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Front Driveshaft

Discussion in 'Chevy Trucks' started by Doc L., Mar 26, 2001.

  1. Doc L.

    Doc L. Member
    Messages: 38

    I've got a '78 3/4 ton Chevy p/u and it needs the u-joints replaced on the front driveshaft. I did the front one alright, it's the rear 2 that puzzle me. How do you take it apart? I see pins or something going through it. I also only got clips with my new u-joints. How do you get those pins out and are the clips right or did I get the wrong joints?
     
  2. reallyrusty

    reallyrusty Member
    Messages: 71

    There should be clips on the inside of the cv joints bearing caps if its the design i'm picturing.
    You need to remove them first then press the caps out
    with a press or a very large vise working all of them off at the same time. Heat from a torch will REALLY help if there as old as mine were.

    hope this helps
     
  3. MTCK

    MTCK Senior Member
    Messages: 346

    Some of the stock ones came with a plastic retainer that looks like a little plastic pin stuck through one of the caps. The way you get these off is to heat them up until they pop off, with a torch. I had those on my stock ones. Make sure you take the shaft off the truck before you hit it with the torch.
     
  4. Doc L.

    Doc L. Member
    Messages: 38

    I kind of had an idea they were plastic. If I heat them with a torch that should just melt them right? I can't figure out how they'll just pop out by heating them. Also, in reply to the earlier post there are no clips on the inside. I'm assuming there will be after I install the new u-joint. NO/YES
     
  5. Alan

    Alan PlowSite.com Addict
    Messages: 1,393

    When you burn out the plastic retainers they will extrude a long snake of plastic ash/melted plastic. Be careful and wear eye protection when you do it. They have been known to spit and sputter as well.
     
  6. Doc L.

    Doc L. Member
    Messages: 38

    Anybody know about the clip situation? The only reason I ask is that I've got a "78 Chevy 3/4 ton and a GMC 1/2 ton and they both have the plastic retainers. Am I one of the fortunate ones that has all original driveshafts on my old iron?
     
  7. reallyrusty

    reallyrusty Member
    Messages: 71

    To my knowledge (the more i learn the less i know) the joints are clip from the inside of the yokes and the clip should rest against inside to retain the caps.
    could be wrong but thats how mine is.
    hope this helps
     
  8. Doc L.

    Doc L. Member
    Messages: 38

    I'm almost positive I made it clear that there are no clips on the inside of my rear u-joints. I know exactly of which you speak realrusty but in this situation it doesn't apply. I have 2 driveshafts and neither one has clips on the inside of the rear joints on the front driveshaft. I believe it's called a cardan joint. There were however, clips on the front joints (the ones that connect it to the differential.) I don't want to dismantle this until I'm sure of what I've got as I may get caught in a situation where I need 4X4 while I'm plowing. Is there anybody that knows definitively if these plastic pinned ones are replaced with a style that has the clips?
     
  9. plowjockey

    plowjockey PlowSite.com Sponsor
    Messages: 622

    Call a dealer to be absolutely sure about this but I seem to remember that back in the 70's they had a groove in the u-joint cap that could not be seen from the outside on the OEM when they were pressed into the shaft then they were injected with the plastic. The plastic took the place of the clips. What you see is the injection holes in the shaft where you think you see a plastic pin. If my memory serves me then the new replacement u-joint will come with a clip since the consumer does not have the means to re-instsall the plastic.

    Hope this helps out some.

    Bruce
     
  10. MTCK

    MTCK Senior Member
    Messages: 346

    Forget the dealer, I've done this a few times. There are no clips on the U-joints now, as those are probably the stock ones taht came on it. You'll have to heat them up to get them off, be carefull as mentioned before. The new U joints should have come with clips, and you DO need those. after you take the old ones out and get the new ones in, the clips will slid into grooves in the caps of the joints on the inside of the axle shaft, near the center of the u joints. I hope that made sense, I can't think of a better way to describe it. The front joint probably already had clips because it's easier to change, and someone already did. Good luck.
     
  11. nysnowman

    nysnowman Junior Member
    Messages: 22

    MTCK is right.Those are the original factory joints>They dont have clips.The replacment joints come with clips.You MUST use them if you want your joints to stay in.
     
  12. Doc L.

    Doc L. Member
    Messages: 38

    OK guys, the next time I see any of you in a bar the beers are on me!!! Thanks, Doc