Transmission leak question - 2003 silverado 2500HD

Discussion in 'GM Powertrain' started by nfs13b, Jan 12, 2011.

  1. nfs13b

    nfs13b Member

    Hello All,

    My transmission has a slow leak out the rear seal which in turn as leaked on the rubber mount (which will need to be changed) - see photo attached

    Also looks like it could be leaking around the reat housing (I think thats what its called)

    My question is, is it a relatively easy mission to remove the tail shaft, take off the rear transmission housing (while transmission is still connected to car) replace the rubber housing, rear seal and rear housing gasket(if it has one)

    transmissionleak.jpg My next question (it its fairly easy to do) is where would I buy these parts from that would ship to Sydney Australia?

    Thanks heaps
  2. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    It looks to me more like you just need a tail shaft seal. which is fairly common and a pretty quick fix, I dont think you have any problems beyond the seal however.
    As to shipping im now 100%, i almost wonder if Holden could order a part for you? since it is a GM owned company.
  3. nfs13b

    nfs13b Member

    I could probably get an aftermarket seal locally but would need to know the inner and outer dimensions of the seal.. Does anyone have these available by any chance?

    Forward of the seal is all sludge build up which is why I thought it might be leaking from the tailshaft extension part as well
  4. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    I dont have the dimensions, but yes the sludge is common when it leaks like that the oil gets kicked up everywhere.
  5. nfs13b

    nfs13b Member

    Can someone tell me what model transmission I have.....
  6. murdog94

    murdog94 Epic Member 5+ Years 5000 Posts

    4L80E. as long as it is the for the HD truck that you have in your Sig.
  7. BornAgainBiker55

    BornAgainBiker55 Rockstar 100 Posts

    The seal wears out over time and miles. it's a fairly easy fix. I did one on an F-150 (shun the unbeliever, I know) a few years back at it's 100k rollover and I found it harder to loosen the drive-shaft u-joint than replace the seal. Just pull the shaft off the rear differential and then out of the tranny. Then I used a few small screwdrivers to slowly work the seal out and a light rubber mallet to drive the new seal in, straight, slow and easy. Just make sure you drain the tranny first or you'll get oil everywhere.
    Last edited by a moderator: Jan 13, 2011
  8. nfs13b

    nfs13b Member

    Does anyone have the part number for the seal and also I figured I would change the transmission filter at the same time.... Does anyone know the filter part number... I have had a bit of a look around and there seems to be a few different types and when I called up some local places they were asking me if it was a shallow or deep pan.... Im not really sure what I have, it looks kinds shallow but maybe my idea of shallow is not really shallow... lol. Also the pan has a drain plug if that helps...
  9. nfs13b

    nfs13b Member

    I am trying to look up part numbers for the rear seal on and I was wondering if the rear seal would be:

    Transmission-Automatic : Extension Housing Seal - TIMKEN Part # 9449 (4L80-E; 4 speed trans.; Exc. Booted)

    Or perhaps:
    Transmission-Automatic : Seal - SKF Part # 18860 (4L80-E; Rear)

    Or is it a different one altogether perhaps??? I want to order a seal and hopefully change that and the trans fluid/filter on saturday so any help would be fantastic.


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