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Discussion Starter #1
I have a 200-4R in my 68. It has been rewired so that the converter will only lock up in the overdrive position.

I use a mechanical switch to interrupt power so the converter will not stay locked when driving around town.

Can I drive my car at highway speeds, in the over drive shift position, without locking up the converter?

Is there a converter on the market that I could install in my transmission that does not have the lock up feature.
 

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I did just the opposite - I wired my lockup circuit to work on demand in the top 3 gears. Better mileage, cooler running transmission, quicker at the strip, etc. I used a simple toggle relay circuit - push a momentary switch to lock the converter, unlock it by tapping the brake using a mid-80's GM 2-section brake switch.
 

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200-4R and 700-R4 transmissions cut off flow to the oil cooler when in overdrive. So you need lock up to avoid overheating when driving in 4th gear. This can be modified for cooling flow in all gears, but you need to do that when building the transmission. Extreme high stall converters generally don't have lockup, the rest do.
 

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Discussion Starter #5
Why would you not want to lock up the converter? It's one of the benefits of overdrive.
I am trying to overcome a problem.

Under light acceleration, my trans will shift up to 4th at around 30 MPH.

The converter locks up immediately.

This lugs my engine down.

I think I could delay the up shift if I adjusted the Lokar cable, but think it would also make the shifts harder.

I do not know the stall now, but do you think it would help if I had more stall in my converter?
 

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Discussion Starter #7
The transmission has been in there for several years
Sounds like the transmission cable is not adjusted right. If it's not adjusted right you will have major problems shortly.
I think I am pretty close on the cable adjustment, but still cannot resolve my early 4th gear upshift and converter lockup.

That transmission was installed in March 2013 and now has about 8,000 miles on it.

Any thoughts on a converter with more stall?
 

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shifting into 4th at 30 mph isn't right. my 700 shifts into 4th at 44 mph with normal acceleration .
 

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onecarnut, Just curious... what is your differential ratio?
Sometimes, a lower ratio (higher numbers - say, 410's) will make the governor in the trans think you are going faster then you actually are. I have read that you can increase the up shift speeds by removing a small amount of weight from the governor weights.

To help solve your issue, just splice the positive feed wire (that goes to the transmission) into an on/off toggle switch before going to the trans. That way, you can control when you want to lock-up the convertor in 4th gear.... this is how I have my 2004R wired. I only lock-up the convertor when I'm on the highway. I leave the toggle switch off when I am just cruising around town and do not want the convertor to lock-up when the trans goes into 4th gear.

Or... you could get one of these (see link below).
It's basically a fancy speed controlled on/off switch for the lock-up convertor.
 

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Don't attempt to change the shift points or shift firmness with the TV cable. But, if you don't have the correct geometry at the throttle arm, you'll never get this right. So if you need to, get the "corrector linkage" for your carb or throttle body.

The governor is the main thing controlling shift points. That's what you need to work on. The TV cable only modifies what the governor does, similar to what the modulator does on older transmissions.
 

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Discussion Starter #13
onecarnut, Just curious... what is your differential ratio?
Sometimes, a lower ratio (higher numbers - say, 410's) will make th

To help solve your issue, just splice the positive feed wire (that goes to the transmission) into an on/off toggle switch before going to the trans. That way, you can control when you want to lock-up the convertor in 4th gear.... this is how I have my 2004R wired. I only lock-up the convertor when I'm on the highway. I leave the toggle switch off when I am just cruising around town and do not want the convertor to lock-up when the trans goes into 4th gear.

Or... you could get one of these (see link below).
It's basically a fancy speed controlled on/off switch for the lock-up convertor.
[/QUOTE] I have stock 3.08 gears and like the idea of moving to a higher number (3.73/4.11)

I am doing what you suggest with a simple on/off toggle switch. I think that is why my transmission has lasted so long.

I run in 3rd gear around town and below 50 MPH, which simulates the exact configuration when the car was new.

When above 50 MPH and for long stretches, I toggle to "on".

I am tired of doing that !!!!

I am going to look at the speed controller and definitely think a higher number rear end gear would help.
 

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Discussion Starter #14
Don't attempt to change the shift points or shift firmness with the TV cable. But, if you don't have the correct geometry at the throttle arm, you'll never get this right. So if you need to, get the "corrector linkage" for your carb or throttle body.

The governor is the main thing controlling shift points. That's what you need to work on. The TV cable only modifies what the governor does, similar to what the modulator does on older transmissions.
I think that is good advise to not adjust tv cable. I already have a correction linkage on the carb.

I need to head to my local transmission shop and get educated on how the governor works.
 

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Yes non lockup converters exist for 2004rs , but I think the trans must be set up for it. Calif Performance Transmissions is a leading 2004r specialist.
 

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  • You say you think you have the cable set right. Did you use a pressure gauge to check line pressure in the gears to make sure the cable was set right?
  • I had the same issue with my 2004r and I'm using a lokar cable . I checked my pressure and they were on the low side for a built 2004r according to info I found on pressure readings. I re adjusted my cable tighter to raise the pressure and it now shifts into overdrive around 45 and when it locks the converter it doesn't bog the motor down like it did before. I didn't have to adjust it much maybe an 1/8".
  • Here's a link for pressure readings.
  • TCI Transmission Line Pressure
 

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Discussion Starter #17
  • You say you think you have the cable set right. Did you use a pressure gauge to check line pressure in the gears to make sure the cable was set right?
  • TCI Transmission Line Pressure
I initially tried to set the shifts by feel and speed, but the shifts were too soft or too hard. I took it to my local transmission shop and they did the adjustments. It now shifts normally with the exception of the up-shift from 3rd to 4th gear.

If I could get that shift in the 45 MPH (or higher RPM) range) I would be OK.

In the meantime, I will continue to use 3rd gear around town and 4th, with lockup, at highway speeds.

I appreciate all the input that everyone has provided. I will use your comments as I work to correct this issue.
 
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