700r4 only shifts P, R, N, and 1st. Will stuck TV valve do this?

[G-NUT]

Looong story but my '83 700r4 worked fine until it didn't. When it didn't, what happened was I was driving my burb pretty easy, it shifted 1, 2, 3, 4 and as soon as it went into 4th it dropped back to 1st. No it shifts beautifully into P, R, N, and 1st. I will not shift into any other gears automatically NOR manually.

When I shift manually from 1st to 2, 3, or D the trans just stays in 1st (low). I've scoured the net for several weeks. I've read in detail the factory service manual and the 1984 GM 700r4 transmission manual.

A while back I installed a new Monster Trans 1800 stall T.Q., new front and rear seals, filter, fluid, and a B&M shift kit in the Heavy Duty option. I'd put about 100 miles on it after doing all that before this occured.

I've verified fluid levels, TV cable adjustment. No go.

Verified the Governor was ok, and it was. But I went ahead and replaced it with one from Monster Transmission. Still no change.

I pulled the valve body back down. Broke it down to a bare casting. Cleaned the V.B and all valves and components. Put it all back together. Same issue.

I've read online about the Throttle Valve sticking being a "known issue", and that there is a modified TV valve for this that TransGo sells as part of their SK700 kit. I'm thinking about getting this and installing it to see if it helps.

Before I buy the TransGo kit, my question on here is whether or not this may fix my issue. Would a sticking TV valve affect the shifting only in automatic mode or both automatic AND when I manually shift through the gears?

[AussieinNC]

The attached image shows the clutch application chart for the 4 speed trans....

The image makes reference to solenoids A & B ...ignore those references...

The common point for 1-2 and 3-4 shifts is the second band apply system...pull the servo and make sure the end of the band has not snapped off...also look for broken springs and pin on the servo...

You will need a pressure gauge to set the tv pressures correctly...

Hope the chart helps...

[AussieinNC]

Just an FYI...installing the Transgo SK700 kit correctly and entirely will take you at least 7-8 hours....

[Bigdav160]

Even if the TV is completely stuck the governor will force an upshift eventually if you go fast enough.

Every one that I've seen that refuses to shift (and still has reverse) is a governor circuit problem. Usually the governor itself but you've replace it already.

[G-NUT]

Thanks for the responses. I appreciate it. I removed the valvebody again last night & the new governor. Visually all that looks good. I verified the TV valve moves freely. I'm going to get it off jack stands tomorrow and try to drive it again. If same issue then I'm going to pull the trans, open it up, and have a look inside. I've never rebuilt one. May give it a shot. Rebuilt motors and othe mechanical stuff. Just never a trans.

[AussieinNC]

Before you take it off the stands, engine off, put trans in N, remove the governor cover and turn the drive shaft....make sure the governor is turning freely...

[G-NUT]

Thanks for that idea. I did that already. It does spin freely. Mind boggleing. I don't know if something is in the fluid passages from the governor or what.

[AussieinNC]

Wait,,,,the governor should not spin freely, it should only turn when output shaft is turned...

I suspect the front band has snapped or the servo pin has collapsed...preventing band apply....

No Band apply and you dont get 2nd or 4th...and ya cant rev it high enough to get it into 3rd....

[G-NUT]

Originally Posted by AussieinNC

Wait,,,,the governor should not spin freely, it should only turn when output shaft is turned...

I suspect the front band has snapped or the servo pin has collapsed...preventing band apply....

No Band apply and you dont get 2nd or 4th...and ya cant rev it high enough to get it into 3rd....

I misspoke. When I said freely I meant when I put the trans in N and spin the driveshaft with my hands the governors spins, follows the worm gear in the shaft.

I ended taking off the tailshaft housing to have a look. All looks good.
Ultimately I ended up removing the trans yesterday. I'm going to buy a used unit with a 30 spline input shaft. This one is a 27 spline input shaft unit.

I've watched some lengthy YT videos on teardown and rebuild. I also have a 700r4 trans manual. So I've toyed with the idea of trying to rebuild it, but since I have the 27 spline input shaft and my motor is not at about 400hp with 3.73 gears, traction loc, and 32" tall rear tires, I'd feel more comfortable with a 30 spline unit.

Thanks again for the response.

[AussieinNC]

Make sure you get the correct convertor for the new used trans....

[G-NUT]

Originally Posted by AussieinNC

Make sure you get the correct convertor for the new used trans....

Posted a new thread in regards to issues with my new "used" trans and torque converter. I pulled them from a 1988 c1500 5.7L. While out I did preventative maintenance as well as installed a Transgo SK-700JR kit. Now with this trans, every gear, R/D/3/2/1, when in this gear you have to accelerate pretty high, RPM's up, to get it to go in that gear. And when it does its very sluggish to start. Almost like you put it in gear and your buddy has to push the vehicle to get it to go. Once going it will go.

[G-NUT]

Found the issue with my "new" used trans. When installing the Transgo upgraded pressure relief valve spring I guess I didn't fully seat the snapring or didn't set it in the correct location. Checked the pressure port on the trans and only had 10 psi. Dropped the pan and there was my pressure relief valve train.