To flush, or not to flush, that is the question....

[John SD]

Bought a new to me 2000 Dodge 3/4T with V10 and auto tranny :banana: Has just under 100K miles on it.

This is the pickup in its everyday clothes before I bought it. It's sporting DeeZee aluminum treadplate running board and bed rails now. 8)http://boa.sd.gov/divisions/property/im ... /CJ088.JPG

Would an auto trans flush with new fluid and filter be good PM, or if it ain't broke, don't fix it?


Trans has good clean crisp shifts and the fluid looks and smells good. TIA for replies.

 

[skyhightree1]

Bought a new to me 2000 Dodge 3/4T with V10 and auto tranny :banana: Has just under 100K miles on it.

Would an auto trans flush with new fluid and filter be good PM, or if it ain't broke, don't fix it?


Trans has good clean crisp shifts and the fluid looks and smells good. TIA for replies.

Any used auto vehicle I buy I do a complete flush and filter change. It can't hurt. I do a line flush where it pumps all old out and pumps new in not a drain and re-fill.

 

[James T]

That's a tough call. Logic says change the fluid and any filters but, I have had transmission specialists tell me to leave it be unless I know it was changed regularly before I bought the vehicle. Not clear on why but it had something to do with the seals.

 

[skyhightree1]

With me I change all fluids and filters to my specs and my maint program that's everything for me whether a generator or a track loader. There is a reason why you call PM ..PM to try to prevent problems.

 

[lavacarancher]

Yes sir, good idea to flush and filter change. Take it to a transmission shop where they can get the old fluid out of the convertor before adding the new stuff. Just draining the pan only gets less than a forth of the old fluid out so when you put the new stuff back in you've contaminated it already.

 

[Calhoun Farm]

Depends on what you're calling a flush. I always heard not to flush higher mileage auto transmissions because it stirs up the metal shavings that have settled over time and will mess up the valve body and clog things up. Draining the fluid and changing the filters should be fine, but I myself wouldn't let some fly by night oil change place hook a pump up and run clean fluid thru it "flushing" the transmission.

 

[Mat Man]

A few years ago i bought wife a used car.
I flushed trans and changed oil and filters the week i bought it.
The next week rev. started acting up.
A week after that we had to put trans. in it.
Dang if you do/dang if you dont?

 

[James T]

I believe it. Calhoun filled in nicely about how changing it might screw things up. The specialist who had told me that said if you had a new car then change the trans fluid as per the maintenance schedule for that vehicle. Otherwise, leave it alone. If you purchase an older vehicle and change out the trans fluid your taking a big chance. If you have money to burn then I guess it does'nt matter much.

 

[Calhoun Farm]

Totally different vehicle, but I have an 03 accord I use for a work car. The correct way to change the fluid in it is to drain/refill the fluid three times. No flushing just changing fluid. After the third time of the drain/refill you can drive the car for around 50k miles.

 

[skyhightree1]

Totally different vehicle, but I have an 03 accord I use for a work car. The correct way to change the fluid in it is to drain/refill the fluid three times. No flushing just changing fluid. After the third time of the drain/refill you can drive the car for around 50k miles.

The machine I have you hook to the tranny lines and it siphons out the old while pumping in the new and you can see the color on th emachine and when you get consistent new you stop the machine and hook the lines back up.

 

[lavacarancher]

Totally different vehicle, but I have an 03 accord I use for a work car. The correct way to change the fluid in it is to drain/refill the fluid three times. No flushing just changing fluid. After the third time of the drain/refill you can drive the car for around 50k miles.

The machine I have you hook to the tranny lines and it siphons out the old while pumping in the new and you can see the color on th emachine and when you get consistent new you stop the machine and hook the lines back up.

YES, this is what I was talking about. Most of these types of machines have a sub-micron filter associated with them. Another common term for this type of machine is filter stand. This is what most of the competent transmission shops have and use. I don't know what you folks mean who are saying don't "flush" the transmission. When I say flush I mean get ALL the crap out of the transmission and clean the pan out - sorry, clean the TRANSMISSION pan out and change the transmission filter while you have the transmission pan off. Don't use a gasket sealer when putting the transmission pan back on unless you know what the heII you're doing. The reason I am saying to "flush" the transmission is because draining the oil only gets about 2 qts of fluid (or less) out. The other 10 to 12 qts is locked up in the torque convertor with no way to get it out unless it has a plug on it. The vains on the inside of the convertor will hold dirt, microscopic pieces of clutch material and metal shavings which will not come out with a simple drain. Man, you sure have to be careful what you say on here otherwise folks don't get it.

 

[skyhightree1]

Lava, I said the same thing go figure. :lol: I guess I didn't learn a thing out of my automotive classes I took for 3 years in high school :lol2:

 

[Calhoun Farm]

Totally different vehicle, but I have an 03 accord I use for a work car. The correct way to change the fluid in it is to drain/refill the fluid three times. No flushing just changing fluid. After the third time of the drain/refill you can drive the car for around 50k miles.

The machine I have you hook to the tranny lines and it siphons out the old while pumping in the new and you can see the color on th emachine and when you get consistent new you stop the machine and hook the lines back up.

What you're describing here is what I've heard of people doing and it stirring up shavings/junk in the crevasses and ends up killing the transmission. To each there own.

 

[skyhightree1]

Totally different vehicle, but I have an 03 accord I use for a work car. The correct way to change the fluid in it is to drain/refill the fluid three times. No flushing just changing fluid. After the third time of the drain/refill you can drive the car for around 50k miles.

The machine I have you hook to the tranny lines and it siphons out the old while pumping in the new and you can see the color on th emachine and when you get consistent new you stop the machine and hook the lines back up.

What you're describing here is what I've heard of people doing and it stirring up shavings/junk in the crevasses and ends up killing the transmission. To each there own.

They must have cheap machines remember you get what you pay for. My machine removes shavings and all fluid well I cant say ALL but it darn sure gets I would bet a years salary of 99% out.

 

[Calhoun Farm]

I'm not a transmission expert by any means so I don't know. I'm just relaying what I've heard/been told about auto transmission in general regarding "flushing". I don't like autos in anything other than passenger cars so my G56 behind my cummins is easy to change the fluid on

 

[skyhightree1]

I'm not a transmission expert by any means so I don't know. I'm just relaying what I've heard/been told about auto transmission in general regarding "flushing". I don't like autos in anything other than passenger cars so my G56 behind my cummins is easy to change the fluid on

lol I buy the machines which is made by snap on and have been using one for years with my trucks and used ones I buy because flushes were costing 300 bucks or more a pop I flush yearly. it seems to be working for me.

 

[Hook]

Most mechanics will tell you of the tans has been flushed regular since the beginning it should be fine. On a neglected tranny, they recc a standard drain and fill sonit doesn't stir things up as mentioned previously