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-   -   can someone explain the difference between these (http://www.jeepgarage.org/f73/can-someone-explain-the-difference-between-these-18991.html)

Rosewood 02-16-2011 11:28 PM

can someone explain the difference between these
 
5-speed automatic w/OD and auto-manual

5-speed multi-speed automatic w/OD and auto-manual

JTS97Z28 02-16-2011 11:32 PM

Re: can someone explain the difference between these
 
Good question I to have always been curious.

Thanks,
James

GR33N D3M0N 02-16-2011 11:49 PM

Re: can someone explain the difference between these
 
on my wk, when i put it in autostick, it seams to shift twice on some gears. if that makes sense, and im not redlining it, i will go from 3k rpm to around 2k rpm, same throttle position, so maybe thats the difference?

BrianK 02-17-2011 02:21 AM

Re: can someone explain the difference between these
 
The multi-speed auto has two different second gears--one for upshifts and one for downshifts.

mjw930 02-17-2011 07:41 AM

Re: can someone explain the difference between these
 
Quote:

Originally Posted by BrianK (Post 357737)
The multi-speed auto has two different second gears--one for upshifts and one for downshifts.

Additionally it has an "underdrive" setup that is used when in tow/haul mode. I imagine it's actually a byproduct of the 2nd prime gearing but I don't have a schematic of the inner workings handy.

It's actually a pretty slick transmission, if they can get the torque converter issues straightened out ;)

The 5 speed in the V6 is a variation on a Mercedes trans, I think. It's probably based on a ZF, Getrag or Asin (?sp).

OneCent 02-17-2011 10:44 AM

Re: can someone explain the difference between these
 
Quote:

Originally Posted by mjw930 (Post 357883)
The 5 speed in the V6 is a variation on a Mercedes trans, I think. It's probably based on a ZF, Getrag or Asin (?sp).

I think its a Mercedes construction.

mhassler 02-17-2011 10:52 AM

Re: can someone explain the difference between these
 
There was a thread asking about the function of the Tow/Haul switch on the 5.7 Hemi's and there was an excerpt from the manual within the thread:

5.7L Engine
On vehicles equipped with the 5.7L engine, use of ERS (or TOW/HAUL mode) also enables an additional underdrive gear which is not normally used during through gear accelerations. This additional gear improves vehicle performance and cooling capability when towing a trailer on certain grades. ERS 1, 2, and 3 are underdrive gears; ERS 4 is direct drive. ERS 5 (Overdrive) is the same as the normal 4th gear. When in the DRIVE position in first through fourth gear, the first tap to the left (-) will display the ERS designation for the current gear (the transmission will not downshift). For example, if you are in DRIVE and are in third (direct) gear, when you tap the shift lever one time to the left (-), the display will show 4 (ERS 4 is direct gear). Another tap to the left (-) will shift the transmission down to ERS 3 (the added underdrive gear). When in the DRIVE position in fifth gear, the first tap to the left (-) will downshift the transmission and display 5 (ERS 5 is the same as normal fourth gear). Another tip to the left (-) will shift the transmission down to ERS 4 (direct gear).

WARNING!
Do not downshift for additional engine braking on a slippery surface. The drive wheels could lose their grip and the vehicle could skid.

Screen Display 1 2 3 4 5* D
Actual Gear(s) Allowed 1 1-2 1-3 1-4 1-5 1-5

* Applies to vehicles equipped with 5.7L engines only.

NOTE: To select the proper gear position for maximum deceleration (engine braking), move the shift lever to the left D(-) and hold it there. The transmission will shift to the range from which the vehicle can best be slowed down.

The original thread is located here: http://www.jeepgarage.org/showthread...highlight=play

Hopefully this helps....

Rosewood 02-17-2011 08:56 PM

Re: can someone explain the difference between these
 
so which is better?

Technosavant 02-17-2011 09:36 PM

Re: can someone explain the difference between these
 
Quote:

Originally Posted by Rosewood (Post 358541)
so which is better?

They're just different. It isn't a better. The 545RFE (5 speed multi speed) used with the Hemi is a transmission intended for use in high torque and high load applications. Hence the extra gears for when you're hauling more than tail. The W5A580 is a more passenger-oriented engine; not that it is a weakling, but that it wasn't engineered for hauling heavy loads through mountain passes. IMO, it is much smoother, as you'd expect out of a Mercedes product, but if you hooked it up to a Hemi and tried hauling an RV through the Rockies you'd probably burn the thing up in nothing flat (although the design limit of the W5A580 is such that it should be able to handle the torque of the Hemi, it's starting to get pretty close to its limits).

They're different transmissions for different applications.

jeep2011 02-17-2011 10:49 PM

Re: can someone explain the difference between these
 
The two second gears has been used since 1999 with the 4.7L. It was designed for better passing and acceleration when needed.


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