When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Here is the story. Had a 700r4 put in my "80". From the first I had to rev high to get it to upshift, even had a lag. Not be into trans. I had it done. Got to looking on the web at 700r4 installs and found one that was very informative.
I now think the TV cable was installed wrong and is entirely the wrong bracket. I included several pics of the throttle linkage. Ideas appreciated. Thanks.
You need an add-on bracket for the throttle lever for the TV cable. The TV cable has to share the same rotation path as the throttle lever. What you have now is just a quick path for the demise of your transmission. It takes very little time to destroy the trans with a malfunctioning cable installation.
Here is the story. Had a 700r4 put in my "80". From the first I had to rev high to get it to upshift, even had a lag. Not be into trans. I had it done. Got to looking on the web at 700r4 installs and found one that was very informative.
I now think the TV cable was installed wrong and is entirely the wrong bracket. I included several pics of the throttle linkage. Ideas appreciated. Thanks.
Your linkage is WRONG for a 700R4 (ie. you are using the stock linkage connection points). Get the correct linkage adapter for your model carb. Also, set line pressure properly. BTO has excellent literature on the procedure. When I fitted the BTO stage 2 700R4 to my q-jet, I bought the adapter and glad I did. The trans shifts solid under load and shifts lazily under light load just like the old TH350 it replaced. Can't be happier.
You need two kits: the adapter for the throttle linkage and the adapter to position the TVS cable properly. BOTH should be level and 'pull' points set precisely.
I have the q-jet but you will see in my picture how the correct plates for the cable mounting (one for TVS and other for throttle) ensure proper location of the cables and are key to proper 700R4 performance and longevity.
I would almost venture to wager that BTO can set you up with the proper brackets and TVS linkage adapter (adapter has to fit over the Holley linkage to set proper geometry).
On my q-jet, there is the linkage that mounts above the carb plate and the other that is sandwiched between the two gaskets that are between my carb and intake. In your instance, it would likely go between the carb and spacer as any linkage point below the spacer will add a severe angle to the cable travel and throw off trans performance.
The TV cable is very sensitive on the 700r4 but you would rather have too tight (late shifting) than too loose. Buying the correct bracket and adapters is the easiest but you can also fab a bracket from a late 80s early 90s GM truck isn't hard. Pay close attention to how far the cable attaches from the throttle blade shaft on the GM truck and drill your hole accordingly. This should get you in the ball park. Right now it appears your cable is mounted to far away from the center of the throttle shaft. Creating the late shift. You can also adjust the govenor to gain an earlier shift at WOT.
Did you make sure the cable travels fully ? And is all the way out once your at WOT .
Idle in park the correct setting is usually 1/2 or slightly less pulled out of trans . Are you set in these 2 areas this way ?
Some brackets can be to close or to far away from your linkage making TV adjustment almost impossible. To far and your pressures are to high to close and your pressure is to low.. DOUBLE check WOT if it is to far away cable will be lose and if it is to close the cable will stop linkage from fully opening. Once you have this sorted out then adjust ..
To adjust: depress lock release on the TV cable then depress accelerator peddle to the floor that will give you your starting point which will be very very close to perfect, minute tiny adjustments after that are best done with a pressure gauge but stay in the rule of 1/2 inch or less pulled out at idle.
Shift speeds are a governor function so lets say first shifts at 30 with normal throttle and the TV is adjusted correctly your gonna have to pull the governor and change springs.
I am no expert but the angles of your cables look much better now to me. It also looks like the TV adjuster is almost all the way back which means not much adjustment left.
I would try the following test. With the car off:
* disconnect the TV cable from the carb.
* Then have someone get in the car and mash the accelerator to the floor.
* Finally, manually pull the TV connector out as far as it will go and note the position in relation to the post on the carb linkage.
If you pull the connector out manually and it extends past the linkage post by a significant amount, that may indicate that more adjustment is needed somehow. You might perform this test and post a pic of the results.
I tried to snap a pic of mine to show the relation. I was having to work the throttle and pull the cable at the same time but hopefully the idea will convey.
Last edited by johnt365; May 17, 2015 at 12:20 PM.
With the pedal on the floor, the TV cable should be fully extended, sounds like yours is fully extended before full throttle? ( That will give higher shift points) Then after that is set, you really need a pressure gauge on the trans to make sure your minimum setting is correct and that the pressure starts to rise with the slightest throttle opening.
700R4 Not Shifting Right
