Bear with me, long story.

I bought a ’91 Bravada from my friend. He had swapped a 305 TPI into it that had died so I put in a 350 TPI. I used the 4L60 that was original to the truck, as had my friend with the 305. The truck sat for almost a year before I put the 350 in. When I tried driving it the transmission slipped really bad so I thought maybe the TV cable needed to be adjusted because it was the original cable from the 4.3 Vortec and was a couple inches shorter than a TPI one so my friend had lengthened it with stiff wire to reach the throttle linkage and it worked fine for him. The black sheathed part was long enough to be mounted in the bracket correctly, it's the actual exposed cable that's a little short and had to be extended. I set it so that at WOT the cable was at maximum extension, per the Mitchell manual. The transmission still slipped so I figured maybe something got rusty or clogged up in the time the truck sat so I had the trans rebuilt and added a shift kit and got a TV cable from a spare transmission I had. The spare trans was from an LB9 Camaro but interestingly this TV cable which should have been the right length was the same as the Vortec one. So in the end the rebuilt trans is still slipping and I have no idea why. How can I check what the problem is? Is there a way to measure fluid pressure?

 

Oh also, I had disconnected the wire for TC lockup because I was using a manual chip and the same wire that controls lockup in autos also controls the shift light in manuals. I don't see how that should make a difference, though.

 

The wrong tv set up will kill a 4l60 dead every time. Also, no lock up means no fluid to the cooler.Pressure port is on the side of the trans just behind the bell.

 

Is there a special kind of gage I need? Also, the cooler is getting fluid because I forgot to tighten the lines all the way and when I first started it they were leaking pretty good.

Just remembered, I have a mechanical engine oil pressure gage with a 1/8" NPT end, will that work? What kind of fitting is in the transmission? NPT, compression, etc? Also, what is the acceptable range of pressures?

 

The plug is npt. I believe it is 1/4 npt. Consult the atsg manual for pressures. They vary from model to model. 75-150 psi is a general range. The manual will give the specific numbers.

 

First, get the TV sorted out. That will kill a 4L60E, or 700R4 in short order.

Second, if the trans was rebuilt using all the stock parts then it is not up the the 350 TPI. A Corvette servo kit may band-aide it by giving more appply pressure to the band.

Third, if using a non-lockup converter you should change the valve in the pump to a non-lockup valve available from Trans-Go.

Sounds like a fun truck. Is it AWD?