Is a transmission flush bad at high miles?

[Q_SHIP]

My father has always told me that Im better off leaving the trans alone in a car with high miles and you are unsure if it has been changed on a regular basis. He says that there is a high risk of failure if it has been a Very long time since the last service. Any truth in this?

[guadofreak]

That is the rule I have always heard. And Have seen it come VERY true on multiple occasions.

Always a high mile unknown service history. It either helps out or finishes off the transmission shortly. It's a gamble IMO.

[Jesda]

Examine the fluid. Nasty or just dirty? If nasty, just drain and fill every 6 months until it looks better, and change the filter.

If its dirty but not yet like coffee, then flush!

[maxnix]

Never understood how removing decayed fluid and its transmission detritus can be harmful. If your transmission is shot, it is shot, period.

Doesn't anyone ever read Q45tech's posts?

[Jesda]

If your transmission is shot, it is shot, period.

^^Youthful slang for "I agree with you, sir."

[Q_SHIP]

Doesn't anyone ever read Q45tech's posts?

Im usually tired by the 3rd paragraph.

He is very smart and informative though.

[Q45tech]

The BG machine has a sight tube and a sample valve to see and do the white paper towel comparison.

My guess is about 33% of the time a flush does not come out perfect [the new ATF color is not as brand new]. We try to talk the owner into another immediate flush since the machines is already connected........save about 15 minutes [$20] plus a can of conditioner and flush/solvent [Another $15] so we do the 2nd flush for $90 or to come back in 30 days for another flush.

At half the time we are successful in talking the 3rd into it.

We can see from the backpressure and time of the exchange [3.5 minutes max] the condition of the transmission pump and seals.

Customers try to blame shops and sometimes try to sucker them into to work [knowing from another shop that the transmission is about to fail] to get them to pay for a new transmission. This is the reason most don't want to do the service on old abused trannies.

We just note that the transmission fluid is bad and the results are variable and assume no reponsibility for future work and make customer sign the work order in advance.

To my knoweledge we have never had a Q/J/G/LS/GS/SC fail immediately after the flush service. But we do a test drive prior to make sure all the gears are there and decent shifting.

I would always recommend a pan drop and filter change prior to the first flush...........that way we see the amount of metal on the magnet and worn clutch sludge/breakdown prouducts in the pan.

Choices are simple do nothing and wait or try everything to prolong the day of reconning.

[elwesso]

I agree with tech, you should do pan drop first... Clean al lthe crap out and see how it looks inside, and at least get SOME Fresh fluid in there..

[Q45tech]

I guess I should point out that we do very few Q transmission replacements now as most of out customer have already had a replacement [OR TWO] [with a external cooler mandatory].

Most of our trannies now go into Lexus vehicles

The act of shelling out the $3k taught most of them a lesson so they come in for their annual transmission flush now...........we have a customer that gets a flush every other oil change [we told him that's way way over kill] $250 a year but he insists.

[nuQ]

don't want to get too off subject here, but, if the fluid is changed yearly,(along with having an ext. cooler installed) is spending the extra money on synthetic trans fluid worth it? definitely raises the cost of fluid replacement for those of us on a budget (although i use mobil1 now).

[Q45tech]

Dirt [worn clutch/friction material] is one thing and fluid degradation from heat, shearing and oxygen is another. Internal seal changes from heat is a third.

I have gone back to conventional bulk ATF [Exxon/Mobil 111h] with Lubeguard flushed every year just easier for me.......as the ATF comes out almost as new color. But then again I've only got 100k on transmission number 3.

With the engine at 305k I expect some serious failures some time in the next 3-4 years.

[maxnix]

If you warm it up every time before you drive and don't do hills, cities, nor high speeds, nor drive in the summer, probably not.

The synthetics will provide a wider range of operating temperatures and resist high temperature breakdown better.

Like oil, the best ATF is fresh ATF.

I believe in Q45tech's 176K regimen of M1 frequently with pan drops for his second OEM transmission and his documented almost zero degradation in performance when he sold it.

[Jesda]

Is PA hot and humid? If so, go synth.

[elwesso]

I have gone back to conventional bulk ATF [Exxon/Mobil 111h] with Lubeguard flushed every year just easier for me.......as the ATF comes out almost as new color. But then again I've only got 100k on transmission number 3.

This is what I do personally and highly recommend it over using synthetic and going longer.

[Jesda]

So the NICO-approved method of transmission maintenance has changed? What the hell? After all these years espousing the resistance-to-breakdown-under-heat advantages of Mobil 1?

Screw it. I'm going to fill my transmission with red kool aid and flush it each day with a garden hose until you folks make up your minds.

[IvoryJ30t]

Dirt [worn clutch/friction material] is one thing and fluid degradation from heat, shearing and oxygen is another. Internal seal changes from heat is a third.

I have gone back to conventional bulk ATF [Exxon/Mobil 111h] with Lubeguard flushed every year just easier for me.......as the ATF comes out almost as new color. But then again I've only got 100k on transmission number 3.

With the engine at 305k I expect some serious failures some time in the next 3-4 years.

actually, i have a quick question.

last time i did a flush, i drove the car for 15 minutes with the BG at quick flush in, and then let the car sit [not running] for an hour before i actually connected the bg machine.

is it bad to let the bg flush solvent sit in the trans [1 hour] or drive while it is installed?

[maxima trans]

i ran through all the gears while connected, and the flow meter in the sight glass indicated very good pressure [dont remember exactly. it was better than most cars we hook up]

[Q45tech]

I wouldn't think so the cleaner is much milder than the engine versions because the contaminants are different [no fuel] and the ATF doesn't get exposed to water vapor [much] top vent tube.

We always let it circulate 15 minutes on the BG Machine to see the color of ATF and let ATF warm up to operating temp before switching to exchange mode.

[IvoryJ30t]

good, i was afraid that i had redeposited the contaminants, or harmed the clutches from the overexposure. next time i have to make sure the front lift is clear before pouring it in.

the flush works very well. the fluid was considerably darker going through the sightglass, than it was before the bg qc treatment.

i put about 13 quarts atf in the machine just to make sure i got it all out.

[Infinitiguy19]

With the engine at 305k I expect some serious failures some time in the next 3-4 years.

This man is the next Nostradamus.

I found this by mistake as I was looking for the Q45 Transmission fluid capacity, Such as what more can do for us!