2018 Sport JL Transmission: Auto vs Manual?

[Torero]

If the fuel injectors were completely closed and you are on an automatic, then the engine would quit running and you would not be able to restart it without using the starter. Since you cannot push start an automatic, I seriously doubt

If the fuel injectors were completely closed and you are on an automatic, then the engine would quit running and you would not be able to restart it without using the starter. Since you cannot push start an automatic, I seriously doubt that happens. Some amount of fuel must still be flowing.

For many of the vehicles that I've driven, if you let off on the accelerator, there is noticeable drag with an automatic. With a manual transmission, there is drag if you leave it in gear, but if you depress the clutch or put it in neutral, you are mainly just subject to wind drag (and rolling resistance from your tires). There's a bit of variation in the feel of automatic transmissions though... For example, back in the late 1980s, I was looking to buy a Porsche 928[S/S4]. I test drove a few of them, but every one the dealership got in was with an automatic. I hated them since when you let off on the accelerator, they did not have the drag of a manual that was still in gear. Sure, they had less drag than a manual in neutral, but it was entirely too little drag for how I tended to drive a sports car.

you are dead wrong.
Google it. Even carburetors shut off fuel while in compression mode.

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[BPrince]

Hey everyone! Thank you all so much for the good in depth thought provoking reasoning on both the auto and manual transmissions! I do like both and when I went to the dealer to purchase one today, the automatic was sold so guess what? I had 2 choices left...keep looking and wait, or...buy the manual. So I went with the manual! .

I do like it a lot! However, driving it home (3 hours) from the dealer I must say I noticed a few times a slight grinding noise when shifting into 3rd! It was louder if I went faster in 2nd bringing the rpms higher before my shift to 3rd, then during the shift or maybe when letting off the clutch and gassing it in 3rd, the grinding noise was louder. Now it's been a while since I've driven stick and maybe it's my fault by not having the clutch fully out while gassing in 3rd, but...it hasn't done that noise in any other gear, just 3rd.

It's got me a little worried since I've read some reported issues with similar problems but primarily on the JK's... but also some with the JL's. Mine is a 2018 Sport JL, but is my first ever Wrangler, so not sure if it's an issue or possibly driver error.

My dealer I bought it at is 3 hours away from where I live, but there is a couple Jeep dealers within 30 mins... so any thoughts on if I should take it in to be checked? If so, can I take it to any Jeep dealer? Or should I just wait and see a few more days and practice driving it better? Any recommendations would be appreciated. Thanks in advance!

 

[Spank]

My dealer I bought it at is 3 hours away from where I live, but there is a couple Jeep dealers within 30 mins... so any thoughts on if I should take it in to be checked? If so, can I take it to any Jeep dealer? Or should I just wait and see a few more days and practice driving it better? Any recommendations would be appreciated. Thanks in advance!

Congratulations on the new Jeep!

Absolutely get it checked. It's a brand new vehicle and even with discounts and incentives, I'm sure it wasn't cheap. It should perform flawlessly and your transmission should be smooth and quiet.

 

[NavyVet1959]

you are dead wrong.
Google it. Even carburetors shut off fuel while in compression mode.

Apparently DFCO (deceleration fuel cut off) is a newer feature and was not on my pickup. Apparently, Dodge started adding it in 2009. It also seems that even today, not every new vehicle that has an automatic transmission has it, but it seems to be getting more common.

Oh, and BTW, Quora is not a definitive source for an answer to a question. It is just a web site where people can give what they think is the answer and as such, is no different than posting a link from the comments by trolls on YouTube. Some of the answers might be right, but there is nothing to guarantee it.

 

[Torero]

Apparently DFCO (deceleration fuel cut off) is a newer feature and was not on my pickup. Apparently, Dodge started adding it in 2009. It also seems that even today, not every new vehicle that has an automatic transmission has it, but it seems to be getting more common.

Oh, and BTW, Quora is not a definitive source for an answer to a question. It is just a web site where people can give what they think is the answer and as such, is no different than posting a link from the comments by trolls on YouTube. Some of the answers might be right, but there is nothing to guarantee it.

Quora is not my source, was the first thing that pop up. On this matter my job is my source. So much less credible than Quora. Lol

 

[Taxman]

Congrats on your new JL! I would have the transmission checked or have a buddy drive it to make sure it’s not user error. It’s a very soft clutch and may take you some time to get used to. There should be no grinding noise. The MT is silky smooth and shifts flawlessly. It’s one of my favorite MTs of any of the seven Jeeps I’ve owned over the last 20 years.

Enjoy and congratulations again!

 

[NavyVet1959]

Quora is not my source, was the first thing that pop up. On this matter my job is my source. So much less credible than Quora. Lol

I've looked at Quora before on some of the topics where I'm rather knowledgeable and some of the answers just made me wonder if the posters had any idea whatsoever about the topic since their answers were so wrong. For example, some people would be adamant that anything over a certain voltage can kill you. Anyone who knows anything about electricity knows that voltage means little after it gets high enough to overcome the body's resistance and it is the amperage that kills you and it doesn't need that much of it if it's going across the heart.

Regardless of whatever your job might be, I personally have never owned a car that had DFCO. The JL that I ordered replaces a 14 year old Ram, so I don't change vehicles that often. I don't think the Cayenne Turbo that I used to own had it either since it appears that they didn't add it until 2011 and mine was before then. On the other hand, my wife's 335d has some sort of regenerative braking system where the battery gets charged when you are coasting or braking. From what I've gathered, it does not charge if you are just sitting still in your driveway. So, if you had to jump start it and thought that you could just let it run for awhile to charge up the battery, that might not work. I have to wonder if that would cause problems for someone who just used it for short neighborhood trips for a period of time.

 

[cbr954]

My YJ and TJ were both manual transmissions and I never had an issue. By all accounts the JL manual is smooth as butter. I am going to go with the manual for fun and the fact I have no desire to spend $2,000 for the AT. That money will be better spent on new tires and other upgrades.

 

[bobzdar]

Having driven the 8 speed in a grand Cherokee, I didn't consider the manual - and I was such a die hard manual guy I've converted an auto to a manual. First time for everything.

 

[stangken]

Who makes the manual transmission? Anyone know the model number?

 

[homerun]

Who makes the manual transmission? Anyone know the model number?

The transmission is made by Aisin, Jeep has used them for their manuals since my YJ. The model that went into the JL was all new and I believe this is its first application. Not certain but I want to say the model number is D478.

 

[stangken]

The transmission is made by Aisin, Jeep has used them for their manuals since my YJ. The model that went into the JL was all new and I believe this is its first application. Not certain but I want to say the model number is D478.

Thanks!

 

[NavyVet1959]

The transmission is made by Aisin, Jeep has used them for their manuals since my YJ. The model that went into the JL was all new and I believe this is its first application. Not certain but I want to say the model number is D478.

Back in the old days, the manufacturers designed and built their own transmissions and other parts of the vehicles. I notice that Aisin makes transmissions for a lot of different manufacturers, so that apparently changed at some point. Do the car manufacturers still design the transmissions and subcontract out the manufacturing of the transmissions to other such companies, or do they just provide basic size and performance criteria and companies like Aisin do the design from there?

 

[homerun]

Back in the old days, the manufacturers designed and built their own transmissions and other parts of the vehicles. I notice that Aisin makes transmissions for a lot of different manufacturers, so that apparently changed at some point. Do the car manufacturers still design the transmissions and subcontract out the manufacturing of the transmissions to other such companies, or do they just provide basic size and performance criteria and companies like Aisin do the design from there?

If you are asking me, I have no idea. I could however make up some pretty convincing BS if you would like.

 

[johnnymiz]

Actually, back in the old days, car companies made their own, but also bought transmissions from companies like borg warner, new venture, getrag and clark.

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