Seeing how I will never purchase a new trk, too old-too poor, I have been replacing needed parts to my 04'F150. Stuff like Monroe Load Leveling rear shocks, front struts,oil and filter, serpentine belt,w/s wipers etc. Next is the transmission fluid and filter. I picked up the filter kit yesterday. The last time I had the tranny stuff chg'd was when the trk had 50K ish miles on it. It now has 122,000 miles. Time to change IMO. Have you had your fluid and filter chg'd lately? For those of you that have an Old trk.....!! I bought my filter kit at Advanced Auto Parts in Tx City. If you look online, you can get a 25% discount (with purchase code applied). I didn't order it online, I just took a pic of the ad and showed the clerk.It cost me a hair under $20, Reg $25 and chg.

I have never changed the fluid in an automatic transmission except during a rebuild. I do change the filter and top off what drains from the pan every 75,000 miles. Never any additives.

I always add an additional transmission cooler to every vehicle I buy.

That cooler will be my Last addition I hope !! I acquired a 23.4" travel Trailer from my X. I've been informed I may need that.

I consider dropping the pan and changing the filter and topping of changing the fluid.

Get your trans fluid from Walmart, cheapest place to buy oil gear lube etc.

"and topping of changing the fluid".......??????

The pan probably holds 4-6 quarts changed periodically it changes a large enough percentage of the fluid.

I lived in a 26 foot for a while. It works for one person, but not good for two.

What does your living in a 26 footer have to do with the above subject?

What does you acquiring a 23.4" travel Trailer from your X have to do with the subject?

Transmissions are $1,700-$2,700 exchange. Fluid and filters are cheap.

I have worked for a Major transmission distributor for 40 years. Temperature will kill them!!!!!

A good additional aftermarket air to oil cooler, and synthetic oil is your best bet. This oil will drop operating temps 10-25 degrees based on load.It's worth the money.

Service intervals should be in your owners manual. I would not exceed 50-75K per change if you tow.

Be Safe

Happy towing

I WOULD NEVER change the trans fluid period, trans fluid is one of those things that seems to become mated to the trans, it seems like people change their trans fluid and boom the trans goes out very soon after.

It is a CLOSED system like your power steering system and you DONT change the ps...

I worked in a few auto related places over the years and this is my honest opinion and its the same opinion you will get from transmission shops who arent trying to sell you something or hoping to get your trans rebuild job down the road.

Considering your user name and your experience with transmissions, what is your honest opinion on the Allison 1000 bolted behind the Duramax?

Straight BS!

Yes if you neglect it too long then no changing it wont do a thing. Stick to the maintenance schedule and it will prolong the life of the transmission.

Got two of them well over 200k miles. Pulled 18,000 lbs with one not long ago shifts and runs like new... the transmission has been serviced every 75-100k miles. It is easy to service the Alison they have a drain plug, however there is 2 filters, one internal and one spin on external. I think they are great transmissions.

I would say like anything else if your going to modify your engine/programming to make more power you need to do the same with your transmission or your living on the edge or borrowed time.

This^^^

We do 4-6 trans services a day and I can't remember when one ever came back that wasn't already messed up and they thought a service would fix it.

Gotcha, I for some reason would make this up and state it as my personal experience... why?

If I worked in the transmission industry like other posters above.... I too would SAY you must change it bla bla bla.

Its a sealed system, do you change your power steering fluid? If the manual said to change the summer air for winter air would you do it?

Enjoy.

I�m only guessing you make it up because you don�t know any better. Your obviously wrong. It is not a sealed system, it�s vented and the fluid breaks down over time due to heat cycles and yes contaminants.

I asked the guy that rebuilt my trans a couple years ago when should I change the fluid in it. He said if I got 315,000 miles on my last one towing every weekend and working construction I should probably keep doing what I had been. I've never changed trans fluid in my life and that was the first problem I've ever had out of one.

Straight bs. A vent doesnt make a hydraulic sytem a open system or introduce contaminants. Thats like saying you can catch a cold from a fart going out your azz.

Exactly like I stated in my original post would happen, people who want to make money off others will chime in..

You and 99 percent of the population....

I make no money off of transmission services and have nothing to gain by recommending it. Sure you can get lucky and get high miles without a problem or without servicing one but if you want a reliable high mileage transmission in the big picture it�s going to require service bottom line.

More than 99% of the pop will trade long before they need to service or before the big problems emerge or likely right when the first signs of problems emerge.

Yeah I have 208k on mine, one at work has 953,000. I think they're great too, just wondering from the dude that seems to have lots of experience with transmissions.

I changed my fluid/filter about 10,000 miles ago. The fluid was just clear red, no metal shavings at all anywhere, just a very clean transmission. I still change my spin on filter every oil change.. I put Valvoline Dexron VI synthetic in it, but I think next go around will be Castrol TranSynd. I don't run mine hard at all, but from what everyone tells me, I'm sitting on borrowed time with a 100hp tune.. They're probably right, but I baby my truck. Either way, I'm waiting on it limp it's first time so I can build it. But, that may never happen.. Most folks said I'd limp it within the first few hundred miles of having the tune.. That was 11,000 miles ago.. still the smoothest shifting truck I've ever driven

That one at work with 953k is an '07 LBZ so it has the 6 speed. The motor has had it's typical repairs (alternator, water pumpS, etc..) Most major repair done to it was injectors around 650,000. BUT. That Allison has never, ever been opened up.. Just fluid/filter changes, nothing more. 953,000, all original from the factory, and she still shifts as good as mine. That, my friend, is a Cummins owners DREAM.

My brother owns a welding shop, and his entire fleet of work trucks have been Duramax's ever since the LLY came out in 2004. He's had his issues with motors here and there (mostly electrical and fuel related), but not once in that time frame has he ever had a single problem with the Allison's bolted to them.. I'll say too, they are poorly maintained.. But those Allison's yet to give him a problem.

I don't make money doing services. We have kids that do that. I make money when people don't do services.

For one it is recommended that you change your power steering fluid. This sealed system thing shows you don't know what you're talking about. Only sealed system I know that is service free are bearings. It's not dust or dirt that kills the transmissions but the worn internal parts that contaminate the system and cause sticking in the valve body among other things.

Please Jeff keep doing what you've been doing. My wife wants a new Yukon.

Thanks for your permission to do what I want.

Your poor wife should set her standards higher than a yukon.


A TRANSMISSION is a CLOSED loop system. A VENT or Overflow does not make it a open system. Wow.

I have a so called sealed transmission. Lack of a dipstick is the only reason people call them sealed. Mine has a drain plug, fill plug, and a test plug. I change it every 60k even though draining the pan only removes maybe 25-30%. It is really less trouble than the old drop the pan and change the filter type. Just put back in a little more than you drained, warm it up to operating temp and pull the test plug. I wish they were all like the Escape my daughter had. Pull the drain plug, let it drain, replace plug and fill.

Your brakes, engine, cooling system, hydralic power steering, transmission, front differential, and rear differential are all sealed system. All require maintenance.


or don't do it so my wife can get her a new yukon

Which is it? Sealed or not sealed?

Not sealed they are all vented. When they get hot air and fluid inside expands and pushes air out. When they cool everything contracts pulling outside air, moisture, dust, dirt, whatever is on the vent in. They don't need to be serviced as often as the oil because they are not dealing with blow-by carbon and unburnt fuel from he cylinders etc. but they do have a finite life span.

Im not big on servicing the differentials but its probably not a bad idea, the transmission is different. Diferential have gears and bearings and that's about it, transmissions have extensive valve bodies clutch packs seals etc and degraded fluid will affect their function.

I know I'm actually messing around by the stated "sealed" and "closed loop" systems. Not confused on what a sealed system is. AC systems are completely sealed system but we service it too. The only "sealed" mechanical part I can think of that does not require maintenance are most of the bearings now days.

Power steering and brake fluids get hurt by outside contaminates more than other fluids and is most of the reasons for servicing them. I'm not saying this isn't an issue with other fluids but it's only part of the reason for needing service. Transmissions, engines, and differentials are exposed as you said but they should be changed for way more reasons than just that.

As you said blow-by and fuel is why we change our engine oil but will add there is metal in that oil too. Automatic transmissions have clutch material on steel plates riding against other steel plates, clutch material on bands that rub and wear on steel, and they have steel gears moving against each other steel gears. The front if 4x4 and rear differentials also have moving steel parts rubbing against other steel parts so that's the main reasons why we change those fluids. Yes where you live is a factor but also how you drive.

I'm not trying to argue your point and agree with you. Trying to argue his off point that even if it was completely "sealed" as he thinks and didn't get contaminated by outside influence, that it still needs to be done.

You can even grease many of the "sealed" front wheel bearings by squirting greese in through the abs sensor port... it is rumored to make them last a lot longer.

It's not a recommended maintenance. probably because it still has sealed bearings inside the housing and the manufacture likes a nice clean gap between the sensor and reluctor ring for it to work correctly all the time every time. We avoid shade tree fixes because peoples lives are at risk. Sealed bearings have been around a long time and for the most part work great as is.

I'm not sure how you would know if it last longer or not. My truck with sealed bearings (external sensor and reluctor) has had one side replaced at 250k and the other side is original with 330k. I might have tapped a curve once, turned hard right more often, or it just got worn out first. No science behind rumors. There is science behind why we change our fluids.

Had it all changed today and found out I already have a transmission cooler on the trk. Shows ya how much I look at the radiator. Did have both hoses replaced and new fluid put in today....another GOOD fuel filter too. Just got back in town from La. A dear person had a Massive stroke.

I remember when cars had grease zerks. Every time I changed oil, I greased everything.

Far as I know they are still not sealed. If you pull the wheel speed sensor out you can see down in there to grease. Sounds like you have had good luck with them and that's great. Many go out much sooner even before 100k miles. I much preferred the serviceable bearings they had in the 90's and before.

Have put both fronts on one of our d maxes at a little over 100k. Put one on our other at 250k the other is original. Ive never added grease to mine but ive talked to people I trust who grease theirs and have better luck.

When everthing is CVT all of this will become irrelevant over time.