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2019 159 EXT HR (3500) in WA
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I would love to know also.

My guess is that mechanically it would fit, but I think that there would be issues getting an older computer to talk to the newer transmission.

What do you think, @Kip-on-truckin and @PromasterTECH ?
 

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It’s a good question. Chrysler has always been pretty good about keeping parts uniform. That’s smart because it reduces costs for everyone. So I suspect that the case for the 9 speed has provisions for east-west and north-south mounting. It’s in the Pacifica behind a pentastar, and it’s in the Cherokee behind a 2.4 (I think). So yeah, it probably fits, and it probably had the same output splines to match our axles.
Controlling it is relatively simple. At the end of the day, shifting a modern transmission is just a matter of voltage to the shift solenoids. You could shift the 9 speed or our 6 speed with push buttons or toggle switches if you wanted to.
A problem would be the computer going into limp when it doesnt see a trans hooked up. Possibly solved by using a Jeep ecu programmed for a manual trans. Not that simple, but not insurmountable.
Of course, the real question would be why. Lots of things to complain about the 62te, but the ratios are pretty perfect. Burns the tires in 1st, turns 2000rpm at 60. You’d also want the 9 speed to turn [email protected], because that’s the sweet spot for the engine. If for some reason you want it to turn [email protected], but on bigger tires. If you want [email protected], put on smaller tires. Or you could just swap in a minivan diff. It’s 4 bolts, and it fits.
More gears can get you better acceleration, and better highway mileage. But only up to a point. The mileage of the van is pretty much dictated by physics - it’s never going to get 30mpg on gasoline. For 99% of people, 0-60 isnt important in a 5400lb van. 9 and 10 speed transmissions exist to ace the EPA emissions tests more than anything else, really.
If the goal is max mileage, I think it may be possible to put a turbo 4 in place of the pentastar. That, and some aero tricks would yield bigger gains than more gears, I suspect.
 

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Discussion Starter · #4 ·
My reason for the interest in the change is to increase the smoothness of the ride at all speeds. Down shifting in heavy highway traffic, going up grades on the highway and general smoothness of shifting at various speeds. Am I logical in my thinking? My wife has a 9-spped in her Honda Odyssey and the shifting is really smooth at all times so it seems.
 

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It’s a good question. Chrysler has always been pretty good about keeping parts uniform. That’s smart because it reduces costs for everyone. So I suspect that the case for the 9 speed has provisions for east-west and north-south mounting. It’s in the Pacifica behind a pentastar, and it’s in the Cherokee behind a 2.4 (I think). So yeah, it probably fits, and it probably had the same output splines to match our axles.
Controlling it is relatively simple. At the end of the day, shifting a modern transmission is just a matter of voltage to the shift solenoids. You could shift the 9 speed or our 6 speed with push buttons or toggle switches if you wanted to.
A problem would be the computer going into limp when it doesnt see a trans hooked up. Possibly solved by using a Jeep ecu programmed for a manual trans. Not that simple, but not insurmountable.
Of course, the real question would be why. Lots of things to complain about the 62te, but the ratios are pretty perfect. Burns the tires in 1st, turns 2000rpm at 60. You’d also want the 9 speed to turn [email protected], because that’s the sweet spot for the engine. If for some reason you want it to turn [email protected], but on bigger tires. If you want [email protected], put on smaller tires. Or you could just swap in a minivan diff. It’s 4 bolts, and it fits.
More gears can get you better acceleration, and better highway mileage. But only up to a point. The mileage of the van is pretty much dictated by physics - it’s never going to get 30mpg on gasoline. For 99% of people, 0-60 isnt important in a 5400lb van. 9 and 10 speed transmissions exist to ace the EPA emissions tests more than anything else, really.
If the goal is max mileage, I think it may be possible to put a turbo 4 in place of the pentastar. That, and some aero tricks would yield bigger gains than more gears, I suspect.
I completely agree. The 62TE with its 4+2 configuration is well matched to the PM. Not perfect, but just fine really, and it has a known track record in the PM.
Only time will tell what goes with the 948TE. For instance, it really doens't like to be overheated at all. But one thing for sure is that it's relacing the 62TE to exceed EPA emissions, not to provide a better driving experience. Gotta love the green transmission fluid.
As for MPGs, adding a roof rack and solar panels is going to knock gas mileage more than the 948TE could ever improve it. Now turbo 4, that's an interesting swap!
 

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I think about this kind of thing a lot. Best I can tell, you could mate the 62te with the 2.4 either from a modern Journey/Dart/200, or possibly from a SRT4 Neon/SRT4 Caliber.
I’m sure you see where I’m going with this.
It’s probably a terrible idea. If you want more power (why would you in a cargo van?) just hang a turbo on the pentastar. If you want better mileage, there are better ways to reduce the displacement - just inject a bunch of exhaust into the engine and it will act like a smaller engine. The pentastar currently just gets it’s exhaust from camshaft timing - simply reprogram that and it’s basically on-demand EGR.
But finally, I dont know how much more mileage there is to be had. Going from 20 to 22 is a big deal, but it’s not that much of a big deal. Over 100,000 miles at $3/gallon it’s a savings of $1364. That’s not much of a budget to justify risking the reliability.
 

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Yeah, it's a lot of tricks too. I remember back when Hyundai pulled the spare tire and completed the conversion of the windshield to a structural element, and then they still lied about the 40 mpg highway mileage.

That 2.4 conversion would be interesting to try, maybe on an old PM with a worn out Pentastar. I am learning to really like the Pentastar though.
 

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The powertrain is too integrated into the vehicle electronics to make this a viable DIY exercise. The 9-speed is a really complicated transmission, and due to the presence of two dog clutches inside it, it relies on tight communication with the engine ECU in order to "rev-match" when engaging either of the dog clutches. Parts swapping ain't like it was in the old days. I have no doubt that the transmission can be made to mechanically fit ... but making it work "properly" is a whole different ball game.

Modern vehicle electronics don't just open and close the throttle in response to you pressing the accelerator pedal ... they interpret your pedal input as a request for torque, and then they juggle throttle position and valve timing and transmission co-ordination in order to achieve what you are requesting. In order to do that, the logic that controls the engine needs to know what the transmission is doing and vice versa, and they each need to be able to tell the other to do something when they have something that needs doing (e.g. rev-matching to engage those dog clutches, or carefully slip the torque-converter clutch while juggling throttle position so that you don't notice torque converter lock-up or unlocking, or carefully juggle line pressure and throttle position while changing gear to minimise shift shock, etc).

Keep in mind that the Pentastar engine that's attached to the 9-speed isn't exactly the same as the original-design engine that came attached to the 6-speed, which means even if you swap wiring harnesses and controllers, it still won't be right. 'Course, you could swap the ENTIRE powertrain and wiring harness ...

... or you could do the sensible thing if it really bugs you that much, and trade the whole van in for a new one!
 
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