TH350 Rebuild Online: Free DIY Post

Discussion in 'Transmission & Driveline Topics' started by jakeshoe, Jun 3, 2006.

  1. jakeshoe

    jakeshoe Veteran Member Lifetime Gold Member

    8,859
    1
    Dec 8, 2000
    Republic of Texas
    David,
    I use a used low reverse friction, I scrape the material off with a razor blade, but any method will work fine. You can wire wheel it off, use a sander, whatever.
    No specific thickness. The idea is to add some shim behind the intmediate piston to take up some of the clutch clearance and get a cleaner crisper apply because it takes less fluid volume to move the piston the lesser distance.
     
  2. 74Camaro454

    74Camaro454 Veteran Member

    Jake,
    Do you do anything to increase the line pressure with your buildups? Or are your feed hole size recommendations assuming stock line pressure? I was thinking that most shift kits include a heavier spring to increase line pressure? Just curious. I am almost finished building up a trans with all your recommended mods. Can't wait to get it in the car and see how it runs.:p Thanks, Chris
     
  3. jakeshoe

    jakeshoe Veteran Member Lifetime Gold Member

    8,859
    1
    Dec 8, 2000
    Republic of Texas
    It depends on the application. I have heavier pressure regulator springs I use on anything over ~450 HP. Up to that point the stock spring works fine with the mods.
     
  4. 74Camaro454

    74Camaro454 Veteran Member

    I am building this trans to go behind a 400 cube Pontiac motor in my 68 Firebird. Hey it's still an F car.:crazy: I have run as fast as 13.2 in the quarter with 1.9 60 foot times. I am thinking if I am not at 450 Hp I am pretty darn close. Reason for doing this buildup in the first place is because I smoked the direct clutch pack in the th350 that was in the car. So now I have a 5th clutch in the directs, I am dual feeding, sounds like higher line pressure is probably a good idea to. If you don't mind my asking, where do you get the heavier spring you use? Is it a factory spring from another application or do you have a custom source? I considered using a shim or spacer of some sort but I think a different spring with a higher rate is the better approach. Thanks, Chris
     
  5. jakeshoe

    jakeshoe Veteran Member Lifetime Gold Member

    8,859
    1
    Dec 8, 2000
    Republic of Texas
    Has your trans ever had a valve body kit installed before? If so the spring was probably upgraded. If it is white, blue, or orange it is probably an aftermarket spring.

    I buy the springs in bulk from a trans supplier. They are $8 each. I'll have to check and be sure I have some left.
     
  6. 74Camaro454

    74Camaro454 Veteran Member

    Jake,
    Trans has not had a kit put into it that I know of, but I don't know it's complete history. It was in the car when I bought it. Only took about a month after I put the new motor in to smoke it. I took a quick look at the valvebody and it looks to have a yellow spring in it now. Am I right in assuming that any good trans parts source should have high pressure springs? If so what do I need to ask for? Will I have more than one to pick from? There is a pretty good place not to far from my work I could try it at lunch on Monday. I got most my other parts there so far. Seems like a pretty good shop. Thanks for all the help, Chris
     
  7. brad1974

    brad1974 New Member

    5
    0
    Nov 11, 2007
    knoxville, tn
    TH 350 anti-clunk spring

    Do I need this part in my TH350? I had a buddy rebuild it and it didn't get put back in. I had another TH350 that we torn apart and it wasn't in there either. He said that all it would do would make the transmission noisy...
     
  8. jakeshoe

    jakeshoe Veteran Member Lifetime Gold Member

    8,859
    1
    Dec 8, 2000
    Republic of Texas
    I always install either a anti-clunk or case saver.
    I actually prefer to use the anticlunk if the case is in good shape.
    I see no reason to leave it out. Pure laziness IMO.
    GM used it and still uses it on the 4L60 series trans, you can bet they wouldn't waste the money if they felt it wasn't needed.

    It will operate without it though.
     
  9. brad1974

    brad1974 New Member

    5
    0
    Nov 11, 2007
    knoxville, tn
    Thanks!

    I appreciate the quick response! It had been about 9 years since he had done it and didn't realize that it was left out until after we started assembling the valve body... Just got the tranny bolted back in this evening and it won't go through the gears... It just sits there... My buddy said that he forgot to check to make sure that the shifter assembly in the valve body was functioning properly. This is my first tranny rebuild and almost like his first since it has been so long. any suggestions on what to check on that? Thanks in advance!
     
    Last edited: Nov 11, 2007
  10. jakeshoe

    jakeshoe Veteran Member Lifetime Gold Member

    8,859
    1
    Dec 8, 2000
    Republic of Texas
    Drop the pan and be sure the S-clip is hooked on the rooster comb and manual valve.
     

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