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ron mexico75
07-09-2010, 11:59 AM
Wondering if some of you can help me out. I am about 500 miles away from hitting 100,000 miles on my 2002 2500HD Silverado with a 6.0 gas engine. As part of the 100K tune up would you even mess with the trans fluid?

I mean, would you drain and add new fluid, flush and add new fluid or just leave it alone. I ask because you always hear horror stories about transmissions that are flushed and then problems start.

This truck has been GREAT to me. Not one issue at of the ordinary in 7 years. I don't want to create a problem. So I ask, what would you do?

ancjr
07-09-2010, 12:28 PM
I've often wondered this myself. I've changed the trans fluid and filter before in vehicles where the fluid was starting to get brown & oxidized. Cleaned out the pans as well, but never bothered with draining the converter too. Don't really know if I helped or hurt them, but I've never had any trans problems.

ron mexico75
07-09-2010, 12:55 PM
I've often wondered this myself. I've changed the trans fluid and filter before in vehicles where the fluid was starting to get brown & oxidized. Cleaned out the pans as well, but never bothered with draining the converter too. Don't really know if I helped or hurt them, but I've never had any trans problems.

Yeah, I think I'm leaning toward just draining and refilling especially with 100k on the truck. Seems like on older transmissions when you flush them out you clear out gunk or debris that is actually helping in some way if that makes sense. At least I have heard numerous people say that.

rlitman
07-09-2010, 01:07 PM
Its somewhat of a toss up.

Depending on the service schedule, you may have been due for several transmission flushes already.
I've heard a number of stories just as you described, but in general, those transmissions were likely to fail pretty soon anyway, and probably because of lack of maintenance.
If you're experiencing transmission issues already, or if your transmission fluid smells burnt, then a flush can loosen up sludge, and hasten its failure.

Transmission fluid isn't bad when it loses its red color (the dye fades before the fluid goes bad), but the additive package (corrosion and wear inhibitors) do get depleted eventually. On the bright side, its not subjected to the dirty environment that engine oil sees, but the filter will pick up crap over enough time.

So, if everything seems ok, it may be a good time to change the transmission fluid, before things go bad.

BTW, Chevy's REQUIRE a special type of ATF (it should be in your manual, and is probably ATF+4), and using the wrong type (or just a generic ATF not specifically for Chevy transmissions), can be disastrous.

whole9er
07-09-2010, 01:40 PM
Im taking care of mine this weekend, this spring I bought a 04 2500hd with 52k Im closer to 58 now, my mechanic who im close friends with told me not to buy something with miles closer to the 100 mark for this issue. From my understanding the new fluid runs thinner and cleaner and acts differently on the valves and seals than the old fluid which makes the tranny gum up aka what your worried about. if you've cared for it I would probally do it but its a toss up, see what others say I have no real knowledge of this other than what my mechanic has told me. Just my 2 cents from what i've heard

360ci
07-10-2010, 10:51 PM
I do as much work as I can on my vehicles. I change the fluid on my Dodge every two years, irregardless of miles, even if I put on 20K, I change the fluid. From empty, including a dry torque converter the system holds about 15 quarts. Replacing only 4 (standard trans fluid/filter change) still leaves 10 or so quarts in the system. So after 60K on the ODO it's best to change it every 2-3 years, especially when towing or hauling moderate to heavy loads.

Now, if you had done a transmission flush at 60K, I'd advise to keep doing it every 40K thereafter, and not having to just change the trans fluid and filter every 25-30K. By flushing fluid early, you'll have a better chance of not having a problem. It's more prominent on earlier Dodge transmissions, where a transmission flush can dislodge larger gunk that has built up in the transmission, and can clog up the valve body starving the transmission of proper cooling and thus it overheats and you need to spend $2500 on a rebuild. Not fun. Not saying that that won't happen, but it's better to be overly cautious than going to long between services.

Again, if you haven't had the fluid changed, spend the $90 or so and get out what fluid can be changed, and fill it with fresh fluid and replace the transmission fluid filter. It's better piece of mind down the road. Heat is what kills transmission fluid. A transmission flush, besides potentially clogging up the valve body can also move chunks of gunk into transmission cooling lines and can cause a failure when you least expect it.

For about $50, and some mechanical knowledge, you can drop the transmission pan, drill a hole and thread in a temp sensor and install a gauge in the cab to keep an eye on fluid temperature. If you're OK with changing the fluid yourself, you can save money there as well, AND you can check the bottom of the pan and wash it off even if it looks clean.

360ci
07-10-2010, 10:55 PM
I'll add that you should run synthetic fluid. Most manufacturers have their own fluid such as Mercon (Ford), Mopar ATF+4 (Dodge) and GM (Dextron?). Transmission fluid made in the last eight or so years is almost all synthetic based. Read the label if you want to change brands before you decide. Otherwise, stick with what the manufacturer recommends. For GM and Ford, Amsoil ATF and Mobil1 ATF are a good option if you want lower cost fluids with similar, if not better performance.

Some fluids are thinner than others in terms of viscosity, but again, everything is stated on the bottle

ron mexico75
07-14-2010, 02:34 PM
Well, thanks for the recommendations. It has never been flushed or changed. So, I'll just go for draining and replacing and forget the flush. No issues with it, but I figure 8 years old with 100k miles it has to be due for fresh fluid.

360ci
07-14-2010, 05:17 PM
but I figure 8 years old with 100k miles it has to be due for fresh fluid.

You got that right!

Bigred350
07-14-2010, 06:46 PM
I always drop the pan and put a new filter on then fill it back with fluid.\

I have a 02 2500hd and its not to hard. Takes about a hour.

unkownfl
07-14-2010, 06:56 PM
I take my fluid cooler lines off and use one to suck new fluid in and one to pump old fluid out. In your truck I would just flush the fluid and change the external filter most new transmissions don't have an actually filter in the pan anymore its just a mesh screen and shouldn't ever need cleaning.

topsites
07-16-2010, 04:12 AM
I hate to break the news but remind me not to buy your truck when you get ready to sell it,
the transmission is one of the most commonly ignored components on a car,
it is a wonder how few of these actually break in consideration of this, take
it from someone who has had to pay the price for it, too.

That having been said...
Transmission fluid and filter (yes, both) are supposed to be drained and replaced
every 10 thousand miles if on a DIY basis.

Yes, EVERY 10 thousand miles.
In my case I do it every third oil change, sounds like a lot but a new transmission?
Seriously, have you priced a rebuild of these dang 4 speed O/D's of late?
On a later model truck, 3, 4, 5, 6 thousand and more.
A rebuild will run you 2 grand, for starters.

Cost of fluid and filter, get a big pan, takes an hour, maybe two,
cheap insurance in comparison.

I do as much work as I can on my vehicles. I change the fluid on my Dodge every two years, irregardless of miles, even if I put on 20K, I change the fluid.

You appear to be one of the folks who actually keeps up a lot better than most
so don't take it as hard criticism but I thought I'd mention that is a lot
better than doing nothing for 100,000 yet that's for a vehicle that doesn't
see much city driving, also doesn't account for towing.

And you might be all right with your interval yet, but that 100k stuff is a no no.

I think I may have mentioned that I do mine myself, e.v.e.r.y. 10 thousand miles.
Fluid, AND filter.

360ci
07-16-2010, 08:41 AM
You appear to be one of the folks who actually keeps up a lot better than most
so don't take it as hard criticism but I thought I'd mention that is a lot
better than doing nothing for 100,000 yet that's for a vehicle that doesn't
see much city driving, also doesn't account for towing.

And you might be all right with your interval yet, but that 100k stuff is a no no.

I think I may have mentioned that I do mine myself, e.v.e.r.y. 10 thousand miles.
Fluid, AND filter.

I look at it like this: since a vehicle isn't an investment, I buy it for what it can do. I also try to keep it running in a sense that I like to avoid any and all downtime. Of course some things can't be looked at in terms of a bad alternator during a heavy work day for instance, as I'd have to call for a tow. But the more common items I'm all over. It's also a daily driver and if my wife needs to use it, I know it shouldn't give her any trouble.

JCLawn and more
07-16-2010, 08:52 AM
that seems on the over kill side, but if you have the time, then there is nothing wrong with that. If you snow plow, then I can see every year. It only cost like 130 or so to have mine done on my 1500 dodge.

Mark Oomkes
07-16-2010, 08:57 AM
I realize I plow with mine also, but I get them flushed annually.

Same with coolant.

Pulling a trailer in the heat of VA and most likely hills would fall under severe or extreme duty and should be changed way more frequently than what you have.

ron mexico75
07-16-2010, 10:41 AM
I hate to break the news but remind me not to buy your truck when you get ready to sell it,
the transmission is one of the most commonly ignored components on a car,
it is a wonder how few of these actually break in consideration of this, take
it from someone who has had to pay the price for it, too.

That having been said...
Transmission fluid and filter (yes, both) are supposed to be drained and replaced
every 10 thousand miles if on a DIY basis.

Yes, EVERY 10 thousand miles.
In my case I do it every third oil change, sounds like a lot but a new transmission?
Seriously, have you priced a rebuild of these dang 4 speed O/D's of late?
On a later model truck, 3, 4, 5, 6 thousand and more.
A rebuild will run you 2 grand, for starters.

Cost of fluid and filter, get a big pan, takes an hour, maybe two,
cheap insurance in comparison.



You appear to be one of the folks who actually keeps up a lot better than most
so don't take it as hard criticism but I thought I'd mention that is a lot
better than doing nothing for 100,000 yet that's for a vehicle that doesn't
see much city driving, also doesn't account for towing.

And you might be all right with your interval yet, but that 100k stuff is a no no.

I think I may have mentioned that I do mine myself, e.v.e.r.y. 10 thousand miles.
Fluid, AND filter.


Hey ******sites...........this is straight form the owners manual;



my 02 owners manual says:

Change both the fluid and filter every 50,000 miles

(83 000 km) if the vehicle's GVWR is over 8,600 or

if the vehicle is mainly driven under one or more of

these conditions:

In heavy city traffic where the outside temperature

regularly reaches 90F (32C) or higher.

In hilly or mountainous terrain.

When doing frequent trailer towing.

Uses such as found in taxi, police or delivery service.

If your vehicle's GVWR is not over 8,600 and you do not

use your vehicle under any of these conditions, change

the fluid and filter every 100,000 miles (166 000 km).


I missed ONE change according to the manual. There are NO shifting or slipping problems at all. So inferring that the transmission has something wrong with it is bullsh*t. Not ever selling the truck. Running it until it cant be run anymore.

Truck has 100k and has NEVER been in the shop for anything. Replaced the battery one time. That is the ONLY thing ever changed on the truck besides the regular fluids. Oh yeah one edit......did brake pads and new rotors last year.

R & R Yard Designs
07-16-2010, 11:19 PM
All the trucks get flushed twice a year. Spring an fall, doing that got me to 245000 in my 2000 ford. The trans blew out do to age and wear and it cost 4500 to rebuild. So yes flush it often
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