Input/output won't turn in 1st,2nd,5th and rev

[HOGIE]

Pulled this trans out of a 85 2wd 720. Truck was wreck, front end damage.

 

I can easily shift in and out of all gears but the input/output will not turn in 1st, 2nd, 5th and rev. Although it will turn freely in 3rd. 4th gear turns but there is some resistance( sounds like rubbing not grinding)

 

I'll openly state that I've never taken apart a transmission before, so I'm a dumb ass noob. Got it. Check. I've done 'some' searching and found threads about people who's trans are stuck in gear but like I said the shifter moves freely between gears. Could a similar issue with the shifter rods cause this problem?

 

I don't have a service manual for this year model so I'm asking here, what's the first step to diagnosing this issue and does this sound like something that can be salvaged relatively easy?

 

I didnt take a picture of the greasy ass trans but I will when I get into it.

[Rhino13]

Also turns free in neutral

[datzenmike]

If in neutral and you turn the input.... does the output turn????

[Rhino13]

Yes it was turning

[datzenmike]

Transmission may be stuck in 3rd. All gears will lock. Forth should also but....

[HOGIE]

Would a crash, front impact, cause this to happen?

[HOGIE]

Transmission may be stuck in 3rd. All gears will lock. Forth should also but....

Going to check the shift rods hopefully that us just the issue. Pry them back into place like this.

 

Photo stolen from another thread

 

Mike do you have pics of what the correct orientations? And what it would look like stuck in 3rd?

[DanielC]

When the transmission is in neutral, the gaps in the shift rods should line up.  This is so the finger that goes in the slots can moves side to side, and choose the 1-2, the 3-4, or the 5-reverse shift rod.

 

There is are two oblong balls between the shift rods.  It can move into notches in each of the three shift rods.  The oblong ball must move into the notch on one shift rod, to allow the shift rod next to it to move.  This way, you cannot put the transmission into 1st, and 3rd at the same time, or 3rd and 5th at the same time.  Same idea, you cannot put the transmission into 2nd, and 4th, or 4th and reverse.

 

However, if the 3-4 shift rod is in neutral, it is possible for the 1-2 shift rod to go into a gear, and the 5-reverse rod to go into a gear.

[Stoffregen Motorsports]

A broken roll pin can cause this problem and it can be hard to detect because the shift pawls can line up and appear that everything is fine.

[datzenmike]

Something in the 3/4 shift rod?

 

Lets say it's stuck in 3rd. All other gears 1,2,5, R will jam. (you can't be in two gears at the same time and have motion)  But 4th is on the same shift rod so if you shove it towards 4th it may disengage 3rd enough to turn the input. As soon as you pull out of 4th it returns to 3rd and is jammed. Shift fork is likely not held on the shift rod by the roll pin.... at least not properly. 

 

 

A broken roll pin can cause this problem and it can be hard to detect because the shift pawls can line up and appear that everything is fine.

 

Very very possibly. Or the shifter end of the shift rods, they have roll pins also.

[Draker]

Crack that bitch open and start snooping around. You'll find it pretty quick I think.

[datzenmike]

You only need to take the front case half off to get at this.
 


Bottom shift rod is first / second. You can see the rear most roll pin and the one on the shift fork at the front (right).

 

Next one up is third / forth and the shift fork is extreme right..

[KoHeartsGPA]

Interesting...mine has same issue...neutral turns and in gear it freezes up....still in my to do list to open her up, I'll keep an eye on this thread :)

[H5WAGON]

Just cracked one of mine open last night....The tail section first.

 

Getting a better view to fix another 5spd from my friend.

 

The pin holding the shifter rod came out and the fork is not aligned properly now.

[KoHeartsGPA]

Yikes!

[datzenmike]

Picture.

[H5WAGON]

What is the trick to getting the shift fork in the proper spot when putting it back together?

[KoHeartsGPA]

Pictures!

[H5WAGON]

This is what I found in one of my mystery trannies

 

Counter shaft is wasted....The bearing was pretty much gone. And some(one set)gears chewed up in the the bell housing section.

[H5WAGON]

This is the pin I was talking about.

 

This transmission has been rebuilt.....but then the pin came out and the shifter fork came out of place.

[KoHeartsGPA]

Ewwww sludge

[H5WAGON]

Looks like mine is in Reverse...so I probably need to take the rear section off and get it in to neutral to get the shift fork in properly.?

[H5WAGON]

This is the messed up trans....Red speedo gear. Fills on the left with 2 switches.

[docbainey]

Pull that mess out of the case so you can see the shift forks, More pics!

[datzenmike]

This is the pin I was talking about.

 

This transmission has been rebuilt.....but then the pin came out and the shifter fork came out of place.

 

That pin helps center the shifter part you can see in the picture with the 'ears'. Not the shift lever.... the part that hold the shifter. It's caller the striking rod guide and it can move side to side but not forward and back. The striking rod is the part that the shifter fits down into.