Thoughts on changing transmission fluid

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tmt502

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So my “new to me” Tahoe has 221k on the clock. I’m calling the last shop of service recorded on Carfax (213k was the last service back in February - shows as oil change and tire rotation) tomorrow with hopes to get some input on the service history of the vehicle. Records show they’ve done all of the regular service since 54k miles back in ‘14. Before that was all at the local dealership it was purchased from new. The only exception being a torque converter replacement at 76k miles, which was done at the dealership.

My intent is determine if the service shop, which is also local, has done any transmission maintenance, ever. A couple of the entries on carfax just show “vehicle serviced” with no detail, whereas all others give some detail of the services performed. None of the service details indicate a trans service.

The question I have is this, should I change the trans fluid and filter if it hasn’t been done since the torque converter replacement at 76k? The dealership confirmed For me today that they did replace the fluid and filter along with that service. I’ve heard/read plenty of anecdotes that you shouldn’t change the fluid if it’s never been serviced or hasn’t been serviced over 150k miles (which I’m coincidentally right on), otherwise this will cause the trans to fail in short order for various reasons. It feels strong and shifts great for what little (150ish miles) I’ve been able to drive it over the last few days I’ve owned it.

If that’s the case, should I just plan on replacing the trans to remedy this? This is a second vehicle I use for work travel (I’m an engineer that visits project sites and clients), but I plan to start towing with it soon too.

I’d appreciate some input. Thanks!
 

swathdiver

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So my “new to me” Tahoe has 221k on the clock. I’m calling the last shop of service recorded on Carfax (213k was the last service back in February - shows as oil change and tire rotation) tomorrow with hopes to get some input on the service history of the vehicle. Records show they’ve done all of the regular service since 54k miles back in ‘14. Before that was all at the local dealership it was purchased from new. The only exception being a torque converter replacement at 76k miles, which was done at the dealership.

My intent is determine if the service shop, which is also local, has done any transmission maintenance, ever. A couple of the entries on carfax just show “vehicle serviced” with no detail, whereas all others give some detail of the services performed. None of the service details indicate a trans service.

The question I have is this, should I change the trans fluid and filter if it hasn’t been done since the torque converter replacement at 76k? The dealership confirmed For me today that they did replace the fluid and filter along with that service. I’ve heard/read plenty of anecdotes that you shouldn’t change the fluid if it’s never been serviced or hasn’t been serviced over 150k miles (which I’m coincidentally right on), otherwise this will cause the trans to fail in short order for various reasons. It feels strong and shifts great for what little (150ish miles) I’ve been able to drive it over the last few days I’ve owned it.

If that’s the case, should I just plan on replacing the trans to remedy this? This is a second vehicle I use for work travel (I’m an engineer that visits project sites and clients), but I plan to start towing with it soon too.

I’d appreciate some input. Thanks!

These 6-speeds are a different animal, change it.

I called the dealerships that serviced my truck before I bought it. One asked for proof of ownership which I emailed and they sent over all the service records right away. The other dealer emailed them to me on my honor.
 

ivin74

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I did the first tranny oil change at 170k, no issues what so ever and it's been over a year.
 

kbuskill

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Have you looked at the transmission fluid on the dipstick? How does it look and smell?
 
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tmt502

tmt502

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Have you looked at the transmission fluid on the dipstick? How does it look and smell?

I have. It has some brownish tint, but still a little pink on a white paper towel. Faint smell of ATF fluid, but not as strong as new. Not sure if that makes sense...
 

kbuskill

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I have. It has some brownish tint, but still a little pink on a white paper towel. Faint smell of ATF fluid, but not as strong as new. Not sure if that makes sense...

My guess is that it has been serviced at least once since the torque converter swap... but again, just a guess.

If it's not slipping or giving any indications of problems then I wouldn't be afraid to service it.

I flushed mine using the transmission cooler line method and refilled with full synthetic Dex 6 at 208k miles and haven't had a single issue. That was about 45k miles ago and I have the 4L60E 4 speed transmission.
 
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Hook up a Tech2 and see what % the trans oil life monitor is at. If a dealership did any trans service they should've reset it, much like the engine oil life monitor.

Sent from my SM-G930V using Tapatalk
 

cfmistry

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Definitely sounds like yours has been changed before. I’d go ahead and replace it, but be mindful that your transmission could be near the end of its life with that mileage.
 
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tmt502

tmt502

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So I got in touch with the local service shop. They confirmed they don't have records of a transmission service being performed there. I went ahead and asked them to quote me a Jasper transmission and rear main seal replacement. We'll see what they come back with and I'll let y'all know what I decide to do.

Any thoughts on Jasper transmissions?
 

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