What stops a 700r4 from going into OD after rebuild
08-21-2014, 07:07 AM
#1
Instructor
Thread Starter
What stops a 700r4 from going into OD after rebuild
Not new to Chevys just stepped out of a 29 350/350th 8 yrs daily driver! Built myself frame up! Have a 88 Vette just rebuilt 700r4 can't seem to get it to kick overdrive! Recent rebuild and installed myself! I feel the TCC working in other gears the peddle switch works it is shifting Nice into all four gears! Get around 60 put it in OD the same but if I let off throttle engine drops to idle and won't engage till I bring rpm back up ! Is od 4th with tcc locked? how can i lock tcc for 4th! i dont race just drive to work! Tranny guy says just keep driving it ! But need OD for fuel millage! I did try the f-a on ALDL no change! Any ideas I would appreciate ! Thankz!
CLIFF
CLIFF
08-22-2014, 01:23 AM
#2
Race Director
I have had two 700r4s that would not shift into OD after a rebuild. The first one I ran it up to about 70 MPH in D and then backed off and it finally shifted into OD. The second one shifted into OD when I held it at about 60 MPH in D. My theory is that air gets into the valve body during the rebuild and keeps the shift into OD from working. I have seen several weird things happen right after a rebuild that worked themselves out after driving for a while. Make sure you manually go into 1st and 2nd gear. The valve body passages that are used in manual 1 and 2 do not get used when the trans is in D or OD and shifts through 1 and 2.
TCC will lock in ANY gear at 40 MPH. It's programmed into the ECM, which is what controls TCC lockup.
TCC will lock in ANY gear at 40 MPH. It's programmed into the ECM, which is what controls TCC lockup.
08-22-2014, 05:48 AM
#3
Instructor
Thread Starter
I have had two 700r4s that would not shift into OD after a rebuild. The first one I ran it up to about 70 MPH in D and then backed off and it finally shifted into OD. The second one shifted into OD when I held it at about 60 MPH in D. My theory is that air gets into the valve body during the rebuild and keeps the shift into OD from working. I have seen several weird things happen right after a rebuild that worked themselves out after driving for a while. Make sure you manually go into 1st and 2nd gear. The valve body passages that are used in manual 1 and 2 do not get used when the trans is in D or OD and shifts through 1 and 2.
TCC will lock in ANY gear at 40 MPH. It's programmed into the ECM, which is what controls TCC lockup.
TCC will lock in ANY gear at 40 MPH. It's programmed into the ECM, which is what controls TCC lockup.
Cool cool thankz Cliff! It shifts soft but all is there haven't stomped on it yet nervous about all the stories of TV cable sure I have it good just want to get to work ! I tried that on way to work couple times! Thankz again grew up in Anahiem hills myself! Have a good day bra!
08-22-2014, 01:18 PM
#4
Race Director
Make sure the tv cable is adjusted correctly.
08-22-2014, 03:53 PM
#5
Instructor
Thread Starter
I can pull it out about 3/8 when it tightens and it stops when throttle body is open all way! To tight? To loose? Had it tighter and would have to let off throttle to get it to shift but that was a week ago! Maybe tighten back up a little would make harder shift?
Thankz for replying
Cliff
Thankz for replying
Cliff
08-22-2014, 06:24 PM
#6
Safety Car
I can pull it out about 3/8 when it tightens and it stops when throttle body is open all way! To tight? To loose? Had it tighter and would have to let off throttle to get it to shift but that was a week ago! Maybe tighten back up a little would make harder shift? Thankz for replying Cliff
http://www.cpttransmission.com/tech_tvcable.htm
08-22-2014, 07:07 PM
#7
Team Owner
Member Since: Dec 2000
Location: SE NY
Posts: 90,675
Likes: 0
Received 300 Likes
on
274 Posts
Cruise-In II Veteran
I did try the f-a on ALDL
If you rig a simple SPST switch you will see this by watching the tach when you close the sw.
08-22-2014, 08:05 PM
#9
Instructor
Thread Starter
Thankz for reply bro
Cliff
08-22-2014, 10:41 PM
#10
Team Owner
Member Since: Aug 2005
Location: Riverside County Southern California
Posts: 34,988
Received 501 Likes
on
342 Posts
Co-winner 2020 C4 of the Year - Modified
2018 Corvette of Year Finalist
2017 C4 of Year
2016 C7 of Year Finalist
St. Jude Donor '09-'10-'11-'12-'13-'14-'15-'16-'17-'18-'19-'20
08-22-2014, 10:49 PM
#11
Race Director
The 700r4 is completely different. It uses the TV cable to adjust the internal pressure and the governor to determine when to shift. Everything else is controlled internally by the transmission. It doesn't know anything about vacuum, coolant temperature or oil pressure. The only thing you need to get the transmission into OD is to set the shift lever to the OD position. Everything else is done inside the transmission.
08-23-2014, 05:29 PM
#12
Instructor
Thread Starter
I found it!! I found it! Getting on freeway I rolled it to 105mph and OD kicked in! Fell out then kicked in @ 90 the. 75!! Getting better thankz for all the quick help Vette guyz!!!
08-25-2014, 08:56 PM
#13
Instructor
Thread Starter
That configuration was for the TH400 transmission.
The 700r4 is completely different. It uses the TV cable to adjust the internal pressure and the governor to determine when to shift. Everything else is controlled internally by the transmission. It doesn't know anything about vacuum, coolant temperature or oil pressure. The only thing you need to get the transmission into OD is to set the shift lever to the OD position. Everything else is done inside the transmission.
The 700r4 is completely different. It uses the TV cable to adjust the internal pressure and the governor to determine when to shift. Everything else is controlled internally by the transmission. It doesn't know anything about vacuum, coolant temperature or oil pressure. The only thing you need to get the transmission into OD is to set the shift lever to the OD position. Everything else is done inside the transmission.
Hi Cliff!
Would you know what tells OD to kick in? I ran it up to 105mph and OD kicked in then around 80! But it still takes up to 86 to kick in the. I can run it down to 73 before it falls out! Be It i only drive freeway 10 min! Shoul I just get it I. OD and drive longer? Before rebuild OD would kick in 55! Thankz for your help!
