tranny drain and fill question...

[07JeepXK]

ive been draining and filling my tranny every 15k since 60k, so within the last 30k its had its fluid changed a couple times. lol so there isnt that much old fluid in there.

matt- i like your idea on disconnecting the cooler lines.

Is there a reason why you have been doing it every 15K. Both of my brothers work at transmission shops and say thats not good to do. Something to do with the detergent in the fluid messes up the clutches in the transmission??? I think thats what they said. They always told me if I have a high mileage vehicle (150,000+ miles) to just leave the old transmission fluid in it and dont flush it.

[Matt]

Its not bad to change the fluid frequently as long as its done within the recommended time frame.

If you have an older vehicle that has never had the fluid changed then what happens is the additives break down as well as the trans clutch friction materials wear off due to the lack of functional additives. The friction material becomes suspended in the fluid and almost acts as a friction promoter for the worn clutches. So when you change the fluid in this case, you remove all the clutch material and the new fluid cleans off the worn clutches.... and usually this combination results in a slipping trans.

[HueyPilotVN]

Here is a thread on installing a drain plug / sending unit on the transmission if anyone needs it.

http://www.theultimatejeep.com/showt...pan?highlight=

[Sal-XK]

I know I'm going to catch a bunch of smart a** remarks but every other trans service for me I have the Jeep dealer flush it. I get all the old out well, we all know how it works. Just something I've always done and yes I know Chrysler doesn't recommend it I've read all the posts. All my vehicles last a long time and are in great working order when sold or traded in so pretty much if the system I use aint broke I'm leaving it alone ahahahahha let the flaming begin!

[lekmedm]

I know I'm going to catch a bunch of smart a** remarks but every other trans service for me I have the Jeep dealer flush it. I get all the old out well, we all know how it works. Just something I've always done and yes I know Chrysler doesn't recommend it I've read all the posts. All my vehicles last a long time and are in great working order when sold or traded in so pretty much if the system I use aint broke I'm leaving it alone ahahahahha let the flaming begin!

I think the whole issue starts with when you take ownership of the vehicle. If you've owned it since [nearly] new, then you can do fluid changes once a month if you like and always have a great running trans. I think it gets trick when you buy a higher mileage vehicle, and you don't know the service history. That's when you can get into a situation like Matt described. Also, for a trans flush, I think the machine pumps the fluid in the opposite direction of the normal trans pump. It's not recommended by Chrysler because that would mean the fluid is backing out of the filters sending those particles back into the trans. Other vehicles don't use filters, but screens instead. Supposedly, trans flushes are OK with those types. Then again, I'm no transmission mechanic. This is just what I've heard/read/made sense.

[paroxysym]

just for future reference for everyone.. per matts advice, ordered from wholesale-mopar and saved myself roughly $20-$25, thats with all parts/fluids shipped. still saved myself money.

[Synthetic Advantage]

Matt pretty much hit it on the head. Installing a drain plug and then doing fluid drains every 30k with regular ATF is a great way to keep the transmission in great shape with good fluid. You can extend that drain to 50k at a time switching over to synthetic ATF.

[duneslider]

All ATF+4 is synthetic. I would stick with the recommended change interval at the very least. 30k for transmission is a good interval.

[07JeepXK]

I will probably service my transmission in the next couple weeks. I did it at 75,000 like the owners manual says and im now at 118,000 miles. My fluid still looks brand new but I know it could use a swap.

[Matt]

I bet their trans "flush" is really just a fluid transfer like I described with the buckets.... except its a machine that does the pumping instead of the trans. No big deal with that.

I think Chrysler recommends staying away from flushes the push a cleaning solution through....