Truck won't roll in reverse

[team39763]

I was trying to push my truck in reverse a few days ago, and it won't go.  I put the shifter in N,D,3,2,1 and it still wont' go.  The brakes aren't locked up because it still rolls forward.  The only thing that I did to the truck was jack up the truck from the differntial so I could install a new torque converter.  I had just rolled the truck backwards and forward a few hours before that.  Just a few minutes ago, I jacked up the rear and spun a tire to see what it would do.  It spun forward while the other went backwards(I thought posi's rolled the tires in the same direction).  But when I tried to roll it quickly, it would slam to a stop.  Did I ruin the differential by lifting it from the pumpkin?  I noticed the driveshaft doesn't turn when I spin the wheels- is it supposed to?  The torque converter isn't bolted to the flexplate yet(I need new bolts).  What could I have done to cause this.  Thanks.

[VileZambonie]

Posi will not turn opposite while jacked up. You either have an open differential or a problem if you are saying it's a posi. Pull the drums and check the brakes. Pop the meatball cover off and take a peak

[Captkaos]

what year truck?  Gov-loc rearends will act that way, or you have an open diff.  Only true way to tell if you have a limited slip is to pull the cover.
You can't ruin it by lifting at the pumpkin.  Does the wheels spin when you turn the driveshaft?
In an open diff, you can spin one wheel and it won't spin the driveshaft, hence open diff.

[Toolmaster]

Disconnect the drive shaft at the rear diff.
Check to see if the trans will turn by hand, check the pinion yoke and see if it will turn.
Be sure to use Jack stands and lift the rear end off the ground.
Let us know what you find.   

[team39763]

The truck is an 82.  The previous owner said he put a posi from another car or truck.  I've seen it lay down two nice black strips several times. I'll pull the cover in the when in a couple hours and see if anything looks out of place and also do the driveshaft and pinion yoke check.

[team39763]

Ok, I pulled the driveshaft.  The yoke seems to turn both directions freely.  It seems like I have a limited slip unit in there since one tire turns a few rotations then the other kicks in the same direction.  When I lifted the rear, I could turn the driveshaft to make the wheels go forward, but it wouldn't go the opposite direction.  So does that mean a trans problem?

[Lt.Del]

you won't hurt the differential by jacking the truck up under the pumpkin.  i do it all the time. 

[Captkaos]

When I lifted the rear, I could turn the driveshaft to make the wheels go forward, but it wouldn't go the opposite direction.  So does that mean a trans problem?

It sounds like you had the transmission in drive and not in neutral if you can't turn it in both directions.

[team39763]

I'll go check again in the morning.  I'm gonna feel stupid if that's all it was.  But I'm pretty sure I had it in neutral(it's hard to tell with this ratchet shifter). 

[team39763]

I got under the truck to check the converter and it won't move/rotate at all.  So I'm guessing I installed it wrong.  But I did it just like I was told to - should feel 3 seperate engagements while rotating it on.  I'm gonna pull the motor and try again. 

[Captkaos]

Stupid question, but is it bolted to the flywheel?
When installing it you need to push it on the pump input and spin it slowly while pushing until it "drops" and engages.

[VileZambonie]

So basically you replaced your torque converter and now the truck won't move? You unbolted the torque converter from the flexplate and it won't spin? If that's the case you probably broke your pump. You 1st engage the input shaft into the impeller, then the stator onto the stator support and then the hub into the oil pump lugs. I wouldn't pull the engine I'd pull the trans and replace your pump drive gear or at least carefully inspect it.

[team39763]

No, I didn't bolt it to the flywheel because I couldn't get it to turn to line up the holes.  I installed it just like what was said - let it drop in and engage while rotating it slowly.  Would lack of trans fluid make it hard to turn?  It had some in it, but I don't know how much.
   Do you really think I broke something this soon?  It hasn't moved but maybe 3 or 4 feet - thats 2 feet forward with driveshaft in and 2 feet in reverse with no driveshaft.  I'm hoping that it's just not seated right. 

[VileZambonie]

if you bolted the trans to the engine block and the converter won't spin you are not engaged on the lugs on the trans oil pump but rather up against it. As you tighten the engine to the transmission you are squashing the converter hub into the pump. The pump drive gear is very weak and this will most likely cause a fracture. You migh get lucky and be able to just reposition it and put it back in but if not it's going to grenade and take out your converter with it. Loosen the bellhousing bolts and see if you can get it to engage the pump.

[team39763]

Well, I hope it's not messed up.  Will I visually see the damage if it is?  With my luck, it probably is broken.  If it is broke, I'm gonna toss the trans and go look for a th400.