Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

700R4 tranny swap

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by TheEmissary, May 30, 2000.

  1. TheEmissary

    TheEmissary Registered Member

    Joined:
    Apr 15, 2000
    Posts:
    63
    Likes Received:
    0
    Location:
    Houston, Texas
    I recently salvaged a 700R4 tranny (KCM code, 1990) out of a 1985 Jimmy 4 x 4 in a Houston-area wrecking yard. I ended up with a gem (a 1990 core, instead of the hand grenade 700s of pre-1987 vintage), and salvaged the tranny, transfer case adapter, and crossmember. My Blazer came with an NP208 transfer case, and will recycle the old transfer case with the new tranny and adapter.

    There was another 1985 Blazer (with a hacked frame; someone used the forward frame section to repair a straight axle Chevrolet/GMC 1/2 ton 4 x 4) in the same yard, and salvaged the following:

    throttle cable (recently installed)
    rear tailgate harness
    tranny adapter (didn't need the tranny, because it's a 1985 core)

    I noticed that the transfer case adapter (700/208) is shorter than the 350/208 adapter, and one thing that I can conclude is that my stock driveshafts can be reused.

    I even salvaged the following with the tranny:

    crossmember (1985-91 vintage)
    TV cable
    dipstick tube
    TCC wiring harness (external and internal)
    dust cover and strut braces

    My plans will include the following:

    reconditioning job (new seals, o-rings, clutches, valve body modifications)
    4th gear lockup
    9 clutch discs in the 3-4 clutch pack

    I will dismantle the core tranny in my garage, and is there any difference between the B & M 6-pack clutch disc (3-4) and the 9-clutch setup (common with Art Carr, JET Chip, and Darrell Young overhaul kits)?

    I have 2 4L60 cores, and one of the cores is out of a 1990 Caprice 9C1, originally behind a 350. One thing that I will do during the rebuild is to use the valvebody from the Caprice tranny, since the shift points are harder. Most of the internal hard parts from my parts trannies are 1987-present vintage (eg. 10 vane pump, hardened ring gears, larger forward sprag roller clutch assembly).

    I am in the process of fabricating an NP208 scaffold (made with a couple of 2 x 4s bolted to 1/4" steel plating) for the purpose of lowering the transfer case, and having the 700 reconditioned for HD use.

    The Emissary

    The Emissary
    1981 K5 Blazer 4 x 4
    305 (LE9)/THM350C/NP208

    Other vehicles:
    1975 Nova
     

Share This Page