whats the point in a locking torque converter
Thread Starter
Member
Joined: Jan 2009
Posts: 218
Likes: 0
From: Erlanger, Ky
Year: 1990
Model: Cherokee
Engine: 4.0L Inline 6
what is the point in it??? I just dont understand it.
I seen it here in the write up section
https://www.cherokeeforum.com/f51/manually-lock-your-torque-converter-tc-14114/
and im just trying to figure out the use for it
I seen it here in the write up section
https://www.cherokeeforum.com/f51/manually-lock-your-torque-converter-tc-14114/
and im just trying to figure out the use for it
CF Veteran
Joined: Aug 2008
Posts: 6,588
Likes: 495
From: Chico, CA
Year: 1986
Model: Cherokee
Engine: 4.3L with headers and full 3" exhaust system
There are more reasons to have one than not. First is better gas milage in high gear. Second is less transmission heat. Third, acts like a standard tranny going down hill. Fourth, it gives us something to yak about on the net.
Last edited by 4.3L XJ; Jul 18, 2009 at 02:48 PM.
A "locking" torque converter differs from the previous type by having a mechanical clutch inside of it (usually actuated hydraulically,) that turns the torque converter into an effective 1:1 coupling. This circuit is typically activated in steady-state cruising in third gear or higher.
The primary benefits of a locking (corr: "lockup") torque converter are twofold: 1) By shifting to a mechanical coupling (vice hydraulic,) fluid shear is drastically reduced - thereby reducing operating temperature of the coupling and the transmission as a whole. This contributed significantly to transmission unit longevity. 2) By changing from a "slip-prone" fluid coupling to a 1:1 mechanical coupling (akin to the clutch in front of a manual transmission,) the cruis crankshaft speed can be made more consistent, and planning for more efficient cruise RPM - and therefore better fuel economy.
So there are two principal economic benefits to the lockup torque converter, as stated above. The ability to override the lockup circuit (and to turn it on in any gear range at steady-state) can also be useful, but this should be used judiciously. I'd probably find such ability most useful with low-speed hauling and towing (like in a "yard truck") more than anything else - but I'd probably use a four- or five-speed with a gear splitter for that instead, given the opportunity.
Does this make any more sense to you? I hope I didn't get overly detailed...
The primary benefits of a locking (corr: "lockup") torque converter are twofold: 1) By shifting to a mechanical coupling (vice hydraulic,) fluid shear is drastically reduced - thereby reducing operating temperature of the coupling and the transmission as a whole. This contributed significantly to transmission unit longevity. 2) By changing from a "slip-prone" fluid coupling to a 1:1 mechanical coupling (akin to the clutch in front of a manual transmission,) the cruis crankshaft speed can be made more consistent, and planning for more efficient cruise RPM - and therefore better fuel economy.
So there are two principal economic benefits to the lockup torque converter, as stated above. The ability to override the lockup circuit (and to turn it on in any gear range at steady-state) can also be useful, but this should be used judiciously. I'd probably find such ability most useful with low-speed hauling and towing (like in a "yard truck") more than anything else - but I'd probably use a four- or five-speed with a gear splitter for that instead, given the opportunity.
Does this make any more sense to you? I hope I didn't get overly detailed...
Member
Joined: Jun 2009
Posts: 197
Likes: 0
From: Bucks County Pa.
Year: 1987
Model: Cherokee
Engine: 4.0 Renix HO. head
If you have a cherokee and you have an auto tranny then you already have a lockup converter... It was necessary in order to achieve higher MPG during highway travel. Its one of the reasons whyyou get better mpg highway then city.
If you have the AW4 auto behind the 242ci six, you have a lockup torque converter, and it should feel like a "soft shift" from third or fourth when you hit a steady-state cruise.
The "Baby 904" used behind the 1984-1986 w/2.8L V6, I think, didn't have a TCC. I'm not sure about the slushbox used behind the earlier fours, either (later fours ended up getting the AW4, I believe, after the bellhousing pattern was changed from the GM V6-60 to the AMC I6/V8.)
Thread
Thread Starter
Forum
Replies
Last Post
jeefersjeepers
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
5
Nov 28, 2024 01:48 PM
Psiegrist1
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
34
Mar 17, 2022 02:15 PM
jhamXJ
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
11
Nov 9, 2021 08:20 AM
eagle11401
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
4
Sep 10, 2015 09:06 PM
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)



