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TH350 Mystery

Discussion in 'Automatic Transmission' started by Raider L, Sep 1, 2020.

  1. Raider L

    Raider L Full Access Member

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    Truck Year:
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    Truck Model:
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    Engine Size:
    355
    SirRobyn0,

    No, I'm not here to take and give nothing back. It's due to my overall lack of computer knowledge that keeps me from being able to put stuff on this site. I just don't have any idea how to do anything. I don't even know how to make a CD are you kiddin'.
    To begin with I'm 71 years old, disabled and have had this truck since 1981. It used to be my old work truck and is in that group of year Chevy pickups that rusted out real bad over the rear wheels on the bed sides. It was a one owner who was some old man from Mena, Ark. I bought the truck from a gas station parked out front. I got a job as a aircraft welder and it was at this gas station near the airport one day. I paid sixteen hundred for it back in 1981. It wasn't until 1992 when i got disabled when I was working at a large manufacturing plant here in Shreveport that built some of the largest weldment for refinery towers. I was doing submerged arc welding there. I'm a certified pressure vessel welder, and aircraft welder. I'm qualified and certified in stick in all positions including mig in all positions, and tig in all positions. I'm experienced in welding most steels including stainless up to 347DL which is what is used to make aircraft exhaust systems. While at the airlines I was doing welding on 22 aircraft by myself for a large regional commuter airline but for only seven years and took all I had learned while trained as a aircraft mechanic and put that experience into my truck. In '92 when I got a settlement when I became disabled at this big plant I had all this money. I knew that it was going to be all the money I would ever have because I could never work again, and always wanted some kind of hot rod. Now I wish I had spent the money differently and built a real hot rod and just repaired the truck and put a crate motor in it and use the truck to tow the hot rod around. As it ended up I used what I had and restored the truck frame off doing most of the work by myself when I could except for the engine and paint and bodywork. A couple of guys I had met when I was working at the plant were street racers and they knew people who knew how to do the other stuff I couldn't do or didn't know how to do.
    The engine as we found out was a Z28 engine from the factory, the block, the crank was a nodular crank, and had "B" rods in it. They had stuck a couple of 882 EPA heads on it with a 2bbl. carb. It had 4 bolt mains which was the first thing we noticed because Chevy stopped putting four bolt mains in light duty pickups in '72 so we were already ahead of the game with what we found in the motor. My racer friend found me a pair of heads out of a 1970, 350 300 horse Z28 to compliment the rest of the Z28 engine I already had. Now I've got a '70's Z28 engine in the truck. I read that those heads had the best flow of any cast iron heads at the time they were made. They were made so you could do all the mods you wanted to do to them. No water jacket problems or anything. They were thick where they needed to be. We opened them up to 2.02", 1.60" valves with a three angle valve grind, put in the hardened exhaust seats three angle on them, silicone bronze guides, but I decided to keep the press in studs from the factory instead of machining them with screw in's. I gasket matched the intake myself and that's when I discovered that we forgot to check whether or not those old heads were square on the intake and exhaust ports. So just to save time since the difference wasn't that much, I had the intake angle milled so I could use a standard intake gasket. And that decision was made because I did not ever plan on racing this truck. It's got a stock trans. and a Richmond 3.50:1 rear gear. The truck is blue with a tan interior. I replaced all the factory gauges with Autometer gauges including fuel pressure so if the fuel pump goes out I'll know what is going on. See, I love airplanes since I was a kid with models hanging from my rooms ceiling and used all I learned working for the airlines and wanted the truck to look look a airplane inside. I even have a small Autometer tach in the engine compartment. Including a vacuum gauge, oil pressure gauge on the engine itself. I can do carb adjustments and ignition tuneups on the side of the road. I have a vacuum gauge in the cab as well along with a Autometer shift light, and a MSD timing control on a bracket I made off the dash. You can control the point when the coil fires from inside the cab with a dial that has 7 1/2 degrees retard and 7 1/2 degrees of advance. It's cool. People always used to ask what that was when I used to show the truck. It was in a bunch of car and truck shows back in the late '90's and never won a trophy less than second place, People didn't usually put all that kind of money into a old long bed. I ordered a set of Nascar wheels for it when one day I was over at a local dirt track shop looking for some bits and pieces for the truck. It's got a whole MSD ignition system on the engine but just the 6A not the 6AL with the rev limiter. I didn't plan on ever bumping up against the rev limit so I opted for the 6A instead.
    I'm disabled and I knew I would never have any money to be buying engines and blown engine parts. So I had to build an engine that would last as close to forever as could be built. I know it won't last forever but anything that needed replacing I knew how to do that. I changed cams on my own, I changed all the valve springs on my own, and I can do all that sort of stuff, but I don't have any of those friends anymore they all moved on with their lives and I have no one to help me do anything anymore. I'm certainly not complaining just it is what it is. I'm sure I don't know anything that would help anyone because I never did do car stuff like all you guys have done, my life was different from you all's. But it wasn't like I was oblivious to automotive stuff due to when I was in high school I did have a couple of friends who drag raced and watching them and asking questions learned things about the craft. You don't find yourself scrubbing around under cars when you get the image in your mind hearing the word "geek" the guy with black rimmed glasses with white tape on the corner holding an arm on. That guy.
    I doubt seriously I would know anything that could help anyone that ya'll would know ten things better. I've got a hot rod truck that's about it. I've never done this before and never knew anyone in my life that did this kind of thing before, and don't know anyone anymore who does do this sort of stuff anymore.
    If I did have anything to give I wouldn't be asking for help I'd be fixing the thing myself, I wouldn't need any help I'd be helping somebody else. So if anyone needs jhelp in how to weld some nickle alloy other than that i don't know enough to help anyone. Like everybody knows how to solder two wires together. Anyone can take a part off and put another part back on. That's about the limit of my experience. I have many years of industrial mechanics and use that to do everything I know how to do. I did have a company I formed based on designs I made for custom power steering and alternator brackets for small and big blocks that for years my products were advertised in "Chevy High Performance" and "Super Chevy" magazines back in the late '90's, there's that to. I've got some left over would ya'll like one? I was able to do this because I have a lot of design experience that I discovered I could do when I worked for the airlines. I could design anything like that sort of thing. But those days are gone. Now I just want to get the truck restored so when I go my family can drive it for whatever they need a truck for.
     
  2. Raider L

    Raider L Full Access Member

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    First Name:
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    Truck Year:
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    Truck Model:
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    Engine Size:
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    I'm a book worm. I've read hundreds of articles from hundreds of hot rod magazines. I even managed to save all the car and drag racing magazines from when I was in high school from the '60's. It's cool to see brand new car ads of 1967 GTO's. I somehow managed to keep them in new condition. I've read books and articles on everything you guys have had years of experience in actually doing. You've overhauled thousands of transmissions, I've never seen the inside of a trans- mission except in articles or on the internet. You've done the work, I've read about doing the work. You want to talk cam profiles, ramp speeds, let's talk cams. You want to talk head flow, let's talk head flow. It's because you've actually put heads on an engine and ran them and you know why one head is better than another one, Brodix, Dart, whatever, I've read books on heads and can talk heads. See the difference? You guys have done the hand work, I've read about how to do the hand work. I can sit around and listen to guys talk about stuff they've done ,and I love hearing about all that stuff and can converse with them, but all along I know they are talking about whatever because they actually did it, I'm able to talk to them because I read a bunch of articles on the subject that's it. I have nothing to add to the conversation because I have done the work and know what works and what doesn't. So if it's taking and not giving, I have next to nothing to give. Sorry. Do I have years of mechanical experience, yeah, decades. But is it in hot rodding? Nope. Can I take care of what I've got, properly? Yeah, I sure can. And do it the right way? Yeah.
    Uh oh. What happen to the print? Now it's in Italic. What did I do? Did I push a wrong key or what? Help me out guys. Is there something up on that tool bar I can push and get it back straight?
     
  3. idahovette

    idahovette Full Access Member

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    You're very long winded????
     
  4. gotyourgoat

    gotyourgoat Full Access Member

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    smokin' 305
    The small circled I button is the cause of the larger circled area with italics. Screenshot_20200913-192650_Firefox.jpg
     
  5. Raider L

    Raider L Full Access Member

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    gotyourgoat,

    Yeah, I clicked on that to turn it off but nothing happened. Now it's back like it was before. I didn't click on anything up there. I'm typing away on my keyboard and suddenly it's in italic. But now it's back. See? My daughter gave me one of her old cell phones so I could call her because she doesn't have a land line. We do at my home along with all the wifi stuff to, you know. If you think I'm terrible with computers you ought to see me on a cell phone, it's comical. But the phone she gave me doesn't make phone calls, I text her on it. If I want to call her I use a real telephone. She had to show me how to turn the cell phone on and how find her number on it. I'm telling you guys, with some stuff it's pitiful. I'm the typical technology clueless ol' guy. But then again 70 is the new 40. If it wasn't for my truck and PayPal all I'd have to do is watch the grass grow. I can't walk but about to the end of my driveway, and it takes me about an hour and a half to change my spark plugs. So I plan for a whole afternoon to do that job. It took me a week and a half to change out the intake gasket and get everything buttoned up again. That's 'cause I have so much trouble with my arms and back and legs.
    Some days it's pretty good though like when I was under the truck on my creeper putting in the tubular trans cross member, laying down I got a lot done each day. And since it had been awhile since I was under there I saw several things I wanted to replace and upgrade. I rebuilt the whole drive line with all new u-joints. I cleaned the shafts, long bed split shaft, and all painted with black semi-gloss. It looked great. Then I saw how the polyurethane bushings looked in my traction bars and decided to replace them. I've got a pair of Super Lift traction bars that have one end plate that repalces the leaf spring mounting plate with one with ears on it for one end of the bar. You know it's a round bar with eyelets on each end with poly bushings on each eyelet. The other mounting is bolted to the leaf spring hanger.
    My whole suspension is Energy Suspension polyurethane bumper to bumper. There is no rubber in my suspension even the dust boots are polyurethane and I found that that was a wise decision because they don't sag and crack like rubber and have kept my ball joints and tie rod ends clean and in serviceable condition. I'm going to get my whole front suspension overhauled and the frame straightened as soon as my steering column comes in I finally broke down and bought. That way the repair shop will be able to steer the truck in and out of the shop. It took me a long time, like years of saving to finally get the money and slowly buy all the bushings and what not.
     
  6. gotyourgoat

    gotyourgoat Full Access Member

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    The italics went away because the reply page/box resets after a post, actually I think it resets after enter is hit. You would have to select it again to turn it on. Bold, Italics, Underlined Red Big small. Courier font. Smileys:) And random :happy160:Graphics plus pictures, links and a lot more.

    A well appointed toolbar with more options than really needed but it is nice to have available.

    For someone who says they're terrible on a computer I have to say I appreciate your grammar. ;)

    Have you figured out how to post pictures?
     
  7. Rusty Nail

    Rusty Nail Whatever!

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    Lololo keepin it real. :waytogo:
     
    Ricko1966 and gotyourgoat like this.
  8. Matt69olds

    Matt69olds Full Access Member

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    I’m getting a little more comfy with computers, and I’m about half your age! I always joke that I need a ten year old kid to show me how to do some of the things a computer savvy person finds simple. Having said that, I learned something from this thread! I always wondered how people changed fonts in only part of the comment.
     
  9. Raider L

    Raider L Full Access Member

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    First Name:
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    Truck Year:
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    Truck Model:
    C10
    Engine Size:
    355
    Many years ago before I rebuilt my truck there was this really bad looseness in the column. So I pulled the column out and found that the "outter sleeve" was broken in half. I have no idea how it got like that, nothing had ever happened to the column, but no matter. I took the column completely apart to get that "sleeve" off and took it to the plant where I worked and tig'd it together. But it gave me an opportunity to put the column back together by the book. It's fairly complex especially those plastic ball bearings that are in there to keep the shift tube straight. They sit in a pair of grooves between the shift tube and the sleeve and you have to make sure they all don't slide up past the grooves. There's a a little "window" where you can see them for a moment as you are sliding the shift tube back up and that's the only time you have to make sure they're okay. Don't do this more than once. Make sure you get it right the first time. I did, but I imagined how those kind of things go when you try to do it over again and you end up having to do it three or four more times trying to keep those little suckers from coming out of the grooves.
    I'm getting a (new) steering column that should ship this Thursday and maybe I might get it either Sat, or Monday next week.
    But when I was putting the bearing support back together I noticed the "shift gate" was worn real bad. The "shift gate is the metal thing that has the cut out positions where the shift stick lays into as you move through the gears. Like a larger version of this very small piece of metal would be some racing shifters that have the places for the shift lever to go that are cut out and you move the shifter from cut out to cut out as you move through the gears. The "shift gate is a much smaller version of one of those. It's a place for the lever to go in the gear position referenced by the shift indicater, i.e. "Park, Reverse, etc..
    So I went to my local Chevy dealer and they couldn't get one. This was before the internet so they made a couple of phone calls and the local Oldsmobile dealer had one, not for the truck but I think for a La Sabre (correct spelling). Beautiful big ass car back in the '70's with a hood that looked like a mile long. So that may be part of when the trans. seems to be in neutral? It may actually be doing like manual transmissions, it's "slipping" out of gear. TRANS. GUYS! What are those teeth called inside the trans. housing next to the valve body assymbly just inside the housing where the shift linkage attaches to, "pawls", the half moon shaped plate thing that has a "tooth" for the shifter linkage to spring into as you shift into gear? The "shift gate" isn't lined up with those teeth and is allowing the shift linkage to slip off the "pawls". Isn't that correct? I was really paying attention the other day when I was driving and it felt just like that. And if you think about it what gear is the next up from Drive? Neutral!
     
  10. Matt69olds

    Matt69olds Full Access Member

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    The technical term is “rooster comb”.

    I can tell you for a fact that not all the column detent shifter plates are the same. Some have detents for 3 speed transmissions, 4 speed, others just have detents for park, reverse, neutral. If you can’t get the column shifter detents to line up with the transmission detents, either you have some serious slop in the linkage, or mismatched parts.


    You can do some serious damage really fast if the manual valve in the transmission isn’t in the correct position. If the valve isn’t fully in the drive position, you can have line pressure that’s suppose to be applying the clutches for the forward clutch bleeding off into the neutral position (technically a vent). Same thing for reverse.

    If you can’t get it adjusted, either install the right shifter gate, or grind off the detents for everything but park. Get a extra detent spring for the rooster comb, cut off the roller as close to the end of the detent spring as possible. Bolt both the modified detent spring and the one with the roller intact (modified goes on top of the original). That will give you an extra solid detent spring tension, you will definitely feel when the trans is in each gear.

    I use the double detent spring on guys who off road, helps prevent knocking the trans out of gear when the truck is bouncing around.
     
  11. Raider L

    Raider L Full Access Member

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    Matt69olds, Yes, exactly! That's right, "rooster comb". I remember that from reading this site I came across recently about this guy who is showing rebuilding the TH350. Since I believe there is a problem there that particular part of the photos seemed to stick in my mind. I guess I must have been thinking about this "slipping out of gear" thing my trans seems to have, those photos stuck in my head. So where did I hear "pawls"? Is that something in a manual trans.?
    Is there any way to get to the rooster comb and change out this detent spring without removing the trans.?
    Yeah, I was telling a guy tonight about how important it was to make sure beginning with the gear indicator, least important but it's there anyway, but the shift lever where it attaches to the shifter linkage at the end of the column down there, I was showing him on my truck, where it attaches to the trans., and what is going on inside the trans at the "rooster comb", all that has to be lined up so to speak to make the trans. shift correctly. I was telling him that is what I think is what's wrong with mine, it seems to be shifting out of gear and it probably is.
    I'll tell you something odd when I was talking to the guy from TCI a few weeks ago. He said the trans. I was looking at buying only has a automatic valve body in it! I was really surprised it wasn't going to be like mine that came from the factory with a full manual valve body. I asked him if he could swap the automatic body out for a manual valve body? There was a moment of silence. I figured that meant no. I asked the guy from TCI, "You mean I can't whind it out between gears? I would think with this trans. you would have built it just to be able to do just that since it's for "street rods"." It's called the "Street Rodder" model. It's the least expensive model made for lightly modified engines and hot rods.
     
  12. Matt69olds

    Matt69olds Full Access Member

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    A manual valve body is just as the name says, full manual, no automatic shifts, whatever gear you put the shifter in, that’s the gear it’s going to go to, no matter what engine or vehicle speed. If your going a 100mph and put the shifter in 1st, it’s going into 1st gear. If your sitting at a stop light in 3rd, when you hit the gas when the light changes, it’s going to be in high gear.

    you can remove the rooster comb and manual shaft with the trans installed. Remove the pan, remove the one bolt that holds the detent spring in position. There is a stout U shaped clip that goes over the manual shaft, it’s purpose is to keep the manual shaft from excessive moving in/out of the trans. It’s easily removed with a screwdriver. Once the clip is out, there is a nut that holts the rooster comb to the manual shaft. Remove the nut, the shaft will slide out. It’s best to take a small file and remove any burrs left on the shaft by rooster comb, the burrs can cut the manual shaft seal and create a leak that wasn’t there before.

    you can buy ready to install manual valve bodies, as long as you want one with a standard shift pattern and one that maintains engine braking in lower gears they can be installed with the trans in the truck. However, no matter what valve body you use, the shifter linkage needs to be right!


    Here is a TCI manual valve body,standard forward shift pattern, that keeps engine braking in the lower gears.
    https://www.jegs.com/InstallationInstructions/800/890/890-321000-1.pdf

    https://www.jegs.com/i/TCI/890/321000/10002/-1

    However, I don’t think this is the solution to your issue. The best valve body and transmission will only do what the shifter tells it to do. Either put a aftermarket floor shifter in, or get the right combination of column parts so that the detents on the column line up with the ones in the trans.
     
    Snoots likes this.
  13. Raider L

    Raider L Full Access Member

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    Matt69olds,
    Ohhh okay. So maybe I'm thinking wrong on the manual shift valve body. I must be thinking a automatic and manual valve body like the one that's in my truck now. I thought that was a manual valve body one that you could put in Drive and it would go through the gears and like you were saying that would slow the vehicle down as you slow, and would shift into first at a stop. But while stopped if you wanted you could shift to first and start out and manually go through the gears until you were in Drive. That's NOT a automatic valve body then, right? A automatic body is one where you can't shift into first if you want to and go through the gears until you were in Drive? And leave it in Drive and it will shift on it's own? With the slowing of the vehicle and all that? If I'm confused I'm not sure of the terminology. Mine is like I discribed above where you can do whatever you want, leave it in Drive or shift into first, either one.

    I've been looking at some different stick shifters on line, but when my (new) column comes it will have the correct shift gate in it already and everything will line up right.
     
  14. Matt69olds

    Matt69olds Full Access Member

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    What your describing is what most refer to as a auto/manual valvebody.


    Most of the better shift kits retain the automatic shifts when the shifter is in drive, and will also allow you to hold 1st or second gear until you move the shifter, or you drive over the crankshaft. . The will also allow you to downshift to any gear at any speed. Every factory valvebody has a safety feature that won’t allow downshifts over a certain vehicle speeds, or will upshift regardless of shifter position. I’m guessing GM calibrated the transmissions like that to limit warranty claims.
     
  15. Raider L

    Raider L Full Access Member

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    Matt69olds,

    Now, the guy I was talking to from TCI said that a auto/manual valve body wasn't offered. He said that in the next trans. models up from the one I was looking at is called the "Street Fighter" and it has only a manual valve body in it for street racing. And the trans. up from that one is just for racing all the way up to full race transmissions. I just wanted one like the one in my truck and after I talked to him I realized that the best thing to do was to just get mine rebuilt. Get a real good overhaul kit, rebuild the valve body, or whatever parts need replacing, the pump and whatever, and either get a stall converter just above stock, no more than 1800 or 2000 and then it'll run for another 25 years and I'll be able to do what I want with what I've got.
     

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