Good day all,

I am new to the forum, having found it while searching for some solutions to a transmission problem I am having with my 79 Ford F-350 U haul truck. To make the story short, my truck stuck in gear (between 2nd and 3rd) while driving home about 100 miles or so out of Phoenix.

I was hoping that someone might know the best way to proceed troubleshooting it and getting it running again. A mechanic friend said if I get it to him, he can check it out and repair it if its cost effective to do so as opposed to replacing it with anther (used) one.

He also said that it may be the shifter that is stuck and not that the tranny itself is bad. I am not sure my next steps but here are some of my my questions:

1) Is there an access cover that can be removed to peer inside and see if it is something simple to fix?

2) Whats the procedure for removing it? Is it pretty straight forward? Looks like it is.

3) What tranny comes with this model and where do I start looking for one? I think several years ago when all this happened (its been sitting for two years) the U haul parts guy here in Phoenix said its a New Process NP-135 transmission. Does that sound right?

4) Can I swap out with another tranny that bolts right in? This way I can broaden my search.

I need to get this thing running as I am counting on it to help me clean clear out things from our home to sell off. I mate it up to a trailer so I can haul and old Jeep with an auger, non-running Unimog that I need to bring to Phoenix to get running to sell, etc. etc. etc.

We are planning to move and this truck is strategic to making that happen.

Thanks for any help you can provide,

Tony

 

Is it 4 speed manual with really low first gear (NP435)? I don't think it is possible/practical to do much with it in chassis but somebody who knows that chassis better should comment.

Other choices are tow it to your buddy or swap transmissions where it sits. Near Phoeniz at least it shouldn't be freezing. I'd be inclined to find a transmission, and ask your buddy if he wants to take a road trip and change it with you where it sits... maybe better than a ?? $300 tow bill.

Even if you did get the current one freed up, I guess it may stick again and it sounds like you need the truck to work.

 

Hi Blue and White,

thanks for the reply and suggestions. I'm trying to remember the shifting pattern, but I believe its a 4 speed with a pulling gear (granny gear?) on top of that, giving it five speeds. Does that sound right?

I remember because when I was using it at our place up in the mountains here in Arizona, I used it to haul things up some inclines and used the low gear to crawl along. I think I had to shift way to the left and up, outside the normal four speed pattern.

The revers was in the opposite direction and appeared to be geared similarly. Would this make it a five speed?

Now that I think about it. I may be wrong on this one. We have an old 1970 Bluebird "shorty" bus (converted to an RV) based on a Chevy heavy truck chassis and I think THAT'S the one that has the five speed pattern and not the U haul.

Thanks,

Tony

 

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

Item #4 in the 1st pic is what pushes down and twists, #8 is the pins that get broken.

 

Hi 77&79F250,

That was really great information. Thanks. It sounds like this can be done without lowering the transmission. Is that so?

 

All depends on if you have a transmission tunnel cover that is bolted on....I think 2wd truck NO, and 4wd Yes.

A 2wd NP435 trans is very common, if you have to go that route. At least in my local JY it is.

 

Hi all,

I was just about to drop the transmission today and was unable to disconnect the speedometer cable retainer clip. I can't see how its done. From my vantage point (laying on my back looking up at it) I could not see a visible nut to loosen to remove the speedometer cable.

The retaining clip looks like the end of an open end wrench that has a round tube like protrusion on the end. The clip itself looks like it fits into a slot and then screws into place so it cannot wiggle back and forth.

I used a mirror to peer inside the tube and saw what appeared to be a small hex bolt. However the opening is so small I don't have a socket that can fit in there. See the pics.

Can someone please tell me how to remove that thing. Its the only thing holding me up. I want to put another transmission in tomorrow but can't take the old one out.

Thanks ahead of time for your help,

Tony


Can't see how to remove the speedo cable.





I thought it was an allen screw sunk inside this tube looking thing. It wasn't.




Is there a special tool to remove the speedometer cable retaining clip?




Any ideas how to remove the speedometer cable/

 

Wow, that looks odd, sorry I have not seen that before. Worse case remove the speedo cable from the back side of the instrument cluster and remove it with the trans.

Just squeeze the white plastic clip with your HAND and pull it and the cable out the back side of the cluster, the white clip comes out with the cable.

Then figure out how to remove it once the trans is setting on the shop floor. I know a few FTE member that have just removed there 4 spd trans, let me PM them this thread.

 

Thanks for the help. I wonder if this is a U-haul specification? The parts guy at the U-haul parts center here in Phoenix several years ago told me that these trucks are custom ordered and do not use stock components usually associated with the year and model of truck. Thus an auto parts store may not find the right part for a given truck just going by the make and model.

If I remember correctly, under the hood there is a sticker with the part numbers for such things as an oil filter, distributor cap, etc. so the right replacement part can be found.

Maybe something like that is going on.

Thanks,

Tony

 

Sorry to hear about your troubles. If I had to take a guess, I'd think it might be #30 in the 1st photo of the exploded transmission. On the shifting forks there are some nylon or plastic 'wear' pads and one or more might have just fallen apart and cause your shifting problems. I know that speculation does not help you any at this point.

As to what holds on the speedo cable, it should be a hex nut. The blurry photo looks like what you described - a socket. Have you tried taking some vice grips to it and see if you can get it to turn left? It shouldn't be too tight.

I rebuild mine (1st time) without too much hassle or special tools and for not much money. It's too bad its not a 4x4 because you could open the top side up without having to pull it out.

Best of luck to you.

 

My 78 F350 custom cab 1 ton dually has a nice big plate in the floor that when unbolted and removed leaves a hole big enough to pull a transmission through it. The last time I did it was in january of 2013. Your truck should have that same transmission tunnel plate. use a pair of vice grips on that speedo clip if you need to, I think it's a 5/16 hex if you can get it into the hole. the speedo cable will pull out by hand. the gear is plastic/nylon so don't hurt it by laying it on the ground where someone can step on it. Good luck and keep working.

 

Thanks for the info on using the top for removing the transmission. I have never heard of such a thing, always used to removing trannys from underneath.

Does this mean that you used a cherry pick to pull it out?

I finally got the tranny out, as suggested I disconnected the speedo cable from the back of the speedometer. Three layers of diss-assembly that I did not anticipate.

1) taking the dash apart to do the speedo thing.
2) had to take the exhaust pipe off the manifold in order to give needed clearance.
3) Had to drop the exhaust pipe hanger in order to let it drop lower so the tranny could clear the firewall.

I don't think I have ever worked with a transmission that had such tight clearances. It was a bitch to put it mildly. We are talking like 1/4" clearances. I had to finagle the thing slowly, at times holding up the output housing with a ratchet strap spanning and hooking to the bottom of the cab until it finally let me drop it down.

I took the transmission to a mechanic friend who figured out that the speedo cable was being held in place by a 5 sided bolt inside that "tube" looking thing.

He used a screwdriver grabbing one of the side and loosing it and finally get it loose. This exposed a bolt that held the cable in place. Actually that top piece that had me fooled is not needed to hold the cable in place as to remove the cable still required removing a bolt.

Finally the replacement tranny is not the same and I am going to take it to another friend that also rebuilds transmissions to see if it is easy to swap the tail housing between the two as the replacement is shorter having come from a 4 wheel drive truck whereas mine is from a two wheel drive uhaul truck.

I'll know more tomorrow. Does anyone happen to know off hand if it is difficult to swap the tail pieces between the two trannys shown in the pictures. The one with the open top is the one I pulled out. The "clean" one is the replacement. The guy I bought it from gave me a week to return it if it didn't work out. My gut feeling is it won't work. Anyone have any thoughts on it?

Thanks,

Tony

 

I wonder if that was a "miles" theft deterrent for uhaul making it harder for someone to just run a truck with the speedo unplugged to save on the per mile rate

 

Double check the spline count on your tailshaft as some 4x4 trans had a 28 spline shaft and 1 tons usually have a 31 count spline tail shaft

I turned the trans so that the front shaft was pointed towards the passenger side firewall, put a 2" wide cargo strap around the trans and across my shoulders and picked it up by the stickshift. It's a tight fit, when you put it in the tail shaft enters the hole first. Pulled the trans 3rd week of January, 2013, had a stroke Sept 3 2012. I do things like that to intimidate the unwanted low lifes in the nieghbourhood. the next pic is my "bottle of courage" LOFL

 

Here is how you use a engine hoist (cherry picker) to drop a transmission, auto, standard, and even with a transfer case attached to it. But you first have to have that removable floor panel.

Was hoping for you, that you would be able to figure out the problem with the original trans, instead of you having to do a complete swap out.

Looks like that U haul truck set up has definitively gave you a challenge.

Hang in there.