Transmission troubles

[justin 620]

Hello there, I'm having serious trouble with my trani.

I have a 79 620 with a 5 speed, and it's been acting up lately. Whenever I go in reverse, then try and go forward again, it physically doesn't do it. It shifts into 1st no problem, but when I try to go, it won't move.

 

It gets worse. Yesterday, I was coming up my driveway, and I stopped to close the gate and parked it in 1st. But when I got back in, it felt like it was stuck in 1st, the weird part is, when I stepped on the clutch, it didn't roll, at all. I honestly have no clue what could be wrong with it, I'm going to pull it out tomorrow I do believe, so I can look at it better, any idea or help would be greatly appreciated, pics even more, thank you all for your help.

[Pumpkn210]

I would check the fluid, if thats not it your gonna prolly have to pull it. Does the stick act all wierd and sloppy?

[I'm BLUE]

that sucks

 

bent shift fork possibly ?

[datzenmike]

Does this only do this after using reverse????

 

 

If YES.....

 

After using reverse, try shifting forward into 5th before shifting into 1st. This will move the 5th/rev shift fork and rod the maximum distance away from reverse and may be the ticket. This isn't a fix. It may get worse.

 

 

How is 5th gear? any problems up or down shifting into gear?

[ggzilla]

It could be the clutch slave cylinder. Don't pull the transmission until you check it.

 

the weird part is, when I stepped on the clutch, it didn't roll, at all

A bad transmission can't cause this problem. A bad clutch can.

[datzenmike]

the weird part is, when I stepped on the clutch, it didn't roll, at all.

 

 

 

It could be the clutch slave cylinder. Don't pull the transmission until you check it.

 

A bad transmission can't cause this problem. A bad clutch can.

 

I think it can. If it's not coming out of reverse and you put it into any other gear, the transmission is effectively locked. If you let out the clutch the engine can't turn it and will stall. Like wise the drive shaft can't turn either and truck cannot roll.

[justin 620]

I would check the fluid, if thats not it your gonna prolly have to pull it. Does the stick act all wierd and sloppy?

 

It was never a firm shift, but that's just the age and usage of it, I've driven worse and never had this problem. And the firmness didn't get any worse as this all started to happen.

 

And fyi to you all, I was already going to pull it to replace the rear main seal, so it had to come out anyways.

[justin 620]

I think it can. If it's not coming out of reverse and you put it into any other gear, the transmission is effectively locked. If you let out the clutch the engine can't turn it and will stall. Like wise the drive shaft can't turn either and truck cannot roll.

 

That's exactly what it feels like, when this all started i would just pop it into reverse for a sec, or just roll backwards, then i could move, but when I'm on a pretty steep hill, it wouldn't work. It feels like it is a gear lock of some sort, it's not soft or squishy like you would expect from a fluid problem, it's hard, and does not move.

 

And if this is the case, how would I go about fixing this? I know it'll be easier for you all to help when I have it out, but I'd like to get some idea on what to look for before hand...

[ggzilla]

If you let out the clutch the engine can't turn it and will stall.

 

yes, but if you engage the clutch (push the pedal down) it should roll -- even if the transmission is totally locked up.

[datzenmike]

I don't think so. If it was stuck in any one gear yes, the weight of the car could turn the drive shaft with the clutch disengaged. Two gears connected there would be a conflict as the input shaft can't be turned at two different speeds at the same time. Hard to explain. My '57 jammed in reverse one night. If I put into any other gear and let out the clutch the car would lift slightly in the middle but wouldn't move. In neutral it would back up if I let the clutch out. I drove it backwards 15 miles home. At night. In the rain. I had been drinking.

[datzenmike]

 

And if this is the case, how would I go about fixing this? I know it'll be easier for you all to help when I have it out, but I'd like to get some idea on what to look for before hand...

 

If coming out anyway might as well remove the tail stock and inspect the 5th/rev shift rod and fork. Perhaps shift in and out of reverse and see if it hangs up.

 

You want to look for something out of whack in this area....

 

[ggzilla]

Oh I see what you are saying. The back wheels won't turn if the transmission is locked up. Yes, understood. I should had a beer first.

[justin 620]

Well I got it out, but got decided against taking the thing apart, and now i regret it, cause the damn thing is bound up, again, and the clutch is making a nast clicking noise whenever I push the pedal in all the way, this thing is cursed! :frantics: