Notices
1999 - 2003 7.3L Power Stroke Diesel  
Sponsored by:
Sponsored by: DP Tuner

TC Lock-Up Switch Question

Thread Tools
 
Search this Thread
 
Old Jun 7, 2006 | 08:25 AM
  #1  
cnd999's Avatar
cnd999
Thread Starter
|
Senior User
Joined: Nov 2005
Posts: 370
Likes: 0
From: Maine
TC Lock-Up Switch Question

For those that have done the torque converter lock up switch, how often and when do you use this great modification? I find myself switching my tc on many times while cruising around town simply cause the computer just holds off too long sometimes to engage it especially when going around 30-40 mph up a grade. Towing is when the ability to control this really shines. The torque generated by these monsters needs to be applied to this tranny judiciously though as to not granade it. Heat can quickly build.
I also get a much lower rpm manually locking tc in 3rd and od on those occasions when the pcm, for some reason, doesn`t see the need to give me more efficient power transfer. I am careful not to lug the engine though. I love being able to control this and was just wondering others` experiences with it.
Havn`t contributed for awhile so I thought i`d chime in to keep the posting monitors happy.
 
Reply
Old Jun 7, 2006 | 08:29 AM
  #2  
wbhinton's Avatar
wbhinton
Senior User
Joined: Mar 2006
Posts: 171
Likes: 0
From: Houston, TX
I use mine on a fairly regular basis... really nice for long stretches of 45+ mph
 
Reply
Old Jun 7, 2006 | 08:55 AM
  #3  
PowerstrokeJunkie's Avatar
PowerstrokeJunkie
Post Fiend
Joined: Jul 2005
Posts: 14,582
Likes: 12
From: 21791
i use mine all the time. it is always on, i like to tractor mine around at 1200rpm or so. i also like to do smokeouts, pull it down into second gear, and then lock the TC up around 1000 and rolll on the throttle
 
Reply
Old Jun 7, 2006 | 10:00 AM
  #4  
cnd999's Avatar
cnd999
Thread Starter
|
Senior User
Joined: Nov 2005
Posts: 370
Likes: 0
From: Maine
Strokin it, your rig looks sweet with the new lift. Need some honkin meats now.
just my 2cents your 33s look kinda like 13 inch in those wheelwells don`t take offense. Got dialup in my new old house so it blows tryin to download your pics.
Comcast coming soon. Nice Rig!
 

Last edited by cnd999; Jun 7, 2006 at 10:02 AM.
Reply
Old Jun 7, 2006 | 11:49 AM
  #5  
sumtoy's Avatar
sumtoy
New User
Joined: Mar 2006
Posts: 16
Likes: 0
Where is the best place to buy a TC lockup switch?
 
Reply
Old Jun 7, 2006 | 11:58 AM
  #6  
wbhinton's Avatar
wbhinton
Senior User
Joined: Mar 2006
Posts: 171
Likes: 0
From: Houston, TX
Radio Shack for about $5....

mine is DIY... quite easy

took me a couple tries to find the right wire.... but when I found it I new it.

the TC lock switch just grounds out a wire that runs from the PCM to the Tranny. Its purple w/ an orange tracer.

the PCM uses voltage to control the TC (12v unlocked; 0v locked with varing degrees of slippage in between)

find the wire, hook the switch, ground the b^tch out and then she'll lock right up.

WB
 
Reply
Old Jun 7, 2006 | 03:08 PM
  #7  
ryaneverk2's Avatar
ryaneverk2
Logistics Pro
20 Year Member
Joined: Mar 2004
Posts: 4,221
Likes: 3
This is something I still need to add to my rig.... just haven't gotten around to it yet.
 
Reply
Old Jun 7, 2006 | 05:33 PM
  #8  
BuickTurbo's Avatar
BuickTurbo
Elder User
Joined: Aug 2005
Posts: 763
Likes: 0
From: Dallas, Texas
I agree with Strokin, rolling the throttle and blacking out an intersection is pure joy.

If I don't forget it's there (when not towing) I use it often. One of the best mods I've done.
 
Reply
FTE Stories

Ford Trucks for Ford Truck Enthusiasts

story-0

Top 10 Ford Truck Tragedies

 Joe Kucinski
story-1

AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

 Brett Foote
story-2

Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

 Michael S. Palmer
story-3

Ford's 2001 Explorer Sportsman Concept Looks For a New Home

 Verdad Gallardo
story-4

10 Best Ford Truck Engines We Miss the Most!

 Joe Kucinski
story-5

2026 Shelby F-150 Off-Road: Better Than a Raptor R?

 Brett Foote
story-6

2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

 Michael S. Palmer
story-7

10 Most Surprising 2026 Ford Truck Features!

 Joe Kucinski
story-8

Top 10 Ford Trucks Coming to Mecum Indy 2026

 Brett Foote
story-9

5 Best / 5 Worst Ford Truck Wheels of All Time

 Joe Kucinski
Old Jun 7, 2006 | 05:41 PM
  #9  
GarrettShields's Avatar
GarrettShields
Senior User
Joined: Jun 2005
Posts: 172
Likes: 0
From: Amherst, WI
Originally Posted by sumtoy
Where is the best place to buy a TC lockup switch?
We offer a lighted TC Lockup Switch Here
 
Reply
Old Jun 7, 2006 | 06:25 PM
  #10  
Rich in CO's Avatar
Rich in CO
Senior User
Joined: Apr 2005
Posts: 324
Likes: 0
Ok I'm confused which is not nothing new. When I drive around town I keep the truck in OD, and when towing up hill or going down hill I pull her out of OD. Is going from OD to out of OD locking in the TC?

If not how would this mod help me while towing? or driving around town.
 
Reply
Old Jun 7, 2006 | 07:27 PM
  #11  
arninetyes's Avatar
arninetyes
Posting Guru
Joined: Dec 2004
Posts: 1,248
Likes: 0
Originally Posted by Rich in CO
Ok I'm confused which is not nothing new. When I drive around town I keep the truck in OD, and when towing up hill or going down hill I pull her out of OD. Is going from OD to out of OD locking in the TC?

If not how would this mod help me while towing? or driving around town.
No. They are unrelated. IF you have a stock tranny and stock PCM, the TC can act in slightly different ways. But one thing is common - once the TC locks, it will UNLOCK if you touch the brakes.

I don't yet have a TC lock switch. Maybe I'll do it this weekend. But I have Jody Tipton's trans tuning with my chip. In OD, it the TC will stay locked down to 38 even if I am using the brakes; if I lock out OD, the TC will stay locked down to 28. While not a controllable as a switch, it makes a HUGE improvement over the stock (stooopid) TC lockup settings.
 
Reply
Old Jun 7, 2006 | 07:54 PM
  #12  
PowerstrokeJunkie's Avatar
PowerstrokeJunkie
Post Fiend
Joined: Jul 2005
Posts: 14,582
Likes: 12
From: 21791
i also like to use it to help slow me down. going to and from Vo-tech every day there is a 8 or 9% grade that you start out around 50 and then have to stop at a light at the bottom and then go back up the other side. i like to have it in D, and when it goes to 1750 or so, pull it down into 2nd and rev up to 2600 or so and coast down to the light in style. i try to have the TC locked as much as possible. keeps temps down, less slippage and wear on my noodle-slushboox..


edit, thanks for the comments. i have set the go mods aside and im saving up for 18" motometal wheels like JTharvey, and 35" Toyo Open Country MT's or even 37's if i don't get too many tickets between now and when these wear out. i also would regear to 4.30's if i had the 35's or 4.56's if i got the 37's. but before that i am going to upgrade my front rotors and pads.
 
Reply
Old Jun 7, 2006 | 08:16 PM
  #13  
cnd999's Avatar
cnd999
Thread Starter
|
Senior User
Joined: Nov 2005
Posts: 370
Likes: 0
From: Maine
Originally Posted by Rich in CO
Ok I'm confused which is not nothing new. When I drive around town I keep the truck in OD, and when towing up hill or going down hill I pull her out of OD. Is going from OD to out of OD locking in the TC?

If not how would this mod help me while towing? or driving around town.
Rich, when my tc is controlled by the pcm I frequently found that it locked and unlocked at very inopertune times like oposite of when I needed it or didn`t. I hate when I am going from 3rd to od and I get a drastic rpm drop when the converter locks at the same time. I can fix this by simply flipping my switch earlier and locking out before the shift. The Sonnax springs have helped this problem also by giving me more line pressure thus seemingly delaying my shift points slightly and making them much quicker.

Sometimes while towing I found my rpms would be too high for the given terrain or grade and I got to realizing that when the converter finally locked in I didn`t need all that reving. You will find the torque your engine has! Now that I have control over the tc I am learning when to use it and when I don`t need to switch manually. I just think of this as a clutch that needs to be disengaged when speeds drop below 28 or so. I must confess though I have forgotten the switch was on a couple times and it is just like slowing down too much in a manual tranny with the clutch out, it aint graceful!
 
Reply
Old Jun 7, 2006 | 08:29 PM
  #14  
PowerstrokeJunkie's Avatar
PowerstrokeJunkie
Post Fiend
Joined: Jul 2005
Posts: 14,582
Likes: 12
From: 21791
yes i did embarass myself in front of a chick last weekend. pulling up to a stop sign, i didnt take notice of the green light on in the pillar, and i did not unlock it. instead i stopped and the truck kept chug-a-lugging and stalled in the middle of the intersection. thank god there were no cars coming...

however i do find myself using it at really low speeds, such as trying to slow down trailers (the rare times i pull a trailer with no brake controller) i have no trailer brakes. i use the shifter lever alot more to help slow me down. sometimes i leave it locked in 1st gear, and as long as my engine is over 900 rpm i leave it in and then flick it off as the rev's churn down to idle. i like tractoring it around at slow speeds in 1st or second gear.
 
Reply
Old Jun 7, 2006 | 08:32 PM
  #15  
ryaneverk2's Avatar
ryaneverk2
Logistics Pro
20 Year Member
Joined: Mar 2004
Posts: 4,221
Likes: 3
Originally Posted by arninetyes
I don't yet have a TC lock switch. Maybe I'll do it this weekend. But I have Jody Tipton's trans tuning with my chip. In OD, it the TC will stay locked down to 38 even if I am using the brakes; if I lock out OD, the TC will stay locked down to 28. While not a controllable as a switch, it makes a HUGE improvement over the stock (stooopid) TC lockup settings.
This was one of the first things I noticed after installing my chip from Jody, slowing down for an exit off the freeway. HUGE improvement over the retarded stock setup. Say you have to slow some for a merger... hit the brakes, but the TC stays locked and rpms stay up, and then when it's time to blow around the guy or just get back up to speed, the power is right there.
 
Reply



All times are GMT -5. The time now is 10:48 PM.

story-0
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-1
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-2
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-3
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-4
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-5
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE
story-6
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!

Slideshow: Everything You Need to Know about the 2027 Super Duty Carhartt Package!

By Michael S. Palmer | 2026-05-07 17:51:06


VIEW MORE
story-7
10 Most Surprising 2026 Ford Truck Features!

Slideshow: 10 most surprising Ford truck options/features in 2026.

By Joe Kucinski | 2026-05-05 11:17:22


VIEW MORE
story-8
Top 10 Ford Trucks Coming to Mecum Indy 2026

Slideshow: Here are the top 10 Fords coming to Mecum Indy 2026.

By Brett Foote | 2026-05-04 13:49:49


VIEW MORE
story-9
5 Best / 5 Worst Ford Truck Wheels of All Time

Slideshow: The 5 best and 5 worst Ford truck wheels of all time

By Joe Kucinski | 2026-04-29 16:49:01


VIEW MORE