94 b3000 won't move

[Johaco]

Hi, I'm having an issue and at a loss where to even begin.

I have 1994 b3000 manual 4wd. It's got ~80k miles on it. New clutch, oil, plugs, ignition coil, and wires about 2k ago. The only previously known issue is that the fuse for the turn signals blows regularly. Just trying to make sure I give as much info as possible.

Driving today, I began making making a left hand turn out of an intersection and it started moving, then quickly lunged to a stop. It would rev in every gear a seemed like it had resistance (kinda like a parking brake still on, but I couldn't overpower it), but wouldn't move forward. I tried to put it into 4wd and it still would not move. Finally tried reverse. Backed up a foot no problem. Went into first. It went forward a foot then seemed to lock up again. So I reversed carefully about 10 feet, went forward, and everything was fine. Carefully and slowly drove it the half mile home. Parked it. Tried forward and reverse and all seems to work. I'm stumped. I'm happy to research the actual repairs, but I just don't even know where to start. Failing drum brake? Parking brake cable? Transmission? I would love any suggestion as to where to begin as this is a confusing one for me. Thanks!

 

[Bgunner]

Could be a few things. First some more info would help us narrow some things down.

Was there any grinding noises when it would not move? could point to bad gear in the transmission. Doubtful its a differential since locking in the 4WD didn't make you move.

If you have manual hubs did you lock them in? if no then this adds the possibility of bad gears in the differential.

Please try, At home, moving a foot forward at a time stopping each time to check to see if there is a gear broken. Basically checking for a broken tooth in a gear. This will not tell what gear is broken but the first stage in finding a broken gear.

When going up a hill does the engine now rev but speed does not increase? basically checking for the clutch slipping.

 

[Johaco]

Hi, thanks for the super quick response!

There's no grinding at any point. Everything sounds normal. It also didn't rev extra hard like if you gas it out of gear.

They are manual hubs, and I did hop out and twist them to engage them.

I had one very steep hill up and one down on the way home and it acted perfectly normal, powerwise and otherwise.

I just tried stepping it a foot at a time to the end of the street and back, with no issues.

Basically, it seems normal now. I can't get it to replicate any problems. But obviously I want to fix it rather than have it happen at speed later.

I did forget in my original post - I tried to push it out of the intersection and it wouldn't move. So I assumed brakes. But I have never seem backing up fix that. Plus it fixing and then recatching in the same spot after a small movement didn't seem right.

 

[RonD]

E-brakes don't hold very well in reverse, but do hold in forward direction
i.e. you can back out of a parking space with e-brake on but can't move forward

But doesn't really read like e-brake issue
Can't say I recognize anything about the description of symptoms

 

[Bgunner]

Without being able to replicate the issue it will be hard to pinpoint the issue. Only going by your description it points towards a clutch issue but the exact issue is still a mystery due to not being able to replicate the problem again. IF it happens again please report back using the same thread here and we will try to help more with the data you collected then.


EDIT: Its a long shot but did you not put it all the way in gear? its the last thing I can think of without being able to replicate it.

 

[Johaco]

It was definitely going all the way into gear, and I tried it in every gear. They seemed to engage, as it didn't shoot the rpms up like it would've out of gear when I tried to gun it to get it moving. But it wouldn't move an inch. It would rock slightly, but not budge.

Thanks for your help. And if I have any more symptoms, I'll definitely report back. Or if I somehow track down an obvious cause, just for future reference.

 

[Johaco]

The e-brake thing makes sense... and almost fits, too! This is the issue I'm running into. It (with my limited experience and knowledge) feels almost like it falls between problems I have seen in the past.

 

[Bgunner]

With an e-brake sticking and being a standard shift (manual trans) it would stall out with the clutch let out. This is why to me it points to a clutch issue. Clutch isn't fully engaging or is slipping. If the RPM's are not sky rocketing, like they would in neutral, then the clutch is still engaging but is slipping. Or at least that is how you have described the issue leads me to think.

 

[Johaco]

Ah, gotcha.

I was giving it gas as I let up on the clutch, otherwise it'd absolutely have stalled.

Also, during the initial event, it didn't start going and then lose power and coast to a stop, but rather, I started to pull through the intersection and it lurched to a very sudden stop as though I'd hit a wall and I couldn't get it to move after that. I could carefully balance the clutch and gas to try each gear in the hope that I could crawl forward out of traffic in a higher gear and resolve the issue in a safer setting, but zero luck (until I tried reverse).

I'm super sorry for not making that more clear. I think I was kind of still fight or flight mode when I posted and probably not the clearest I could've been, but I very appreciate your help with figuring this out!

 

[Bgunner]

Ah, gotcha.

I was giving it gas as I let up on the clutch, otherwise it'd absolutely have stalled.

Also, during the initial event, it didn't start going and then lose power and coast to a stop, but rather, I started to pull through the intersection and it lurched to a very sudden stop as though I'd hit a wall and I couldn't get it to move after that. I could carefully balance the clutch and gas to try each gear in the hope that I could crawl forward out of traffic in a higher gear and resolve the issue in a safer setting, but zero luck (until I tried reverse).

I'm super sorry for not making that more clear. I think I was kind of still fight or flight mode when I posted and probably not the clearest I could've been, but I very appreciate your help with figuring this out!

I may have just missed you mentioning it also.

In this case, the E-brake/rear brakes would fit the issue. It seems weird that all of a sudden the parking brake would cause issues while driving so if it were me I'd pull the rear drums and check the brakes. At the same time I would also make sure the Parking brake cables worked smoothly and freely and the front wheels spin freely. A sudden lurch to a stop, So you were on your brakes as you came to the intersection and it lurched, came to a unexpected sudden stop?

If so this could also be a sticking caliper in the front. Does it pull to one side or the other when stopping? Or even just driving down the road now?

As a vehicle slows it takes less brake pressure to stop the vehicle so we actually lift off the brake peddle as we slow down, If there is a sticky brake as you let off it would not release causing the lurch effect you mentioned.

 

[Johaco]

So that's probably the most frustrating thing. I had just let up on the brakes and they'd released.

I was in a turn lane at an intersection, waiting to turn. I came to a complete stop. All normal. Traffic let up and I started to go. Foot was completely off the brake and giving gas and the truck started moving forward. Normal at first. The truck went maybe a foot or two perfectly normally. Then it just stopped moving. Rocked forward and back. It didn't feel like it went out of gear. It felt more like I'd hit a low wall. I literally got out and looked under the truck to see if something had wrapped up underneath.

The truck doesn't pull to either side though. And I have tried a couple of times to stop/go a foot at a time and see if it catches. I've also done a few laps through the neighborhood to see if it happens again, but so far no luck (or I guess technically it's really frustrating good luck?) replicating the problem. Checked brake and trans fluids to be safe and they're both good.

I know I WANT it to be brakes (as miserable as those rears will probably be), but the whole reverse undoing it thing is baffling to me if that's the case. I'm very very far from an expert though.

 

[Bgunner]

I know I WANT it to be brakes (as miserable as those rears will probably be), but the whole reverse undoing it thing is baffling to me if that's the case. I'm very very far from an expert though.

Have you done any work in the axles, even differential fluid change?

Nothing I can think of fits the exact scenario without making major assumptions. Here is a theory for you to look into/consider, Something is loose in the differentials or trans and got stuck in the gears causing them not to move forward but when backed up the blockage fell out and allowed for the free movement of the gears again. It fits with what is described but is a guess with hopes of pointing you in the correct direction.

The reason for the question about the axles is if you didn't snug up the lock bolt, sometimes requiring a drop of blue lock tight, for the pin in the spider gears they can back out on there own. It is also possible that a chunk of shim is getting thrown around in the gears and just happened to get stuck then. Keep in mind this is a guess but fits with your situation. I am not a Master Mechanic myself but have formal training and worked in the business for years so take my advice for what it is worth.... It's free and could be wrong.

Brakes that release when backing up sounds like E-Brake but wouldn't just randomly stick out of the blue without being used immediately before hand. Not pulling to one side or the other says both front calipers are working and not sticking. To me this leaves something in the gears causing the issue, and if it happens while rolling can grenade the affected gears. If the lock bolt falls out the pin falls out and so do the spider gears causing gear breakage so this is most likely not the case but a thin piece of metal or a chunk of a broken gear can cause this issue in the differentials. I am less familiar with the transmissions in these things than the diffs so maybe someone else has a suggestion on the trans gears getting something in them.

Hope this info helps point you in the right direction.