700r4 sluggish to go into any gear, have to rev motor up

[G-NUT]

I just bought a "good" used 1988 700r4 trans and torque converter from a salvage yard. It came out of a 1988 C1500 5.7L. I pulled it.

Before installing I replaced front/rear seals, new TV cable, installed the Transgo SK-700JR kit, new valvebody gaskets, and new trans filter and Dex VII fluid.

Installed, adjusted TV cable, added fluid, started up, let motor and trans get warm, checked trans fluid on level ground with motor running and trans in neutral like the GM manual says.

When I put it into R to backout of the garage it was very sluggish to move. I had to give it some gas and get the RPM's up for it to move. I figured it was low or high on fluid. Once out of the garage on the driveway the fluid level was fine. So when I put it in D the burb moved but just like in R, very sluggish / slow to move. I had to rev it up quite a bit to get it moving forward. Once going it did shift from 1, 2, 3rd. Then I tried to turn around. Same R issue. Once turned around to go back, same issue in forward gears.

ANY THOUGHTS ON THIS? COULD THIS BE SYMPTOMS OF A BAD TORQUE CONVERTER OR WEAK/BAD FRONT FLUID PUMP?

[Bigdav160]

It sounds like a pressure issue. That doesn't mean the pump is bad. You could have an internal leak (since you had the VB out).

I would put a pressure gauge on to verify.

A bad converter could give the same symptoms but is more unlikely. Again the pressure needs to be checked.

Is the filter and seal installed correctly? That could make it suck air

[G-NUT]

Originally Posted by Bigdav160

It sounds like a pressure issue. That doesn't mean the pump is bad. You could have an internal leak (since you had the VB out).

I would put a pressure gauge on to verify.

A bad converter could give the same symptoms but is more unlikely. Again the pressure needs to be checked.

Is the filter and seal installed correctly? That could make it suck air

Thanks for the quick response. I also was thinking maybe a low fluid pressure issue. I also considered the torque converter not applying to power. I felt like the way it shifted into each gear it just needed more pressure.

I do not have a pressure gauge. I'll have to see about getting one.

When I pulled the VB I reinstalled using new gaskets and torqued each bolt to manual specs.

I had the trans upsidedown on my work bench, so when I installed the VB gaskets and plate I tried very hard to ensure they were perfectly lined up. I may have to pull it back off and check again.

I made sure to remove the old filter seal. Replaced it with the new one and the new filter. I made sure to seat them well.

I have rebuilt motors and done a fair bit of tranny work over the years, but I've never had the guts out of a trans.

[G-NUT]

Found the issue with my "new" used trans.

I bought a gauge set. Connected to the line port according to the GM manual. Checked pressures accordingly. I never got more that 9-10psi !!

So I dropped the pan. In the bottom, at the magnet was my pressure relief valve train.
I guess when installing the Transgo upgraded pressure relief valve spring I didn't fully seat the snap-ring or didn't set it in the correct location.

[Bigdav160]

Easy to do. There's a step in the bore that feels like a stop. Usually the trick to getting the valve train fully installed is to jimmy the plug up and down with a long screwdriver. Suddenly it will push in another 3/8 inch and expose the snap ring groove. Don't let up in the screwdriver as the spring will push the whole line up back out the hole.

[G-NUT]

Originally Posted by Bigdav160

Easy to do. There's a step in the bore that feels like a stop. Usually the trick to getting the valve train fully installed is to jimmy the plug up and down with a long screwdriver. Suddenly it will push in another 3/8 inch and expose the snap ring groove. Don't let up in the screwdriver as the spring will push the whole line up back out the hole.

Thank you. I'll will be more cautious this time.