Installing Speedi-Sleeve and Rear Main Seal on 1st Gen 6BT

Discussion in '1st Generation Cummins' started by The Warden, Apr 23, 2014.

  1. The Warden

    The Warden MiB Impersonator Supporting Member

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    Good evening!

    Over the last couple of weeks, I helped a friend with some work on a Cummins 6BT out of a '91 Dodge W-250. I did some of the clean-up work, but my friend did most of the install work, which gave me an opportunity to take some pictures and write this up, in the hopes that it will help others ;Sweet

    First step (of course easier said than done) is to remove the transmission, along with the torque converter or clutch assembly. Given that the engine's not currently in the truck, we were already ready to go :D
    2014-04-07 20.33.36.jpg

    Now, remove the flexplate (or flywheel):
    2014-04-07 20.56.10.jpg

    Next, you'll want to remove the starter and, if equipped, unbolt the back of the transmission cooler assembly from the adapter plate. Once those are free, remove the 8 bolts holding the adapter plate in place, and the adapter plate should come right off:
    2014-04-07 21.26.06.jpg

    The rear seal housing needs to come off now. There are a total of 10 bolts: 6 8mm bolts holding it onto the block, and 4 10mm bolts holding it to the oil pan. Looking at this picture of the tail end of the crankshaft after the housing has been removed, you can see a few grooves cut into the surface. These grooves will immediately cut up a replacement seal, so a Speedi-Sleeve will be needed:
    2014-04-07 23.01.39.jpg

    The back (visible) part of the rear seal housing after being removed. The seal was surprisingly loose in the housing; I don't know if that's normal or not, but given the effort needed to install the new seal, I suspect it's not:
    2014-04-07 23.02.04.jpg

    The front mating surface of the rear seal housing after being cleaned up:
    2014-04-07 23.02.11.jpg

    SPEEDI-SLEEVE TIME!!! The sleeve is placed in the installation tool, with a pair of hands to give you an idea of the scale of this thing. Even compared to the front main seal on this engine, it's bloody huge...CERTAINLY far larger than most rear seals you'd see on an engine this size. Note that there's a slight lip on the seal; this appears to be an attempt to keep too much oil from getting to the seal:
    2014-04-15 02.06.28.jpg

    Square the installation tool on the crankshaft end and go to town with a BFH. Make sure to hit alternating sides to keep it square. You do NOT want it to be crooked! It's all the way in when the installation tool bottoms out:
    2014-04-15 02.07.15.jpg

    Speedi-Sleeve installed on the crank. Some say that you should put an adhesive on the inside of the sleeve, but it's a tight enough fit that we deemed it to not be necessary:
    2014-04-15 02.10.36.jpg

    Using the included installation tool to install the seal itself. Like with the Speedi-Sleeve, be sure to hit it evenly on all sides so that the seal goes in square. Also like with the Speedi-Sleeve, the seal's properly installed when the installation tool bottoms out. Per instructions, you do not want to use any additional sealant between the seal and the housing:
    2014-04-15 02.18.58.jpg

    (More in next post)
     
  2. The Warden

    The Warden MiB Impersonator Supporting Member

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    (Continued from last post)

    Rear seal fully installed, as seen from the back side. The clear plastic sleeve is there to help the seal go onto the sleeve smoothly and will be removed after the seal/housing are installed:
    2014-04-15 02.20.23.jpg

    Rear seal fully installed, as seen from the front (mating surface) side:
    2014-04-15 02.24.29.jpg

    And, last but not least, the housing re-installed on the engine! We removed the plastic sleeve immediately after taking this picture. The seal kit should come with a gasket for the mating surface between the block and the seal housing; not ethat it does NOT come with a replacement for the piece of oil pan gasket that you'll have to take off in the course of this installation. We will be replacing the oil pan gasket at a later date, so we didn't seal up the bottom. We did use some Permatex Aviation Form-A-Gasket to paint both sides of the gasket; between the clean mating surfaces and this stuff, there shuld never be a leak from the housing ;Sweet
    2014-04-15 02.39.08.jpg

    The oil pan bolts should be torqued to 18 ft-lbs; the rear seal bolts should be torqued to 48 INCH-pounds. Given that the rear seal bolts were going into cast iron; we figured that "snug" was more than sufficient. Also, all holes are blind holes, so no sealants are required.

    Hope this can help someone ;Sweet
     
  3. Dsl_Dog_Treat

    Dsl_Dog_Treat I lost my face to the jaws of a poodle Staff Member

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    Nice writeup Tim! ;Sweet
     
  4. The Warden

    The Warden MiB Impersonator Supporting Member

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    Thank you, Ron ;Sweet hopefully this will help some people :)
     

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