Why will my manual transmission not go into gear when vehicle is running ?

Your pcm has gone into “Fail-Safe” mode, which is there to “Warn You” not to drive the vehicle. If you do drive the vehicle you Will damage the transmission and need to replace it again, or rebuild it. The reason it is in fail-safe (the reason it stays in 3rd gear) must be determined first by a qualified technician-possibly using a scan tool.

There are a few possible reasons why your 2014 Fuso 515 manual transmission might not shift from neutral into gears when the engine is running but will shift when the engine is not running. The clutch is not disengaging properly: The clutch is responsible for engaging and disengaging the transmission from the engine. If the clutch is not disengaging properly, it can cause the transmission to not shift gears properly. The synchronizers are worn or damaged: The synchronizers are located in the transmission and help to match the speed of the engine and the transmission when shifting gears. If the synchronizers are worn or damaged, it can cause the transmission to not shift gears properly. The transmission fluid is low or dirty: The transmission fluid lubricates and cools the transmission. If the transmission fluid is low or dirty, it can cause the transmission to not shift gears properly. The transmission is faulty: If the transmission is faulty, it can cause the transmission to not shift gears properly. If you are experiencing this problem, it is important to have your vehicle diagnosed by a qualified mechanic to determine the root cause of the problem. Once the cause of the problem has been identified, the mechanic can recommend the necessary repairs. Here are some tips to help prevent this problem from happening in the future: Use the clutch properly: When shifting gears, use the clutch to disengage the transmission from the engine. Have your transmission serviced regularly: The transmission fluid should be changed according to the manufacturer's recommendations. Avoid shifting gears when the engine is under load: When the engine is under load, it can put stress on the transmission and cause problems.

Start the vehicle and check the transmission fluid level, if the level is low the vehicle will not move.

have a tranny filter fuid change soon

If the engine starts and runs fine in Park, try Neutral as well. If it runs and holds steady IDLE at both positions the issue is with your transmission. In the C1500 silverado series/GMC they had a period of bad trannys. In your case it sounds like the torque converter has gone bad and basically when you engage in gear its preventing your engine from turning over, thus the die. Its an easy diagnosis using above, but the fix is costly. A new transmission for these trucks run about $2300 or more to be installed. If you are able, a local mechanic may install a used one from a junk yard a lot cheaper... issue is there you have no warranty. So if this is an everyday driver/primary vehicle I would trust a transmission shop. Otherwise find your local trusted guy and ask them about a second hand job, or a rebuild.

The seals inside your transmission are bad and leaking by and they don't start to seal until the tranny fluid warms up and swells the seals. To temporarily fix this problem you can pour some brake fluid into your transmission fluid. This will swell the seal in the transmission and it should start working again. This is only a temporary fix however, eventually you will ned to replace or rebuild your tranny. I used this method on a turbo trans 350 and got a year of service out of it that way before I had to replace the tranny. Just do not put too much brake fluid into the tranny, I would recommend one or two capfuls to start with.

Manual transmision gears actually bathe in oil and distrubute the lubrication around the gearbox simply by the gears being connected to each other. In these boxes, the oil is not pumped as it is in automatic transmissions.

Some automatics build up oil pressure to shift gears while others use computer control. Manual trannies do build up pressure slightly because the of the meshing gears and the forcing and displacing of oil between the teeth, but nothing like an automatic.

The fluid in auto transmissions is pumped through the filter like it is in the engine. Since manual transmissions don't have a pressurized oil system, you will need add a suitable pump which will take oil from the lowest point in the tranny case and run it through a filter head (available at any hydraulic supply house) and from the filter output, back into the tranny.

You could position the filter in the engine compartment if you like. It sounds like a lot of work with little benifit. You will still need to drill into the tranny to access the oil and back in to replenish it.

I would recommend placing a magnetic plug on the drain (if there is drain) to catch the worn metal parts. If your really eager, just change the tranny oil more often and clean the metal off the magnetic drain plug.

rebulid tranni or install different tranni.

Check the condition of the tranny oil on the dipstick. If it's black and smelly, the tranny clutches might be worn out. Make sure you have enough fluid in there first. Check the fluid with the car engine running and the tranny in park. The level should be between the 2 marks.

if memmory serves me correct its been a while since last tranny rebuild and adjustment
on a 700-r4 type transmission
make sure that the shim kit was used properly with this transmission cause wrong sized length of linkage can make the trans. shift improperly
you have the linkage under neith adjusted wrong the shift bar on tranny should face 90 degrees up towards front of vehicle engine for proper adjustment