Conference ssdevo::4wd

    After coming off the on-ramp and merging with traffic, I noticed my
    truck would not accelerate at all. Then after a 1/2 mile or so the
    truck was responsive to the throttle. Am I correctly assuming that my
    tranny is slipping? The vehicle is an '86 Blazer with 700r4 tranny.
    The problem is only intermittant. I need help diagnosing the problem in
    order to fix it myself. Worse case, how involved would it be to change
    trannies. I like the 700r4 for trailering my ski boat so I would
    replace it with a rebuilt 700. Any help is appreciated.

    If you pulled any kind of G-FORCE on the on ramp ---- perhaps you are
    just low on tranny fluid.  
    
    First, change fluid and filter, then go for the larger $$$$MONEY$$$$
    swap job.
    
    Dave

    I agree with the routine servicing.  If it has over 35K miles, it's
    due...ESPECIALLY if you consistently tow loads over 1.5Klbs. 
    
    Also have the service done at a tranny shop like AAMCO and have them
    re-adjust all the clutch and band settings to factory specs. 
    Don't let them snow you about non-adjustable electronically controlled 
    tranny's.  They ALL are adjustable until the  clutches and bands wear 
    out completely, and yours is probably due.
    
    If the servicing doesn't help, the 700 is a computer controlled tranny,
    and the engine has Fuel Injection, go for a new throttle position
    sensor, (on the engine, at the pivot point where the throttle linkage
    hooks up).  It is often the cause of a tranny either `hunting' for the 
    right gear or not responding to your demands through the accelerator. 
    
    If it is not a computer controlled, F.I. vehicle, then have the
    kick-down (passing gear/downshift) linkage checked out... it could
    have fallen off or broken.
    
    Regards,
    
    John

         Thanks John and Dave, I saw an advertisement for AAMCO and they'll
    do a free diagnostic. From your information, my tranny isn't shot or in
    need of replacement, just a tightening up of the clutches. My concern
    is how much should I expect to pay? In the WANT ADVERTISER a company is
    selling bluprinted and rebuilt 700's and turbo 350's for $450.00 with a
    two year warranty. Invest money in the old or go for the rebuilt?
    Additional info in my truck, 350 4-barrel, 700r4 tranny with over 100k.
    I guess its off to AAMCO. Thanks for your replies.

    Ref .88
    
    Wow! Only $450 for blueprinted and rebuilt 700's?  I just rebuilt a 
    Volvo (British built Borg-W) 2 years ago and it cost me $1200.00!!!
    
    If that's an exchanged and installed price, I think I'd buy one if the
    tune up on your old one doesn't work out to your satisfaction.  But 
    first, a coupla thoughts...
    
    - If your 700 is leaking AT ALL, it'll continue to leak... don't bother
    to tune it up... go for the rebuilt with all new seals and innards 
    and service it regularly (more on that later).
    
    The rebuild shop is a local outfit, not a national chain.  Guarantee or
    no, when it breaks, YOU gotta get your vehicle from where it broke to
    THEIR shop, which could be a "forget it" proposition if you happen to
    be in Bum Fork, Montana. 
    
    As for Turbo 350's... light duty...primarily CAR tranny... wouldn't use
    'em in ANYTHING requiring punishment (either a truck or a street-rod).  
    Turbo 400's are the ONLY way to go.  The only 3 speed automatics that 
    could take lots of abuse were built by Chrysler and Ford, not GM.
    
    A 700 is a true TRUCK duty automatic.  I seriously doubt she's shot yet,
    but if she's never been serviced in 100K mi., the lifespan, (should be 
    over 250Kmi. with routine servicing), may have been shortened somewhat
    from clogged filter reduced servo pressures etc. which makes clutches 
    slip and wear.  But I wouldn't think there are any major problems in 
    your 700 unless you've been ignoring the sloppy/slippy shifting and 
    never bothered to check the fluid for a loooong time (like over a coupla
    months).  
    
    It seems that automatics that are serviced regularly tend to last
    forever... I had an old K-car that's still out there with the original
    tranny AND engine and it's got OVER 250K on it... but I changed the oil
    and filter and added 4oz of Slick 50 every 3K mi., and I serviced and 
    adjusted the tranny to spec. every 35-40K. The trans showed no signs 
    of slipping or sloppy shifts, and the tranny guys always commented how 
    clean everything was inside. 
    
    To answer your question...
    
    A tuneup and fluid/filter change should only run $50-$75 depending on
    how many quarts of fluid and filter prices.  Look for a trans-tuneup 
    special or cupon in the papers from one of the major chain shops... that
    way it's covered all over the U.S. if they screw up.
    
    Regards,
    
    John

         Thanks for your reply John. I purchased the truck 2 1/2 years ago
    and have put less than 20k on it. At the time of purchase, I was told
    all the fluids in the vehicle were changed (to include the tranny). I
    verified this by unscrewing the plug and checking for color,etc.. The
    price for the rebuilt is with exchange BUT NOT installed. That's why I
    origionally posted the note to inquire if this is a fairly straight
    forward replacement or a pro only install. I appreciate the guestimate
    figure as a point of reference when I take it to AAMCO on Friday. If
    the cost is close to what you said with no major damage, I'll
    definately have them service it for the reasons you listed. If the cost
    exceeds 150-200$, I'll seriously take a look at replacement.
    
                                                                Barry

    Right decision, Barry.
    
    Slide under the vehicle and check for leaks of the red fluid...dampness
    doesn't count, but droplets and soaked chassis/driveline componens 
    aft of the leak site DO.  Also, check the fluid cooling lines up to your 
    radiator or auxiliary cooler in FRONT of the A/C condensor & radiator
    for leaks... if anything's wet or leaking, have it fixed NOW.
    
    Best of luck,
    
    John