73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: caunchman on August 24, 2014, 09:27:15 pm
-
So finally finished installing a 700R4 that I had professionally rebuilt locally. I am having a major issue with. After filling it with fluid roughly 14 qts I went to set the TV cable. I took it out for a ride and noticed it was not shifting at all. It seemed like it would stay in first gear, I didn't want to push it. Anyways I tried shifting manually with no joy. So I hooked a pressure gauge up to the test port to see what it was reading for pressures. Here is what I found all readings were taking at idle roughly 1000 RPM.
Park - 120 PSI
Reverse - 90 PSI
Neutral - 120 PSI
Drive /w OD - 120 PSI
Drive - 120 PSI
2nd - 120 PSI
1st - 120 PSI
Another thing to note is that these reading stay the same weather the TV cable is connected or not. The TV cable was adjusted and has a very light preload. Also I read tugging on the TV cable at idle I should see a jump in pressure. I am NOT seeing this. After reading up on similar issues the term Failsafe or limp mode have come up. Does this seem like the case here? Also, what is the best course to proceed? Is there anything I can visually verify if I drop the pan? The builder may think it is a stuck inner throttle valve. Since I am seeing no deflection when tugging the TV cable. Any help would be GREATLY appreciated. Thanks.
-
since your saying 700r4 i doubt it has a safe mode. if you said 4l60e then yes could be but afaik the 700 doesnt have a limp mode since its not computer controlled. i would get a hold of the trans builder and talk to him. your tv cable wont effect it not shifting at all
-
It just seemed to me like the a TV issue since I'm seeing constant pressure in all gears except reverse. Could the inner throttle valve be stuck in the "in" position and the plunger still move freely. I noticed TRANSGO uses a spring behind the inner throttle valve to almost bounce it back, if there is no spring there what would normally bring that back to the starting position? Also no deflection in pressure when pulling the TV cable doesn't that indicate the valve is not moving?
-
I don't know a lot about transmissions but I know the 700 will shift with the TV cable unhooked. It will just cause the trans to burn up
-
Yes you are correct without the TV cable connected it will shift on the govener at a VERY high RPM, could probably push it to shift, but since it is behind a 258 inline in my Jeep I really don't want to rev the piss out of the motor. The TV does aid in shift points though, but does not control them. Getting that the correct pull rate for the TV cable was quiet the project for this Jeep. I'll keep this post updated for anyones future reference.
-
Maybe a stupid question but, is the TV cable correct for the carb? I am not a Jeep person and didn't know the 700R4 came in them.
-
No...but the geometery is correct on the pull/return rate...I'm using a Holley 350 cfm carb with the proper corrector bracket and a lokar cut to fit 700R4 cable. You are correct though alot of people treat the TV cable like a kickdown cable. It isn't....also the proper way to adjust the TV cable is with the tranny pan OFF and watching the plunger while you have an assistant work the carb linkage. The whole clicker-self adjusting method gets you in the ball park though.
-
No...but the geometery is correct on the pull/return rate...I'm using a Holley 350 cfm carb with the proper corrector bracket and a lokar cut to fit 700R4 cable. You are correct though alot of people treat the TV cable like a kickdown cable. It isn't....also the proper way to adjust the TV cable is with the tranny pan OFF and watching the plunger while you have an assistant work the carb linkage. The whole clicker-self adjusting method gets you in the ball park though.
Thanks for clearing that up. Most do use the click method and wonder why the trans burns up. I prefer manual transmissions, simple and they give you a warning when something starts going wrong with them.
-
True, I'm just sick of shifting...this was actually a manual to automatic swap. I originally had a Puegout BA-10/5 5 speed tranny in the Jeep. It was a pretty intense conversion bell housing adapter, spacers for torque converter etc...If I had to do it again though I think I may have done the full monte and installed a 350...Jegs price of $1900 for a long block was very tempting! Don't worry though I am a Chevy owner too so don't ban me. Restoring a 1965 C-10...
-
Had a 63 C10, 64 C10 and 66 C10. Loved that body style!!!
-
It is a cool body style, it's weird how this project went. Had the cab forever, it's in AWESOME shape, on a 80's 4x4 chassis. The rear of the chassis turned to swiss cheese after a sandblasting so came along a original '65 chassis. I was able to blast that seal, prime and paint it looks better than new. Found some trailing arms with a 12 bolt cleaned all that up. I had a 2wd 78 C-10 I'm using the front suspension from that, for the disc brakes and better steering box. Everything is ready for assembly now. I have boxes of everything from Summit, , and Brothers to put the chassis back on it's suspension. Cab is in awesome shape so I'm just going to have it painted, I do have a fleet side bed but it needs TLC so I may just go with a MAR-K bed kit. Power plant is will be a slightly warmed up 454 with a TH-350 behind it. I think it will be a nice truck once it's done...
-
My 90 1500 transmission started acting weird 1 day,so I hammered it wide open.It downshifted to low and stayed there,no upshift at all.So I figured something broke inside and without even thinking about it I pulled it out and tore it down.Everthing inside looked perfect so just resealed and put it back together.Checked the valve body and low and behold tv stuck in full position.It looked as if a piece of v\b gasket material was stuck in it.I cleaned it out and reinstalled and still working today some 100,000 miles later.By the way originally I had installed sk700 jr shift kit as I do in all 700's to prevent just that,sticking tv
-
Hey All,
Just an update on this. After talking to the transmission builder I drained the tranny, dropped the pan, and valve body. Long behold found a stuck TV. Cleaned it out, and put it all back together. After reinstalling everything getting normal pressures, TV is adjusted and tranny is shifting awesome.
I'm guessing it was stuck because it sat so long after rebuild in my Jeep with no fluid in the pan. Lesson learned 4 qts of fluid if you are going to let tranny sit or enough to keep the VB soaked. Thanks for the feed back on this.
-
Thanks for the update and know we know what could cause a no shift problem
-
Glad it worked out happy tranny= happy driver
-
Yea shifts great...had to shim the starter slightly....weird cause you aren't suppose to have to shim Ford style starters, then again you probably ain't suppose to put a chevy transmission behind a Jeep engine...but while rotating the flex plate would contact the starter gear a .0625 shim brought it out just enough...I can't emphasize how valuable a pressure gauge is for these transmissions.