Changed the trans in freinds 94 chevy pickup today with a used one now when I put it in reverse or 1st it feels like their fighting against each other. But in D it feels normal. The trans I took out has a grey and white plug and the one I put in has a grey and green plug with one more pin. Do I need to switch pins in the plug or is the new one not compatible with the computer in the truck. I dont know what year the new one is but the plug looks the same as the 99 trans I have sitting in the garage.

 

Can I switch the internal wiring harnesses. and it would work maybe ?

 

When you say first is this a manual low position or the OD position?

The case connector has used a few different colors over the years and I do not normally identify them from this. I always look at the internals for what it is worth. From what you have going on here I would have to think that it is an internal issue to be honest. Bad clutch pack or damaged internal component. Also the internal wiring and components are not correct for a 94 unit.

If the trans you installed has the same amount of pins as a 96 and later unit it definitely has the wrong electronics in it. Also the pump, valve body, separator plate and the internal wiring harness are all wrong. A picture of the front of the valve body would help me tell you what you have.

94 units use a non pwm pump. The internal harness will only have a 3-2 solenoid (on/off)in front portion of the valve body near the pump/front of trans. There will be a TCC solenoid that will bolt to the case and the snout of it will be in the pump. Not to confuse the two solenoids.

Now in a 95 it will use a pwm pump. The internal harness will have just like the 94 except there is a second solenoid for the tcc in the valve body. Both the 3-2 solenoid and the LU solenoid in the valve body will be the same style solenoid. This unit uses a different spacer plate for just 95 units.

In the 96 and later units they will be set up much like the 96 however the added solenoid for the lock up will be a pwm style solenoid. Also the internal harness will have changed because the plug for this solenoid changed. This unit will use a separator plate for 96 and later pwm units.

To sum it up you have the wrong trans for your application. Vince

 

Yes in manual low and rev. it does this. Here are pics the first one is the old trans. With the harness unpluged its ok but wont down shift to low to take off from stop. I think the prob. is in the electonics the trans was realy clean inside its also a GM reman. These are the codes stamped on them the old one is 4CCD328A and new one is 4SHD328H they both appear to be 1994's but maybe the new one was updated when rebuilt. I see the diffrence in the wiring now. it has the extra seliniod at the front. so what year would it be for.

 

I assume that the picture on the left is the original 94 unit and the picture on the right is the 96 and later unit currently in the vehicle.

Not having a wiring schematic in front of me I wonder if the issue with the binding with the harness connected has something to do with the 3-2 solenoid. Not sure but sorry to say you definitely have the wrong trans in the vehicle.

You could try to swap the electronics from the old to the new however I do not think this is going to last long and you might have issues with the TCC function. I personally have never tried to do this so I can not tell you for sure what is going to happen.

Also you do run the risk of damaging the computer. I hope I have been of some help. Vince

 

Could I switch the complete valve body, spacer plate and electornics to the new one?

 

Yes you could do that. I would however switch the pump as well. Keep in mind that you will need gaskets for the pump and the valve body. Also I would get a new oring for the outer pump seal. You will need to make sure that you use early VB gaskets. These gaskets can be identified as having a "V" on the valve body gasket and a "C" on the case side gasket. Vince

 

Its begining to get to involved. Think he can just go find the right trans for it. Thanks for the help Vince.

 

Your welcome. I would have to agree that starting with the correct unit first is the best option. When you guys go to look for another unit obviously there paper tag on the bell needs to have a 4 in the first digit. Also there is a place where the unit is stamped on the side of the pan rail on the passenger side. Getting the exact 4 digit code would be best. Vince