700r4 Not Shifting

[Samuel Churchill]

I have a 92 k1500 with the 700r4. I started to have an issue with the transmission delaying upshift into second gear much higher than expected. Eventually the only way it would upshift to 2nd or 3rd would be if I revved to around 3500rpm. I disconnected the tv cable and pulled it back and forth quite a few times then tried again and all of a sudden it shifted like nothing ever happened for a few times, then it had the same issue of not wanting to shift till almost WOT.

Figured I'd see if anyone here has had similar issues or know of what would cause this. I only found a few other forums where people had the same problem and of course no solution was given. All the responses to similar issues are to adjust the TV correctly, it's like the go to.

 

[NickTransmissions]

I have a 92 k1500 with the 700r4. I started to have an issue with the transmission delaying upshift into second gear much higher than expected. Eventually the only way it would upshift to 2nd or 3rd would be if I revved to around 3500rpm. I disconnected the tv cable and pulled it back and forth quite a few times then tried again and all of a sudden it shifted like nothing ever happened for a few times, then it had the same issue of not wanting to shift till almost WOT.

Figured I'd see if anyone here has had similar issues or know of what would cause this. I only found a few other forums where people had the same problem and of course no solution was given. All the responses to similar issues are to adjust the TV correctly, it's like the go to.

Did you verify your TV cable adjustments were correct via a line pressure test?

 

[Samuel Churchill]

No but It has shifted great for years with the current adjustment at the correct mile per hour. When I pulled the tv cable off to pull it by hand and see if it was stuck, it started shifting great again for a few accelerations going through all gears until it stopped shifting again. I did not change the adjustment when I removed the cable from the throttle linkage.

 

[Drunkcanuk]

No but It has shifted great for years with the current adjustment at the correct mile per hour. When I pulled the tv cable off to pull it by hand and see if it was stuck, it started shifting great again for a few accelerations going through all gears until it stopped shifting again. I did not change the adjustment when I removed the cable from the throttle linkage.

I would listen Dr Nick.... he's the transmission specialist around here. Doing anything else but verifying the line pressure is probably just guessing.
Finding out the line pressure will help him diagnose what's ACTUALLY going on in there, before it's destroyed.

 

[NickTransmissions]

No but It has shifted great for years with the current adjustment at the correct mile per hour. When I pulled the tv cable off to pull it by hand and see if it was stuck, it started shifting great again for a few accelerations going through all gears until it stopped shifting again. I did not change the adjustment when I removed the cable from the throttle linkage.

There's two tools that a DYIer should never be without when it comes to transmissions:

1. A bidirectional scan tool capable of live data and adaptation resets.

2. A transmission pressure gauge (0-300 psi)

Get yourself a transmission pressure gauge, Amazon sells a variety of them and can be sent to you overnight if you're a PRIME member.

In the meantime, pull the govenor out and inspect the gear and governor valve. Put the governor in your hand upside down and squeeze the weights to see if the valve is moving when you do so. Its possible the valve is sticking. If it's not moving freely, remove the gear, valve soak and polish the bore with bench buddies (fine abrasive hones).

 

[Erik the Awful]

Get your TV cable right. If you don't, you will burn up your transmission.

Here's my experience.

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[yevgenievich]

Sounds like a sticking tv valve. Jr shift kit includes the part that would fix it if confirms that that is what is happening.

 

[Samuel Churchill]

Ok I ordered a gauge and 6' hose. If it was not adjusted correctly I would imagine it would have burnt up years ago but I will double check it.

Didn't know pressure was the best way to ensure proper adjustment. I will do it this way from now on.

In the mean time, I will check the governor.

 

[Erik the Awful]

The TV plunger and sleeve can be worn out, and your pressure won't come up. I had a cheap rebuild done on the transmission in the video, and the rebuilder shimmed the plunger with a washer. It was so wore out that the pressure still wouldn't come up. The plunger and sleeve aren't cheap, but if you need them, you need them.

More Information for SONNAX 7796694K

 

[NickTransmissions]

Ok I ordered a gauge and 6' hose. If it was not adjusted correctly I would imagine it would have burnt up years ago but I will double check it.

Didn't know pressure was the best way to ensure proper adjustment. I will do it this way from now on.

In the mean time, I will check the governor.

Yep, now you know...To be clear, we are not diagnosing your TV cable set up or adjustment from the internet but informing you how to rule it out as a possibility.

@Erik the Awful has you covered, I'll just add these print instructions for TV cable set up, adjustment as well as a reference chart for your pressure testing so you can compare your values and see if you're in line with them. A trans pressure gauge is a must for anyone who DYI maintenance on the transmission.

The Sonnax Plunger and Sleeve kit that Erik recommended is something I install in all my 700R4 rebuilds...There's two different versions - one allows for full-throttle 3-4 upshift ( 77966-94MK) while the other mirrors the stock design. I use the stock design unless the vehicle will be raced, then I used the other one.

Let us know if you have any questions or run into problems when doing the test.

If governor and TV adjustment aren't the source of the problem, my next suspect would be the valve body, as @yevgenievich mentioned in post #7. Install the Transgo 700R4 Jr shift kit, check all valves for freedom of movement (disassemble the entire valve body, hot tank the casting and clean off all the valves - reassemble with WD40 or ATF) and that should resolve the problem; if not, VB has to come out and be replaced.