Manual transmission not shifting in to 1st or 2nd

[phucheneh]

The linkages are used to shift into every gear. If there was an issue with shifting into every gear the linkage is a likely culprit. You've got an issue shifting into two gears, thus it is likely an issue with something that those two gears share, like a shifter fork or their shaft, not something like the linkage.

If the shaft is no longer spinning (or seized) for whatever reason, its gear sets will never properly engage. This could be similar to trying to put a parked car into gear without depressing the clutch, if the gear teeth just happen to line up it'll engage perfectly, but if the teeth not lined up you're hosed. If the shifter fork is broken or jammed, for whatever reason, only those two gears will be affected and nothing else.

I don't think the garages are necessarily trying to hose you with an excessively costly repair, their conclusion that the transmission needs internal work does follow what symptoms we know. Personally, I would still want to clap eyes on what they've looked at.

If someone is quoting you a price for the largest component possible without actually having any idea what the problem is, I would call that 'hosing.'

And no, the linkage does not have to affect every gear. He has forward and back, so the top rod is working fine. But if that rod that moves the sideways selector (goes between 1-2, 3-4, and 5-R positions) has a problem, it could easily knock out either the two gears on the right, the two gears on the left, or both. I could not see it affecting 3 and 4, since that's the 'straight up' position.

 

[phucheneh]

well, the 2nd opinion same as the first one :-( I still can't get anything more over the phone than "technician checked the linkage and it is fine. so it must be something inside the transmission".

I'm sorry people suck so much. Honestly. It is just NOT difficult to disconnect the damn linkage and move the levers at the trans so that they can actually check the function of the part that they are condemning.

If your son is not prone to slamming the crap out of first and/or second gear, I don't see this being an internal trans problem. But that's just my best guess...the problem is, the people looking at the car seem to also be guessing; and I think their guesses suck.

 

[sontakke]

Which shaft are we talking about? The diagram shows many gears on the main shaft. If any of the rotating shafts have seized, at least from looking at the pictures, I just do not see how transmission would be able to function. Given that the car has been driven since that time, how could the gear teeth would always line up "badly"?

If the respective fork no longer wants to slide, then it would explain this behavior. But what would cause the fork not to budge from its neutral position? It has interlocking check ball / plunger / spring but that is all sealed and I don't see how something can jam it.

Another possibility is the synchronizer hub refusing to move but once again what would cause it bind to its shaft? And if it does bind, would that lead to other symptoms?

 

[JCH13]

If someone is quoting you a price for the largest component possible without actually having any idea what the problem is, I would call that 'hosing.'

And no, the linkage does not have to affect every gear. He has forward and back, so the top rod is working fine. But if that rod that moves the sideways selector (goes between 1-2, 3-4, and 5-R positions) has a problem, it could easily knock out either the two gears on the right, the two gears on the left, or both. I could not see it affecting 3 and 4, since that's the 'straight up' position.

Recall this very specific symptom from OP's son: "When he tries to select 1st or 2nd, it is as if he is hitting a metal wall. He can hear something blocking the shift stick when he tries to move the lever to 1st or 2nd gear." A broken or lose shift linkage will generally feel dead/empty or simply won't put the car into gear. I find it highly unlikely that there is this 'hitting a metal wall' sensation in the shifter, for two gears only, and the problem is the shifter linkage.

It MIGHT be possible that something else magically got in the way, or some part of the linkage broke in a very special way, and is jamming the shift linkage in both directions only in the 1-2 position, but these situations seem REALLY unlikely.

A complete transmission rebuild is a big-ticket item, sure, and might be overkill to simply restore 1st and 2nd gears. On the other hand, a transmission rebuild isn't unheard of in a car with 180k miles, it might even improve shifting and driving in general.

Like I said prior, OP should get eyes on the linkage before making a decision, but it's entirely possible, if not likely, that the issue is internal to the transmission.

Which shaft are we talking about? The diagram shows many gears on the main shaft. If any of the rotating shafts have seized, at least from looking at the pictures, I just do not see how transmission would be able to function. Given that the car has been driven since that time, how could the gear teeth would always line up "badly"?

If the respective fork no longer wants to slide, then it would explain this behavior. But what would cause the fork not to budge from its neutral position? It has interlocking check ball / plunger / spring but that is all sealed and I don't see how something can jam it.

Another possibility is the synchronizer hub refusing to move but once again what would cause it bind to its shaft? And if it does bind, would that lead to other symptoms?

Many trans-axle manuals use multiple gear shafts to package the transmission more effectively, unlike the howstuffworks image. It's possible 1st and 2nd are on their own axle, separate from the other gears.

The jamming is exactly this, in my opinion. As for the cause... a tooth or piece of a tooth might have chipped off of a gear and jammed the fork, part of that ball/plunger/spring assembly might have failed (manufacturing defect like a casting void or crack), or something else that I've never heard of before.

 

[sontakke]

 

[sontakke]

As far as I can see from the diagrams, it is a two shaft transmission. A broken part inside would sound pretty bad. Both the mechanics said that they didn't hear anything bad. They just looked at the linkage and did not notice anything abnormal there.

The problem is even reputable transmission shops balk at opening and finding what is wrong with the transmission, assuming they came to conclusion that it is indeed bad. They will suggest putting a used one at this mileage. Funny thing is, all the used ones have more miles than mine and costs huge money.

 

[JCH13]

Hrm, looks like a broken shaft is unlikely to cause your symptoms given how the car's transmission is setup.

 

[JCH13]

As far as I can see from the diagrams, it is a two shaft transmission. A broken part inside would sound pretty bad. Both the mechanics said that they didn't hear anything bad. They just looked at the linkage and did not notice anything abnormal there.

The problem is even reputable transmission shops balk at opening and finding what is wrong with the transmission, assuming they came to conclusion that it is indeed bad. They will suggest putting a used one at this mileage. Funny thing is, all the used ones have more miles than mine and costs huge money.

A transmission shop local to me will do rebuilds for $1k-$2k generally, I don't know if that includes removal/installation of the transmission though. If it came to it, I would prefer a rebuilt transmission over installing a used transmission.

 

[sontakke]

The only possible and simple explanation making sense is that for whatever the reason, the "pull shift lever towards driver" motion is not fully reaching to the transmission i.e. transmission "thinks" driver is trying to put the shift lever in to both 1st&3rd and that action is explicitly blocked by the check ball mechanism.

The only way to condemn the transmission to observe the yoke (15) in the shift control component and see if all the shift lever motions are transferred to it correctly. Even better would be to disconnect the shift control rod and move that yoke using big vice grip. Neither mechanic would confirm that they did that :-(

 

[phucheneh]

Recall this very specific symptom from OP's son: "When he tries to select 1st or 2nd, it is as if he is hitting a metal wall. He can hear something blocking the shift stick when he tries to move the lever to 1st or 2nd gear." A broken or lose shift linkage will generally feel dead/empty or simply won't put the car into gear. I find it highly unlikely that there is this 'hitting a metal wall' sensation in the shifter, for two gears only, and the problem is the shifter linkage.

If the selector lever is stuck inbetween positions, he will most assuredly not be able to push it into gear. Think about taking a manual shifter, putting the shift knob right between 1-2 and 3-4, and trying to push or pull it either way. It's not going to go anywhere.

You're thinking of a problem with play in the other rod, which would allow you to push/pull the lever freely without engaging the gear.

As for why it would take out 1-2 and not 5-R...I honestly can't say. I just know that I've seen enough weird shit to not consider that at all outside the realm of possibility.

And like I said, I'm not saying I KNOW it's the linkage, or it HAS to be the linkage. I'm just saying that it doesn't sound like anyone is taking the most basic of steps that can be used to both rule out the easy/cheap fix AND know for certain that it is an internal trans problem.

 

[sontakke]

what would be your suggestion to hundred percent ascertain than it is an internal trans problem? also after looking at the diagram, can you come with an explanation which will back up the internal fault for the symptoms given? There is a tiny spring #5 shown on the gear components diagram on the synchronizer hub and if that is damaged, that can be cause of the "will not shift" according the service manual. It does seem unlikely to get it damaged suddenly out of blue.

 

[LTC8K6]

Has anyone tried filling it with fluid since one shop said it was low?

 

[sontakke]

The first guy has claimed to have added fluid. he did show the left over bottle to my son, so we can assume it was done. I never asked to check the clutch because if it can go in the other gears, I would think clutch can not be the culprit.

 

[sontakke]

guys who have dropped transmission; can you tell me how much effort is needed to shift using a vice grip on the linkage yoke right at the transmission?

 

[phucheneh]

what would be your suggestion to hundred percent ascertain than it is an internal trans problem? also after looking at the diagram, can you come with an explanation which will back up the internal fault for the symptoms given? There is a tiny spring #5 shown on the gear components diagram on the synchronizer hub and if that is damaged, that can be cause of the "will not shift" according the service manual. It does seem unlikely to get it damaged suddenly out of blue.

guys who have dropped transmission; can you tell me how much effort is needed to shift using a vice grip on the linkage yoke right at the transmission?

I'm assuming you now know the answer to the question in first post- like I've said, try and move the levers by hand at the trans.

I'm not positive what the levers look like on that trans. I was trying to discern if they're in the picture above, but I'm having a hard time telling if that stuff towards the rear is internal or external. It looks like that picture is all internal, but those exploded diagrams can be kinda hard to analyze without an 'assembled' view.

Usually, though, they're steel brackets that are at least maybe 2-3" long...the shorter they are, the less the force multiplication.

I've always moved them by hand. The one that is mounted to a shaft pointing toward the rear of the car (or otherwise in line with the vehicle- bracket moves side to side) is the lever that controls which shift fork you'll be moving. A stiff push with the palm of your hand should move the bracket over a notch. It should move between three different detent positions. It will kind of 'click' into place; should not move loosely.

The other lever is the opposite (shaft goes side to side, bracket on it move forward/back) and should have a neutral position, and then move equal amounts forward and back to shift between the two gears that share a fork.

Basically, I would: put the shifter in neutral. Disconnect the linkage from the sideways lever. Move lever all the way to one side. See if shifter (leave it straight up, since you're controlling the side movement seperately) moves forward and back and feels like it is engaging gears. Move sideways lever to the opposite side (two clicks). Check shifter movement again.

If the lever you're moving by hand will not go into one of the positions, there is an issue relating to the selector shafts/arms/ect inside the trans. Could be a very simple fix once the trans is opened up (...but the trans will have to be removed and at least partially disassembled). If the aforementioned lever hits all three positions, but you cannot move the shifter forward or back in one of them, there is an issue with the 1-2 fork or synchro.

If, OTOH, everything works fine during this test, it's gotta be a linkage problem.

You should not need vicegrips to move the lever in question. If you do feel the need to use vicegrips or pliars, BE GENTLE and double check that the other lever is in the neutral position.

 

[sontakke]

Looking at the figure 2.3 and 3.15b from the following makes me believe that the transmission end only moves back and forth and twists and NOT go sideways.

 

[phucheneh]

That's possible; I'm just used to seeing a setup with two seperate levers. Either way, it's a means to an end. One action is going to select the fork, the other is going to move it into position.

 

[sontakke]

if you believe broken axle clip was left in the transmission when the axle was replaced, can that explain this type of locking?

 

[JCH13]

if you believe broken axle clip was left in the transmission when the axle was replaced, can that explain this type of locking?

A loose piece of metal could cause a lot of issues, including jamming the shifter. I would be a little surprised if it wasn't caught by the magnet trap in the drain plug, but if you have a known piece of metal inside the transmission... well... that could explain a lot.

 

[phucheneh]

It depends on how the trans is made. Nissan (...so far as I know) has always shared fluid between the differential and actual 'transmission' section, but depending on the case design, I don't know if that piece would be likely to make its way forward to the pump. It would be more likely to damage, say, the spider gears in the diff, but that would have happened immediately after the axle change. The longer something has sat in there without causing a problem, I would say the less likely it is to ever cause a problem.

It would be one hell of a shot for that c clip to get slung into a synchro, too. More likely to get caught between some spinning gears and break some teeth. But it's not outside the realm of possibility.

My incorrect advice about the setup of the control shafts/levers on the outside of the trans aside...that still needs to be checked. As I said, whatever the setup, the theory is the same. I just can't tell from those pictures exactly what is going on, so I can't give specific instructions. Unfortunately, that thing is a little more complex that your typical cable setup, which usually just means removing a couple clips to get the cables off. And it doesn't look like any solid linkages I've dealt with. But if you just remove everything and play with it a little a little bit, you should figure it out. Again, just be fairly gentle with it.

I mean, there are really only two alternatives here- one, the shift linkage is causing the issue, or two, something inside the trans is causing it. Option two is going to mean trans removal, and them either disassembly/repair or replacement.

edit: as usual, after I post, I see what's going on...that thing is actually rather simple. The rods aren't working indepenently...the one with the bushing is really doing everything, with the other rod just adding stability so everything articulates correctly. It's basically the same as what I described before, just with both motions on the same shaft- Push the yoke in to shift one way, pull out to shift the other. So find neutral, then try rotating the yoke all the way to the left (driver's side) to find the 1-2 position, and see if you can still move the yoke in and out.

 

[sontakke]

Big story but three months and couple thousands mile ago, mechanic had a hell of a time replacing the axle seal while we found his previous axle replacement had resulted in leak. He had to struggle for an hour before axle came out and put the new seal in it. Well that too was leaking, so he went to change the seal again. This time he was struggling to get the axle out for four hours and it still did not come out. He then removed the other axle and tapped it through the differential and knocked the axle out. It got badly mangled and I noticed that it only had part of the circlip when it came out. I looked all over the floor. "Don't worry; even if it is in there those hardened gears will shred it; besides we can't open the transmission to look for it!". He put the new axle in on his dime. The new axle seal is still leaking. I have been going to this guy for last twelve years. He is good and he does work with me. May be I should have been adamant and forced a full flush on the transmission but was not even sure if the missing broken clip piece would come through the plug hole.

Obviously, because I was there under the car with him, I know this. If I had just dropped off the car in the morning and picked it up I would have never even knew about this incident.

 

[phucheneh]

That's your good mechanic?

Either he can't tap a seal in properly, or there's something up with the axle that's shredding the seal. Or the associated bearing, but you'd probably be hearing that.

Or maybe a loose/overly-expanded c clip was what was tearing it when he installed and removed the axle...my question would be how did it get like that, and why is there still a problem after the clip was replaced.

It kind of sounds like he may have already replaced the clip once, and it being stretched out too much (or not even the right clip) caused the removal difficulties...then it came off inside the trans, and he replaced it again without learning his lesson.

 

[sontakke]

Sequence of events (same mechanic):-
Dec 2011 Replaced driver side axle
June 2012 At the oil change, I notice leak and determined it was coming from the new axle
June 2012 I buy new seal and ask him to replace - 1hr of banging to get the axle out
July 2012 New seal is leaking
July 2012 Decided to replace it yet again. Now 4 hours of banging but axle is still not coming out; removes the other axle and pushes it out from there. when the axle came out, it no longer has the complete c-clip. it is mangled and half of it is missing. If it is not on the floor, where is it?? when I asked him where is he going to find the new clip, he told me he will be replacing the axle. He orders new axle which comes with the new clip and installs along with new seal. His day was ruined and so was mine.
Jul2012 It still leaks; Looking at Maximaforum, the worn carrier bearing can be culprit of the leak; I give up and just make a resolve to check the transmission oil at every oil change.
Oct 2012 shifter jams.

At this stage, it does seem like remnant of the c-clip found its way to jam the fork or the synchronizer hub.

My previous guess of being between the two planes does not hold true. I asked my brother to see if he can get similar blockage between 3th and 5th. He says it is buttery smooth and it always goes in to 3rd or the 5th and he can not find a point where it does not go in forward. He did think that distance between 1/2 and 3/4 plane was little less than 3/4 and 5/r plane in terms of the movement but he has not driven my car.

I am wondering if it is worth to tap the shifter back and forth and hope to unjam it. Assuming it jammed when trying to put it 1st, tap it words 2nd and see if it budges little bit. then tap towards 1st and repeat the cycle. Obviously, I don't want it jammed in 2nd or 1st! At least now the car is (barely) drivable

 

[sontakke]

The verdict:- yes, it is jammed inside; used transmission for that car is outrageously expensive about $2500 for to put another used transmission and new clutch; the whole car is not worth even that much :-(

 

[phucheneh]

I can't imagine that trans having a R&R time of more than 10 hours.

They want 1500+ for a USED tranny? I wouldn't expect a new one, from the dealer, no less, to cost much if any more than that.