I recently bought a level 2 700r4 from a vendor and it’s an awesome unit but the only problem I’m having with the new transmission is that I’ll set the cable by sheathing it all the way back and going WOT with the engine off so it clicks out where it needs to go, however when I do this the shifts are very early and soft, if I go 6 or so clicks in, it feels excellent but then when I go WOT again it resets for whatever reason. I have all the correct brackets and geometry for the TV cable and they worked great with my previous transmission. I reused the TV cable with the new one and I’m leaning towards this being the issue


plunger getting stuck? cable too short? Maybe bottoming out inside the TV cable sleeve where it bolts to the trans? Honestly don’t know.

 

Sonnax Transmission Company AS1-01K Sonnax TV Cable Corrector Kits | Summit Racing

 

Post a picture of your setup if you can.
There's a common misconception about the "best" method for adjusting the TV cable. Setting it fully retracted then applying WOT isn't necessarily the way to go.
My latest builder offered another method, one which will also identify problems with cable length, geometry correctors, etc.
His method involved taking a few measurements and the important thing is that with the throttle wide open, the cable is fully extended.
First was to measure the distance from the TV cable attachment point (on the corrector used) to the face of the cable mounting bracket. This is done by rotating the throttle shaft by hand with the cable disconnected.
The second step in pull the cable tight (while still unattached) and measure the the distance between the mounting clip (on the end of the cable) to the same spot on the cable mount. The cable must be tight.
One should exactly match the other. It matters little how far the ratchet is pulled out. If the lengths match, then after this adjustment, the cable will never be extended further.
What I found that by doing this, WOT was set perfectly. However there was now some slack at idle.

The solution to that was to use the Sonnax part mentioned above.
The problem with loosening the cable as you've been doing will result it automatically reextending to the WOT position. Without the cable being tight at full throttle, you'll cook the transmission.
The Sonnax spring will produce more line pressure at low to mid throttle positions and the shifts should more in line with what you expect. Assuming of course there isn't an inherent problem with the transmission (which I had though might be the case with mine).

 

Or a governor difference between the old and the new?

 

The core they rebuilt is out of a truck from what I can gather from the numbers on the side of the casting, It could be the governor from that very core just scotchbrited. I've personally had it to where governors cause weird behaviors like shifting way too early regardless of TV cable setting when I was tracking down a true z28 governor. I still have one that has perfect 5500 RPM shift points and good part throttle shifts from my previous transmission if I do want to test it, my only concern is the line pressure won't be sufficient enough if I put the other governor in since the TV cable will be at a more relaxed position like my previous trans (if swapping the governor does work work part throttle shift points) I'm not sure of the relationship between line pressure, the governor and the TV cable. I'm led to believe the governor is completely independent of having any affect on the line pressure in the transmission but I may be wrong, if anybody knows, let me know and I'll try swapping them out. I just really do not want to fry my new trans


Here's a pic of the setup I have. The corrector is from edelbrock and the bracket is a TCI copy. I've always had to have the cable sheath at least 2 clicks in farther so the part throttle shifts would be good and at WOT, the bracket out flex out enough not to slick back out if that makes sense, when I hooked up the cable I have a little preload on the plunger at idle and at wide open it's all the way in, this worked perfectly for my previous transmission, the problem I'm having with the new transmission is if I have the plunger set to be all the way in at WOT and letting the cable fall where it does naturally at idle then the part throttle shifts are very very soon, leading me to put the cable a few clicks so the shift points at light throttle aren't horribly soon and limit myself from going WOT at all because if I do then the plunger resets right back to its sloppy part throttle shift position even though it is theoretically correct at WOT.

 

My understanding is that the governor has nothing to do with line pressure. It just redirects fluid at the appropriate RPM.
Sounds to me like this is worth investigating.
Now, having said that, triple checking your TV cable adjustment is also worth revisiting. While what you had may have worked well on the previous unit, I also experienced the same sort of change when going from one transmission to another. The new one also being a truck core from a 91 or 92 model.
My main concern was line pressure. The shift points at that time weren't at the top of the list as much as making sure my new high $$$ shift machine didn't burn up. I rigged a pressure gauge and taped it to my windshield and drove around for several days observing pressures at various speeds and trans temperatures.
What I found was the following:
If I adjusted the TV for maximum tension at WOT (by whatever method suits you although measuring to ensure your geometry correctors are accurate isn't a bad call) I found there was a great deal of slack on the cable at idle. Line pressure was fearfully low. Image below.
If I ratcheted out the adjuster so the cable had some tension at idle, line pressure improved but I couldn't achieve WOT as the cable was drawn out to it's maximum before the throttle was opened fully. It would have to ratchet out further to go wide open but then I was stuck withe slack at idle and the resulting low pressure.
The cure for that, as it turned out, was the Sonnax spring posted earlier. This had two results. One was that WOT could be achieved while at the same time the spring kept some tension on the cable at idle. Line pressure went up a satisfactory amount. Image number 2.
The second result was that at low to mid throttle positions the increased tension on the cable kept the line pressure up and shift RPMs were affected. Now I didn't have any real issues with shifts in the first place but there was some cause and effect to be noted.
The cable adjustment is everything to these transmissions.


Idle pressure too low


Idle pressure after refinement


Pressure just off idle (mid cruise)


ATSG manual indicating line pressures.

Whatever you do, just be sure that you've got this sorted. It reads to me, your shift points notwithstanding, that you are in the same situation I was.

 

Ordered the sonnax spring and I'm looking forward to getting this sorted soon, I don't wanna toast this new transmission, it works great so far minus this little hiccup, right now I'm only limited to 80% throttle and it sucks for racing lol. In a similar thread dana from probuilt automatics stated that he always installs the sonnax TV valve system, I think he's referring to this kit: Sonnax 77966-94MK In the product description it says the plunger can wear inside and cause poor line pressure rise, which might be happening with my trans but I find it weird since it's a fresh build and the plunger seems to be backed by a pretty hefty spring that I'm assuming is part of the shift kit. Worst case scenario if this spring does not work for me I'll do this kit and maybe throw in the 3-4 upshift valve.

I know for sure the plunger goes in all the way at WOT but I'm worried that I won't have sufficient line pressure at WOT for the same reason that my part throttle shifts are soon when set it regularly, almost like the plunger is "lagged" behind if that make sense. I'm not sure if that's even possible but I'm praying it's not. Hopefully plunger all the way in = nowhere for line pressure to leak and full TV pressure through the trans

 

It's worth the peace of mind to tap in a pressure gauge and observe for yourself what the requisite pressures are. It's part of any rebuild really. I did it on my previous build (which had excellent pressure across the board but still cooked the 3/4 clutch pack for one reason or another).
As shown, I've got the gauge taped to my windshield and am monitoring and recording the values in various gears and throttle positions. My latest builder made this request as he didn't install it and had no way of knowing if things were in spec. Once I told him what I was seeing (pre-Sonnax spring) our conversation turned to getting the spring in place and going for more tests and observations. I'm glad I did. I was watching some video I took of the gauge while driving around town and at a couple of points it was 50 PSI! Which is far below any of the recommended minimums in the chart I posted.
I may incorporate the gauge and have it tucked under the cowl so I can keep an eye on it. Same with trans temp. That upgrade is next on the list.

 

I'll be purchasing a gauge and a trans temp sensor, that's my next upgrade as well since I have a stall speed and don't want to cook the trans alive with my 2.73's out the back (I really need to get my 9 bolt 3.27 in but I'm too lazy). I have a .500 boost valve so I'm not sure how it would affect those readings. I have a problem where in order to get the trans to kick down from 3rd when I'm going slow I have to REALLY get into the throttle for it to downshift back to 2nd, it's weird, I still don't have the sonnax spring yet but hopefully that fixes it.

 

My suggestion, and it's an easy install, is a pressure gauge. I've the.500" boost valve and .300" int/reverse valve and with the TV cable misset as it was, I still saw less than the prescribed pressures. You really owe to your yourself to get one for testing and analysis. If nothing else, at least you'll know. Best case, you save yourself a trans case full of crispy parts.

It really sounds like a governor issue as we had discussed. If the governor installed is from a truck, there's no telling when it'll shift.
Pretty sure you've seen this:
https://www.thirdgen.org/forums/tran...springs-2.html
I also saw your thread about governor so you're obviously no stranger to it. Great thread too I should add!
But seriously, get a gauge on it. Then you'll know. If for some reason your builder messed up, at least you've preempted potential destruction. That cable adjustment and it's function is the virtual life support plug for the transmission.

 

This does feel all too similar to the governor issues I was experiencing with my previous transmission, the governor I ended up using I had down to an exact science with how it performed and where it would shift, it was perfect for my car. I still have it on my headrest, maybe it's worth throwing it in. The shift kit that this transmission has is supposed to have smooth part throttle shifts and then shift hard when fully into the throttle. At part throttle with the lever in D3 I'm slowing the car down at lets say a stop light, the downshifts feel like they're gonna rip the u joints right out of the car even though im in the brake and not on the throttle and my upshifts when part throttle (even 2-3) are borderline violent, overdrive the 1-2 shift is extremely firm and the 2-3 shift feels very firm. Maybe this is indeed a governor after all, time will tell.

I wonder, maybe this governor is out of a truck that had 35's or something stupid and is tuned for that, maybe that's why it shifts so soon when set standard?

 

Quick update: The sonnax spring came in. I put it on and it's a very big difference from before, even my part throttle shifts are perfect now and it doesn't take till 58 mph to finally shift into overdrive. I now have full throttle sweep and it's fully in the plunger at WOT. My WOT shifts are very hard but still a little soon (4800-5000ish 1st to 2nd and 4700 2nd to 3rd), the governor is probably to blame for that. I'll experiment with it more some other day, the only problem I still have is those part throttle downshifts when slowing down in 3rd gear and getting into the throttle so it'll downshift into 2nd as I come off the highway; I can manually downshift it for now with the gear selector (governor is probably also to blame for that). I think it'll be worth to test throwing in my other governor to see if it corrects the inital issue I was having solely for the sake of experimentation and having it documented for anyone else looking for help with this issue, showing that there's multiple routes they can take to get it diagnosed and fixed.

 

"Nothing succeeds like success!" as I'm fond of saying. My success or someone else's. Hats off raptere. This is good to hear.

Funny in that I'd considered the spring to be a gimmick. But when my builder suggested it then it was worth a try. When there was support from others too ( @Airwolfe ) it was worth endorsing further,. While I didn't have a shift issue I did have a pressure issue and this appears to have curbed that (I still say you owe it to yourself to put a gauge on it. What works today may slowly be dissolving and "inquiring minds want to know!")

If you do get deeper into the governor (again) I'll be all ears. I may have gotten off lucky in that regard as I've no idea what governor is in this new transmission of mine although it does shift at appropriate revs. Maybe my builder followed my instructions and carried that over as the previous trans was spot on in that regard. I'm of the mind too that the shift kit (TransGo Reprogramming Kit 700-2&3) is doing it's job. I've also got a 3800 stall converter (Edge) which may play into how the shifts are "felt". That is a change from the earlier trans FWIW.

Anyway, again, good to hear.

 

Once I got it on the road today I was really impressed with how it did, shifts are very solid and at WOT it shifts great, nice and firm like it should, that issue with the part throttle 3-2 downshift when slowing down can be corrected by just putting your foot into the throttle slightly more, It's definitely there, just not what I was used to, my old tranny used to kick down at 1/4 throttle and this one is more like 1/2, which is inline with what people say it should be. Most importantly I was able to finally feel the pickup of my new engine without it being in front of a slipping trans and what a difference! It's actually got some ***** now. Hopefully down the road this thread will help somebody.

 

I sincerely hope it does prove helpful to other. To me, that's the whole point of posting related experiences.
Thinking about what the spring is doing and it's really nothing more than bumping up the line pressure at idle to part throttle positions. That there is a cause and effect to me demonstrated that the pressure was lacking. What's more, there was fully born out with the before and after on my test gauge. I'd hate to think that I'd have gone on unaware that this situation existed. Transmission demise would surely have followed. Unlike you, despite the poor TV cable orientation, the transmission worked well. It's just that it wouldn't have for long.
Anyway, thumbs up raptere.
Now go and burn rubber!!

 

I sincerely hope it does prove helpful to others. To me, that's the whole point of posting related experiences.

Thinking about what the spring is doing and it's really nothing more than bumping up the line pressure at idle to part throttle positions. That there is a cause and effect to me demonstrated that the pressure was lacking. What's more, this was fully borne out with the before and after on my test gauge. I'd hate to think that I'd have gone on unaware that this situation existed. Transmission demise would surely have followed. Unlike you, despite the poor TV cable orientation, my transmission worked well. It's just that it wouldn't have for long.

Anyway, thumbs up raptere.
Now go and burn rubber!!

 

For testing sake I threw the other governor I had out of my other transmission in today just solely to see what it would do, it was from a tpi transmission that would shift at 5500 1-2 and 5500 2-3.

My new transmission shifts 1-2 at 4800 rpm and 2-3 at a lame 4300 RPM, just throwing in the governor from my other transmission resulted in the same part throttle shifts, albeit a tiny tiny bit heigher BUT the 1-2 shift wanted to happen at over 6000 RPM, I had to let off so it could shift, for obvious reasons I didn't test the 2-3 shift. I guess this is the result of the valvebody mismatch, I.E. a z28 governor needing a z28 valvebody and such.

The two governors seem to have the same larger weights but the inside weights are completely different from each other.

 

It reminds me of one of my earliest 700's. IIRC, it was an 86 IROC stocker that had .500"/.300" boost valves, most of a TransGo 2&3 shift kit and a Corvette servo. I could never get it shift at a reasonable RPM with the TV cable adjusted as per the book. It required about two clicks less and I never really sorted it out. I had been talking with Dana at Pro Built about it and we concluded that the reason it was surviving with the misadjusted cable was due to the boost valves doing their thing. Never put a gauge in it so I can't say for sure. I'm not recommending that fix to anybody though.
It went a ton of miles before the eventual failure of the 3/4 clutch pack. Cause and effect? Possibly. High mileage and plenty of abuse? Most definitely.

I'll be following to see how you sort out your governor.
For me, all my competitive shifting is done manually. The shift kit has the "hold in any gear" option so I can shift at the RPM of my choice. Which in this case is 6500 when at WOT.
Pedestrian driving and it'll shift according to throttle input but always well before any excessive revs are reached.