Transmission will not go in any forward gears?

Good morning,

If you have reverse but no forward gears in any range, then you have an internal failure in the transmission assembly. It could be clutches that are worn out.

https://www.2carpros.com/articles/automatic-transmission-problems

When you have reverse and no forward, this is mechanical, not electrical.

It will have to be removed and inspected for the failure.

Roy

You are welcome.

Always glad to help.

Roy

You and your family as well.

Roy

I just wanted to add some information for you.

https://www.2carpros.com/articles/transmission-replacement-removal-manual

If you plan on doing it yourself, you will need a lift, transmission jack and an engine support for when you release the motor mounts for the removal. The engine remains in the van and transmission comes out by itself.

I attached a you tube video of the transmission removal. It is a 4X4 but is the same except for the transfer case.

Roy

There is no electronics to control going into gear. That is mechanical.

The main line pressures need to be checked to confirm there is sufficient pressure to apply the clutches. I attached a flow chart for this process.

Roy

Hydraulic test pressures range from a low of one psi (6.895 kPa) governor pressure, to 300 psi (2068 kPa) at the rear servo pressure port in reverse.

An accurate tachometer and pressure test gauges are required. Test Gauge C-3292 has a 100 psi range and is used at the accumulator, governor, and front servo ports. Test Gauge C-3293-SP has a 300 psi range and is used at the rear servo and overdrive ports where pressures exceed 100 psi.

Pressure Test Port Locations

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Test ports are located at both sides of the transmission case.

Line pressure is checked at the accumulator port on the right side of the case. The front servo pressure port is at the right side of the case just behind the filler tube opening.

The rear servo and governor pressure ports are at the right rear of the transmission case. The overdrive clutch pressure port is at the left rear of the case.

Test One - Transmission In Manual Low

NOTE: This test checks pump output, pressure regulation, and condition of the rear clutch and servo circuit. Both test gauges are required for this test.

1. Connect tachometer to engine. Position tachometer so it can be observed from driver seat if helper will be operating engine. Raise vehicle on hoist that will allow rear wheels to rotate freely.
2. Connect 100 psi Gauge C-3292 to accumulator port. Then connect 300 psi Gauge C-3293-SP to rear servo port.
3. Disconnect throttle and gearshift cables from levers on transmission valve body manual shaft.
4. Have helper start and run engine at 1000 rpm.
5. Move transmission shift lever fully forward into 1 range.
6. Gradually move transmission throttle lever from full forward to full rearward position and note pressures on both gauges:
Line pressure at accumulator port should be 54-60 psi (372-414 kPa) with throttle lever forward and gradually increase to 90-96 psi (621-662 kPa) as throttle lever is moved rearward.
Rear servo pressure should be same as line pressure within 3 psi (20.68 kPa).

Test Two - Transmission In 2 Range

NOTE: This test checks pump output, line pressure and pressure regulation. Use 100 psi Test Gauge C-3292 for this test.

1. Leave vehicle in place on hoist and leave Test Gauge C-3292 connected to accumulator port.
2. Have helper start and run engine at 1000 rpm.
3. Move transmission shift lever one detent rearward from full forward position. This is 2 range.
4. Move transmission throttle lever from full forward to full rearward position and read pressure on gauge.
5. Line pressure should be 54-60 psi (372-414 kPa) with throttle lever forward and gradually increase to 90-96 psi (621-662 kPa) as lever is moved rearward.

Test Three - Transmission In D Range Third Gear

NOTE: This test checks pressure regulation and condition of the clutch circuits. Both test gauges are required for this test.

1. Turn OD switch off.
2. Leave vehicle on hoist and leave Gauge C-3292 in place at accumulator port.
3. Move Gauge C-3293-SP over to front servo port for this test.
4. Have helper start and run engine at 1600 rpm for this test.
5. Move transmission shift lever two detents rearward from full forward position. This is D range.
6. Read pressures on both gauges as transmission throttle lever is gradually moved from full forward to full rearward position:
Line pressure at accumulator in D range third gear, should be 54-60 psi (372-414 kPa) with throttle lever forward and increase as lever is moved rearward.
Front servo pressure in D range third gear, should be within 3 psi (21 kPa) of line pressure up to kickdown point.

Test Four - Transmission In Reverse

NOTE: This test checks pump output, pressure regulation and the front clutch and rear servo circuits. Use 300 psi Test Gauge C-3293-SP for this test.

1. Leave vehicle on hoist and leave gauge C-3292 in place at accumulator port.
2. Move 300 psi Gauge C-3293-SP back to rear servo port.
3. Have helper start and run engine at 1600 rpm for test.
4. Move transmission shift lever four detents rearward from full forward position. This is Reverse range.
5. Move transmission throttle lever fully forward then fully rearward and note reading at Gauge C-3293-SP.
6. Pressure should be 145-175 psi (1000-1207 kPa) with throttle lever forward and increase to 230-280 psi (1586-1931 kPa) as lever is gradually moved rearward.

Test Five - Governor Pressure

NOTE: This test checks governor operation by measuring governor pressure response to changes in vehicle speed. It is usually not necessary to check governor operation unless shift speeds are incorrect or if the transmission will not downshift. The test should be performed on the road or on a hoist that will allow the rear wheels to rotate freely.

1. Move 100 psi Test Gauge C-3292 to governor pressure port.
2. Move transmission shift lever two detents rearward from full forward position. This is D range.
3. Have helper start and run engine at curb idle speed. Then firmly apply service brakes so wheels will not rotate.
4. Note governor pressure:
Governor pressure should be no more than 20.6 kPa (3 psi) at curb idle speed and wheels not rotating.
If pressure exceeds 20.6 kPa (3 psi), a fault exists in governor pressure control system.
5. Release brakes, slowly increase engine speed, and observe speedometer and pressure test gauge (do not exceed 30 mph on speedometer). Governor pressure should increase in proportion to vehicle speed. Or approximately 6.89 kPa (1 psi) for every 1 mph.
6. Governor pressure rise should be smooth and drop back to no more than 20.6 kPa (3 psi), afier engine returns to curb idle and brakes are applied to prevent wheels from rotating.
7. Compare results of pressure test with analysis chart.

Test Six - Transmission In Overdrive Fourth Gear

NOTE: This test checks line pressure at the overdrive clutch in fourth gear range. Use 300 psi Test Gauge C-3293-SP for this test. The test should be performed on the road or on a chassis dyno.

1. Remove tachometer; it is not needed for this test.
2. Move 300 psi Gauge to overdrive clutch pressure test port. Then remove other gauge and reinstall test port plug.
3. Lower vehicle.
4. Turn OD switch on.
5. Secure test gauge so it can be viewed from drivers seat.
6. Start engine and shift into D range.
7. Increase vehicle speed gradually until 3-4 shift occurs and note gauge pressure.
8. Pressure should be 469-496 kPa (68-72 psi) with closed throttle and increase to 620-827 kPa (90-120 psi) at 1/2 to 3/4 throttle. Note that pressure can increase to around 896 kPa (130 psi) at full throttle.
9. Return to shop or move vehicle off chassis dyno.

This sounds like your input shaft speed sensor for the transmission is not working right. Here is the location please let me know what happens:

Check out the diagrams (below).

Please let us know what you find. We are interested to see what it is.

Cheers

Good evening,

The last 2 codes are the key. Incorrect gear ratios are the signs of a slipping clutches in the transmission. That means the internals are worn out and the transmission needs to be replaced.

The 700 is an information code.

I attached the other codes below.

Roy

Hi:
Take the truck to an Auto Zone or other nationally recognized auto parts store, and have them scan it for trouble codes. If there is a problem with a sensor, the truck's computer will have it storred and they will be able to tell you what it is.

Let me know if this helps or if you have any other questions.

JOe

If you think it's a solenoid then the check engine light will be on but get it scanned for codes to be sure. If the cv axle broke I'd tend to think it's something else like may a clutch pak in trans or seal bad. Or maybe even a tcase problem.