Tranny fluid flush for FE?

[brucepick]

This past couple weeks FE hasn't quite been what I expected - off by maybe 1-2 mpg. Had been consistently 30-32 mpg before the slight dropoff.

So this past weekend I changed the oil and tranny fluid as both were due, per the odometer (3K mi. for oil, about 25K for tranny fluid).

Tanked up today and had a best-ever tank, 33.42 mpg. Granted it was all good roads and fair weather but even so, it makes me think that maybe fresh fluids are good for FE, not only good for your beast's long term health.

I flushed the tranny fluid with Penzoil non-synthetic stuff. System holds just under 8 qt. and I cycled 16 qt through it, changing 2 qts. at a time. Standard procedure for these cars however 12-14 qt does a very decent job too. Thankfully even Volvo says to leave the tranny filter/screen alone, not even look at it! Ask me again why do I love these old rwd bricks?

I've been using WalMart synthetic 10W-30 for nearly a year now. Just under $3/qt if you get the 5-qt. jugs. I can deal with that, I just can't deal with $5-6/qt. for the really good synthetics.

[StanleyD]

Originally Posted by brucepick

.... I flushed the tranny fluid with Penzoil non-synthetic stuff. System holds just under 8 qt. and I cycled 16 qt through it, changing 2 qts. at a time. Standard procedure for these cars however 12-14 qt does a very decent job too.....I've been using WalMart synthetic 10W-30 for nearly a year now. Just under $3/qt if you get the 5-qt. jugs. I can deal with that, I just can't deal with $5-6/qt. for the really good synthetics.

I dont get it. If your tranny holds 8qts, then how do you 'cycle' 16 qts through it. I must be misinterpreting something here. Can you please be more elaborate or actually more 'layman' for a regular Joe like me. I DO, however. understand that there is a FULL tranny flush that replaces ALL the tranny fluid in your system and a tranny drain-and-fill that replaces just the fluid in your pan (about 1/3 of total), but I only understand this through reading brochures at dealers that already want you to spend more money, so I dont take any of that info to full heart.

[brucepick]

Originally Posted by StanleyD

I dont get it. If your tranny holds 8qts, then how do you 'cycle' 16 qts through it. I must be misinterpreting something here. Can you please be more elaborate or actually more 'layman' for a regular Joe like me. I DO, however. understand that there is a FULL tranny flush that replaces ALL the tranny fluid in your system and a tranny drain-and-fill that replaces just the fluid in your pan (about 1/3 of total)...

Sorry. Sometimes I'm waaay too wordy. That time I left out too much.

Yes, you can drain the pan and you get out ~1/3 of the fluid. Of course that leaves plenty old fluid in the system.

On the rwd Volvos and probably many other cars you can do similarly to what the shops do for a full tranny fluid flush. We open the tranny fluid upper cooling line at the radiator, which on these cars is the return line to tranny. Hook up a hose going to a jug marked in quarts. Idle motor till 2 qt. in the jug, that takes maybe 2 minutes. Empty the jug. Add 2 qt. new fluid to tranny via normal fill opening at dipstick tube. Repeat multiple times till you've cycled 12-16 qt. through the system. Check fluid level when done and again next time car gets fully warmed up.

Since you only take out 2 qt. at a time you never get 100% new fluid in the system. I did a spreadsheet to calculate the %age of new fluid after each 2-qt. cycle. After 12 qt. it's in the low 90% range (I think), after 16 qt. its something like 98 or 99% new fluid.

[ffvben]

the dealer trans flush machine can flush a bunch of fluid at a time. one dealer had a Winn flush machine, 16qts. in my place bg machine uses 10qts. its basically put in-line with the cars cooler lines, as the car runs its trans pumps the fluid to the cooler, instead of colling it goes to the machine. the machine is pressurized by the car and old fluid pushes on the bladder inside to push the new fluid into the car. their is a site glass on some machines , some times the fluid is black, after 3-5mins its a nice deep red color.
I've heard of some people leaving a cooler line off while running, using a funnel to add new fluid but some cars have high pressure that would shoot the fluid all over the floor.

[brucepick]

Thanks, ffvben. Good background that I'd been missing.

My reason for the orig post was to raise the question whether changing oil +/or auto tranny fluid is known to raise FE. I seemed to get a pretty good increase right after the change.

Any one else have any similar experience or related information?

[itjstagame]

All my cars always run smoother and feel a bit more powerful after and oil change, and I do typically get slightly higher tanks. I've never cycled the transmission fluid (I'm very bad to my automatics), but I would suspect that would help too.

I mean you're adding fresh, slicker fluid rather than the gunked up old stuff. Makes sense to me.

[Raccoonjoe]

Originally Posted by brucepick

I seemed to get a pretty good increase right after the change.

Any one else have any similar experience or related information?

No hard results close at hand, but I have also noticed a sharp increase in FE for the first couple to tanks after an oil change.....

[brucepick]

Shoot, I'll change the oil every other day now!

Seriously though, what I do hope to do is change maybe twoor three quarts of tranny fluid at each oil change. Calcs follow...

If I change oil at 4 k mi. intervals and change 2 qt tranny fluid at each, I'll change 16 qt. tranny fluid spread out over 8 oil changes = 32K miles. If I do 3 qts t/f every 4 k miles then I'll change 15 qt in 5 oil changes = 20k miles which is what the book specifies.

What I really like about that is that I might be able to manage the cost of synthetic tranny fluid if only changing 2-3 qt at a time. I just never could face buying 14-16 qt synthetic tranny fluid at once at the going price.

[ffvben]

just buy 2-3 qts and put them in the back of your garage until you have a full case if your changing 2 qts. at a time, the rest of the old nasty fluid will mix with the small amount of new fluid. this might be a waist of money.

[brucepick]

Originally Posted by ffvben

just buy 2-3 qts and put them in the back of your garage until you have a full case if your changing 2 qts. at a time, the rest of the old nasty fluid will mix with the small amount of new fluid. this might be a waist of money.

Maybe. But read below.

I did some serious calcs about a year ago. Bottom line, after changing 2 qt at a time 8 times, there's 90% new fluid in there (my car). After 7 times it's 87%. Of course that's if you do it all in one session

Anyway, if you spread out those changes swapping out 2 or 3 qt with every oil change of course it works out differently but still a good thing. With the regular system, you drive on brand new fluid for a few minutes, then over the next 20K or whatever, the whole batch gets older + older till you replace it all.

This way, there's always a mix of new, sorta new, medium worn, etc. etc. fluid in there. Should be good, I think. Maybe every 30 K miles or so I'll do a full flush. Something like that. Shucks, plenty people drive 100-150K with no maintenance and then the say "gee, the tranny is slipping, they just don't make 'em like they used to".

[itjstagame]

Originally Posted by brucepick

Shucks, plenty people drive 100-150K with no maintenance and then the say "gee, the tranny is slipping, they just don't make 'em like they used to".

That'd be me!

I think I seriously need to learn the flush and filter change intervals to increase the lives of my automatics, up until now I've never really driven that many miles per year so it didn't matter and I would just buy a 'new' used car for $500 or whatever and lament that I did not own more manuals, but I don't want this truck to ever die and don't plan on trying to swap a trans (even if it would be super beneficial), so I better get my act together.

[01_fast_ride]

brucepick
I agree that the trans flush was a great thing for both the longevity of the tranny and possibly helping raise your numbers a bit. And I think your idea behind full flush combined with 3K mile drain and fill is smart. I hear alot of people are doing similar things over on VolvoForums. Its cheap insurance for your trans to renew the additive packs.

I am getting ready to do a full flush on my '01. (Maybe I was naive to follow Volvo's recommendation to not change the fluid until 105K.) I think I'm going to add a Magnefine filter inline on the return hose for added protection. I am actually quite nervous to see how much crap has been circulating through the tranny all these years.

[brucepick]

You must be the same SSixty that's on CleanMPG.
Good to see you here!

I don't know too much about the Volvo fwd cars. I know the AW (Aisin Warner) auto trannies in the rwd cars are pretty much unkillable.

Good luck on the flush! FWIW, when I drain from the bottom of the tranny pan I get fluid but no junk. I never pulled the screen, on the rwd bricks there are hazards to beware of re. the dipstick tube attachment to the pan. So I leave it alone. FWD, I don't know about really.

[01_fast_ride]

Yeah, you got me... I go by that alias. And I have seen Sven on the mileage logs over there as well. Nice skills.

Thanks for the words of encouragement. I began researching 'the flush' a few months ago, so right now I could probably do it in my sleep. A few of the other forums I've visited all seem to slam me, WWE-style, for owning the '01. They claim its a lemon - that they don't last beyond 70K miles.

[vt420]

on a only partially related note. I've always seen an increase in MPG after changing the oil in my manual transmissions, but I've changed to a semi or full synth (depending on the car and my finances at the time) so the first change had a huge impact (nearly 10% in one car going to semi-synth)

I just changed the 240sx over to redline mt90 so we'll see how that goes


I would tend to think the the effect would be at least as good on an auto, especially since sutos actually pump the fluid around and through small valves and orrifices, not just splash it around like most manuals.

If you haven't yet, I would change the diff oil also. a good semi-synth (i've used valvoline durablnd gearlube in the past) would only cost maybe a dollar more a quart than a quality dino-oil. Even a full synthetic wouldn't be overly expensive since you shouldn't need more than 2-3 quarts. I don't remember all the brick fluid capacities off the top of my head, but most rearends don't need more than 3.

Jeff

[brucepick]

Yeah - I've been meaning to change the rear end fluid out for synthetic. Just didn't get around to it. I'm progressing on changing over the tranny fluid. 2.5 qts swapped at every oil change. It will be due again in just a few weeks.

[smay665949]

Look at getting a high quality synthetic like Amsoil. After I replaced the radiator on my 2001 Impala I topped off with 1 quart of Amsoil ATF and the whole car seemed smoother. I can't wait to change all the transmission fluid. I have already changed the engine over to Amsoil and gained an average of 2-MPG while driving the exact speed limit with the cruise on. I expect a similar gain with a full ATF change. You may also want to look at the gear oil in your rear differential. I have a friend in North Dakota who changed the gear oil in a ford truck in the winter after a 7-degree night. When he pulled the cover the gear oil it was like frozen orange juice and took 2 hours to completely thaw and run out while the Amsoil gear oil that had sat in the back of the truck all night sloshed in the bottle like motor oil. In addition Amsoil can go for longer drain intervals, which makes up for the higher cost.

http://www.lubedealer.com/T&SMay/fea...ductsview.aspx

Good luck,

[8307c4]

I couldn't tell you whether it increases mpg, but what I do know is it prolongs the life of the transmission considerably. I understand most folks never do it, I didn't either for many years, but I started about 6-7 years ago and never looked back, doing that stuff is like money in the bank.

Now I don't cycle it, I just do it every 10k miles, drain, replace filter, refill.

[brucepick]

Originally Posted by 8307c4

... Now I don't cycle it, I just do it every 10k miles, drain, replace filter, refill.

I'm glad there's somebody else out there doing this!

As I understand things, you actually are cycling it if you drain and refill. Because draining it only gets out part of the fluid (in my case, 32%). The rest of the fluid is in the torque converter and elsewhere in the system like cooling lines.

You can check your owners manual for the total system capacity and see how much drains out of the pan. Mine has 7.8 qt capacity and 2.5 qt drains from the pan. That's the 32%.

I built a spreadsheet that calculates the % of new fluid in the system after x number of drain/fill cycles. I'm one of those obsessive nerdy types.

For Volvo rwd auto trannies we don't change the filter/screen. Even Volvo recommends leaving it alone. I'm good with that because changing it is a PITA, you have to remove the dipstick tube which sometimes breaks etc. etc. Dunno about your car - if changing the filter is a reasonable process then doing it makes sense to me.

[Brontegirl]

This thread is very imformative. My car is 6-years old with 66k miles and I've never had the trans fluid flushed. Per the manual, it is not due until 100k but keep in mind that this is the same manual that recommends oil changes every 7,500 miles! No thanks! I'll do it every 3k since my mileage is better and it is better for my car. Now to tackle the trans fluid! And me wondering about my next weekend project!

[Jay2TheRescue]

If the factory is recommending a 100K mile service schedule, they may be putting in synthetic ATF. If you replace synthetic with conventional your mileage may go down.

[Brontegirl]

Originally Posted by Jay2TheRescue

If the factory is recommending a 100K mile service schedule, they may be putting in synthetic ATF. If you replace synthetic with conventional your mileage may go down.

I would be replacing with synthetic.