91 Suburban Trans

Discussion in 'The Choo-Choo shop' started by 83Stage1, Oct 5, 2004.

  1. 83Stage1

    83Stage1 Well-Known Member

    I've been wanting a running 4x4 in the "family" for a while. I've also been itchin' for a wagon. Seems a Suburban is the perfect answer. After all, that's really what an SUV is, isn't it? Just a tall wagon... :laugh::laugh:

    I found a nice 91 locally at a very reasonable price. Before I bring it home, I'm curious what trans is in it? Did the 91 still use a 700R4? Or were they into the 4L80's already? If its the 700, aren't these later ones supposed to be a lot better than the early ones?

    Either way, how much computer control is on the trans for a 91? I fully expect I'll convert the truck to 455 power within a year or two, so I'm curious if the trans will work w/o the computer. I'd like to keep the overdrive. (yeah, yeah, I know - a chevy trans can't take that much power & I'll burn it up. I'm hoping with a quality cooler, remote filter, and baby'ing, it would survive for a while...)

  2. Stage2Scott

    Stage2Scott Well-Known Member

    took the 700 out of my suburban (2wd) and installed a t400. losing the od is a pain in the gas but no more trans trouble. the 700 wont bolt up to a 455 buick without an adaptor of some kind. after my experience with the 700 in my suburban, i wouldnt wish one on my worst enemy.
  3. 83Stage1

    83Stage1 Well-Known Member

    Yeah, I realize I'll need an adapter. What year was your 700?
  4. Stage2Scott

    Stage2Scott Well-Known Member

    89 is the year-trans was warantied, repaired, special this special that-t400 cured all ills. this truck is used to tow ski boat at 2800 lbs to ocean boat at 9800 lbs and 4000lb car on 1500 lb trailer. ocean boat killed the 700 every time. doesnt even faze the 400.
  5. 69GS400s

    69GS400s ...my own amusement ride!

    later year 700R4's are 4L60e's not 4L80e's (basically a comp. controlled 700R4). Only the 2500 series Sub's got the bigger one.

    4L60e's are the known weak point in the 94-96 LT1 Roadmaster/ImpySS's. Hard parts are available to make them stronger and the factory is finally addressed this now with the new 4L65e

    I know they make stand-alone computers for using a 4L80E in older stuff....prolly available for the 4L60e to

    Of Course, the best solution would be a Gear Vendors attached to a TH400
  6. Stage2Scott

    Stage2Scott Well-Known Member

    thats the ticket!!

    alan has it right-thats the direction im headin with mine-now that i know the 400 will do its job towing the heavy boat, a gear vendors will restore the extra gear when im not towing the heavy boat-just need another year to save up that chunk of cash.
  7. cadmanzx

    cadmanzx Master Yachtsman

    Scott, is your Sub still mouse powered? I'm planning on installing a 455 in my 4x4 and maybe my 2wd. Did you have to modify your driveshaft? Shorten? I'm sick of the 700 problems. I was thinking of going 455-TH 350 for my 4x4. Then maybe 455-TH400 for the 2wd. I use em for towing too. Need to get rid of the mice and install torque and reliability.
  8. BOOST!

    BOOST! Love Drunk


    My 1991 3/4 ton Silverado 4X4 came with a TH400. I think it is the only way you could get the 3/4 and 1 ton?

    What makes my mileage a pleasure is the 6.2 diesel. I get 18 around town and 22+ hwy. That should be comparable to most Gas/Overdrive combos. It has now 229k and has never been apart. I have had a spare motor motor waiting for a while, but it will not quit. Changed the injector pump ever 100k and keep water out of the fuel and it has been trouble free.

    One more comment; the 3/4 ton gives me a alot more piece of mind. I also have a F150 extended cab I used to pull with. It took a great deal of concentration to tow. I was always having to correct the squirrelies and sway. With the car trailer and GS, or the 22 ft Ranger, the 3/4 truck is in charge and the boat or car follows along nicely.

    Hope this helps.
  9. Stage2Scott

    Stage2Scott Well-Known Member

    factory 454 2wd

    my 88 is a factory 454 2wd model. someone added the 700 as an experiment that failed to the point i bought it cheap from my friend who bought it new. reinstalled the t400 that came in it and it is perfect.
  10. 83Stage1

    83Stage1 Well-Known Member

    Can I highjack my own thread? heehee

    Ok, to keep a looong story short, I lost out on the 91 with the 700R4 in it. Also lost out on an 89, but scored this *very* nice 84 Suburban for a fair price. (pic attached)

    That brings me to - something has to leave my yard. My 84 GMC is the logical choice. So, what do you think its worth:

    84 GMC 3/4 ton 2wd Pickup
    1974 455 w/170k+ on it, but runs like a champ
    passenger side nice, driver side has some rust on the box sides
    cab corners have small rust holes, same for rear quarters

    I assembled this truck two years ago to replace an extremely worn out 1/2 ton, so 'new' below means less than 2 years old.

    I bought the truck with no motor, no trans, no driveshaft for $400
    new 400 trans: $400
    new tires: $400
    new wheels: $400
    new brakes: $400
    new driveshaft: $250
    new exhaust: $250
    misc install parts: $250
    seat recovered: $250

    Amazing how my "$400" pickup ended up costing me $3k...

    I'll post pictures over the weekend. It looks like a work truck, its seen its use, but its mechanically solid.

    The engine is a little tired with that many miles on it, but I wouldn't give a second thought to a round-trip tow to Texas with it. It easily outpulls everything else I've ever driven or anything my friends drive. It'll run 80 down the interstate all day with my heavy (all steel) trailer, full size car on back, and a box full of tools & spare parts. It was rare to ever kick down out of drive - just open the secondaries & away you go...

    Considering she's all set up with the 455 already, think it'll be of interest to board members? And what would be a fair asking price?

    Attached Files:

    Last edited: Oct 14, 2004
  11. 69GS400s

    69GS400s ...my own amusement ride!

    Nice "Burban !!!

    Looks like a station Wagon on Steroids......I NEED ONE NOW !!
  12. 83Stage1

    83Stage1 Well-Known Member


    I'm pretty happy with it. Even more so when I discovered the TH400 behind the 350 engine. I've found a few quirks with it I need to work over, but only the usual piddly stuff (hinge pins, slow PW's, dome light switch on the door, etc.). Its a nice solid truck. I got lucky getting this one considering some of the others I looked at in the same price range. The new motor is great - 50+ psi oil pressure at idle on a warm engine! Gonna be a shame to yank it for a 455 in a year or two... :laugh:
  13. crossy

    crossy Active Member

    i've been doing 73-87 Chevy trucks as a hobby for 20+ years and burbs are basically the same animal and i mean BIG animal. if there is anything that baffles you I guarantee I've already broke/fixed it so don't be afraid to ask.
    check for rust in UNobvious areas on them like above tire up top ,INSIDE rear wheelwell (there is a long seam at the top) and across the rear door/tailgate jamb from underside. DAVE

    Attached Files:

  14. 69GS400s

    69GS400s ...my own amusement ride!

    Member Race Lutz sent me a detailed description of what is needed to swap a BBB into a 'Burban. I'd PM him and ask for a copy....I cant find mine now
  15. 83Stage1

    83Stage1 Well-Known Member

    Thanks for the tips & the offer. I'll be sure to check out those spots tomorrow. Planning a little 'quality' time with it to really check it over. So far though everything appears to be in great shape.

    Have you ever found a source for the dark brown interior parts? I think GM called it Mahogony? I have catalogs from the usual places like LMC, but they only carry the tan.

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