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Discussion Starter #1
does anyone know how to lock up the converter manually?
 

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there is a couple threads floating around.do a search and it sould come up.
 

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What year truck do you have? Its different depending on year.
 

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The only real difference between year is the wire color that you tap. Other than that, this will work on all 3rd Gen trucks 2003 thru 2006, 47RE or 48RE trans. If you have a 47RE trans, the truck will immediately shift into overdrive when you hit the switch, regardless of speed, unless your at WOT (did that make sense). On 47RE trucks, this works great at the track, but not very good for daily driving unless you lock out overdrive…..then its a blast to use in town. No issues that I am aware of on 48RE transmissions. Your wire colors may be different by year, so definitely check pin numbers before you to tapping. I found some really good pics of this procedure on a 2006 truck on photobucket that I'm gonna "borrow". Hope the guy doesn’t mind. This guy did a real nice job with his install and the pics will help tremendously. It should look relatively the same on all years. CAUTION: The stock converter and shafts are not designed to withstand locked shifts, so be aware and use this at your own risk.

This will make a manual lock-up switch. This will lock the converter in any gear, whether the truck is moving or not. It will not lock the converter if the truck is in neutral, reverse, or park. If you are in drive, 1st, or 2nd, and flip the switch, the converter is going to lock, even if your at idle which will kill the engine. So be careful. The converter locks up normally if the switch is off. Basically, be aware of when your locked.

You will need an on/off toggle switch of some kind, some wire, and a wire tap. The idea is to take the 12v converter signal and ground it with the toggle switch. When this signal drops below 6v, the converter locks. You will also need to run a short jumper wire between two pins on the transmission relay in the fuse box under the hood. This will prevent the ECM from throwing a code P2769, Torque Converter Clutch Circuit Low.

Step 1: Crawl under the truck on the drivers side and look at the transmission. There is a squarish plug and a round 7-pin plug. The wire you want to tap is pin# 7 on the round 7-pin plug. If you take the round plug off, the pin numbers are on the inside (bottom of the plug). The clip holding this plug on is facing to the passenger side. Just push the clip in and pull up on the plug. Find pin# 7 and put a wire tap on the wire going into this pin. On your 2006 truck, this will be the yellow wire with light blue stripe. Everyone else should probably pull the connector and find pin #7 (good light helps see the numbers, they are very small) to ensure you have the right wire. Colors sometimes change through the years.

Run a wire from this wire tap into the cab and connect it to your toggle switch. Connect a wire to the other side of your toggle switch and run it to some metal under the dash somewhere or any decent grounding point. This will ground out that signal when you flip the switch.

Step 2: Now open the fuse box under the hood and find the transmission relay. This will be listed as relay # 59 on the fuse box cover. It's next to the fuse marked 50. Pull the relay (lift straight up) and look underneath for the pin numbers. Put a short piece of wire connecting pins #30 and #87. Make sure this wire has some insulation in the middle as not to short out any other pins. Just wrapped the ends around the two prongs and plug it back into the socket. There is also a pin marked 87A. Careful not to run the jumper to 87A by mistake or you will set the dash light, get a code P2769, and put the truck into limp mode.

Possible problems with codes. There really is only two things that can go wrong and both will be user error.

If there is something wrong with your jumper on the transmission relay (wrong pins, not touching both pins, touching more than just these two pins), it will set a P2729 code. The truck will go into limp mode and not shift out of 3rd gear.

If you forget to unlock your converter and accidentally kill the engine, you will get a code.

Here are the pics of this procedure on a 2006 truck that I mentioned above. This guy did a real nice job with his install.

Here is a picture of the proper plug/location that you want to tap:


The plug removed:


The yellow wire with light blue stripe that aligns with pin #7 on your 2006 truck:


A quality wire tap on the pin #7 wire:


Finished wire tap, all wrapped up with electrical tape:
 

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Discussion Starter #6
thanks a lot!! that was the most detailed answer to a question that i have ever recieved, looks easy, thanks for the info and help!!
 

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Your welcome. :thumbsup
 

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On my 05, I didn't need to go into the relay. I just used a 33 ohm (not 33k ohm) reisistor and placed it between the switch and the grounding point. Works the exact same way. Locks in any gear at any speed. Only problem that I have noticed is that once locked (switch turned on), it will not downshift even at WOT. So I just turn off switch so it acts like normal, when needed, to have tranny downshift and then hit the button again to lock it up and off I go.

Those are great instructions though.
 

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Man, am I ever glad I own a manual.
 

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Discussion Starter #10
I have a gmc Syclone, with the converter locked manually its worth 2 tenths, 2 mph in the 1/4. not sure what its worth with these big rigs but i guess i'll find out!!
 

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Do you have an aftermarket trans (stupid question, but gotta ask)? If your brave enough to use it with the stock transmission, it actually helps a lot due to the really loose stock converter. I have seen reports of picking up 3/4 second in the 1/4. With an aftermarket trans, probably see .4 to .5. They work pretty good.

You can lose time if you lock too early (engine bog). Locking in second works best for me. :thumbsup
 

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Discussion Starter #12
yes, the truck had 5K miles on it when i first changed the motor oil, then i changed the trans fluid to synthetic, changed the filter, and added TCI's deep cast all. pan which hold 4 extra qts. The truck is my daily driver, i dont race it that much at all, maybe once a year, but when i do id like to get everything i can out of it.
 

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for some reason mine wont lockup with a switch...on my 03 its the orange and black wire..tapped it, put the jumper around #ep and #87, tried the 33 ohm on the ground side. i got nothing. only thing the trans has done to it is a triplelok and mag hytec dd pan. any ideas?
 

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is this on a 47RE trans?
 

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48re, and it isnt an instant lockup, i have to let up then get back in for lockup
theway the valve body was made maybe?
 
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So I just did this to my truck and I love it!! The only think I changed was the jumper on the trans relay. I soldered it in and ran it on the out side of the relay to make sure it never shorts out. I can provide pics if anyone would like to see. Gotta take it easy with a stock tranny though, this thing shifts with authority with the TC locked at WOT!! I'll be buying a billet tranny in the near future, I just know it.:fist:
 

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So I just did this to my truck and I love it!! The only think I changed was the jumper on the trans relay. I soldered it in and ran it on the out side of the relay to make sure it never shorts out. I can provide pics if anyone would like to see. Gotta take it easy with a stock tranny though, this thing shifts with authority with the TC locked at WOT!! I'll be buying a billet tranny in the near future, I just know it.:fist:
Id like to see pics if you dont mind!

Many thanks!


Lock on dudes.... LOL


Chad
 

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Id like to see pics if you dont mind!

Many thanks!


Lock on dudes.... LOL


Chad
Gimmie a day. I will post some tomorrow.
Chuck
 

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Is there a way to do this on a '99? If so, could someone post a link to instructions, or explain it to me? Pictures are awesome, as well. thanks! :hyper:
 
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