doc5339

Looking down the road, do you guys see any reason why the new JL Aisin D478 manual transmission could not be easily mated to a 3.6 Pentastar in a JK/JKU?

From Jalopnik:

https://jalopnik.com/the-2018-jeep-w...ett-1821160227

"The Aisin D478 manual transmission comes with a granny-like 5.13:1 (up from 4.46:1) first gear ratio; when mated to the 4:1 low-range gear and the 4.10:1 axle ratios found in the Rubicon, that yields a crawl ratio of over 84 (up from 73)."

Can't wait to see what the input torque rating is as well. Looks like a step-up from the NSG370. Soon as a few 2018 wreck they should be available.

dmwil

I'm not sure if it would fit, but it sure looks like a promising transmission. I don't hate on the NSG 370, though. I've enjoyed the heck out of the one in my JK. I've got a new JL with the Aisin on order, but I'm keeping the JK and intending to enjoy it for years to come. I can't wait to feel that first gear. I'll be using it up, though, when I put 35's on it.

doc5339

Thanks and please advise of how the Aisin compares to the NSG370 after you have driven a bit.

dmwil

I sure will. I'll be driving them back to back, daily. My NSG 370 is actually new, as well. They replaced it under lifetime warranty because it slipped out of 3rd gear about once a month. No joke. Other than that, the old one felt just fine after about 116k miles. The new one (Fiat-Chrysler factory rebuilt) feels like they made some improvements, so it will be basically a new NSG370 compared to a new Aisin, so it should be close to apples to apples. I know lots of people criticize the NSG 370, but I've always enjoyed it. It definitely feels like a truck transmission, but hey, it is in a truck.

I believe there is a delay in production of the manual on the JL because they wanted to fix or adjust the clutch. There were complaints in preproduction of the clutch lacking feel and engaging too quickly. Jeep says they have a fix, but production should have started in November but appears to still be on hold. FCA has told me mine was to be produced two weeks ago, but I checked again Friday and they said it was "sequenced for production" and all the parts were at the factory. We'll see. Right now, I feel like I'll be lucky if I see it in January.

silverbullet88

dmwil

Yes, and it is simply outstanding. It is better in every way than the NSG370, and that includes both the clutch and the shifter/shift linkage. That said, I still drive my JK quite a bit and still love it. It is more like an old truck transmission, whereas the JL feels like a highly refined sports car. I'm loving the gear ratios, too, although I'd like to see a little less gap between 3rd and 4th, then a slightly shorter 5th. 6th can stay right where it is, as can 1st to 3rd, which are perfect, even with 35's. That's just nitpicking, though.

How are you liking yours?

silverbullet88