Economics of auto transmission maintenence

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Never seen hard proof that frequent changes or boutique fluid ensures auto transmission life, but likely most here are confident it does. When you look at the expense and inconvenience of a transmission failure, and balance this with the relative pittance of overkill maintenance, penny pinching might be foolish.

I've had a mix of manual and auto transmission cars and have generally followed an overkill schedule on the auto trans cars and have had mostly good service. I'm running Transynd in my 2003 Silverado and doing full replacement (Hoot method) at 25K intervals. It currently has 45K miles on it. My 2000 Concorde got fluid and filter at 60K (bought it used) and several dip stick pump outs at 120K miles. It currently has 140K miles.

I suppose transmission expense paranoia drives my fluid regimen, even though I would rebuild myself if one failed. The job would be difficult to remove without a lift and a transmission jack.

Anyone else driven to overkill maintenance due to fear of auto transmission replacement or rebuild expense? What overkill steps do you take?
 
Clean fluid will not stop low quality parts from failing but will add to the life of the components that do not break.
 
I replace 2 litres of redine MTL annually, replaced both driveshaft oil seals and replaced the diff rivets for bolts when I first got the car, and more recently replaced the linkages with heim joints although more for enjoyment than maintenance.

It's just a whole lot easier than worrying about having to pull the whole box out for maintenance
smile.gif
 
I've had 4 Chrysler minivans that are known for bad transmission. 1996-8- and two 99s. I don't do much maintenance at all for a transmission. Fluid and filter every 100,000 miles if not longer. Instead, I drive them very easy and I've never had one fail.
 
I'm overkill with the maintenance because failures are expensive. IMO the odds of getting a rebuilt unit to be as good as the OE unit are slim to none without quite a bit of down time and luck.
 
Absolutely worth it.

I got a 92 cutlass ciera for $400 and the seller was kinda fishy and didn't want me driving it around the block because he "didn't have insurance". I then found that 1st was the only strong gear and I had to feather it through the upper gears.

Got it home and discovered the pan totally full of silt from clutch wear, and the filter presumably clogged, lowering line pressure and entering into a self-destruct feedback loop.

Put a new filter on it, new fluid, some "stop leak" goo to thicken stuff up, and a "red stripe" adjustable modulator. Came right back to life. Gave it to my brother-in-law who got another 18k miles out of the 4T60 tranny before blowing it.

Also helped an 02 corolla 4sp with brown fluid to have new, red fluid in there. Took the moosh out of the shifts.
 
I agree with solid maintenance, but do not live in fear of a failure.

I had a friend that had a transmission slipping at about 110,000 miles. He did a pan drop and refill every 5000 miles for 15,000 miles. After that, the transmission was good for 150,000 more miles. You can't argue with those results.
 
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Auto trans fluid itself doesn't wear out so much. Even if it looks kind of old and smells a little funny, it still usually functions well within it's operating parameters for lube and protection. The fact that the filters in automatic transmissions are so darn coarse is proof that the fluid lives an easy life.... only if kept cool, though.

BY FAR - the biggest killer of auto transmissions is HEAT. I have had automatic transmissions run at max torque capacity for hours on end, and only by having massive amounts of cooling capacity do they stay alive.
 
Most cars never get their transmission fluid changed and go to the junkyard with their original factory fill ATF! Transmission shops say most of the problems they see could've been easily be prevented with fluid changes.

Even a fluid change every 60k or 100k would go a long way. And if it has a drain plug, it's so easy that there's no reason not to do it.

Of course, there are exceptions, like the early 2000's Honda V6 automatics which grenaded by 60k even with annual fluid changes using Z1 from the dealer. But you still shouldn't NOT change it!
 
Originally Posted By: Linctex
Auto trans fluid itself doesn't wear out so much. Even if it looks kind of old and smells a little funny, it still usually functions well within it's operating parameters for lube and protection.

BY FAR - the biggest killer of auto transmissions is HEAT. I have had automatic transmissions run at max torque capacity for hours on end, and only by having massive amounts of cooling capacity do they stay alive.



Transmission fluid will oxidize quicker if overheated and cause varnishing of valving and clutch surfaces. Overheating changes the fluid viscosity and modifies the inhibitor, dispersant, and FM chemistry.

Changing fluid every 30k or so also reduces the particle load of clutch material and steel clutch plate material that the fluid has to carry.

Metal inhibitors only work when there is a low loading of steel clutch plate material. When the loading increases, there is an increased chance of further oxidation and fluid chemical changes.
 
If the design and build of your tranny is without factory defects (terrible GM 4T60 / 4T65, etc) then sticking to the schedule for your use is all that’s needed.

For bad GM trannies you’d need to go further equal to the issues you’ve had, over service with fluid and filters may not help.

For the GM trannies mentioned and P1811 codes, etc, yearly filter changes may be needed most, using Seafoam Trans Tune helps and finding a spot in the pan for more magnets helps too. (not a lot of clearance in there, so watch out)

Using tranny coolers can cause OBDII codes (that don’t set the MIL light) for temp performance that locks out adaptive shifts and TCC! In non-electronic trannies, coolers were great, but it can backfire on newer ones.

Visit Sonnex.com and other aftermarket part makers for the rebuild industry and see if your tranny is listed with lots of upgraded replacement parts, (ie, meaning lots of problems) if so, I’d look at extra specific work to avoid failures once you have an idea of the rebuild industry experience is.
 
I agree with the prevailing sentiments here...

Overkill is overkill. It won't fix a bad design or a broken transmission. Normal, regular ATF replacement (with a suitable high-quality ATF) is good for any automatic transmission.

Temperature control goes both ways. Transmissions are designed to be driven with warm fluid, not cold. If installing an aftermarket ATF cooler, but it in the loop BEFORE the radiator pass-through, so the radiator can warm-up overcooled fluid. That's the reason it passes through the radiator in the first place- not just to cool down hot ATF, but to warm-up cold ATF.
 
Originally Posted By: HangFire
I agree with the prevailing sentiments here...

Overkill is overkill. It won't fix a bad design or a broken transmission. Normal, regular ATF replacement (with a suitable high-quality ATF) is good for any automatic transmission.

Temperature control goes both ways. Transmissions are designed to be driven with warm fluid, not cold. If installing an aftermarket ATF cooler, but it in the loop BEFORE the radiator pass-through, so the radiator can warm-up overcooled fluid. That's the reason it passes through the radiator in the first place- not just to cool down hot ATF, but to warm-up cold ATF.



Good points. Some of the better coolers are designed to somewhat "self-bypass" when the fluid temperature is cold.
The B&M Super Coolers come to mind here.
 
Originally Posted By: HangFire

Temperature control goes both ways. Transmissions are designed to be driven with warm fluid, not cold. If installing an aftermarket ATF cooler, but it in the loop BEFORE the radiator pass-through, so the radiator can warm-up overcooled fluid. That's the reason it passes through the radiator in the first place- not just to cool down hot ATF, but to warm-up cold ATF.


I've never heard anything about this before. I suppose if one drives regularly in arctic temps, warm trans fluid for a manual trans helps too!

Anyone know where I can get a transmission fluid heater?
 
Originally Posted By: HangFire
Transmissions are designed to be driven with warm fluid, not cold.

You should probably sit-down and have a good conversation with my 4L80-E. It's has an OEM cooling setup, and running down the road at speed (tons of air coming through), you have to work hard to get the gauge to move from 100°F in cooler weather.
 
For the minimal cost involved, it only makes sense to give decent maintenance to any gearbox.
It is a bit more trouble than an oil change, but it isn't required nearly as frequently.
Could a little maintenance over the years and miles make the difference between being able to use an original gearbox for the life of a vehicle rather than sending it to the yard because it needs a tranny?
Maybe.
As the OP noted, R&R on an automatic is no joke, especially a FWD with a cradle that will need removal as well as an assembly that will then require that it be held up from the top. Automatics are pretty heavy as well as compared to manuals.
 
Debatable if its overkill but by OE specs I suppose it is. Did my truck ATF at 80k and will do again at 160k (rated for something like 100-150k interval). A lot longer than older stuff but who knows.

Otherwise, I try to stick to a generally OE spec change schedule which I figure is still better than most.
 
Once I owned 1997 Chrysler Stratus 2.5 v6 with A604 tranny
I had read many horror stories on issues with that gearbox prior to purchase
When I got the car, the trans fluid was yellow instead of red and there was lot of jiggle when shifting between N,1 and 2
I kept on changing trans fluid every 2 y or 30 000 kms and had no issues trans. related
 
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