Is torque converter supposed to lockup? - JeepForum.com
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Unread 11-07-2013, 08:22 PM   #1
Malachi73
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1998 ZJ 
 
Join Date: Feb 2010
Location: Ontario, CA
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Is torque converter supposed to lockup?

Ok, not sure what exactly its called, but I understand that after OD, you should drop a few more RPMs when the Torque Converter locks up, right? Or, am I missing something?

Reason I ask is my 98 doesn't seem to be doing that. My last drop in RPM is OD, I run about 2300 or so RPM at 65mph. Is that normal?

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Unread 11-07-2013, 08:42 PM   #2
ZeeJay1997
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If the overdrive control switch is in the normal ON position, the clutch will engage after the shift to fourth gear, and above approximately 45 mph. If the control switch is in the OFF position, the clutch will engage after the shift to third gear, at approximately 35 mph at light throttle.

you should feel it unlock as you coast down from cruise. mine runs 2k at 65
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Unread 11-07-2013, 09:09 PM   #3
JasonStebbins
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Quote:
Originally Posted by ZeeJay1997 View Post
If the overdrive control switch is in the normal ON position, the clutch will engage after the shift to fourth gear, and above approximately 45 mph. If the control switch is in the OFF position, the clutch will engage after the shift to third gear, at approximately 35 mph at light throttle.

you should feel it unlock as you coast down from cruise. mine runs 2k at 65
48mph/38mph in my ZJ.

I'm around 1900-2000 @ 65mph. With overdrive off, around 2300 @ 55mph.
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Unread 11-07-2013, 09:13 PM   #4
ZeeJay1997
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yeah, mine comes in around 48 too.
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Unread 11-07-2013, 09:25 PM   #5
zj97ltd
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My converter stopped locking up on a Monday morning. Wednesday it quit all together and I couldn't move...
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Unread 11-07-2013, 11:49 PM   #6
dnuccio
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you can see if its working by getting up to a cruising speed (45+) and very lightly tap the brake pedal. RPM should jump slightly as the converter unlocks
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Unread 11-08-2013, 04:19 AM   #7
Candymancan
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Like everyone said... You can also keep your foot on the gas (when your above 50mph) and slightly touch your brake pedal it should kick right out and unlock and youll see rpm rise.. If not then your torque convertor isn't working...

Our 4.0 locks at like 50mph, the 5.9 locks at around 35-40mph depending how light im tapping the pedal
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Unread 11-09-2013, 12:55 PM   #8
Mickey_D
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Quote:
Originally Posted by JasonStebbins View Post
With overdrive off, around 2300 @ 55mph.
Using this evidence, sounds like the OP isn't getting into OD, but the TCL is working fine.
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Unread 11-10-2013, 07:11 AM   #9
Malachi73
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Thanks all for the replies.

I'm pretty sure my OD is working, cause if I turn it off my rpms jump up, and if I turn it back on they drop.

But, if I tap the brake pedal at 65mph, the rpms do not jump up. And, I do not get another drop in RPM after 4th gear (OD).

So, it sounds like my TCL is not working.

Any ideas as to the cause.

FWIW, I just bought the Jeep with 158K on the Odometer, but was told by the seller that he just had an engine put in with only 104K on it. So, could it be something that was done wrong with the engine swap?
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Unread 11-11-2013, 12:02 AM   #10
dnuccio
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Quote:
Originally Posted by Malachi73 View Post

FWIW, I just bought the Jeep with 158K on the Odometer, but was told by the seller that he just had an engine put in with only 104K on it. So, could it be something that was done wrong with the engine swap?
could very well be
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