Jump to content
HybridZ

700R4 shifting blues


Recommended Posts

OK, I have a 700R4 in my 355sbc 350hp '74.5z. The shifting never has been right. If I adjust the kick down for decent shifting through the first three, then I can't get it to stay in 4th without downshifting. I even ended up getting embarassed by a 1994 corvette. I had him until I redlined in 3rd (you do the math, 3.54 rearend), then I couldn't go to fourth without downshifting. He eventually left me screaming down the road in third. How embarassing.

 

Anyway, my transmission guy suggest a governor off of a corvette. Would that help tighten up the first three so I can loosen the kickdown for fourth? Anyone know?

Link to comment
Share on other sites

Guest Anonymous

I know mine with the lock up torque converter would never allow me in fourth above 100. I had it set up for strip racing though, so I think that is why. I hated the r4, so I put a t56 in.

Link to comment
Share on other sites

Guest Tht1KSguy

last i heard the 700r4 doesn't allow full throttle upshifts to 4th gear. that's one of the main reasons that if i go sbc that i'll be choosing the 200r4

Link to comment
Share on other sites

quote:

Originally posted by Indiana-Z:

OK, I have a 700R4 in my 355sbc 350hp '74.5z. The shifting never has been right. If I adjust the kick down for decent shifting through the first three, then I can't get it to stay in 4th without downshifting.

 

How do you get it to stay in 4th by downshifting? Mines been worked over heavily by a few guys now and I don't have 3-4WOT, I think their's some ghost they've all missed. FWIW, I was once given the 700R4 TV cable 'pivot point' location and it did not match my 1406 edelbrock carb....I made an offst stud to correct this (AFAIK, nooone offers this) and that greatly improved my overall shift points/quality, smooth bottom and top with improved shift points. Previously I could adjust TV for good smooth bottom or good smooth top.....never both (one would be harsh). Another fella backed that up saying Qjets don't have the correct swing arc either, so if your TV isn't seeing the correct pressure transitions relative to throttle it will not be ideal....I'd love to see those issues nailed down.......mine's an '87 or '88 I believe.

search the forum...it was covered heavily on governor and specific springs before...and I've been told as well a corvette governor is a cheap piece ($45?) to step to a more calibrated setup for our Z's than OEM camaro etc, it's in mine but still not ideal.

 

I expect 383Z will straighten us out here......

Link to comment
Share on other sites

quote:

Originally posted by Tim240Z:

Check out this site for TV cable setup...loks like a very good unit (patent pending I think)

Tim

Looks promising...as long is allows swing arc adjustment and not just cable length. Ahh, now I see that fuzzy pic enlarges and shows they're using various slotted plates to allow positioning the TV end differently. The actual TV mount off the carb plate looks good and MUST be very sturdy as most carb only mounts are not stiff enough for good TV setup (ie. flex of 0.5 to 1mm is too much). That part I can't use as it won't match my proflo base.

 

[ October 04, 2001: Message edited by: Ross C ]

Link to comment
Share on other sites

Oh yes the dreaded 4-3 down shift. What needs to be done to correct this malady is build your valve body correctly!!! Dont buy the crap B&M is selling as a Super trans kit. It does not fix the problem!!! What you need is a properly programmed valve body just like our beloved Z's you can not change just one thing it needs to be done as a system. the main problem is the exhaust port on the TV valve sleeve is only .029" this does not dump fluid fast enough for hi-po usage. The proper valve sleeve is .071" and is made of steel. This requires a new valve, installed into a properly reprogrammed valve body. The govoner can also be changed with a very simple spring kit. Some thing else is a corvette servo. for max apply psi a billet servo is also avalible.(85% greater then the vette unit) this is a neck snapper. Now that being said this .071" valve will only keep you in fourth from 3/4 or less throttle allowing you to cruise at high speed in over drive. Was not this the reason we put over drives in our cars in the first place?? icon_smile.gif Cerberus you hit the nail on the head for 700 longevity there is no adjusted a little high or a little low on the tv cable it's dead on or its WRONG!!this will destroy your overdrive clutches so fast if not funny. also the servo in the aux valve body on the later units has a spring under it to soften the apply these like to break on miss adjusted units this little problem will also cause a ghost problem with 3-4 and 4-3 shifting> Keith Sorry for the rant icon_biggrin.gif

Link to comment
Share on other sites

Guest dankinzle

Hey, I just talked with the guy behind the tv made easy thing and he is really a great guy. He spent like 20 minutes on the phone with me explaining how the system works and how it will allow you to adjust shifting behavior. I couldn't quite understand how something could adjust the shifting qualities if there is the pulll length of the tv plunger is one set length. The system actually allows you to adjust the rate of how fast the tv is pulled when hitting the throttle while still retaining the full 1.65" or whatever the pull length is. If you set it to shift harder it pulls more of the cable initially and vice versa. I'm getting one so we'll see how well it actually works...

Link to comment
Share on other sites

Guest Anonymous

I am definently not an expert on th700's but I have blown 4 of them aoart. The TV cable adjustment cannot be stressed enough! B&M, TCI, and hughes have tried but they all broke. Smoked clutches, bad bands, and even had a torque converter output shaft shear completely off. These transmissions open alot of doors for deep gears and high speed cruising but they do have limitations. The last one I had built (Walnut Creek Trans.) has done the best so far but I don't put slicks on my car(70 El Camino) or launch it real hard (HOW DO YOU LAUNCH HARD WITHOUT SLICKS?) but it has held up better than the major company versions. By the way, I first put the overdrive tranny in in 1992, when it was still kinda exotic in an old chebbie!!!

O/D's rule. My E.C. goes 12's, drafted a Z28 to 145+ and have averaged better than 17 mpg to San Diego on I5!! Imagine in a 2500lb. Z!

Link to comment
Share on other sites

"Now that being said this .071" valve will only keep you in fourth from 3/4 or less throttle allowing you to cruise at high speed in over drive."

 

So, what's needed for full WOT in 4th to redline? That 3/4 throttle stuff I've had for a while and does not suit my highway jaunts or lapping days at all.

 

"Was not this the reason we put over drives in our cars in the first place?? icon_smile.gif"

 

Nope, so I can do over 120mph without going over 6000rpm icon_smile.gif oh yeah, and daily 365day/yr driving I suppose icon_biggrin.gif

Link to comment
Share on other sites

Guest needwaymorespeed

Ross they now make a bracket that will bolt on to youre carb linkage to cure the swing arc of the tv cable ,its in jegs for 28.00 -sounds like you already have youres speced out though-raptor trans also carries it there link is posted on this thread or the one below that s titled 350 vss 700

Curtis

Link to comment
Share on other sites

I will be trying it with a 2004R soon.

Ross,

If you peruse the install instructions, you will see that there are some adjustments for cable angle etc for customizing shift behavior etc, and with the linkage adapter supplied with the kit, it should make carb linkage size a moot point?

 

Tim

Link to comment
Share on other sites

Guest Anonymous

The cable must be a 1 to 1 travel with the throttle cable .Improper tv cable adjustment is why so many burn up .My tci kit stays in the gear i want no down or upshifts wot 4th any time .

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...