I just bought a cobbled together '82 Camaro that has a carbureted 350 engine and a TH350 of unknown lineage in it. Evrything on this car has been taken apart and put back together with something different, chrome plated or 'performance', and maladjusted without fail. I am getting things sorted out one by one, but now I came upon something I need some advice on.
The shift detents were in all the wrong places. I took the console out to discover that the shifter had been cobbled (I mean pieces welded in & such). I figured, OK, now I can sort this out. So I straightened everything the best I could. There is some adjustment available at the shift cable attach point at the transmission (now I wonder if they machined that in themselves, to try to fix what they screwed up). I set the thing up so that the neutral detent inside the trans lines up with the neutral lock in the shifter, it had been way out of adjustment.
To my surprise, the thing still wasn't proper. Several more adjustment attempts, and I arrived where I have it now, temporarily until I can fix it right. That is, I needed the neutral lock in the shifter to correspond with neutral in the trans, so as not to accidentally get reverse, and I need park to work. I got that to happen, but everything is approximately one detent removed from its proper function.
The problem is, that the detents inside the transmission (not at the shifter, I have verified this with the shifter disconnected), do not properly line up with the functions on the valve. In order to get normal operation in any of the forward gears, the thing has to be sitting up on top of a detent. The drive detent (which I believe is really supposed to be the neutral detent) puts it between second gear and drive, but not far enough to lock the band in second (doesn't upshift into third or lock into second). It has to be pushed forward some to get proper Drive behavior. Proper second gear sits on top of the next detent. And the next detent gets first gear. The parking pawl doesn't engage until the shifter is pushed well past the park detent.
Never having been inside one of these, and not wanting to disassemble it without knowing what I am doing, I hit the books. My thought was, obviously, that the linkage to the valve must be messed up somehow in the transmission. OK, so when I look at the pictures, there is the manual shaft, and an S-link that hooks it to the manual valve, and a rod going back to the parking pawl assembly. So far, I can understand. Attached to the manual shaft is a piece of sheet metal with cogs on it. When I saw this, I thought, well this must be it, these cogs must be what make up the detents in the manual shaft rotational travel, and someone screwed with it and got it messed up somehow. But, as I read further in the assembly manual, here they describe putting in a 'detent rod, spring, and ball', the picture shows it going into the valve body right in line with the manual valve. Well, I've been around enough pneumatic and hydraulic stuff in my work life to know that the easiest way to put a detent into a linear travel on a rod sliding in a bore, is to machine a land into the rod, and push a spring loaded ball in at a 90 degree angle to it, so that it snaps into place, precisely locating the rod while giving a positive feel to the location. So now I'm thinking, if that's how they get the detents in the manual valve spool, then what the heck is that cogged part on the actuating shaft for?
I need someone who has had one of these apart to explain it to me, I can't find a book anywhere yet that tells how that part works. If one of the previous owners got in there and mucked it up, I can probably fix it (they weren't smart enough to do too much real damage to everything else they 'fixed'). I just need to know whether that cogged part gives the detents, or whether a spring loaded ball clicking into relief areas on the spool gives the detents. If it is the latter, I suppose the valve body is screwed (could they do this by screwing up a shift kit installation?). I can probably scrape up another valve body and put it in there if I have to. The trans seems otherwise OK, as in no slipping and fluid smells OK, and of course I haven't burned it up yet, so if I can fix it to run until I get an overdrive transmission, that would be nice.
I've read at length how this manual valve operates. So I figure if there is a spring loaded ball sitting in a land to locate it, then that's all there is to it, it's located, and if the trans doesn't behave right, then something is screwed with either the spool or the passages in the valve body. I'm hoping to hear that the detents are derived from the cogged wheel, and either they bent the S link or mis-located the cogged wheel, because I figure I could fix that pretty easily. Maybe they bent it up internally by forcing it with the wrong shifter?
I have read a good deal of this forum and I respect you transmission gurus a lot. I hope you get the time to read this and lend me the benefit of your experience. Thanks!
PS. Yes, I will replace the shifter, but it does function for now.
The shift detents were in all the wrong places. I took the console out to discover that the shifter had been cobbled (I mean pieces welded in & such). I figured, OK, now I can sort this out. So I straightened everything the best I could. There is some adjustment available at the shift cable attach point at the transmission (now I wonder if they machined that in themselves, to try to fix what they screwed up). I set the thing up so that the neutral detent inside the trans lines up with the neutral lock in the shifter, it had been way out of adjustment.
To my surprise, the thing still wasn't proper. Several more adjustment attempts, and I arrived where I have it now, temporarily until I can fix it right. That is, I needed the neutral lock in the shifter to correspond with neutral in the trans, so as not to accidentally get reverse, and I need park to work. I got that to happen, but everything is approximately one detent removed from its proper function.
The problem is, that the detents inside the transmission (not at the shifter, I have verified this with the shifter disconnected), do not properly line up with the functions on the valve. In order to get normal operation in any of the forward gears, the thing has to be sitting up on top of a detent. The drive detent (which I believe is really supposed to be the neutral detent) puts it between second gear and drive, but not far enough to lock the band in second (doesn't upshift into third or lock into second). It has to be pushed forward some to get proper Drive behavior. Proper second gear sits on top of the next detent. And the next detent gets first gear. The parking pawl doesn't engage until the shifter is pushed well past the park detent.
Never having been inside one of these, and not wanting to disassemble it without knowing what I am doing, I hit the books. My thought was, obviously, that the linkage to the valve must be messed up somehow in the transmission. OK, so when I look at the pictures, there is the manual shaft, and an S-link that hooks it to the manual valve, and a rod going back to the parking pawl assembly. So far, I can understand. Attached to the manual shaft is a piece of sheet metal with cogs on it. When I saw this, I thought, well this must be it, these cogs must be what make up the detents in the manual shaft rotational travel, and someone screwed with it and got it messed up somehow. But, as I read further in the assembly manual, here they describe putting in a 'detent rod, spring, and ball', the picture shows it going into the valve body right in line with the manual valve. Well, I've been around enough pneumatic and hydraulic stuff in my work life to know that the easiest way to put a detent into a linear travel on a rod sliding in a bore, is to machine a land into the rod, and push a spring loaded ball in at a 90 degree angle to it, so that it snaps into place, precisely locating the rod while giving a positive feel to the location. So now I'm thinking, if that's how they get the detents in the manual valve spool, then what the heck is that cogged part on the actuating shaft for?
I need someone who has had one of these apart to explain it to me, I can't find a book anywhere yet that tells how that part works. If one of the previous owners got in there and mucked it up, I can probably fix it (they weren't smart enough to do too much real damage to everything else they 'fixed'). I just need to know whether that cogged part gives the detents, or whether a spring loaded ball clicking into relief areas on the spool gives the detents. If it is the latter, I suppose the valve body is screwed (could they do this by screwing up a shift kit installation?). I can probably scrape up another valve body and put it in there if I have to. The trans seems otherwise OK, as in no slipping and fluid smells OK, and of course I haven't burned it up yet, so if I can fix it to run until I get an overdrive transmission, that would be nice.
I've read at length how this manual valve operates. So I figure if there is a spring loaded ball sitting in a land to locate it, then that's all there is to it, it's located, and if the trans doesn't behave right, then something is screwed with either the spool or the passages in the valve body. I'm hoping to hear that the detents are derived from the cogged wheel, and either they bent the S link or mis-located the cogged wheel, because I figure I could fix that pretty easily. Maybe they bent it up internally by forcing it with the wrong shifter?
I have read a good deal of this forum and I respect you transmission gurus a lot. I hope you get the time to read this and lend me the benefit of your experience. Thanks!
PS. Yes, I will replace the shifter, but it does function for now.