How often should you change the transmission fluid? I've had people tell me to not bother with it if it still looks good and works okay because changing it can mess up the transmission. It seem to me that you should change it at least every 50,000 miles. Mine currently has 235,000 on it and it still looks okay, but I am not sure if it has ever been changed. I will say that the torque converter in my f250 went out only about 1,000 miles after I changed the fluid and filter, it could have gone out anyway I guess with 120,000 miles on it. I fixed all that though by swapping in a manual.

 

Expect mixed responses. Trans fluid is a tricky subject, just like asking someone, "how often should I change my oil?".

My opinion is change it. I have had several vehicles over the years that have had over 100,000 miles on them when I purchased them, two had over 200,000 miles. On every vehicle I buy, I change the trans fluid asap. My theory is that changing the fluid is really the only maintenance you can do to a transmission.

I have never had one failure on a transmission as a result of changing the fluid.

 

1. Old ideas were often right in their day, but they can outlive their day. For older transmissions, it might have been true that you should leave them alone. It's not true for the AW4.
2. High pressure transmission "flushes" done by some shops can break loose crud and plug passages, leading to catastrophic failure. This gives "flushes" a bad name.
3. There are also low-pressure "flushes" done by some shops which ONLY use the transmission's own pump to circulate new fluid through the system. These do no harm.
4. A lot of people use the term "flush" very loosely when it comes to transmissions, so you get people confusing changing the fluid several times at short intervals a flush, and some people calling the high pressure flushes a flush, and some people calling a low pressure fluid replacement a flush. Ergo, confusion.

Change your fluid. It's a good thing.

See my sig for a poor man's version of #3. Saved my transmission something like 40k miles ago. I'm due for another one, come to think of it.

 

hijacking the question to ask my own. do you need to drop the pan when flushing the trans (is there a filter to change?) or you can drain it and fill with new fluid from the dipstick? i rencently found a receipt from the PO showing a trans fluid change at 100k km, and now I'm a few shy of 200k, so I wanna do it but have not found a definite answer

 

According to the owners manual that came in my '99 you should change trans fluid & filter every 24 months if you don't have a lot of off road or stop & go, trailer pulling. If you do a lot of off road or the other listed then it should be changed every 12,000 miles

 

Hijacking is never nice! buuttt....

1. No need to change the filter, plainly put it's a huge waste of time
2. You do not need to drop the pan, the drain plug takes care of it
3. A nice funnel and a steady hand and you fill her up straight through that dipstick tube up top!

 

Light/normal duty every 30,000 miles. drain and refill with dex/Merc fluid.

Severe duty, do the same every 15,000 miles.

 

Yes, but there are funnels.... and there are funnels....






That's not a nice funnel.


This is a .






I picked one up at Advance Auto a few weeks ago. Very nice. It's got a lid that goes over the big part, and a captive plug for the small end. Also a valve that keeps the fluid in the tank until you want it to flow, and the side is graduated so you can put in just exactly the amount you want to put in, and you will know how much that is.

So, now you can buy trans fluid in the gallon jugs and save a little coin, instead of having to buy quarts. Oh, and then you are going on a trip and you are almost a quart down and you don't want to overfill so you are guessing about how much to put in...

This lets you be very precise.

BONUS: because of the plug and lid the inside stays clean.

That is a nice funnel.

 

Why do you not need to change the filter?

 

It's a screen, not a filter.

 

Let's see where it mentions this "filter". Post up a pic of that page in the manual please.

 

Why didn't you tell me I can't read?


Can't get the d****d file to stay open when I send.

 

'99 Maintenance Schedule A and B. Trans fluid change.

 

Is it a good idea to take it out and clean it with brake cleaner or something, or just leave it be and drain and refill?

 

leave it be.