ATF change interval - Do you stick to the OE spec ?

[fortec]

As someone else already said it's good to do the very first drain after a few thousand miles, personally I favour a triple flush at that point. After that you are easily safe to go with the OEM prescribed intervals. It's important to realise that the transmission is the most dirty when it's new, once all of the build and break-in debris is gone it should be in good shape as long as you stick to the OEM recommended/approved lubricant.

 

[Jkott]

Engine oil and transmission fluid (both HST and automatic vehicle) are the life blood of a vehicle.

My current truck was about $40-50k about 10 years ago and about $65k to replace a 2500hd diesel pickup now. Is $2500 in maintenance over 10 years really a big deal to worry about cost wise? Compared to a $4500 tranny rebuild or a $8500 engine rebuild?

I replaced all my fluids in everything at 5-10k miles. Manufacturing leaves a lot of shaving and break in wear leaves a lot of dust. It can't do any good to keep that in there for 100k miles so it gets changed.

My truck transmission has a spin on filter that gets changed about every other oil change. The Allison filter costs about $8. I think the manual calls for 25k but I change it about every 15k.

Computer says the engine oil is good for 10k miles. I get about 6-7k miles From top full line to the bottom add more line. If I fill it back up, I only get a couple thousand more miles before I have to add more Engine oil. I do used oil analysis and while it says it's still good for more miles, I believe that if it is using more, something is different about it, so I Change it around every 7500-8500 miles (before the manual calls for).

Transmission Fluid.... How often you change it depends on how you treat it. Heat and contamination will kill it. Oxidation over time will kill it. Heat oxidizes it faster. The additives in get used up. There is a reason the additives are in there, and they sacrifice themselves instead of the expensive transmission. On my truck it's as easy as an oil change to pull the plug and drain the pan, getting 50% of the fluid. Power flushing is absolutely prohibited in my transmission because it forces contaminants and debris into places it shouldn't be. Just drain it and refill. I forget how often the many calls for it, but I do it about every 50k. It's not hard, and it's not that expensive, but clutches in an auto transmission give off debris and you don't want that in the tranny for life. When it oxidizes, it turns to varnish. Fresh fluid has solvents to clean that out and additives to keep it in suspension.

Unless you have upgraded the filter with a bypass filter, Why wouldn't you change it regularly, if not slightly early but at least on the manufacturers schedule? Even if you have a bypass filter, if you over heat the fluid, you still have to change it at some point to replenish the additive packages.

 

[Copperhead]

I have a 2001 Allison transmission behind a 8.1 gasser. It tows a GN horse trailer most of the time. Haven't yet cracked 50,000 miles on the odometer. GM says to change the fluid every 25,000 miles when towing. I missed that part in the severe service fine print so changed it at 45k. The reason is oil shear. The ATF loses viscosity after being churned by the torque converter.
The GM recommendation is Dexron 3 but a little reading says Dexron 6 is better at resisting shear although is starts a bit lower than Dexron 3

yeah, Dexron VI is a full synthetic fluid and is significantly better than Dexron III and it backward compatible and can be used anywhere the D3 fluid is used. If I was using an Allison, I would use the stuff that Allison recommends for it's entire product line.. TES-295. I realize that the Allison 1000 that GM uses, GM builds it themselves, but it was developed by Allison. Allison recommends TES-295 across the spectrum from its own 1000 on up to the TC10TS used in commercial semi trucks. As a side note, I would get all my Allison trans work and fluid changes at a Allison specific shop that the commercial folks use. They know that trans better than anyone else.

On-Highway Fluids

 

[DEWFPO]

Here's of an example report of an oil analysis done by Blackstone on ATF. Transmission Sample Report 1

It's cheap insurance to change it out. Seems like every replacement part on a vehicle today is terribly expensive and the labor to R & R it is even more ridiculous, and add to the fact it's very difficult to make sure that the work is being done right nowadays. At repair shops (especially dealerships), it's all about the throughput and up charges.

DEWFPO

 

[3930dave]

Much of the problem in the light vehicle market is simple ignorance.... people ignore the service intervals altogether, not just the nuances of Severe Service.....

Even if you can R/R yourself, some transmissions are really expensive to buy used (thinking VW).

Pretty much an ounce of prevention is worth 100# of cure....

Rgds, D.

 

[fortec]

You are right. What many people fail to even think about is that the price of a fluid change is a fraction of the price of a new transmission. Also the transmission fluid is the only component in the transmission that contacts all other components. If anything goes seriously wrong with the fluid the effects can be devastating. Also don't 'cheap skate' on fluid, purchase reputable brands, there are a lot of cheap 'knock off' products about that will give inferior performance and may even cause damage.

 

[Copperhead]

I would be willing to bet that if folks put as much effort into oils, lubes, greases, etc for their entire vehicle as they do the motor oil, we could see original equipment autos and pickups that are reaching insanely high mileage life spans. I never cease to be amazed at the number of folks who will change motor oil at 3000 miles, though it probably go longer, yet never address the trans, diffs, or even grease points nearly as often as they should. It is akin to worrying only about one's heart condition while ignoring that the arteries are clogged.

 

[3930dave]

What I do find ironic is what some people will put fresh ATF into, other than transmissions.... some of these same folks are probably skipping trans service on the same vehicle.....

Probably worth another thread on its own..... ATF - Best Rural/Urban Folklore......

Many people don't think about these mechanical items period, but if they do, it's just as a "magic black box".

Understanding the technology always helps, but how simple does it really need to be ? All you need is a basic command of English (here) to understand what is printed in the Owner's Manual - ".... At xx,000 miles, Do This".

With a loaded up 1 ton here heading towards $6 figures (Canuck bucks), how painful does it have to get for some people to get with the program ?

Rgds, D.

 

[sld]

You are right. Engines will almost always outlast transmissions and there is no logical reason for that given proper maintenance.

 

[fortec]

The problem is that most people don't even bother to read the owner manual. Another point is that whilst most have at least some rudimentary understanding of an engine's needs they have pretty much zero knowledge of what goes on in a transmission.