Hello All - New to the forum. Been lurking for a while, but finally have encountered an issue with my rig that I can't sort out or find any intel on the site.

1984 F150 with 300, NP435 and NP208.

Cannot get transmission into gear even without the engine running. I am fairly confident this is not a clutch issue, but welcome criticism on that conclusion. Stick feels different than before and I think something came apart down in there with the shift forks or something.

Can't find any info on the site regarding this issue. All hits from my searches are issues with clutch not disengaging.

I am considering cutting tunnel (she's a work horse, not a show truck) to remove top of tranny and investigate. Uncertain about clearance with dash assembly directly above and whether shift assembly can be cleanly removed and reinstalled without having to force things.

I've heard tell of a shear pin down in there somewhere. Any guidance/intel greatly appreciated. Need to get her back in service as winter is coming! Yeehaw, let the powder fly!

Her name is Benito and she can do amazing things when her plow is attached...

 

I don't know why you would need to cut the floor?
You should be able to unbolt the cover as seen here

Autos don't have this bolt on cover
Dave ----

 

Awesome Dave! Thank you. Will check into this tonight.

Anybody out there have an easy to share exploded assembly diagram for the NP435?

Jake

 

Hello Jake from another Jake!

Here's a document with an exploded view and lots of other NP435 information:
NP435 - Gary's Garagemahal (the Bullnose bible)

Here's a photo album from another member -- contains many pics of the NP435 top cover removed and how to deal with it:
https://www.supermotors.net/registry/2742/11274

To remove the top cover you will have to pull the carpet & shifter boot, unbolt the floor access panel, unbolt the top cover, and make sure the transmission is in neutral before you take it out.
The shifter forks have little plastic/nylon inserts that like to go bad. This could be related to your problem or maybe you have a bad fork.
Also there are 3 shift rods on the underside of the top cover (as seen in pics in the second link I posted) and I have heard of those binding up.

I hope this helps!

 

I think you are on the right track. With the engine off, you should be able to move it through the gears, even if the clutch was bad.

 

Thanks fellas! Floor access panel opened up. Thick dirt/grime layer on top of tranny as to be expected. Scraped for a while, but still need to do some pretty hefty cleaning before I'll be willing to open the tranny up. Will be picking up some degreaser tomorrow.

The links are very helpful. I guess we'll find out more once the top is off.

I really appreciate the help. Thank you

Jake B

 

1/2 shift fork uses different nylon inserts than 3/4 shift fork. Overtime, these crack apart, fall off down into the gears causing more problems.

2) C2TZ-7C430-B .. 3/4 Shift Fork Nylon Insert - 3/4" long x 1/2" overall width // 2) D2TZ-7C430-A .. 1/2 Shift Fork Nylon Insert - 3/4" long x 5/16" wide / Obsolete ~ Available NOS & from auto parts stores.

Pic shows only one fork with the inserts, but they're on both.

Notice 7220 .. This is the 'spring loaded' shift lever retainer cap (B8T-7220-D) that has two notches, it's retained to the shift tower with two pins (7221).

To remove this cap, it must be pressed down by hand and held down while turning it counter clock wise to remove it.

Clueless people use pliers or channel locks to remove it, which tears out one or both of the notches. Not pleasant!

 

While you are at it, check your firewall where your clutch master attaches. "80s trucks crack, and rust and crack, and flex, and this causes clutch issues.

 

I just installed one of these in my project and the gear shift had popped out of one of the rails.

The sliders were very hard to move since it hadn't been used for years.

Took penetrating fluid and freed up all the rails and it shifts fine now.

Getting the spring loaded piece back on is a bit of a pain.

 

I'd like to comment again to emphasize the firewall inspection recommendation. Due to the severity and regularity of the firewall problems in this generation of trucks, you should reinforce the firewall if it hasn't been reinforced already, otherwise it's a question of when it breaks, not if it breaks.
There used to be a firewall reinforcement plate for sale from Ford, and I believe there is an aftermarket replacement available. Failing that, you could make one with the required mounting holes in the right places.

Regarding the spring-loaded cap at the base of the shifter -- the shifter does not have to be removed from the top cover in order to take the top cover off the transmission. However, you might want to remove it anyways to make things easier.
Personally, I have found it extremely difficult to remove the spring-loaded cap without using channel-locks -- just make sure you push the cap down fully before you try to turn it CCW.

 

Thanks you all for the wisdom. Will double check on the clutch components, mounting and linkage as advised. This truck certainly takes a beating in the winter being a plow rig. Last winter the steering box bolts sheered off at the frame connection. I'm very much in favor of pre-emptive repairs rather than having a breakdown during the middle of a storm. There's powder to ski after all! Plowing operations need to be strictly after hours when the lifts aren't spinning, and repairs are preferably during summer when working outside isn't so uncomfortable.

Anyone have any guidance on how/where to find the aftermarket firewall reinforcement?

Been on honey-do's this weekend. Still haven't degreased top of tranny so I can open it up. I had a SM465 in a rig earlier in life, so was familiar with stick removal procedure. Dirt/grit in the spring loaded cap assembly seemed to make it more difficult to remove, but I guess I was blessed with strong hands/fingers. I'm not sure the tunnel access panel would have come off easily without the tranny stick removed.

Thanks again everybody for the input. Jake

 

https://shop.broncograveyard.com/83-...uctinfo/34010/

Just search Ford firewall reinforcement. That one is first up, with several others.

There was an outfit called Terrapin Mfg making them, but he has folded the tent and shut down the website etc.

 

As mentioned if you have a hydraulic clutch check the firewall and master cylinder for movement if you see any buy a reinforcement. Bronco graveyard has one I bought it about 6 months ago installed it 2 months ago. Required me to cut the small side off and weld it back on so it would fit the firewall it was very far off, but rewelding fixed it perfectly. Pretty simple remove the brake master, clutch master, unbolt pedals, remove the bolt on the steering shaft, unclip the wiring on the column, slide out the column and install the plate. I think just sockets, wrenches, drill and maybe welder is needed.

Be sure there is no air in the lines, if so find the problem. Some lines are see through if you wipe them off. Bleeding it is a mission of if it's own dont mess with it unless you have done your research on how. Check for loose bellhousing bolts and that the engine and trans mounts are solid and tight, yes that could cause shifting problems.

Once those are verified pull the trans cover. Start by pulling the boot, use channel locks and press down on the cup with about 30lbs and turn it counter clockwise to pop the shifter off. Take the floor pan off. Take the shift cover off. Inspect the plastic pads on the shift forks and make sure they move right.

 

Hydraulic clutch introduced in 1983 F250/350 with 6.9L diesel & 7.5L (460). Everything else got it in 1984.

 

Okay fellas - I know I said I'd check into the clutch system integrity, but haven't yet. I did finally manage to degrease top of tranny so I was willing to open it up. The culprit is a broken pin at the bottom of the shifter. Somehow it didn't fall into the transmission. Instead it landed on the top front of the cast iron housing at the mating surface between it and aluminum top cover. All the metal flake was down inside the cup between and below the O-rings. It seems to be the remnants of the pin. Now I just need to source the part. All four of the nylon items were intact and appeared to be in good shape. Any recommendations on items beyond the pin and o-rings that might be worth replacing that don't require a full tear down? Pretty sure I'll be looking for magnetic drain plug too...