Teams
Forum List
Toggle sidebar

Transmission flush

isu22andy

isu22andy

Active Member
Sep 17, 2012
423
157
43
33
How often if at all do you flush your cars/trucks transmission ? I have a pickup ive had for ten years with 170,000 miles on it and the transmissions never been touched. When asking a few of my buddies a few say to never touch them or to change the fluid every 40 K one or the other. Whats the thoughts on CF ?? I see some of the new vehicles dont even have transmission dipsticks. Whats the proper protocol to drive one till the wheels fall off, I want to hit 250 K miles.
 
ISUAgronomist said:
With a 170,000 on it and never done before, there's no way I'd touch it.

And +1 to never allowing a pressure flush. Drain and refill only.
Click to expand...

That was my plan was not to touch it , Whats the proper protocol for a new vehicle however ?
 
ISUAgronomist said:
With a 170,000 on it and never done before, there's no way I'd touch it.

And +1 to never allowing a pressure flush. Drain and refill only.
Click to expand...
IMO, this is the right answer. The vehicle's history plays into the decision. If you were talking about a vehicle that had previously had a couple of flushes at regular intervals, I'd say go ahead and do a drain and fill. If it's never been touched, I don't think it's worth the risk of stiring up something damaging.

And as ISUAg said, NEVER do a power flush.
 
I have looked at this a lot, as I have a couple older highline cars that have "lifetime" trans fluid and are supposed to never need replaced. As a result, they are sealed systems, with no dipstick to measure the correct level which is annoying.

My research says "BS". The fluids DO break down over time and need replaced. The problem is, "lifetime" to me might mean 20 years, but to the manufacturer "lifetime" means about 5 years. Then they just sell you a new transmission for $5k when it breaks down.

I do drain and refill on mine every 50k miles. On one car, I just drain and refill like 3-4 iterations, because it's easier to get 90% new trans fluid this way than try to drop the pan and guess on the refill amount.

On the other car, I haven't done it yet (just got it last fall) but not sure if I will do the iterations, or just drop the pan, replace the filter, and hope to figure out the correct amount.

Owner forums for your specific model and youtube DIY videos are your friends!

TLDR:
DO change the fluid if it is 10 years old - drain and refill.

+1000 to the NEVER do a pressure flush, esp on an old car.
 
  • Agree
Reactions: ianoconnor
isu22andy said:
That was my plan was not to touch it , Whats the proper protocol for a new vehicle however ?
Click to expand...

No need to do it, that is what Chevy service keeps telling me.

Had a new transmission put in my pickup at 80,000 miles. Asked the tech if changing the fluid would have prevented the issue, he said no. Asked if I need to flush the system at a given mileage, he said no. I would like to add he is an experienced tech that has some common sense.
 
kingcy said:
No need to do it, that is what Chevy service keeps telling me.
Click to expand...

I struggle with this....like Cascade said, fluids break down. To me, there is no such thing as a transmission fluid that will last the lifetime of a vehicle. Like also mentioned, I feel like stealerships and automakers are more in the business of selling you new cars than they are maintaining and keeping older cars on the roads. However, on the flip side of that, it also wouldn't be good for an automaker's reputation to have transmissions locking up at 100,000 miles because they told their customers that their transmissions didn't need servicing. It would also seem that stealerships would have a vested interest in telling customers that their transmissions need service at certain intervals, as it would be an easy maintenance money maker for them.

In short, not sure what to believe though I don't think I'll let my current vehicle get up over 70,000 miles or so without doing something with the transmission fluid.
 
I had two vehicles, one I drove until 170k miles and another to 198k miles and never did any kind of flush, the vehicles worked just fine. Then again, at those points I felt that the price of any flush would be about the price of the value of the car so I never saw a need.
 
If you pull hard with it and don't have auxiallary coolers I would change the oil every 100k or earlier if there is any discoloration at all. I generally have my vehicles changed every 100k just figuring it doen't cost that much and it won't hurt to get a new filter and oil in it.
 
I get a new filter and fill/change at 100,000. Never have done a power flush thing don't know anything about them.
 
I like to change the filter and fluid, just the stuff in the pan, at 100K and then again at 125-130K if I still have the car. Also, if it starts shifting a little slow or rough. These fluids do break down, as do the parts in the transmission. If you have ever dropped a pan and cleaned the bottom you will find a lot of very fine metal on there and the bottom of the transmission.
 
Have never changed oil in my transmission and don't plan on it. It probably doesn't rank as high in stupidity as different repair shops saying you should change out your brake fluid or charging $600-900 for a brake job but it's pretty close to them. Dealerships make a heck of a lot more in their service department than they do in selling cars so it's just another way to get you in the door and able to charge you $130 / hr. Pressure flushes probably aren't as bad as their reputation, but usually people do them when they start feeling symptoms developing in how the car shifts up or down or if it slips when they're trying to take off. When you start sensing symptoms of a problem, than most likely the pressure flush will finish the transmission off.

Not a lot of heat is built up in transmissions in normal driving conditions unless you pull hard most of the time. Heat is what breaks down lubricants more than anything else. Most are sealed systems now anyways so only contamination that can occur is from metal filings or if too much heat is built up causing the clutch packs to get hot and wear down. When that happens, it isn't caused by you not changing the tranny oil, it's because of how you're driving your car or truck.

Just my 2 cts and it might not be worth that
 
I had a 2005 Chevy Impala that never had any problems until I had the transmission flushed. After I did, the transmission would slip all the time and it needed a new transmission. I asked someone I trust about it and they said that I should never have touched it.
 
I follow what the manufacturer recommends. I make a wild assumption that they know best.
 
It sort of depends on brand and situation.

Dodge/Chrystler suggests early and ofter, used to be every 15,000 miles.

I had a Ford dealer tell me that their are lubed for life. Life span of a transmission now is 150,000 miles.

A mechanic friend told me that if you don't do it regularly then don't do it at all. Even if you drop the pan and change the fluid, the new fluid will melt any sludge that built up and can run that through your transmission. If you haven't done anything, your best bet is to leave it alone.
 
You must log in or register to reply here.

Help Support Us

Become a patron
Top Bottom