To flush or not to flush

[yodaddy4200]

My TB has 68,xxx miles and i dont know the service history. I highly doubt whoever traded it in at 56,xxx serviced the tranny/transfer case. I want to keep this thing as tip top as i can so i went to AMCO and told them i wanted to flush the tranny because i thought this was the only way to truly change all of the fluid. AMCO said they would not service my tranny (flush) because all the crap stopping the leak from being a problem will get knocked out by the detergents in the flush and then i will have a problem and they dont want to be obligated to fix it.

My tranny fluid looks pretty good id say. I know there are mixed opinions on this so i wanna know what you guys think.

My leak by the way never drips on the driveway. The only time it has leaked is when i came home from a 200 mile trip 400 round trip. And the next morning i noticed a tennis ball size area where fluid had dripped. So should i get the stealership to flush it they said they would. Is there a safe way to get all the fluid out? Im holding off until i can figure out whats the best option. THANKS GUYS!!

 

[The_Roadie]

The transfer case is a no-brainer - every 50K religiously, never second guess the designer's requirement.

The tranny issue is a folklore item I've heard about 100K+ mile units. I'd ignore that crap, too. Service it as if you owned it from Day 1 and followed the manual.

 

[RayVoy]

Here is a schedule of your maintenance, from GM: GM Chevrolet Owner Centre - Owner Resources - Maintenance Schedule

The recommended service for the tranny is every 50k (light duty), or every 100k (severe duty).


EDIT: I just noticed I gave you the Canadian chart (metric), 83 kilo = 50 k miles

 

[gmcman]

You're at a good time to flush the trans, unless it has been abused and the fluid is black (doubtful) you should have no issues. Check the length of the cooler lines for corrosion, there has been issues of leaks, failures, along the lines.

Just look above the drip spot for the leak, should be fairly easy to spot.

 

[CaptainXL]

The recommended service for the tranny is every 50k (light duty), or every 100k (severe duty).

This is backwards Ray. Should be 100K light duty, severe duty 50K.

It should also be noted that many transmission shops recommend 30K fluid changes regardless of duty. That's about every 2 years for the average family car. Every two years seems like a very reasonable change interval.

 

[yodaddy4200]

My mother in law came over tonight and works at a car dealership. She said when people trade there car in they change the oil and the tranny if it needs it. I think before i do anything im going to call the stealership and see if they have a service record at all of stuff they did when the vehicle was traded in. If they didnt do it/dont have the record ill get er serviced and probably just do the tranfer case myself. Thanks again guys!!

 

[CaptainXL]

That's the best thing to do. I know some dealerships take pride in what they sell. They know a knowledgeable person will check the fluids. Changing all the fluids in a car up on a rack takes all but one hour. This includes the tranny as well. You can see if they did it but if you really want to know just check the fluid color yourself. For instance if the tranny never had a flush before taking hold of it you would be able to tell if you know what color fresh tranny fluid looks like on a white rag.

 

[triz]

For the most part. I know dealerships do change the oil. Don't really think they service the trans unless it needs it. But as always I would skip the dino oil and drop some good quality synthetic. I've seen too many horror shows this week on my other forums. Here is some info for you.

CAPACITIES:
Engine, with filter..........7 quarts [1]
Cooling System, Initial Fill..........13.7 quarts
AMSOIL Antifreeze and Engine Coolant
Automatic Transmission, 4L60-E Initial Fill..........5 quarts
Automatic Transmission, Total Fill
4 speed 4L60-E..........11.2 quarts
Differential, Front..........1.7 pints [2]
Differential, Rear..........4 pints [2]
Transfer Case, NVG126..........3.8 pints [3]
Transfer Case, NVG226..........3.8 pints [3]
[1] After refill check oil level.
[2] Synthetic lubricant, GM part no. 12378261,
or equivalent product formulated to meet
GM specification 9986115.
[3] Identification: check tag on case.
TORQUES:
Oil Drain Plug.....19 ft/lbs
Transfer Case NV126,226
Fill Plug 20 ft/lbs
Drain Plug 20 ft/lbs

 

[hockeyman]

Since purchasing my Envoy in July of 2012 with 118k on it, I've changed all of the fluids myself -even the brake and power steering fluids. Although, I went mostly with fluids that are required. The only synthetic fluid I used was in the front and rear differential where I used Valvoline Full Synthetic 75w90.

The coolant is the only fluid that I haven't changed thus far. And now that I'm thinking of it, it'll be change it this week. I'll also install a new thermostat while I'm changing the coolant.

 

[triz]

Since purchasing my Envoy in July of 2012 with 118k on it, I've changed all of the fluids myself -even the brake and power steering fluids. Although, I went mostly with fluids that are required. The only synthetic fluid I used was in the front and rear differential where I used Valvoline Full Synthetic 75w90.

The coolant is the only fluid that I haven't changed thus far. And now that I'm thinking of it, it'll be change it this week. I'll also install a new thermostat while I'm changing the coolant.

Its definitely due. Its rated to be changed at 100k. The Dexcool coolant is what I used. A bottle of Coolant Boost helps with the burping process but the Trailblazer burps fairly well.

 

[meerschm]

Title brought me back to the year I lived in a co-op in college. the over-zealous water conservation crew posted signs in the bathrooms. if it's yellow, let it mellow, if it's brown, flush it down.

(not suggesting this is apropriate, but just sharing.)

back to your transmission, what color is the fluid?

 

[Pittdawg]

I bought my Envoy with ~40k miles on it. It came with a "free" 1 year maintenance plan. On my last "free" oil change the stealership told me the tranny fluid "looked pretty dirty" and recommended a full flush and fluid replacement (the "BG" Flush?). I was skeptical but went ahead anyways. I have to admit that the tranny shifted smoother afterwards and the slight slip has all but disappeared. It now gives me some piece of mind I had this done at around 60k miles.

 

[CaptainXL]

The coolant is the only fluid that I haven't changed thus far. And now that I'm thinking of it, it'll be change it this week. I'll also install a new thermostat while I'm changing the coolant.

It's possible that given the year of your vehicle that the thermostat along with the coolant has already been changed recently. How does the coolant look? And why change a thermostat that is working properly when your water pump is usually the next thing to go heading towards 150K? I would just hate to see you doubling or maybe even tripling your time and money spent replacing coolant related parts one one after another.

If the coolant is good a better strategy is to do this....Replace everything all at once and be done with all of it. For instance when the water pump or thermostat actually go bad replace the thermostat, coolant temp sensor, water pump, coolant, the hoses and radiator cap at that time as well. See, now everything is done and you dont need to worry about when the next cooling related item might fail for hopefully a long time.

Another strategy is to treat all of the components in the cooling system as preventative maintenance. For instance set a time in the future (say 150k miles) when all of those parts are changed out for new.

You might be saying this is reaching a bit too far. But not really considering the main cause of engine failure is failure of the cooling system.

Its definitely due. Its rated to be changed at 100k. The Dexcool coolant is what I used. A bottle of Coolant Boost helps with the burping process but the Trailblazer burps fairly well.

Dexcool change interval is in the owners manual. It is every 5 years or 150, 000. Whichever comes first.

 

[Playsinsnow]

Since purchasing my Envoy in July of 2012 with 118k on it, I've changed all of the fluids myself -even the brake and power steering fluids. Although, I went mostly with fluids that are required. The only synthetic fluid I used was in the front and rear differential where I used Valvoline Full Synthetic 75w90.

The coolant is the only fluid that I haven't changed thus far. And now that I'm thinking of it, it'll be change it this week. I'll also install a new thermostat while I'm changing the coolant.

I agree with CaptainXL. If the owner in 2008 followed the five years interval you're due again soon. I would recommend doing what I did and buy a $4 coolant tester and see what your coolant tests to. Water pump is on borrowed time if it has not been replaced. Check the water pump pulley with belt off and see how it feels when you spin it. These two things could save you a lot of meaningless time spent.

Thermostat will throw a code before it does anything that could ruin you. At least mine did. I changed the ECT sensor because it was right there next to thermostat.

 

[yodaddy4200]

So i couldn't get a hold of chevy today to ask them if they serviced the tranny before i made the purchase. Called em three times and left a voicemail. Anyways my mother in law is driving my TB to work tomorrow and going to have the mechanics just see what they think of the leak. Im one thousand miles away from my oil change so ill have them do it as well. im going to look into full synthetic oil. It seems like its pretty popular. I dont want to make that decision without doing some research first. THANKS TO AL THAT REPLIED!! Ill keep ya posted!!

 

[CaptainXL]

I bought my Envoy with ~40k miles on it. It came with a "free" 1 year maintenance plan. On my last "free" oil change the stealership told me the tranny fluid "looked pretty dirty" and recommended a full flush and fluid replacement (the "BG" Flush?). I was skeptical but went ahead anyways. I have to admit that the tranny shifted smoother afterwards and the slight slip has all but disappeared. It now gives me some piece of mind I had this done at around 60k miles.

One year now going on the dealer Wynns transmission flush. We have towed our 6000 lb pound trailer over 1000 miles all over Michigan with no problems at all. It shifts great. Seems to be better each day. Must be the Dexron VI they put in it. It used to have the Dexron III. This year Ineed to drop the pan to change the filter and magnet. If the transmission fluid is old or somewhat burnt and you need to get it all out then I highly recommend the dealer trans flush. Make sure to ask for the Dexron VI instead. Not even sure dealers use Dexron III anymore.

 

[triz]

Thanks for the correction Captain. Owners manual is 150k miles. I changed it a bit early at one point since the water pump and thermostat went out right around 100k. I'm at 121k miles right now.

 

[CaptainXL]

Thanks for the correction CaptainXL. I changed it a bit early at one point since the water pump and thermostat went out right around 100k. I'm at 121k miles right now.

No problem. Just hate to see future members getting the wrong info.

My factory thermostat was changed at 100k as well. Seems like a lot of members fail then as well... give or take 20k miles. Crossing fingers that my water pump makes it to 150k. Barring that I am going to do the preventative maintenance thing I talked about and change everything out then.

 

[CaptainXL]

going to look into full synthetic oil...I dont want to make that decision without doing some research first.

Its a pretty easy decision. I Saw Walmart had Pennzoil Platinum on sale the other week. It was $5 off a $25 gallon of synthetic oil. $20! Cant beat that. Most people spend more than that at the oil change place getting nonsynthetic oil. Of course you need two more quarts and a filter...but still.

 

[hockeyman]

It's possible that given the year of your vehicle that the thermostat along with the coolant has already been changed recently. How does the coolant look? And why change a thermostat that is working properly when your water pump is usually the next thing to go heading towards 150K?

I agree with CaptainXL. If the owner in 2008 followed the five years interval you're due again soon. I would recommend doing what I did and buy a $4 coolant tester and see what your coolant tests to. Water pump is on borrowed time if it has not been replaced. Check the water pump pulley with belt off and see how it feels when you spin it. These two things could save you a lot of meaningless time spent.

Thermostat will throw a code before it does anything that could ruin you. At least mine did. I changed the ECT sensor because it was right there next to thermostat.

Well, the coolant actually does look fine, and I tested it with a Prestone Kit that I have in my garage. It says good to something around -20f. The only reason I wanted to replace the fluid and thermostat is because of uncertainty. I'm not sure if any of the prior owners (I'm the 4th owner) did anything to the fluids on this vehicle. I don't mind spending a bit of money, as long as I know that the parts/fluids are new -on my behalf. Although, I guess I should just leave it alone and wait to reach 150k...

As for the Water Pump;
I didn't even think of inspecting it. I would guess that it's original, but I can't say that with confidence.
Knowing my recent luck, I probably just jinx'd it!!

 

[xtitan1]

I used to not know anything about cars (this was about 3 weeks ago lol) and just would do what the stealership told me. He upsold me on transmission flush because it had been 5 years, as the manual says, as well as a coolant flush. He said the transmission fluid was black and it was a good thing we changed it. That's 45k on a '06 (specs in avatar). I'd just play it safe and start with a known clean slate.

 

[yodaddy4200]

So i got the truck back tonight. My mother n law said they drained all the fluid and replaced it with Dexron VI. (because i asked) Replaced filter and i forgot to ask about the magnet.

The night i gave her the TB i gave her a $100 bill and told her i had more set aside for this so just let me know. She said it would be cheap because she gets a good family rate. Anyways she brought my truck back tonight along with my $100 bill and i said no no no... I have to think of something really cool to do for her!! She said all the guys at the shop liked my truck! She said they would'nt take any money they just want 2 more dozen of her snikkerdoodle's!! They are the best they have ever had apparently!!:wootwoot: I dont doubt that one bit she is an amazing cook/mother n law in general so all i have to say is im VERY VERY lucky!!


Oh and they said the fluid that came out looked great and looked like the transmission had been taken care of!!

 

[xtitan1]

Great news brother!