Hi! I recently purchased a used 2013 GMC YUKON XL 2WD. My radiator cracked recently and while changing the radiator, I noticed that the transmission cooler lines were leaking. Upon close inspection, the ATF oil seems to be dark/burnt. When I Carfax checked service History I don't think the previous owner ever changed it as per maintenance schedules. My question is, is it okay if I change the Transmission fluid and the filter if the vehicle never been serviced for this before? Can it cause Transmission slippage? It seems like the vehicle was towed prior as the tow hook cover is missing. Any suggestions on this appreciated.
Question: Should I change ATF fluid and Trans filter for the first time at 150k miles?
- Thread starter Gideon K
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I can only tell you what I would do in your shoes. Depending on the time and money I have at hand, I would either take it to a place like Grease Monkey or Valvoline instant oil change and have them do a complete fluid exchange, or take it to a transmission shop and have them drop the pan and do a proper drain and refill with a new filter.
Yes, there is risk that you could disturb something in the transmission and cause problems, but with the 6L80E, in my opinion that risk is low, and that by changing the fluid you will prolong the life of it.
I had mine done when they dropped the transmission to install an upgraded TC, so I don't know. But, a call to a top rated transmission shop will net you a pretty solid estimate. I'm guessing around $200 in labor, plus fluid.
I agree with Dave @Geotrash. I wouldn't personally go for a "flush" service, even though some pretty big reputable shops offer it. I would have the ATF and filter changed by someone who did it all the time. I would do it again in maybe 10-20K miles, then go on an every 50K cycle.
In the end, these transmissions don't last forever, so I would start squirreling away a little each month for the eventual reman replacement. Figure about $2500-3K for the job, with a top specialist.
In the end, these transmissions don't last forever, so I would start squirreling away a little each month for the eventual reman replacement. Figure about $2500-3K for the job, with a top specialist.
Maybe there's a difference between a power flush the way you're thinking of it and a fluid exchange the way I'm thinking of it. With the fluid exchange, Grease Monkey or Valvoline just hook up their machine to the transmission cooler lines, and for every quart the transmission pumps into their machine, they return a quart of fresh transmission fluid into the transmission. I've never had any problems after having this particular service done, even on cars with 200K that I'm reasonably sure never had their fluid changed.
IMO, I would do just the trans filter and top off what ever fluid is lost. Then you have fresh fluid mixed in with the old fluid but not at full strength because of the mix. Do again in 10k-15k miles intervals and soon you will have more and more fresh fluid in there and each time a new filter will help trap more and more particles of nastiness in there.
As far as a complete blow to the heart with all fresh fluid, I would not do it but that is just me. Starting with a new vehicle, I am a-n-a-l enough that I do the filter every 30k miles and a complete swap of fluid at the 60k interval. I drive the crap out of my rigs, so I do my maintenance intervals closer than other people. Except for one time when I had an accident, I have never been towed in off the road since 16 years old. I will spend extra money to avoid "uncertainty".
As far as a complete blow to the heart with all fresh fluid, I would not do it but that is just me. Starting with a new vehicle, I am a-n-a-l enough that I do the filter every 30k miles and a complete swap of fluid at the 60k interval. I drive the crap out of my rigs, so I do my maintenance intervals closer than other people. Except for one time when I had an accident, I have never been towed in off the road since 16 years old. I will spend extra money to avoid "uncertainty".
Thanks for the suggestion @PNW VietVet . I might consider changing the filter and top off fluid and repeat after 20K miles.
I actually don't know if there is a difference between what you describe with one of the oil change guys and what I have referred to as a "flush".
My only point of reference is the guy who installed my reman transmission (emergency on the road, far from home, but a really quality individual). He said when it comes time to change your transmission fluid (he recommended I do it every 30K, but I think he was under the impression I was still towing a lot in those days, which I wasn't). He said drop the pan, replace the filter and refill that which you drained with that process. He said never let anyone "power flush" your transmission when replacing the ATF.
The problem is I don't know if what he was referring to was the "Valvoline oil change place hooking the machine to the transmission cooler ports and changing the ATF", or if it was something altogether different (which I suspect it is). For some reason, I was under the impression the "power flush" also included dropping the pan, but am not sure where I got that. I also remember him saying it was "good" to have your transmission cooler "power flushed".
If gonna do an ATF flush, I agree with @Geotrash. You attach at the trans cooling lines and start the engine and let the trans pump swap out the fluid. The trans flush machine does not use any pressure to do the swap.
donjetman
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I would do a complete fluid and filter change.
40k miles ago, when we bought our very used Denali w/6L80 tranny, that's what I did. It's still going strong at 170k miles. But I did change the torque converter at the same time as a preventative mx measure.
40k miles ago, when we bought our very used Denali w/6L80 tranny, that's what I did. It's still going strong at 170k miles. But I did change the torque converter at the same time as a preventative mx measure.
alpha_omega
Full Access Member
Do a complete change. Don’t let your fluid get anywhere near as bad as the previous owner let mine get. I’ll be lucky if I get another change in 30k out of mine without a rebuild close by.
Doing a fluid exchange is pretty simple if you have the know-how and access to some tools. You might even consider looking at a new pan that has a drain plug since you’re going be doing another drain here shortly. B&M makes a real nice pan, but they aren’t nice on the wallet. I liked everything about their pan…except for the mounting hardware. Who uses allen head bolts on a transmission pan? For the cost of it they could have thrown in ARP hex’s or even their 12pt bolts.
Let us know if you need info on doing an exchange. There are some good “how-to” videos and a couple good step by step’s (with photos). Here’s a good one that will give you an idea of what is involved. Different tranny but the same principles apply.
www.gmfullsize.com
Doing a fluid exchange is pretty simple if you have the know-how and access to some tools. You might even consider looking at a new pan that has a drain plug since you’re going be doing another drain here shortly. B&M makes a real nice pan, but they aren’t nice on the wallet. I liked everything about their pan…except for the mounting hardware. Who uses allen head bolts on a transmission pan? For the cost of it they could have thrown in ARP hex’s or even their 12pt bolts.
Let us know if you need info on doing an exchange. There are some good “how-to” videos and a couple good step by step’s (with photos). Here’s a good one that will give you an idea of what is involved. Different tranny but the same principles apply.
How To: 4l60e Transmission Flush/Filter Change
