Transmission "Stuck" in first gear... but shifter is in neutral!

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dieseldatzunguy
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Car: 81 Datsun 720 diesel 5 speed

Transmission "Stuck" in first gear... but shifter is in neutral!

Postby dieseldatzunguy » Sun Aug 30, 2015 8:53 am

Ok, this has been a REPEAT problem since I bought this truck. I push in the clutch, go to pull it out of gear, the stick feels "funny" as it slides into neutral, release clutch... and it's still in gear! Then the stick cant go back to that side anymore because the fork is engaged in first, but the striker lever is in the 3-4-5-r neutral gate. the previous owner said he went through 3 transmissions with this problem, this is my second one with the same issue. The trans I got with it had a hole drilled over the striker lever so it could be put into neutral with a screwdriver on the road (!!!) but the last one didnt, and it did it again!

There's alot of slop in the movement of the stick, the fork rods seem relatively stable, so I'm guessing the shift rod guide is worn?? The striker lever itself doesnt look worn off. WTH is up with these 5 speeds??

Thanks a ton for any help!!


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waynosworld
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby waynosworld » Sun Aug 30, 2015 11:12 am

Ok, my first question would be is the shift lever coming out of the hole it is in just below where the shift lever is connected?
I would then ask if you have all the proper hardware when you mount the shift lever, what I am asking is if you are using the pin to mount the shift lever, or a nut and bolt?
When you fix the issue, do you just remove the shift lever and put the ball back in the hole?
Does the ball have a plastic end like mine does in the photo below?
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Does your lever have the plastic inserts like mine has in the photo below?
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Or does yours look like one of the levers below, do you have the plastic inserts that take up the slop where the pin or nut and bolt go thru to hold the shift lever?
Image
To me it sounds like your shift lever doesn't have the proper hardware on it, and when you changed transmissions, you used the same shift lever on the new transmission.
Have you tried lifting on the shift lever to put it back into the hole(1st)?
dieseldatzunguy wrote:Ok, this has been a REPEAT problem since I bought this truck. I push in the clutch, go to pull it out of gear, the stick feels "funny" as it slides into neutral, release clutch... and it's still in gear! Then the stick cant go back to that side anymore because the fork is engaged in first, but the striker lever is in the 3-4-5-r neutral gate. the previous owner said he went through 3 transmissions with this problem, this is my second one with the same issue. The trans I got with it had a hole drilled over the striker lever so it could be put into neutral with a screwdriver on the road (!!!) but the last one didnt, and it did it again!

There's alot of slop in the movement of the stick, the fork rods seem relatively stable, so I'm guessing the shift rod guide is worn?? The striker lever itself doesnt look worn off. WTH is up with these 5 speeds??

Thanks a ton for any help!!

dieseldatzunguy
Posts: 10
Joined: Sun Aug 30, 2015 8:46 am
Car: 81 Datsun 720 diesel 5 speed

Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby dieseldatzunguy » Sun Aug 30, 2015 10:07 pm

I didnt reinstall the shift lever, it looks like the salvage yard pulled the the transmission without removing it, and I reinstalled the transmission in my truck with the lever still in it. It's held in with the factory pin, looks like it was never removed. When I "fixed" the problem on the transmission that came with the truck, I didnt remove the stick either. The previous owner had drilled a hole in the rear housing right over the shift gates, a screwdriver was used to manually push the fork rods back to neutral through that hole, and a brass plug screwed into the hole to keep the oil from splashing out.

I would assume the plastic hardware is still in the current transmission as that shifter hadnt been removed, but perhaps its worn out? But it seems to me the striker lever jumped over the 1-2nd gear "shift gate" into neutral while leaving the 1st gear fork engaged, which suggests a ton of slop in the shifter rod right?

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waynosworld
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby waynosworld » Sun Aug 30, 2015 10:57 pm

I have changed a lot of transmissions in my life, the fact is I changed one out this weekend in my work truck, I have never heard of anyone being able to pull and re-install a transmission with the shift lever still connected to the transmission.
I suppose it might be possible to change it out in a 720 since the transmission mount cross member is removable, but what a pain that must be, I would never try it myself.
You need to remove the shift lever and see what remains of the plastic shims and cover that goes over the ball, I suspect that the issue lies there, that would make finding a gear very hard and it would be very sloppy, both side to side, and forward and backward.
I have never heard of one of these transmissions doing what you are talking about, but I don't know everything, I believe that if it did do what you are talking about, the lever would jam and you would not be able to get it into the 3/4 or 5/R positions, it would only move sideways, but one would never know what could happen if one drives around resting their hand on the shift lever till it wears the internal shift forks out, I have heard of that before.

dieseldatzunguy
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Car: 81 Datsun 720 diesel 5 speed

Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby dieseldatzunguy » Mon Aug 31, 2015 7:35 am

I believe you're right about the removable cross member, we did have to pull it to get the transmission to come out, as well as unbolting the exhaust, but then we were able to fenagle it out shifter intact. I'm pretty darn sure the striker lever jumped out of the "tabs" on the fork rod, which is why I'm able to shift into 3-4-5-r, but I wont deny the plastic pieces are likely worn out too. I'll try to pull it apart later today and get a better look. Is there a good place to find replacement plastic bits for this transmission? Even better, does anyone sell the rear housing/rod guide/shifter assembly?

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waynosworld
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby waynosworld » Mon Aug 31, 2015 3:04 pm

Here is the thing, that transmission has these ball bearings for each shaft that keep you from being able to put the transmission in more than one gear at a time, so if it is truly in first gear, you should not be able to get the shift lever into 3rd or 4th gear at all, you will be able to get it into 5th or reverse though.
I know this because I have one apart in the garage right now that got damaged last week, and I just went out and tried to put it into 3rd and 4th while it was in first, no freaking way it was going into 3rd or 4th, but I was surprised to find out it would go into 5th and reverse.
Image
Image
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Does the shift lever feel funny now, can you feel it going into other gears?
This is apart because I lost the lower front cluster gear bearing, and one of the bearings got between the cluster gear and the 4th gear, it broke the cluster gear shaft.
Image
This is where reverse and 5th gear is supposed to be.
Image

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waynosworld
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby waynosworld » Mon Aug 31, 2015 9:44 pm

I have another question for you, when you put it in first gear, did the shift lever feel strange when you pulled it back to neutral?
I suppose that if one was shifting hard they could break the dowel on the 1st/2nd rod, but again it would not shift into 3rd or 4th with it in first gear.

dieseldatzunguy
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby dieseldatzunguy » Thu Sep 03, 2015 8:39 am

Ok this is good info. I believe you are correct, it wont go into 3rd or 4th, I had thought it was in 3rd in my driveway as a parking brake but maybe it was in 5th.... either way, it will not go into 3-4 now so you're right about that. The lever DID feel strange when I pulled it back from first into neutral when the problem started, but I was not shifting hard, I was babying it because the last transmission in the truck failed the exact same way. Note that the previous transmission was locking in 1st or 2nd every 5-20 miles in town, gradually doing it more and more frequently until I couldnt hardly get down the street without it locking in a gear and requiring the 'screwdriver in the modified tail housing' method to unlock it. What dowel are you referring to? I'll check it out, but I suspect something isnt outright broken if popping it back into neutral with a screwdriver will enable me to keep driving it until it happens again, it seems to suggest something is loose or worn down enough to allow it to jump gears occasionally but not every single shift, right?

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waynosworld
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby waynosworld » Thu Sep 03, 2015 3:27 pm

See the hole with the dowel on the right shaft 1st/2nd gear selector, if that dowel has broken, then the transmission has to be taken out and apart to fix it.
Image
I just don't see how the selector lever can get out of it's channel unless the dowel has broken, but I don't know everything, if it does have a broken dowel, drilling a hole in the case will not fix anything.
Will the shift lever move over into the 1/2 gear positions at all anymore?

dieseldatzunguy
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby dieseldatzunguy » Thu Sep 03, 2015 9:08 pm

No, it cant move to that side at all. I'll pull off the rear housing tomorrow and take a look...

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waynosworld
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby waynosworld » Thu Sep 03, 2015 9:25 pm

It will be interesting to see what you find, if you cannot move the lever over to the 1/2 position, then it does sound like it somehow got stuck in first, but how that would happen is the baffling part.
Have you tried to put it in neutral, move the shift lever firmly against the side of where 1/2 gears/selectors would be, then pull towards second as far as you can, then release pressure and move towards the dash, and then repeat a few times, perhaps you could catch the side of the selector and push it forward out of first by using friction.
Is this transmission already out of the truck?

dieseldatzunguy
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby dieseldatzunguy » Thu Sep 03, 2015 9:36 pm

yes, it is out of the truck. Thing is, even if I could force the striker lever back into position, nothing to stop it from happening again unless I correct the original problem. Like I said, the last transmission in teh truck did the same thing regularly. Something's worn out. It's just unclear what exactly.

dieseldatzunguy
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby dieseldatzunguy » Sun Sep 06, 2015 8:24 am

Got the tail housing off. Took some fanagling and forcing the fork back into second gear through a 3/4" gap with pliers to get the damn thing off. The fork rods have no play in them, the 1st gear shift gate is a solid piece on the rod and has no dowel, no broken dowels on other gears. The shift rod however has a **ton** of play in it. I can only guess that play allowed the striker lever to move up and over the fork rod gate for some reason. So i guess the question is, where can I find parts to take the play out of the shift rod assembly??

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waynosworld
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby waynosworld » Sun Sep 06, 2015 6:52 pm

This is what a good internal shift lever looks like, it is about 5/6mm thick, and about 10mm deep.
Image
Standing in back of the transmission while it is sitting upright looking forward, the upper shaft on the right is first and second gears, the middle shaft is third and fourth, moving the top right shaft backwards is putting it into first gear, you can see the dowel while standing above the transmission.
You can see the dowel in this photo below, that is the first/second gear shaft, pulling it backwards puts it in first gear.
Image
Image
This is in first gear in the photo below.
Image

dieseldatzunguy
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby dieseldatzunguy » Tue Sep 08, 2015 7:11 am

My shift striker lever appears as yours does, the dowel is intact. The gates dont look too worn either. I'll try to post some pix today to back this up, but the only thing I can see that seems amiss is the fact that I can wiggle the shift rod side to side almost two inches. Of course thats with it not being guided by the center mounting plate, but still seems sloppy doesnt it??

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waynosworld
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby waynosworld » Tue Sep 08, 2015 3:45 pm

That much slop makes me think about the shift lever hardware, stuff that can cause it to be sloppy are no bushings, someone using a nut and bolt instead of a the pin it came with, missing the little plastic thing on the ball on the end of the shift lever that goes into the hole, all these things will make the shift lever sloppy, but that will not cause it to get stuck in first gear while the shift lever is in first, that would be another issue.
I have heard of a transmission popping out of first under compression, I had one do that, but I have never heard of one of these transmissions doing what yours did, you said the former owner had the same issue with another transmission, did that former owner have anything to do with this transmission, or did you get this transmission independent of him, meaning he never ever touched this transmission, sometimes people do stuff to transmissions thinking that they know what's going on, when in fact they don't know anything, like the hole drilled in the transmission you talked about to pop it back into neutral.
Take the shift lever off and look close at it, if you can see any slop/movement, fix it with proper parts.
dieseldatzunguy wrote:My shift striker lever appears as yours does, the dowel is intact. The gates dont look too worn either. I'll try to post some pix today to back this up, but the only thing I can see that seems amiss is the fact that I can wiggle the shift rod side to side almost two inches. Of course thats with it not being guided by the center mounting plate, but still seems sloppy doesnt it??

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waynosworld
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby waynosworld » Tue Sep 08, 2015 4:14 pm

I just thought of something after I posted my last reply, the shift lever has a limiter for side to side movement, this could be an issue if someone removed the hardware, it would in theory let the shift lever move out of position.
In this photo you can see the nut/bolt partially loosened, this is a short shaft transmission, but the limiter is the same as yours.
Image
In this photo the bolt/nut and hardware has been removed.
Image
Here is the hardware that goes into that hole that limits shift lever movement, I remove this hardware because it makes it easier to pull the rear case off and to put it on, if you don't have this hardware, then I would imagine that finding gears might be a challenge.
Image
There are a lot of things that are bolted into the side of these transmissions, if anyone of them are deleted, there quite likely will be consequences.

dieseldatzunguy
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby dieseldatzunguy » Tue Sep 08, 2015 5:16 pm

The limiter is present and working. The rest seems to be there... The previous owner never touched this transmission, this one I had put in after the one that came with it failed. It came from a gasser in a salvage yard, swapped my diesel front housing onto it since the starter is on the opposite side. Used the shifter on the salvage trans and everything, the only thing that even came off the salvage trans was the front housing. Shoved the whole thing in teh truck. Lasted a month or so.

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waynosworld
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby waynosworld » Tue Sep 08, 2015 6:09 pm

With the limiter in good working order, it will only move a predetermined amount, just enough to align with the internals, any more slop is likely the shift lever being sloppy because of the reasons I mentioned 2 posts ago.
Sometimes people will remove that big nut and remover the spring and limiter piece, then just put the big bolt/nut back on, then there would be more side to side movement, it would likely get out of the gates eventually, that could cause issues, but being out of the gates would feel funny, it would move to places it never moved before.
I take the limiter assembly out when I remove the rear case, it lets me move the shifter arm out of the gates and then it's easier to remove the case, it's also easier to put back together.
I cannot remember where you live, I would say buy another 5 speed unless you can positively figure out how it got out of the gates and then fix it so it doesn't do it again, your the first one I have heard of with this issue, and I have bought and sold a lot of 720 diesel trucks over the years, I get them for cheap with bad transmissions, they lose the lower cluster gear bearing and then give up when they find out how much diesel transmissions cost, but you are ahead of the game, you already know that you can transfer the front case, most don't know that, and when I tell them, they don't care anymore, they are just tired of working on it and want it gone.

dieseldatzunguy
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby dieseldatzunguy » Tue Sep 08, 2015 8:51 pm

I live in oklahoma, hard to find those older nissans believe it or not. Any suggestions on where to find shifter parts are welcome.

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waynosworld
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby waynosworld » Tue Sep 08, 2015 10:15 pm

dieseldatzunguy wrote:I live in oklahoma, hard to find those older nissans believe it or not. Any suggestions on where to find shifter parts are welcome.

Do you have any of the mentioned shifter parts as samples?
Can you get a photo of all the pieces that you have?
All shifter levers are not the same, some have springs in them, some have big plastic or rubber pieces, some just have metal or plastic bushings, almost all have the same plastic piece on the bottom, that piece is important, if your missing that piece the whole shift lever will be very sloppy, it will be hard to find gears.
Also some have a short finger below where the shift lever is pinned in, while some have a longer finger.
The tangs that stick up where the shift lever is mounted are not all the same either.
Here are a bunch of different shift levers, see how the later ones(upper left) have a large rectangle hole while the early ones(upper right) have just a hole to mount them.
Image
Here are the different bushings/hardware.
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Notice how the center and right lever ends are different lengths.
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Here is an earlier diesel transmission with smaller ears.
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Here is a later gasser transmission with larger ears.
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I have seen at least one transmission that has the hole much higher in the ears than the one pictured above, but I don't have one to take a photo of, that type of shifter mount with the hole high in the ears would have a much shorter throw(short shift).
First thing that I would like to know is which type of shift lever that you have, the early ones you might be able to buy parts for at the local hardware store, while the later ones with the rectangle hole will need to be bought online, at Nissan, or found in the wrecking yard.
First we need to know what hardware you have if you have any at all.

sanissan
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Re: Transmission "Stuck" in first gear... but shifter is in neutral!

Postby sanissan » Fri Apr 19, 2019 6:11 am

Hi, dieseldatzunguy
i have similar problems in nissan qashqai yersterday.
Could you explain the repair and cost ??

thanks


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