hey all, i just bought my 79 f150 and am trying to figure out what to do with the transmission, its a 4 speed, the guy i bought it from told me it was a toploader, but after looking on the tag on the trans its apparently one of the fake transmission that looks like a toploader but is actually a 3 speed with overdrive or something. my problem is that when driving 3rd gear will fall out if i brake or take my foot off the gas, is the transmission able to be fixed/rebuilt or do i need a new one, the motor is a 302. with a 9 inch read with 3.73 gears. im more looking for it to run and drive rather than race or anything like that.

 

My guess is that it needs rebuilt or that something isn't allowing the shift into 3rd to go fully into gear.

 

if the trans is shot is there a cheaper easy to swap transmission that i could put on?

 

NP-435 or T18 both 4 spd.New Process is NP435 = aluminum top cover w/8 bolts
T-18 = cast iron top cover w/6 bolts
Warranty Plate TRANS code: A = NP435 (N-1965 only) / F = Warner T-18 / P = F350 Warner T-19.
Warner shift lever retainer cap (8MTH-7220) threads on/off.
NP435 shift lever retainer cap (B8T-7220-D) has two notches, is retained to shift tower by two pins. See 1st pic.
To remove this cap, it must be presseddownand helddownwhile turning it counterclockwise to remove it. (Its spring loaded and twists into place, we removed one and it was a 2 person job. Put the trans into 2nd, 4th, or reverse, then one person holds the cap and applies pressure, twisting in a counter clockwise direction. The other person hits it from the top with a hammer to get the cap to go in below the two clips that hold it in.) People unaware use pliers or channel locks to remove it, which tears out the pins. The block of wood trick works great.

Originally NP435: Reverse-down towards the seat while Warner T-18: Reverse-up towards the dash.
The reverse shift pattern was changed circa 1973, but I can't recall for which of these 4 speeds. ( I believe it the NP435)
Note:There's another 4 speed: RUG SR-OD Single Rail 4 Speed Overdrive introduced in 1978 F100/150 300/302, TRANS code B

 

Emil,
My former 1979 F-100 had that 3 Speed W/Overdrive transmission in it. The Overdrive definitely lowered highway speeds RPM and helped with fuel economy. But, in my opinion it was an inferior transmission for a pickup truck, rather ideally suited for a mid size sedan. I had to replace the input shaft bearing three different times while I owned the truck, the first time was at 16,000. miles, shortly after it went out of factory warranty. Before doing anything, take a good look underneath to see if any of the shifting linkage arms are bent, if so try to bend back into shape. Next item to check. On flat solid ground, block wheels and engage the parking brake, crawl underneath to see the shifting linkage and have a companion shift the transmission through each gears and apply the foot brake, try to see what is causing linkage to come off or come out of gear. Hopefully it's a combination of out of adjustment shift linkage, lose shift linkage and or missing cotter keys. The transmission is not in anyway a beefy /stealth transmission and will not hold up to much abuse. For pleasure driving with stock size tires, it an okay transmission.

While actually driving the truck up shifting and down shifting, if it doesn't grind, then it's more than likely: (a) Bent shift linkage, (b) Improperly adjusted shift linkage, (c) combination of both a and b. Lastly, check the transmission fluid level. If you're planning on keeping the transmission, change the gear oil in it and when you re-fill it, consider adding a pint of STP oil additive. Wait a minute, I'm not even sure STP oil addative is even made anymore.

--- Break ---

Rich,
Appreciate you re-posting the NP435 shift lever (tower) removal information, know I read it from you awhile back. This time, I copied and pasted it onto a word document. I need to change the front seal on my NP435 in the not too distant future, perhaps this coming November, post trout season. Take care and be safe over there.

 

[QUOTE=EQCMCAT;19425579]Emil,
My former 1979 F-100 had that 3 Speed W/Overdrive transmission in it. The Overdrive definitely lowered highway speeds RPM and helped with fuel economy. But, in my opinion it was an inferior transmission for a pickup truck, rather ideally suited for a mid size sedan. I had to replace the input shaft bearing three different times while I owned the truck, the first time was at 16,000. miles, shortly after it went out of factory warranty. Before doing anything, take a good look underneath to see if any of the shifting linkage arms are bent, if so try to bend back into shape. Next item to check. On flat solid ground, block wheels and engage the parking brake, crawl underneath to see the shifting linkage and have a companion shift the transmission through each gears and apply the foot brake, try to see what is causing linkage to come off or come out of gear. Hopefully it's a combination of out of adjustment shift linkage, lose shift linkage and or missing cotter keys. The transmission is not in anyway a beefy /stealth transmission and will not hold up to much abuse. For pleasure driving with stock size tires, it an okay transmission.

While actually driving the truck up shifting and down shifting, if it doesn't grind, then it's more than likely: (a) Bent shift linkage, (b) Improperly adjusted shift linkage, (c) combination of both a and b. Lastly, check the transmission fluid level. If you're planning on keeping the transmission, change the gear oil in it and when you re-fill it, consider adding a pint of STP oil additive. Wait a minute, I'm not even sure STP oil addative is even made anymore.

--- Break ---

Rich,
Appreciate you re-posting the NP435 shift lever (tower) removal information, know I read it from you awhile back. This time, I copied and pasted it onto a word document. I need to change the front seal on my NP435 in the not too distant future, perhaps this coming November, post trout season. Take care and be safe over there
Thanks Rich, youre a big help ill give that stuff a try and get back to everyone.

 

No problem, because removing the shift lever sure makes is easier to remove/install the trans.

 

OP has the RUG SR-OD // If the trans drops out of 3rd, the brass synchronizer blocker rings are worn. There are 4 of these, (2) for 1st/2nd, (2) for 3rd/4th. All 4 are the same.

These are the same as the Ford 4 speed top loader installed in cars (C4AZ-7107-D).

 

You can also take the shift **** off and slide a large box wrench on top of the cap to get some downward pressure to remove it.