planing to buy stall converter for 700r4 thats going back in our 39. a little confused on the lock up non lock up issue.looking for pros and cons of each. what are you running?
Go lock-up! The tranny temps run much cooler in lock-up. Heat is a 700R4's worst enemy and will cook the tranny.
If the vehicle is light weight, no lock up will probably be OK. Heavier vehicles or any towing will overheat the fluid when in OD.
search phoenixtrans.com - take you to site of Phoenix Transmission Products, Weatherford, Texas (not in Phoenix, AZ)-they can answer your questions and sell a good variety of parts you may need.
Yup Phoenix or Hughes Performance in AZ. Here are their links: http://www.phoenixtrans.com/ http://www.hughesperformance.com/ Stay away from Bowtie Overdrive.
lock up for sure.....if you use a lock up controller that works off of speed you will have no problems what so ever.
Lock up works for me..plus from what I have read on the transmission it needs to be modified if you are going to run a non lock up converter, oil flow in 4th gear normally needs the lock up. I use the bow tie overdrive kit, you can make up your own but the kit works well.
In OD it's .70 to 1 OD is the only gear that will lockup Yes, the OP should use this feature of the 700R4
Harley Rider, You need to call Phoenix Transmissions as suggested above. They will help you and it shouldn't cost very much to get the OD locking up in your 700R4. Good Luck! X
Go electric, the lockup oil is available anytime after the first to second shift in the 700 and you wouldn't want your converter clutch to apply before 4th gear in most instances, that would kill low speed driveabilty. We wire ours up internally off of a 4th gear pressure switch so when the trans goes into overdrive the converter comes on at the same time. Running a lock-up converter will let both the trans and engine run cooler and provide better lube to the internals, the extra mpg might be helpful too! It is quite simple to rewire most 700's using the existing internal harness and switches. If you have any questions call Phoenix, I'll probably answer the phone.
No, unless you have a transmission set up to do so. It can be done. Some cars/trucks came this way from the factory. I've seen a few.
Other than my hotrods, I also have two Dodge Rams (cummins turbo diesel) tow vehicles. I regularly tow in OD with them. The problem with towing in OD on a 700R4 is the computer is likely to unlock the converter causing the fluid to heat up or worse, overheat. This ruins the lubrication properties of the ATF. I have to check my hydraulic diagrams at work but I thought the cooler circuit was cut off in lockup with the 700R4
This is why the buying public believes Dodge trannys don't hold up. F.Y.I.: There is no computer that controls a 700R4.
One more question & I'll butt out. I do appreciate the information, thankyou. If towing in 3rd gear unlocked is good, then logically it seems that driving, not towing, in 4th gear unlocked shouldn't be a problem with heat build up, etc. I've been driving my current project unlocked and want to be sure I'm not killing the transmission. Easy driving in a 3,400 lb vehicle. Thankyou for the advice.
I agree with the 1:1 lock up - bowtie overdrives aka www.700r4.com Some of the best info out there. They helped me with a 700 behind a blown small block and no one else could figure out. Follow their instructions on setting up and life is good.
Here is a tech link to one of the best GM O.D. companies out there: http://www.monstertrans.com/store/pages/Tech-Info.html
I you are running a converter with a stall speed greater than or close to the cruising rpm, it will generate quite a bit of heat, that is the beauty of the converter clutch. Having a high stall converter where you need it down low, and then being able to lock it up for no heat penalty when cruising makes it a real asset.
I am willing to wager that you don't have a 700R4 behind either of those Diesels. This is a 700R4 thread, so the information here is about the 700R4, and its characteristics, strength, and longevity. You should not be towing with a 700R4 in overdrive. It is not up to the task.
Use the pressure switch to trigger the lock up in fourth gear, switch sees line pressure from the high gear circuit and locks converter electrically. Then, splice in a switch to the power feed to the trans, and now you can have it automaticaaly lock up after it goes into fourth, or, hit the switch to cut power to the switch and run it in fourth unlocked. Works great, best of both worlds.
I run the power wire to the transmission through a brake pedal switch for OD lockup, works great. Got the kit from Bowtie Overdrives but its just basically a brake light switch so easy to make one up
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