When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
1979 f150 4x truck C6 automatic transmission. I just noticed this, this weekend. Ever since I've owned the truck about a year, I have to hold the column shifter tight in the Park position to start truck. This weekend I held it up tight in park position, but it did not start, it appeared everything was dead. I moved the shifter down slightly and it moved through the gears without the key on. Was this normal in 1979?
Sounds like your Nuetral Safety Switch needs adjusting. Set the parking brake, chock the tires, put the gear in neutral, crawl under to the driver side of you transmission and you'll see where the shift linkage connects to the C6. There are two bolts holding a grey "D" shaped switch. That's your NSS. Loosen the bolts, find a paper clip or piece of nailing wire and stick it in the little hole. Move the switch around until the paper clip bottom out inside the hole. Then tighten the bolts, remove the paper clip, and put the truck back in park. Test it and should be good to go.
As for the shifter running unobstructed through the gears you likely have a worn shift collar detent spring or a broken shift collar. The chrome shift arm you grab has a spring that should push the tip of the arm into slots on a detent plate. Is your shift arm stiff or does it flop around?
Sounds like your Nuetral Safety Switch needs adjusting. Set the parking brake, chock the tires, put the gear in neutral, crawl under to the driver side of you transmission and you'll see where the shift linkage connects to the C6. There are two bolts holding a grey "D" shaped switch. That's your NSS. Loosen the bolts, find a paper clip or piece of nailing wire and stick it in the little hole. Move the switch around until the paper clip bottom out inside the hole. Then tighten the bolts, remove the paper clip, and put the truck back in park. Test it and should be good to go.
As for the shifter running unobstructed through the gears you likely have a worn shift collar detent spring or a broken shift collar. The chrome shift arm you grab has a spring that should push the tip of the arm into slots on a detent plate. Is your shift arm stiff or does it flop around?
Thank you for detailed instructions. I'll try it this weekend.
1979 f150 4x truck C6 automatic transmission. I just noticed this, this weekend. Ever since I've owned the truck about a year, I have to hold the column shifter tight in the Park position to start truck. This weekend I held it up tight in park position, but it did not start, it appeared everything was dead. I moved the shifter down slightly and it moved through the gears without the key on. Was this normal in 1979?
Common problem on many FoMoCo vehicles. While turning the key, wiggle the shift lever in Park or Neutral.
1978/79 NSS switch located on the transmission. If the truck can be started in any gear, the NSS either needs to be adjusted or has failed.
The pot metal shift collar has an internal bridge that connects it to the shift tube. Over time, the bridge begins to crack, eventually breaks off.
When the bridge breaks, the shift lever flops around, as the shift collar is no longer connected to the shift tube.
1978/79 collars (A/T & 3 M/T) different than 1973/77 collars. If the 1978/79 has a tilt wheel, it's different again.