1. Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

85 C30 3+3 questions

Discussion in 'GM 6.2 Diesels' started by tanman_2006, Dec 26, 2016.

  1. tanman_2006

    tanman_2006 Just a farm kid...

    5,456
    449
    Feb 15, 2010
    Seiling, Oklahoma
    IMG_0295.JPG So I found a pretty clean 85 C30 3+3 dually with 6.2 and th400.

    The flywheel has missing teeth and can't be started but the engine has decent compression.

    Do you have to pull the the trans out to replace the flywheel? If so this sounds like the perfect time to slide my 4L80 in.
     
  2. ak diesel driver

    ak diesel driver 6.5 driver

    11,795
    1,203
    Feb 7, 2009
    alaska
  3. tanman_2006

    tanman_2006 Just a farm kid...

    5,456
    449
    Feb 15, 2010
    Seiling, Oklahoma
    Drop lower cover And there will be enough room between the crank and Torque converter?
     
  4. Will L.

    Will L. Well-Known Member

    6,066
    3,443
    Jan 25, 2013
    Boulder City Nv
    Sounds snug to me. I have never tried, but thinking about it I guess you could. Just try and if it doesnt fit, no loss, youll be dropping the cover and undoing the tc to flywheel bolts anyways. think shinny thoughts...
     
  5. ak diesel driver

    ak diesel driver 6.5 driver

    11,795
    1,203
    Feb 7, 2009
    alaska
    once you get the convertor bolts out the convertor will usually slide into the tranny enough to give enough room
     
    btfarm likes this.
  6. tanman_2006

    tanman_2006 Just a farm kid...

    5,456
    449
    Feb 15, 2010
    Seiling, Oklahoma
    Now I have to decide how bad I want to do a tranny swap right now or just drive it as is for awhile
     
    Will L. likes this.
  7. EWC

    EWC Active Member

    189
    44
    Jun 14, 2008
    What are the rest of the parts you are using to do the swap ?
     
  8. Will L.

    Will L. Well-Known Member

    6,066
    3,443
    Jan 25, 2013
    Boulder City Nv
    Depends how bad it is if it goes down once in use. If it is going to mess you up to have it break down in first couple months, then do the trans now to eliminate any possible issues with a major component you know is coming out anyways. You just need t fine tooth comb examine it while doing trans. Other factor is --it is going to start out doing a bumch of freeway time, the mpg savings might factor in.

    Otherwise since you just picked it up, maybe just drive it for a while and see what else shows up. You might not know about a leak it has, maybe park brake not right, or other little things have that go unnoticed until in use. Then maybe when you do the trans swap, you fix the other things at the same time.

    I always prefer to down a rig and take care of multiple things at once. Always ticks me off to "fix" a rig then 3 weeks later something else goes. Then you can just pop the flywheel in there, and wait till warmer weather to do the trans.
     
    deejaaa likes this.
  9. deejaaa

    deejaaa Well-Known Member

    1,480
    221
    Sep 19, 2008
    Texas
    good points.
    are you gonna have a build thread on this? are there any other pics you can share? like the 4L80 idea.
     
    Will L. likes this.
  10. tanman_2006

    tanman_2006 Just a farm kid...

    5,456
    449
    Feb 15, 2010
    Seiling, Oklahoma
    Yes I will have a build thread on this truck if the deal goes through. I really want the truck, I have always wanted an 80's crew cab dually and eventually I want it turbo'd with a 6 speed allison but until the a 4l80 with triple disk 2000 rpm converter will have to work while I turbo. Then I will work on interior followed by the allison as long as the exterior holds up.
     
  11. 3500GMC

    3500GMC What T F, over

    5,223
    225
    Jun 7, 2009
    Nashport, Ohio
    Nice rig, looks strangely not rusted out, must not be an Ohio truck.

    More pics YA :wideyed:
     
  12. GM Guy

    GM Guy Manual Trans. 2WD Enthusiast

    4,619
    389
    May 6, 2008
    NW Kansas and SC Idaho
    2wd it looks like?

    What are thoughts on a 5 speed ally? there is a guy in Idaho that sells them for under a grand for the 2wd ones.
     
  13. tanman_2006

    tanman_2006 Just a farm kid...

    5,456
    449
    Feb 15, 2010
    Seiling, Oklahoma
    I bought a 6 speed with converter and tcm for 750. Paid 1500 for a 4x4 with 261 T case (lower mile truck I got to ride in after it was rolled). It's gonna take work to get the allison in though. I only plan to do the 6 Speed for the double OD and higher power rating over the 5 speed, I'd rather be over built.
     
  14. tanman_2006

    tanman_2006 Just a farm kid...

    5,456
    449
    Feb 15, 2010
    Seiling, Oklahoma
    5 speed ally is fine but the allison needs to be about 25% over built for a truck that doesn't defuel. So 300 rwhp needs to hold 375 HP (just a rule of thumb I got somewhere). Those numbers are more in line with the LBZ with a trans go and lml converter.

    I want to do the 4x4 6 speed in a 95 and newer Crew Cab DRW eventually. One at a time though and I think starting with turbo'd 6.2 bottom end, 6.5 top end, banks manifold, a team, and 4l80 will be a start.
     
    Will L. likes this.
  15. deejaaa

    deejaaa Well-Known Member

    1,480
    221
    Sep 19, 2008
    Texas
    did you get it? is this a friends truck? know the history?
     
  16. tanman_2006

    tanman_2006 Just a farm kid...

    5,456
    449
    Feb 15, 2010
    Seiling, Oklahoma
    Guy had it since 03, found it on Craigslist
     
  17. 3500GMC

    3500GMC What T F, over

    5,223
    225
    Jun 7, 2009
    Nashport, Ohio
  18. I don't think I'd stress about any 6.2 or 6.5 over whelming a correct 4L80E.
     
    tanman_2006 likes this.

Share This Page