Riddle me this????

[Proximo]

I'm at 52k miles and have had wonky, late, sticky shifting on my automatic. While accelerating, it would stay in 4th 5th 6th waaay too long then rarely see 8th.
Since doing my royal purple oil change and full synthetic diff change last week, I feel like I'm driving a brand new stock JT. Unbelievably, now every shift is so smooth. Shifts are happening ontime and cruisin 55mph is constantly under 2000 rpm. I hit the expressway and went right through each gear (up to and including 8th) against the wind. In the past year, that just didn't happen. Could such simple maintenance/upgrade of oil and/or diff fluid have such an amazing effect on automatic shifting and gear selection? WHY?
Dealership was ready to order me a new transmission, but I'm super happy with it now.

Sponsored

 

[Saharacane]

Are you attributing some of this improvement to the Royal Purple oil change as well or just the Diff fluid change? Or did you only mention the oil change b/c you did it at the same time as the Diff?

 

[Lunentucker]

I think he's saying that's all he's done different lately, so ...

 

[Lunentucker]

I'm at 52k miles and have had wonky, late, sticky shifting on my automatic. While accelerating, it would stay in 4th 5th 6th waaay too long then rarely see 8th.
Since doing my royal purple oil change and full synthetic diff change last week, I feel like I'm driving a brand new stock JT. Unbelievably, now every shift is so smooth. Shifts are happening ontime and cruisin 55mph is constantly under 2000 rpm. I hit the expressway and went right through each gear (up to and including 8th) against the wind. In the past year, that just didn't happen. Could such simple maintenance/upgrade of oil and/or diff fluid have such an amazing effect on automatic shifting and gear selection? WHY?
Dealership was ready to order me a new transmission, but I'm super happy with it now.

Did you just recently get your first dose of Summer weather?

 

[Mr._Bill]

Changing the fluid can reduce drag and affect shifting. I believe Jeep recommends it be done at least every 30k miles.

I would still let the dealership replace the transmission. It could just be a momentary reprieve on the way to a larger failure.

 

[Proximo]

Are you attributing some of this improvement to the Royal Purple oil change as well or just the Diff fluid change? Or did you only mention the oil change b/c you did it at the same time as the Diff?

Only because I did both at the same time. No clue what has improved the smooth shifting through all of the gears

 

[Proximo]

Did you just recently get your first dose of Summer weather?

No, it's been warm here for a while. Top off, doors off for the last 3wks

 

[Proximo]

Changing the fluid can reduce drag and affect shifting. I believe Jeep recommends it be done at least every 30k miles.

I would still let the dealership replace the transmission. It could just be a momentary reprieve on the way to a larger failure.

Good thinking

 

[Dougstdig]

Unless your diff fluid came out looking like peanut butter which would be an indication that you got water in there I would say the differential‘s had nothing to do with what you’re experiencing.

Transmission wise it’s always possible that it got hot and lost some of its lubricity changing how it interacted with components. It’s also possible that when they did a flush and may have removed a clog in one of the ports or valve (my transmission vocabulary is limited ) that alleviated your problem. @ShadowsPapa would be an excellent source of commentary on this.

 

[Trailman]

Changing the fluid can reduce drag and affect shifting. I believe Jeep recommends it be done at least every 30k miles.

I would still let the dealership replace the transmission. It could just be a momentary reprieve on the way to a larger failure.

The manual recommends for automatics, changing transfer case fluid at 60k if using for "police, taxi, fleet, or frequent trailer towing."

Change front and rear axle fluid at 40k if using for "police, taxi, fleet, off-road or frequent trailer towing."

Both are to be inspected more frequently, which would suggest a change if a problem is discovered.

(Manual transmission, change manual transmission fluid at 30k intervals.)

 

[EgulAye]

I noticed a difference in my JT by having the dealer flash the transmission controller. At 30k miles I haven't considered getting the fluids changed. For me I think the problem is the transmission learning feature that adjusts the shift points and throttle behavior based on my driving. I'd prefer it just never change, stick with the factory defaults, or let me choose something different.

I just had the Jeep at the dealer today and they did their "complimentary multi-point inspection". Maybe I'll check the diff's myself and see what they look like.

I'll be curious to hear more about your experiences!

 

[Proximo]

I noticed a difference in my JT by having the dealer flash the transmission controller. At 30k miles I haven't considered getting the fluids changed. For me I think the problem is the transmission learning feature that adjusts the shift points and throttle behavior based on my driving. I'd prefer it just never change, stick with the factory defaults, or let me choose something different.

I just had the Jeep at the dealer today and they did their "complimentary multi-point inspection". Maybe I'll check the diff's myself and see what they look like.

I'll be curious to hear more about your experiences!

As soon as shadowspapa chimes in, we'll all have a better idea of what may have helped my shifting

 

[Advntrbound]

Does anyone know off of the top of their head what fluid the manual transmissions need?

 

[NachoRuby]

Does anyone know off of the top of their head what fluid the manual transmissions need?

Interestingly, it uses Mopar automatic transmission fluid

 

[Kevin_D]

Interestingly, it uses Mopar automatic transmission fluid

Many manual transmissions use ATF. My mid-80's Ford used it.
Kevin

Sponsored