Hello all,

I recently bought my first car, a 1980 f-150 custom (4.9L, straight 6, 4speed manual trans). After some initial maintenance (fluid changes, alternator replacement, etc..) the truck was running great. But because I could not stay away from the truck, I had to find more things to tinker with, so I decided to change the man trans gear oil. It looked like a relatively simple operation according to my Haynes manual, but it has turned out to be anything but. My transmission looks nothing like what the manual has pictured, and I have struggled to find an identical model online. First and foremost, it was unclear to me as to where the fill and drain holes were. Secondly, after I guessed which they were, I proceeded to fill it with SAE 80W gear oil, which was the fluid specified by my manual. However, since it is clearly not the same trans as the one pictured, I don't know if I should have done that. Right after I filled it, I lost reverse. No slipping, no grinding, it just won't engage. I took it for a short drive, all the forward gears work, though it started bumping me out of 2nd gear towards the end of my drive. Can anyone tell me anything about my trans? Which are the fill and drain holes? Why would reverse go? Is 80W gear oil the correct fluid?

Well it seems that I can't post pictures, but if seeing them would help you answer this question I'll be glad to send them in an email.

Thanks so much

 

Although a T19 wouldn't be original for your truck, it may have been swapped in.
On these transmissions, people often accidently remove the bolt that holds the reverse shift linkage, thinking it is the level plug, & lose reverse gear.
If this is what has happened, you will need to remove the trans lid, & re-install the part.

The 4-spd OD transmissions also did this.

With the T19 there is a clip that fits on the end of that bolt after the linkage is back in place - it will be sitting on the floor of the trans.
I'm not so sure about the 4-spd OD, but I think they also had a similar clip.

 

Double post

 

thanks,
looks like I have the SROD after all. sure enough, the clip was sitting in the bottom of the transmission - now I just have to figure out how to link it back together. at least I didn't do any permanent damage, what a relief.

 

No, no permanent damage. Don't feel to bad, this mistake has been made by many others. It's a PITA, but fixable. Good luck.