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Login to post Forums » Grassroots Motorsports » how old is "too old" to change trans fluid/filter?

April 26, 2011 4:47 p.m. petemc53555 New Reader

After a long search I just piked up a sweet `95 e34 wagon w/ 77K miles that I really wanted (Read: I spent more then I should've).
I want it to last a good long time and am concerned about the longevity of the auto trans. I have read that you should not service the auto trans of cars "with high miles" because the new fluid can potentially mobilize gunk that would otherwise stay in-situ.

I've found an auto-trans service DIY tutorial online for my car and it looks fairly straight forward.

Should I or shouldn't I? --oh great GRM consortium of auto-trans knowledge.

TIA

Pete
April 26, 2011 4:49 p.m. BoxheadTim SuperDork

Aren't these of the "sealed for life" type that tend to fail if you don't regularly change the fluid?

I'd change it, if you have enough gunk in there to blow up the trans it'll do so sooner or later anyway.
April 26, 2011 4:57 p.m. petemc53555 New Reader

Yes, allegedly sealed for life (if you only want 100K out of it)
April 26, 2011 5:04 p.m. slefain SuperDork

That is low, I'd change it.

If it had 150k on it, I'd leave it alone.
April 26, 2011 5:08 p.m. iceracer Dork

The purpose of the filter is to remove the gunk. I really believe that is an urban legend. In a former life I fixed a lot of old,highmile transmission by changing the fluid and filter.
April 26, 2011 5:22 p.m. tuna55 SuperDork

My Dad says folks that don't change their transmission fluid because it's too old keep him in business.

My Dad rebuilds automatic transmissions for a living.
April 26, 2011 5:40 p.m. mad_machine SuperDork

I don;t think the e34 fell into the "Sealed for life" BS BMW is peddling now. The e65 does though.
April 26, 2011 7:21 p.m. Toyman01 SuperDork

Maybe I'm crazy, but I've never changed the transmission fluid in anything I have ever owned. In the thirty years I've been driving, I have broken two of them. One busted gear set in an Olds from a gear drop at 4000 rpms, one in a 626 @ 157K miles. Current fleet all have over 160K several over 250K and one over 400K. The one over 400K is on it's second transmission.

Me I wouldn't change it. Ever.

Yeah I know. Crazy.
April 26, 2011 7:34 p.m. pigeon Dork

mad_machine wrote:

I don;t think the e34 fell into the "Sealed for life" BS BMW is peddling now. The e65 does though.

Nope, the current maintenance schedule for the E65/66 is to change fluid and filter (entire pan) at 100k. I did the fluid at 60k and need to order the fluid and pan to change it now that I'm at 102k. The $250 price tag for the pan and 6 quarts of the proper ZF fluid hurts but maintenance on these beasts isn't cheap.
April 26, 2011 7:38 p.m. tuna55 SuperDork

Toyman01 wrote:

Maybe I'm crazy, but I've never changed the transmission fluid in anything I have ever owned. In the thirty years I've been driving, I have broken two of them. One busted gear set in an Olds from a gear drop at 4000 rpms, one in a 626 @ 157K miles. Current fleet all have over 160K several over 250K and one over 400K. The one over 400K is on it's second transmission.

Me I wouldn't change it. Ever.

Yeah I know. Crazy.

There are people who say that same stuff about engine oil, gear oil, brake fluid, air filters, tires... Just saying... I change mine. Just like oil, it has a finite life in that environment.
April 26, 2011 7:47 p.m. Toyman01 SuperDork

I probably should, but just never have. It hasn't been an issue. Engine oil and air filters regularly. Brake fluid gets changed when the brakes are changed except on the Abomination. It gets it annually. Gear oils, almost never. I do check it and add as necessary.
April 26, 2011 7:58 p.m. KATYB Reader

ive seen trannys start working properly after a change of fluid. ive also changed out fluid on a trans that customer requested because of slight slippage and had the vehicle not be able to move off the rack.
April 26, 2011 8:12 p.m. petemc53555 New Reader

Ok, I ordered the parts for <$40 ( 2 gaskets and filter) I'll change the filter and fluid now and the fluid again in 15K.

Overkill maybe, but since I'm all in on it (see my OP) I may as well.

here it is: http://www.euroltd.com/vehicle_details.php?cid=509
April 26, 2011 9:49 p.m. novaderrik HalfDork

i once had a 94 Caprice 9C1 that had 175,000 miles on it when i got it. i went thru and changed all the fluids because they all looked like they needed it- engine oil, PS fluid, brake fluid, trans fluid. i put synthetic in everything but the trans and brake fluid. a mere 3 years and almost 50,000 miles later the trans started shifting weird..
April 26, 2011 11:52 p.m. Zomby woof SuperDork

I have read that you should not service the auto trans of cars "with high miles" because the new fluid can potentially mobilize gunk that would otherwise stay in-situ.
That's a transmission flush.

Changing the fluid, and filter is pretty safe, especially at that mileage, but I have had friends in the business who've said "if it's working, leave it". I don't usually change fluid in my auto trannies, and it's always worked for me.
April 27, 2011 9:18 a.m. iceracer Dork

I think the filter is the main thing. Over time, the clutch wear and other wear items tend to clog the filter which may reduce the line pressure,
April 27, 2011 9:52 a.m. Greg Voth HalfDork

The only time I changed the fluid and filter in an auto was at 200,000 miles on my 1998 Buick Park Avenue Ultra.

Trans was shifting fine but I was about to move and figured it wouldnt hurt. On my way from DC to Charlotte, NC the following weekend the trans died on me about half way down.

Could have been a fluke but it was acting completely normal beforehand. I wouldnt do it again.
April 27, 2011 11:46 a.m. poopshovel SuperDork

Zomby woof wrote:

I have read that you should not service the auto trans of cars "with high miles" because the new fluid can potentially mobilize gunk that would otherwise stay in-situ.
That's a transmission flush.

Changing the fluid, and filter is pretty safe, especially at that mileage, but I have had friends in the business who've said "if it's working, leave it". I don't usually change fluid in my auto trannies, and it's always worked for me.

^^^WISDOM^^^

Dumbass that I am, while having new tires put on, I let a jiffy-joes shop do a trans FLUSH on my 97 exploder tow vehicle. I'll save you the month's battle worth of details, but it basically destroyed an otherwise great running thousand dollar car.

Drain, replace fluid, filter, gasket. Win. Or leave it alone, but don't flush it.
April 27, 2011 11:56 a.m. 16vCorey SuperDork

KATYB wrote:

ive seen trannys start working properly after a change of fluid. ive also changed out fluid on a trans that customer requested because of slight slippage and had the vehicle not be able to move off the rack.

It can definitely go either way, depending on what is the problem in there. I worked with a guy who had a crappy car with a failing, leaky transmission. If he put new fluid in it when it was low, he wouldn't have reverse. He started putting in crappy old trans fluid from cars at the junk yard (he dismantled cars there), mainly because he was a cheap ass and it leaked about two quarts a week. Reverse came back, but would go away the next time he topped it off with new fluid.
April 27, 2011 1:05 p.m. curtis73 Dork

Its gotta be pretty bad for me to not change the filter/fluid. I don't ever flush them. Filter/fluid is totally safe unless you drain it and find chunks and chocolate syrup. Most manufacturers recommend 60k, so your 77k is not off the mark at all. Make certain of which transmission you have. If its the ZF, be prepared for $30/qt, and there is no substitute. If its the 4L30E, use plain old dex/merc.

Sealed for life is a complete joke. It means the transmission doesn't have a dipstick.

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