700r4 shift points

[4x4blaze]

Well my Blazer is driving me nuts and I was wondering if any of you have any solutions! Its a mostly stock 87 which currently has a 305 tbi (for now, build is well underway) paired with a 700r4. & As all of us on here know, 305's are dogs... Well, the most annoying part of driving this truck are the shift points... I almost always shift it manually because it CONSISTENTLY wants to lug if you leave it in drive. most times it will hit 3rd gear lock up doing 35-40, and sometimes even try to get in overdrive while cruising around town. Whick means I've got roughly the torque of a lawnmower.

Is there any way to adjust these in order to have them hold gears longer? I know 350-400 trannys have modulators, but are there any options for TV controlled transmissions? Am also having a new 700r4 built for my new engine, so not really worried about beefing this one up or a little additional wear.

Thanks!

 

[Babaganoosh]

What gear ratio and tire size do you have? Sounds a little under geared. Also are you sure the TV cable is set properly?

 

[ZooMad75]

Sounds like the TV cable isn't set correctly. Here's a good definition swiped from Bowtie Overdrives page on TV Cable 101

"The TV cable used on the 4L60 (AKA THM700R4) controls line pressure, shift points, shift feel, part throttle downshifts and the detent downshifts."

To that end, if the cable isn't set right the shift timing and quality will suffer. You might want to do some light reading on the subject. Here's a link.
http://www.tvmadeez.com/article/index.php

But Baba has a good point also. Gearing and tire size play a large part that will induce issues into the trans. 33's and 3.08's for example being a very common combo would equal fairly crappy driveability that only would be exaggerated by a tv cable that isn't set correctly.

 

[4x4blaze]

What gear ratio and tire size do you have? Sounds a little under geared. Also are you sure the TV cable is set properly?

I believe the truck has 3.08's, but I've never actually had the cover off to prove that. & My tires are supposedly 31's that actually measure out to be a "true" 29".... They look like they belong on a Geo Metro.... & ive never actually checked the TV cable. How hard is this to do?

 

[ZooMad75]

I believe the truck has 3.08's, but I've never actually had the cover off to prove that. & My tires are supposedly 31's that actually measure out to be a "true" 29".... They look like they belong on a Geo Metro.... & ive never actually checked the TV cable. How hard is this to do?

Trust me, read the link. It explains it so much better than I can. Actual adjustment isn't hard, although a helper is nice. Hell, I've had to do it on a guy's 2wd Squarebody that parked next to us at a car show last spring. Having a helper push the throttle down to WOT while you press the adjuster button on the cable end makes the job easier.

 

[diesel4me]

The 700R4 does have a govenor like a TH350 or TH400,that can be modified to alter the shift points,if adjusting the TV cable doesn't improve it enough to satisfy you...

 

[4x4blaze]

You might want to do some light reading on the subject. Here's a link.
http://www.tvmadeez.com/article/index.php

Wow, Thanks man! That's a great resource to have and really gave me a better understanding of what the TV cable actually does!

But I took your guys advice today after work and "recalibrated" the TV cable.. And needless to say, it made a noticeable difference! My first gear always felt like it was slipping a little bit and would literally bang second.. Now, I may be making it sound worse than it actually was, but it never felt good. And now, it's gone! It feels a lot tighter now..

BUT it's still wanting to lug... As in doing 45 mph spinning 1200... which means my lazy little 305 has no grunt.. & as @diesel4me mentioned, do you think it's worth modifying the governor? It controls exactly what's annoying me.. I assume if you would lighten the weights it would cause the tranny to hold gears longer.. Anyone have experience with this?

& I also am looking for a used 10 bolt 3.73 center section to try out. I have a 3.73 14bsf I plan on swapping down the road, but that's waiting until the tear down!

 

[shima]

Sorry to hijack, but I saw this thread and had to laugh because this question was on my mind last night...

Is there a "standard" point (speed in miles per hour) at which the 700R4 should shift into second, third, etc? I've noticed that the first noticeable shift in my truck always occurs around 15 MPH. The next one is close to 35 MPH. It almost feels "late"!

 

[diesel4me]

The transmission shift point are determined by the gear ratio of the axles,tire size , the TV cable adjustment,and the govenor weights..(assuming its a 700R4 with no electronic controls--later models have a ECM to control the shifting and solenoids..)--others like the Th400 and Th350 also have the vacuum modulator to vary the shift points and firmness in relation to the amount of vacuum applied to it..

 

[Blue85]

Honestly, you really need lower gears in the axles. Check your trans fluid to see if it's burnt from having the TV cable too loose. You can also pull it one click tighter than the procedure sets it at to make shifting more aggressive, but this may go back if you stomp it on the floor too hard. There is also a spring mod that can be done at the throttle end of the TV cable (search). There were various versions of governors offered in the 700R-4. First, make sure your transmission didn't come out of a diesel, because those governors are way low. Most of the other options are similar, but the Camaro/Corvette versions raised the shift points significantly. If nothing else gets it where you want it, you could find a Camaro governor on eBay or maybe a local trans shop.

You can also "fine tune" the shift points by removing the governor (it's easy to pull) and grind material off the weights. However, it takes a lot of grinding to make much difference. If you look at the Camaro governor, there are no weights on it, just the weight of the "cage" where the weights mount to fight against the hydraulic pressure.

 

[Cntymnty77]

Depending on how it’s hooked up, there should be a button on the top side or bottom of the TV cable, just behind the bracket. Once you push that, push the cable and housing back (towards the firewall) and then open the throttle all the way and it should pull the TV cable where it needs to be and will lock it in place. You can do fine tuning from there.