[Wheelman_60]

The transmission in my DGC SXT seems to take too long to shift. Even though this is my 1st car with a 6spd transmission; it feels like (especially under light acceleration) it should shift sooner. Car has 133,000mi. Fluid looks a bit dark; idk if it's ever been changed. Someone, a fellow mechanic at my work, suggested that if I have a fluid change; that would blow the transmission. Any truth to this? Also, does anybody know where I can pick up a legitimate dipstick for the transmission fluid without having to go through flowcharts and some sort of 2' long cable looking dipstick process?
Should I consider having the trans tuned?
Thank you

 

[Jeepman]

Your fellow mechanic needs to explain himself. A properly done fluid and filter change helps replenish the additives in the transmission fluid.
Chrysler says the transmission fluid will get darker with age.
Your motor oil dipstick can be marked off to be used to measure transmission fluid level. Member beat_truck did a good Post on that.

 

[Pgh_AL]

Transmission fluid is a maintenance processes. Does not solve any driveability issues . Its like changing the engine oil to fix a rod knock . Ain't gonna fix it

 

[Baron]

on the 41TE, the 4 speed predecessor to the 62TE you have, this problem is usually solved by cleaning or replacing the input and output speed sensors

it would likely help here too, cleaning them doesn't cost you anything but time

 

[Jeepman]

The transmission shifts differently when cold (up to 15 miles) plus when in econ mode.
What you are experiencing may be normal, can't say without better information. Any codes, abrupt shifting, over revving, slippage? It's best to drive the transmission with a little gusto so the computer can make up its mind rather than be in limbo. How many drivers? The transmission learns to adapt to a driving style.

 

[Wheelman_60]

The transmission shifts differently when cold (up to 15 miles) plus when in econ mode.
What you are experiencing may be normal, can't say without better information. Any codes, abrupt shifting, over revving, slippage? It's best to drive the transmission with a little gusto so the computer can make up its mind rather than be in limbo. How many drivers? The transmission learns to adapt to a driving style.

I'm the only driver, I'm almost all highway; manage about 25mpg. Thank you for your input!

 

[2granddaughters]

How long have you owned this vehicle?
Are you a mechanic? (you mention a "fellow mechanic")
When did this problem appear? Did it appear all of a sudden?

 

[LEVY]

The transmission shifts differently when cold (up to 15 miles) plus when in econ mode.
What you are experiencing may be normal, can't say without bett

This has been said many times, but I haven't noticed and difference on shifting when cold compared to hot. Maybe if you turn engine on and step on the gas right after.

Sincerely, I thing that learning process is just a bunch of bull from the factory. How about rentals? Are those rental vehicles going crazy?

But (a big but), software might be different for rentals. Both of my vehicles are ex-rentals, never noticed any transmission weird behavior.

I travel to Mexico very often, my driving practices are very (very) different there.

 

[Jeepman]

This has been said many times, but I haven't noticed and difference on shifting when cold compared to hot. Maybe if you turn engine on and step on the gas right after.

Sincerely, I thing that learning process is just a bunch of bull from the factory. How about rentals? Are those rental vehicles going crazy?

But (a big but), software might be different for rentals. Both of my vehicles are ex-rentals, never noticed any transmission weird behavior.

I travel to Mexico very often, my driving practices are very (very) different there.

Driving on a secondary road, around 80 kmph (50 mph) when cold, shows higher rpms for the same speed than when hot. I have confirmed that many, many, many, many times. That's typical of an electronic transmission. Lockup is delayed as well. The computer alters the shifting pattern as the transmission warms up.

I have had people point out higher rpms to me, wondering if their transmission was going south. I assured them that that was normal.

It's explained here: Jeep Grand Cherokee Transmission Shifting Problem

On Chrysler 45RFE electronic automatics (which are used in Jeep Grand Cherokees and are similar to Chrysler's 41TE and 42LE transmissions), the Transmission Control Module (TCM) looks at the engine coolant temperature sensor reading when the vehicle is first started and use that as a reference point for estimating the ATF fluid temperature. Once this has been done, the TCM updates the estimated transmission oil temperature as the vehicle is being driven based on torque converter slip speed, vehicle speed, gear position and engine coolant temperature. The estimated oil temperature will be pretty close to the real oil temperature if the vehicle is driven normally and there are no other problems

The Chrysler 45RFE automatic transmission in your Jeep uses several "shift schedules" that are based on ATF oil temperature. There is an "extreme cold" schedule when the oil temperature is below -16 degrees F that allows Park, Neutral, Reverse, 1st and 3rd gears only. If the oil temperature is between -12 degrees and 10 degrees F, it uses the "super cold" shift schedule that delays 2-3 and 3-4 upshifts, and provides an earlier 4-3 and 3-2 coastdown shifts. High speed 4-2, 3-2 and 2-1 kickdown shifts are prevented in this mode. When the ATF is between 10 and 36 degrees, the "cold" schedule takes over and the transmission shifts at higher throttle openings and high speed 4-2, 3-2 and 2-1 kickdown shifts are still prevented. Also, there is no torque converter clutch lockup in the cold, super cold or extreme cold ranges.

Once the ATF is above 40 degrees, the TCM goes to the "warm" schedule which allows normal upshifts, kickdowns and coastdowns, but still no torque converter lockup. When the ATF reaches 80 degrees, the TCM changes to the "hot/normal" mode and begins to engage the torque converter when vehicle speed is above about 22 mph.

You likely start out with a fairly warm transmission "warm mode" so don't notice much, if any, difference. Starting out from a heated garage would be similar, i.e. "warm mode".

Just another reason why cold weather is hard on fuel mileage. The transmission is very smart to protect itself though.

As for the transmission learning the Driver's habits, that's for another time. Rental vehicles must get confused and stay in default mode.

 

[LEVY]

Driving on a secondary road, around 80 kmph (50 mph) when cold, shows higher rpms for the same speed than when hot. I have confirmed that many, many, many, many times. That's typical of an electronic transmission. Lockup is delayed as well. The computer alters the shifting pattern as the transmission warms up.

I have had people point out higher rpms to me, wondering if their transmission was going south. I assured them that that was normal.

It's explained here: Jeep Grand Cherokee Transmission Shifting Problem


You likely start out with a fairly warm transmission "warm mode" so don't notice much, if any, difference. Starting out from a heated garage would be similar, i.e. "warm mode".

Just another reason why cold weather is hard on fuel mileage. The transmission is very smart to protect itself though.

What for me seems to be a cold engine-transmission, it might be a warm engine-transmission to you. 😅

What about the "learning" process?

 

[Jeepman]

What for me seems to be a cold engine-transmission, it might be a warm engine-transmission to you. 😅

What about the "learning" process?

It's 21C and humid here today. Not bad.

I don't expect any cold temperature shifting on my Jeep.

Transmissions are fast learners, so it seems.

DOES AN ADAPTIVE GEARBOX REALLY LEARN HOW YOU DRIVE?

Does an adaptive gearbox really learn how you drive? | Practical Motoring

Plenty of people believe an adaptive gearbox can learn the way you drive, and it does but it's not quite as cut and dried as all that.

practicalmotoring.com.au

An adaptive gearbox does indeed learn the style of the driver, but over minutes.

 

[Sienile]

About the "learning process", these transmissions have an adaptive clutch volume index that adjusts to the driver's input and the clutch engagement time. Usually you don't mess with this unless replacing or rebuilding the transmission.

A fluid change can affect shift times. Did my first at 67k and there was a massive improvement. Do not power flush a transmission. That's where you risk damaging them.

 

[Campermike]

The transmission in my DGC SXT seems to take too long to shift. Even though this is my 1st car with a 6spd transmission; it feels like (especially under light acceleration) it should shift sooner. Car has 133,000mi. Fluid looks a bit dark; idk if it's ever been changed. Someone, a fellow mechanic at my work, suggested that if I have a fluid change; that would blow the transmission. Any truth to this? Also, does anybody know where I can pick up a legitimate dipstick for the transmission fluid without having to go through flowcharts and some sort of 2' long cable looking dipstick process?
Should I consider having the trans tuned?
Thank you

Change your fluid first. Then go from there.

 

[kamesama980]

Regarding learning transmissions: rentals are indeed confused. I rented a uhaul once that as I pulled out of the lot, revved to 3500 before shifting when just feathering the gas. By the time I returned it 150 miles later, it shifted like a sane vehicle.

We just inherited my wife's grandma's T&C. when we first got it, it had two modes: breathe on the gas and drive like granny or anything more than a feather's weight on the gas and it spun the tires. After a few hundred miles of normal adult driving (vs 90lb blue hair) it's starting to normalize a bit.

Changing the fluid breaking the transmission comes from two things: older designs that call for changes <30k miles and missing that until over 100k (and forced flushes that push new fluid into every corner and can push it where it doesn't belong. In older frequent-fluid-change situations, I don't claim to know the detailed chemistry but sort of like a crumbling structure that's still standing, touching it to add support may knock it down. To be clear, the damage is done already by the neglect, not the fluid change. The fluid change just brings it to light. These vans have a long normal change interval to start with so changing it at 133 isn't horrible (I think. Someone with more experience on these transmissions chime in here). From what I've read, just make sure you put the right fluid in to the right level.

 

[Jeepman]

My belief is that the transmission computer contains preprogramed driving styles, say 3 or 4 and changes on the go, depending on the driver. There's the TechiePocket1 style, marvinstockman style, Miron style, and Levy style. So, if you go into road rage, the computer will eventually pick the road rage program that's canned into it. That's likely the extent of the learning involved, short term responses. It may take 15 minutes, or so, of driving, giving time for the transmission to warm up to operating temperature, before a new style is selected. That's just my thinking and works for me.

The transmission fluid is made up of synthetic base oil and a cocktail of additives. It's not subjected to air infiltration and byproducts of combustion, like engine oil is, so should last forever, just like manual transmission fluid does. The additive package contains frictional components that the transmission needs. These frictional components can wear or be depleted under hard going and long term use, hence the replacement with fresh fluids. The filter should be a non issue as many transmissions have them buried inside and not readily replaceable out of the box. Honda for example. Plus, there should be no dirt in there anyway. The ZF based 8 and 9 speed transmissions have lifetime fluid. Go figure. Those transmissions are used across various manufacturers and they all likely have different maintenance schedules. A drain plug on your transmission pan is good thing for replacing transmission fluid on a scheduled basis. Otherwise pump it out the dipstick tube.

The ATF+3, and older Chrysler transmission fluids, had a conventional base oil and the frictional additives in those days didn't last long apparently. ATF+4 has a synthetic base oil and a Lubrizol additive package (much improved over ATF+3) and was designed to have 1) same shifting performance as ATF+3 and 2) lifetime durability.

Yes, don't compromise on quality of transmission fluid by using unlicensed products. That's called being uninformed or dumb.

 

[Sienile]

There's the TechiePocket1 style, marvinstockman style, Miron style, and Levy style.

Depending on the day of the week, I drive like all 4. My trans never knows what to expect.

Clutch Volume Index is what gets learned. Granny driving fills the clutch circuit slower than balls to the walls.

 

[kamesama980]

Depending on the day of the week, I drive like all 4. My trans never knows what to expect.

Clutch Volume Index is what gets learned. Granny driving fills the clutch circuit slower than balls to the walls.

and that's why manual trans for the win lol. there's no guessing what the engineers guessed about how the driver wants things to work.

 

[Sienile]

If Dodge made a FWD manual for the 3.6, you bet I'd be dropping it in. But since I'd have to switch to RWD to get a manual it's not worth it. Plus, if I did all that it'd be Hemi time.

 

[Jeepman]

Depending on the day of the week, I drive like all 4. My trans never knows what to expect.

Clutch Volume Index is what gets learned. Granny driving fills the clutch circuit slower than balls to the walls.

So it doesn't learn anything, it just adjusts, has a retention span of 0.

 

[Wheelman_60]

The 62...6 speed transmission I've been told with just emptying the fluid Pan should be about 5 and a 1/2 quarts. When I drained and removed the Pan I got almost 7. Does anyone have reliable information on how much I will put back in?