My automatic transmission in my 1995 20 series van wont shift into 1st gear unless I pull it in manually, what would cause this ?

There could be a number of possible reasons why your G30 Chevy van is not shifting out of 1st gear. Some potential causes could include:

1. Faulty shift solenoids: The shift solenoids are responsible for controlling the flow of transmission fluid through the valve body, which in turn affects the shifting of gears. If the solenoids are not functioning properly, it can cause the transmission to get stuck in 1st gear.
2. Low transmission fluid pressure: If the fluid pressure in the transmission is too low, it can prevent the gears from shifting properly.
3. Faulty transmission control module: The transmission control module (TCM) is responsible for controlling the shifting of gears in an automatic transmission. If the TCM is faulty or has malfunctioned, it can cause the transmission to get stuck in 1st gear.
4. Internal transmission issues: There could be internal issues within the transmission itself that are preventing it from shifting out of 1st gear. This could include worn gears or clutches, or other mechanical issues.

It is recommended to take your van to a qualified mechanic or transmission specialist to diagnose the issue and perform any necessary repairs.

Pull the trans & rebuild it

Can't fix slipping

If the Linkage is not damaged, you are going to need to pull the Transmission out.

The part that went bad is called the SYNCRO's

That transmission is one that has been used for years in Dodge and Plymouth vans. Do you know when the last time was that the fluid was flushed out and replaced? It's pretty important that it be done every 90K miles.......have it checked out.

on automatic transmissions Ok,1st check the transmission fluid level if low or if any at all, 2nd you might check your trans shift solenoids, or the wiring to the solenoids verify which solenoid you might need to replace by google it can show you a location of the 2nd and 3rd. If this doesn't cover the issue the next step is a tech to work on the transmission cause it could be and internal issue.

You might need to get a transmission cooler. It keeps the transmission cool good for towing or pulling heavy trailers.

The transmission may be in Limp mode. The transmission is on the same fuse as the MAF, O2 sensors and at least one other sensor - if an O2 shorts out, it will blow the fuse and the trans will go into limp-home mode. Be sure the trans has power and the fuse is not blown before doing anything else.

What is "limp-home mode" ? This is a fault mode in which the transmission either loses electrical power or the PCM deactivates all of the electronics. The transmission will default to max line pressure. The driver will have Reverse and 3rd, with manual 2nd available by putting the gearshift in 2 or 1 (doesn't matter). 1st, 4th, and TCC lockup will not be available. It will not hurt the car to drive it like this for short periods, but use manual 2nd to get the car moving, and be aware that the trans will generate more heat than normal while operating in limp-home mode due to increased torque converter slippage during 2nd gear starts and no lockup in 3rd gear.

Trans does not upshift out of first, speedometer reads zero at all times: VSS failure. Easy fix on rear of transmission, but xmember must come out to access VSS.

Car goes into gear but feels very sluggish like the brakes are dragging, but it will roll easily (starts out in 4th gear), you manually shift to 2 to get it moving, once it's moving you put it back in OD and the car shifts 3rd to 4th on its own and locks the converter at the appropriate time: ShiftB solenoid failed: Easy fix in the pan. Or a wiring problem from PCM to trans.. or PCM.

No 1st or 4th available; trans shifts 2nd to 3rd by itself in D or OD and locks the converter : ShiftA solenoid failed. Easy fix in the pan. Or a wiring problem from PCM to trans.. or PCM.

Transmission does not shift automatically, only manually. Swap in a known-good PCM, check wiring, check other sensors such as VSS and TPS.

3rd gear starts, can manually shift through all gears. When car has been turned off for a bit, then back on it will run normally.: VSS dropoff w/ Hi-stall converter. The rpms are too high, but VSS is showing no movement. Happens after a tire burning take-off. Doesn't store a code, will not throw a CEL (I've heard that it will store a code if it happens 3 or more times). Cure: Reprogram PCM for VSS dropoff -- PCMforLess knows about it.

Here are just some of the common things you have described with the issues your transmission has. Good luck and keep me posted.

Trans shifts into gear harshly, car feels sluggish off the line, No 1st, 4th or TCC lockup available, Manual 2nd, 3rd and Reverse are only available gears, CEL is on: Transmission is either in limp-home mode or has lost electrical power. If there are lots of error codes in the PCM, check the under-hood fuse that powers the transmission, and if it pops again, look for a short in that circuit like an O2 sensor harness touching exhaust. Otherwise, check PCM codes for a particular fault in the transmission causing the PCM to put it in limp-home mode.

No 1st or 4th available; trans shifts 2nd to 3rd by itself in D or OD and locks the converter : ShiftA solenoid failed. Easy fix in the pan. Or a wiring problem from PCM to trans.. or PCM.

Car goes into gear but feels very sluggish like the brakes are dragging, but it will roll easily (starts out in 4th gear), you manually shift to 2 to get it moving, once it's moving you put it back in OD and the car shifts 3rd to 4th on its own and locks the converter at the appropriate time: ShiftB solenoid failed: Easy fix in the pan. Or a wiring problem from PCM to trans.. or PCM.

Good luck and keep me posted, there are other things but these things mentioned seam like what you described.

sounds like the governer gear stripped out , its located on the driver side on the trans where the axle inboard shaft goes into the trans

There were two different automatic transmissions in the Sunfire that year,the 3 speed trans designated the 3T40,and the 4 speed trans designated the 4T40.If your car has the 4 speed trans,there will be a circle around the "D" on your gear selector indicator.The 3 speed trans will not have a circle around the "D".The 3 speed trans works off of a cable called the TV or Throttle Valve cable.This cable should be checked where it engages the throttle body around the area where the throttle cable attaches to the throttle body,on the engine.If the cable becomes disconnected for whatever reason,the trans will not shift out of 1st gear in most cases.If the car has the 4 speed trans,this model trans is totally electronic,and the vehicle should have the codes pulled out.For every trouble code,there is a diagnostic route to follow to repair the malfunction.