Automatic Transmission fluid change interval s on 2021 JT

[ShadowsPapa]

I am still seeing no reason to change the ATF on mine...... I've not done it on my other trucks any sooner than 70-80K, no reason to on this one.

If a 1980s vehicle can go 100,000 on 1980s fluid in a non-sealed transmission, these should.

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[Blade1668]

Bill
I'd still like to change mine, I know it's not "required or recommended" but so was the fluid in my LJ manual transmission. I've changed it 3 or so times I'm sure even without a Blackstone lab report that it needed changed. First time got the break-in crud out and the other times it was very dark n cruddy. Heck, I changed brake fluid, power steering fluid regularly in my Jeeps beside coolant. I did notice better brakes and steering afterwards. The XJ's might have been changed a few times more due to blowing up return line. rock crawling.

 

[ShadowsPapa]

Bill
I'd still like to change mine, I know it's not "required or recommended" but so was the fluid in my LJ manual transmission. I've changed it 3 or so times I'm sure even without a Blackstone lab report that it needed changed. First time got the break-in crud out and the other times it was very dark n cruddy. Heck, I changed brake fluid, power steering fluid regularly in my Jeeps beside coolant. I did notice better brakes and steering afterwards. The XJ's might have been changed a few times more due to blowing up return line. rock crawling.

Brake fluid - every 2 years. Otherwise, it absorbs moisture which forms corrosion and acids.

I've seen brake cylinders, caliper bores, master cylinders, even the hydraulic clutch cylinders in our Eagles eaten away in side - at times a nice little half-ring where the cups stop in the bores.

My T5 acted like a new transmission after a full rebuild and putting in the correct AMC spec (later Chrysler spec) syncromesh lube in it. The metallic flakes from grinding gears, wearing synchronizers get into the needle bearings and stuff happens........

I have to add, however, that both of these are at over 160,000 miles, all original.

Pinion bearing -

 

[tonywin]

Does anyone know the cost for filter and fluid change on the 8 speed? Called my local dealer and left a message with a service advisor but never received a call back.

 

[Hootbro]

Does anyone know the cost for filter and fluid change on the 8 speed? Called my local dealer and left a message with a service advisor but never received a call back.

I know it is not dollars and cents specific, but it should not be anymore than the cost of parts and no more than 2hrs labor rate and that is being generous on the hours.

Do not be surprised that they try to talk you out of it if you are not having problems. Many dealerships do not like messing with servicing late model "filled for life" transmissions unless they are in there for other work. They may even quote you a "go away" over inflated price to discourage it.

 

[LostWoods]

I would expect to pay $600-800 for the service depending on your location. If my memory serves me it's like a 2 hr job and the pan is one piece with the filter so it's not cheap either.

 

[FLGladiator]

I can't find anything in the owners manual about the transmission fluid change intervals on 2021 JT automatic transmission.
Anybody has any idea ??

Whatever you do, make sure you don't use Amsoil.

 

[ShadowsPapa]

I'm not going to worry about it until it's got some serious miles on it.

Once all warranties are up, I'll think about it.

I posted a chart somewhere here that showed the fraction of fluid you actually swap out for various transmission capacities and all you are really doing is refreshing a fraction of the fluid.
I towed serious loads with my F250 and the Chevy I had before that, the same, and those weren't "lifetime fluid: transmissions.
These have serious flaws if they can't go as long as my other trucks did.

I may do the checks on fill rates and other diagnostics at some point, but if I don't see any issues, I don't use it hard enough other than towing and so far, it's not gotten any more hot that a basic drive to town.

Off-road use is a different animal. Towing heavy loads with some frontage - more stressful on things.

 

[Bonanza]

Eh. I'll drive mine til the trans fails and the swap the transmission. By that time I'll likely have a rear main leak so I'll replace that when I'm there. I'm never going to swap the fluid on my ZF.

 

[Gren71]

Ive read through the threads on here about this and its has me really thinking its worth doing since I tow a lot. I have 84,000 miles on the JT now and tow probably 8-12 times a "season", averaging around 350 miles a trip with my 6,000lbs camper.

I have the fluid, filter, and new gasket set aside in two websites carts waiting for me to pull the trigger.

But I have some thoughts.

At what point is use considered "heavy use". I gather from the manual that most of jeeps assumptions on heavy use are related to off road use, not necessarily towing. I even glanced through a RAM manual to see if they had a better definition there, no dice. So would my amount of towing, combined with 20,000-25,000 miles of daily driving a year, be considered heavy use enough to bother messing with the trans fluid?

This is how the JT and RAM manuals definre "heavy duty use"
Change engine oil at 4,000 miles (6,500 km) or 350 hours of engine run time if the vehicle is operated in a dusty and off-road environment or is operated predominately at idle or only very low engine RPM’s. This type of vehicle use is considered Severe Duty.

I dont have large tires or anything that would cause extra wear and tare on the fluids or components.

I do have a pretty gnarly "clunk and lurch" when shifting into reverse, and some times drive. But im fairly certain Ive had this for most of the life of the JT, but honestly cant remember. My memory is spotty at times after too many TBIs.


This is the video ive been sorta using as my bench mark of how to do this job.

 

[ShadowsPapa]

Ive read through the threads on here about this and its has me really thinking its worth doing since I tow a lot. I have 84,000 miles on the JT now and tow probably 8-12 times a "season", averaging around 350 miles a trip with my 6,000lbs camper.

I have the fluid, filter, and new gasket set aside in two websites carts waiting for me to pull the trigger.

But I have some thoughts.

At what point is use considered "heavy use". I gather from the manual that most of jeeps assumptions on heavy use are related to off road use, not necessarily towing. I even glanced through a RAM manual to see if they had a better definition there, no dice. So would my amount of towing, combined with 20,000-25,000 miles of daily driving a year, be considered heavy use enough to bother messing with the trans fluid?

I dont have large tires or anything that would cause extra wear and tare on the fluids or components.

I do have a pretty gnarly "clunk and lurch" when shifting into reverse, and some times drive. But im fairly certain Ive had this for most of the life of the JT, but honestly cant remember. My memory is spotty at times after too many TBIs.


This is the video ive been sorta using as my bench mark of how to do this job.

And now we see why I'm in no hurry.
A lot of shifting back and forth while towing would add to wear, but if it doesn't do that and the thing remains "engaged" in a gear most of the time, it's not a lot of added wear.
Mine did switch gears a lot, it's hilly as heck here so there's constant shifting even if done manually. You can't avoid it - you are going up quite a grade and as quick as things settle down you are going down hill, then after a mile, you are going up hill again. You may see 10 gear changes in 10 to 15 miles or less. Still, these aren't like the older transmissions - the design, the pressures, the controls, the bearings, it's all so much better.
But once a transmission (automatic) is engaged in a "gear", it's solidly engaged. There isn't wear on clutches or bands at that point.
Changes between the different speeds is what leads to wear. Once engaged, there just isn't much. As long as the heat (transmission temp) stays down and it's not shifting a lot, there's not much wear. Long drives lead to less wear than someone who commutes through town and a lot of stop and go, up and down shifting. That's wear.

 

[NeatFreq]

Most manufacturers say lifetime fill so that they can lower the cost of ownership, and use that against their competitors. There are other reasons as well, but as was stated above stick to ZF's recommendation, or change it more often if you tow regularly.
Personally, I like to change fluids before what's recommended and usually on intervals I can easily remember. Oil every 5k, diffs, manual trans and transfer cases every 30k and auto trans every 50k. Fluid is cheap compared to a new gearbox.

I agree and subscribe to this as well

 

[Gren71]

And now we see why I'm in no hurry.
A lot of shifting back and forth while towing would add to wear, but if it doesn't do that and the thing remains "engaged" in a gear most of the time, it's not a lot of added wear.
Mine did switch gears a lot, it's hilly as heck here so there's constant shifting even if done manually. You can't avoid it - you are going up quite a grade and as quick as things settle down you are going down hill, then after a mile, you are going up hill again. You may see 10 gear changes in 10 to 15 miles or less. Still, these aren't like the older transmissions - the design, the pressures, the controls, the bearings, it's all so much better.
But once a transmission (automatic) is engaged in a "gear", it's solidly engaged. There isn't wear on clutches or bands at that point.
Changes between the different speeds is what leads to wear. Once engaged, there just isn't much. As long as the heat (transmission temp) stays down and it's not shifting a lot, there's not much wear. Long drives lead to less wear than someone who commutes through town and a lot of stop and go, up and down shifting. That's wear.

which is what Ive been reading elsewhere, and part of what gave me pause. I dont particularly want to mess with something just for the sake of it. But I need to keep this JT for 150,000+ and dont want to risk missing the boat on a doable maintenance task that can prolong the trucks life.

 

[Scrubb84]

which is what Ive been reading elsewhere, and part of what gave me pause. I dont particularly want to mess with something just for the sake of it. But I need to keep this JT for 150,000+ and dont want to risk missing the boat on a doable maintenance task that can prolong the trucks life.

Just my opinion…. You already waited too long. Change the fluid now or pay out-of-pocket for a new trans when it does fail. Seems like a no brainer to me.

 

[Gren71]

Just my opinion…. You already waited too long. Change the fluid now or pay out-of-pocket for a new trans when it does fail. Seems like a no brainer to me.

fair thought haha

waiting this long was just ignorance on my part. I never thought past the manual noting that it "never" needs to be changed.

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