about the color. When I say slightly brown I mean it still has transparent look to it. And honestly looks Like very light colored slightly pinkish motor oil. No chunks of any debris or bubbles on the dip stick. The last owner was an older gentleman who only put about 1I miles a year in it for 10 years.

Joe C

transparent, and pinkish - no bubbles - . I think you may be worrying over nothing. transmission service is all you need - filter and anywhere from 4-6 quarts of fresh fluid.

Purple92

Just my $0.02 - but YES, change the fluid !!!!

There is really no good that will come from keeping old fluid in that the tranny. Yes, I have seen an online survey (on another marque) where a small percentage of the people reported trans failure after a fluid change - but it's quite possible that they already were seeing the upcoming signs of failure, and hoped a way overdue fluid change would "fix" the problem.

The only thing I don't like is that roughly half the trans fluid remains in the torque converter, and will not be removed when you drop the pan. For someone who is doing the fluid & filter change as PM, it's not that huge an issue, but if the fluid is older, or has that lovely burned smell, I don't like the idea that half the old fluid is still in there.
What I've been doing lately is this...

1) Do the conventional pan drop and filter change - add new fluid as appropriate.

2) I remove the line from the return fitting on the auto trans fluid cooler in the radiator. (If at all possible screw in a fitting with a hose barb, and use a couple of feet of hose to direct the fluid that will be coming out into a bucket or some container).

3) Have a friend Start the engine (leave in park or neutral), and let the fluid come out until you see the first hint of an air bubble, this will probably take 30 sec - 1 min or so. At the first sign of an air bubble - shut off the engine.

4) Refill the pan.

5) Repeat two or three times until the fluid coming out looks essentially new.

6) Refill the pan to the proper level, hook the cooler line back up, and go have a well earned adult beverage with your friend!

The reason this "works" better is that supposedly (at least from what I can see) - the fluid flow in an automatic trans is quite complicated, but the trans fluid cooler is essentially near the end of the line for the fluid - and it ends up returning to the pan pretty much after it's gone through the cooler. I've done this on several vehicles, and it seems to have worked pretty darn well.

I would be interested in opinions from others who have a significantly better understanding of the Auto Trannys than I.

Dt86

What fluid is everyone using these days? Are synthetic atf's better? The previous owner of my car had the fluid replaced with synthetic so I guess I'm stuck with that??

gerardvg

Hi

Its normal for the trans fluid to discolor over the years, the slight brown color is from general wear of the clutch plates.
Its NORMAL not a disaster dark brown or black is, light brown just shows some wear over the years.

Yes replace the filter and fluid and gasket

confab

I get mine in bulk. Standard ATF, I just change it more frequently than most people.

aklim

If you do this as a 2 man job, dump the fluid out of the pan and fill. Disconnect the return line and have the other person pour fluid into the trans as the car is running till the fluid comes out fresh. That should flush most of the system out. That or go to a flush station with a flush machine.

I wouldn't bother about the rumours you hear. Most of them probably center around the theme of someone neglecting the trans till it is too late, do a "hail mary" flush and when it failed, the flush caused it.

confab

A flush machine is much better.. That return line is actually the lube circuit, and you could potentially do damage to your trans. (It doesn't just go to sump.)

An actual flush machine has a bellows (or equivalent) in it, and as fluid is being discharged by the pump, fresh fluid is returning to the transmission and lubricating it, and it is doing it under the same pressure as the fluid leaving is under. Thereby not starving your transmission for lube.

confab

PS: If you add a drain plug you can change the fluid more frequently and get it all with relative ease at your convenience.

Change the filter the first time, but a healthy transmission shouldn't plug the filter and you can do regular fluid changes in a few minutes.. Saving the filter replacement for 30 or 40K intervals.

IMVHO.

BlowerWorks

OMG - change the f..king fluid & filter !!!! Please why even ask !!!!
I recommend the AMSOIL Super Shift - you'll love the shifts and it will definitely extend your trans life !!! greg

383vett

Change the fluid. I use Amsoil Supershift also. Wot converter clutch lockups and tranny and converter live season after season.

confab

Adding a drain plug also makes it easier and cleaner to change the F-ing filter, when the F-ing filter needs changed.

Cliff Harris

See this thread:

https://www.corvetteforum.com/forums...l60-4l60e.html