Transmission fluid service.

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Jul 22, 2014
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I have a 2011 jeep grand Cherokee laredo. I purchased it usee I dont know any service history when I got it the odometer was at 130 000 ish km no I am at 150 000 ish runs good not problems. I was thinking of having the trans fluid serviced my local garage wanted me to have the BG trans flush serviced done? I was reading flushing is dangerous to transmission? A pan drop would be more suitable? I called a trans shop they said if it isent giving you problems leave it alone. What's my best opinion?
 
Originally Posted by Mattz
I have a 2011 jeep grand Cherokee laredo. I purchased it usee I dont know any service history when I got it the odometer was at 130 000 ish km no I am at 150 000 ish runs good not problems. I was thinking of having the trans fluid serviced my local garage wanted me to have the BG trans flush serviced done? I was reading flushing is dangerous to transmission? A pan drop would be more suitable? I called a trans shop they said if it isent giving you problems leave it alone. What's my best opinion?

I say it is still not too late, just drain and refill using oem fluid and change the filter if there is one. Never flush. I did that before on not too dirty fluid and while it did not make it blowup the shifts are not as good as previously immediately after the flush. If the fluid is really dirty now, I will do multiple drains in a short interval to get it all out and change the filter on the final drain.
 
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I'm a fan of flushing--clean fluid is never bad fluid.

If it wasn't driven hard it's probably not bad, but probably due. You could do drain and fills, but it'd just be faster to do a full exchange IMO. The trans shop doesn't want to be on the hook if anything happens in short order after changing the fluid, coincidence or not.
 
I wouldn't do a flush. I've had problems after a flush.

Perhaps it's the BG machine, perhaps the BG fluid, perhaps it's stirring something up, but my 1990 4 Runner has regular fluid changes, worked perfectly, and I let a shop flush it to change the fluid, and it was never right afterwards, it overheated on the highway, the torque converter wouldn't lock anymore. Just awful.

But a cooler line fluid exchange of all the fluid, including in a 150,000 mile transmission in which the fluid came out black, has always worked great.

Exchange the fluid.
 
^^^^^^^^^^^^

I agree....

I did 3 drain and refills over 6,500 miles on my car with a CVT transmission at 283,500 miles. It has been perfect since and quieter too.
 
A transmission drain & fill...you know, a flush
A disconnected cooling line pump-out.....you know, a flush
A BG transmission flush service....you know, a flush
Some no-name, violently acting, direction reversing pump attachment machine they attach to your car and walk away from.....you know, a flush
You know?
 
That's only 90,000 miles.

IMO you're at the "Fish or Cut Bait" moment. Ask yourself if you're in the financial position to diagnosis/repair any issues which occur post change? If so, then I would consider a simple pan drop w/new filter and keep on trucking.
 
For the record, had two flushes done at the GM dealer on my 6L90. Everything is fine. YRMV.
smile.gif
 
Drop the pan and add OEM ATF.

Flushes are a rip off to the customer and a great profit for the owner of the flush machine.
 
Originally Posted by Kira
A transmission drain & fill...you know, a flush
A disconnected cooling line pump-out.....you know, a flush
A BG transmission flush service....you know, a flush
Some no-name, violently acting, direction reversing pump attachment machine they attach to your car and walk away from.....you know, a flush
You know?


I am not sure you are accurately describing a trans flush machine. It performs two functions, it receives used trans fluid and pushes new fluid into the pan at the same rate it is receiving used fluid. The pump in the transmission is always the one that pushes fluid through the transmission. Nothing is done in reverse flow.

More accurately it is a fluid exchange machine. You can do the same yourself but have to do it by doing 2 or 3 quarts at a time.
 
Looks like your transmission holds about 10qt, and when you drain and fill you'll remove and replace anywhere from 4-6qts of the fluid, I created some dilution tables here to show if you change out the fluid in the pan a couple times roughly how much of each fill will be remaining, assuming it mixes almost perfectly.

Here's a table if you can only get 4qts out at a time
[Linked Image]

Here's a table if you can get 5qts out at a time
[Linked Image]

Here's a table if you can get 6qts out at a time
[Linked Image]
 
Do a pan drop and filter change if applicable. Only use atf+4 or redline c+ in Chrysler, Dodge, Jeep situations. I do not flush transmissions only pan drops or exact fluid exchanges via dipstick. Good luck and welcome to the forum.
 
[/quote] I am not sure you are accurately describing a trans flush machine. It performs two functions, it receives used trans fluid and pushes new fluid into the pan at the same rate it is receiving used fluid. The pump in the transmission is always the one that pushes fluid through the transmission. Nothing is done in reverse flow.
More accurately it is a fluid exchange machine. You can do the same yourself but have to do it by doing 2 or 3 quarts at a time. [/quote]

That's exactly how it works and why in the end it's a more precise, faster and less messy way to do it.
 
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Hi
Is it the 5 speed NAG1 you have?
If so the Jeep dealers over here just drop the pan, change the filter and refill.
 
Kira is right, "flush" is just a fluid drain and replace machine.

What really matters most is the skill of the user and the ATF used.

Transmissions that have had no service ever have been known to die right after the first fluid replacement. Would they have died anyway?

If this question bothers you, ease into a fluid exchange small amounts at a time.
 
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