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.

Alright, everyone help me out... rebuild tranny myself or not?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by K5thatShmobs, Dec 23, 2002.

  1. K5thatShmobs

    K5thatShmobs 1/2 ton status

    Joined:
    Sep 27, 2001
    Posts:
    353
    Likes Received:
    0
    Location:
    San Luis Obispo, CA
    Ive never rebuilt a transmission before, but my 700R4 in my '89 needs one. B&M sells a rebuilt kit with instructions and a video... Im not sure how good they are, but I just wanted to get the opinions of those that have done this before. I would call myself mechanically inclined, however, still new to the internals of a tranny. Should I try and do this myself?
     
  2. ccox7

    ccox7 Registered Member

    Joined:
    Jul 24, 2002
    Posts:
    69
    Likes Received:
    0
    Location:
    Bayou State
    I would go for it , with tech manual and video you should be ok.Just remember heat kills transmissions.You should always replace the lip seals in the clutch pistons etc.Look for signs of wear on all parts.I rebuilt my turbo 350 , the clutchs were gone.I replaced tailshaft bushings and front pump bushings and all thrust washers.Just be sure to have a nice clean work area. A table made for teardowns with a drain at one end really helps to keep the trans fluid in check.Also before you rebuild you may want to find your nearest Transtar dealer, they too would have rebuild kits and tech manual , lot cheaper than B & M . Good Luck
    /forums/images/graemlins/thumb.gif /forums/images/graemlins/k5.gif /forums/images/graemlins/usaflag.gif
     
  3. K5thatShmobs

    K5thatShmobs 1/2 ton status

    Joined:
    Sep 27, 2001
    Posts:
    353
    Likes Received:
    0
    Location:
    San Luis Obispo, CA
    Did you need any special tools for the job?
     
  4. ccox7

    ccox7 Registered Member

    Joined:
    Jul 24, 2002
    Posts:
    69
    Likes Received:
    0
    Location:
    Bayou State
    I used a seal puller from MAC Tools that I had to remove pump ( the slide hammer variety that takes the screw insert) Took screw insert out and the threads matched up.You will need one of these to get the pump out.Some people just use a long bolt and pry bar against the case to remove pump.
    You will need clutch spring depressor to rebuild clutch packs, maybe a $30.00 tool at most.If you cahnge out any of the bushings etc you may need a bushing driver set or socket to drive in bushing.I was a technician for 10 years until i gave it up.I always figured if i could tear it down ,i could put it back together.Just keep all your parts in order and on your valve body removal, pay close attention to the linkage for shifter.Also follow torque specs when bolting the valve body back on , and always torque from midlle of valve body and work outwards.What is the symptom of the trans? /forums/images/graemlins/thumb.gif
     
  5. K5thatShmobs

    K5thatShmobs 1/2 ton status

    Joined:
    Sep 27, 2001
    Posts:
    353
    Likes Received:
    0
    Location:
    San Luis Obispo, CA
    Thanks for the great reply... Its leaking from the front. Probably the pump seal or the input shaft seal. It was going into all the gears fine until I lost 3rd and 4th entirely on the freeway. Definitely rebuild time.
     
  6. Triaged

    Triaged 1/2 ton status

    Joined:
    Feb 21, 2001
    Posts:
    3,808
    Likes Received:
    0
    Location:
    CA (LA/OC area)
    If it leaked out enough fluid it won't stay in gear (I found that out on the meny stops I had to make to pour in 2-3 of the 24 qts it took me to get it home). It might not need a rebuild...just a seal.
     
  7. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    190
    Location:
    Roy WA
    I haven't rebuilt a 700 before, but I've done 350's, 400's, and a 2004R.

    IMO, the 700 is finicky enough that if you are changing stuff, you'll need at LEAST a dial indicator(?), one of those that you would use to check runout on something like a brake rotor. There are a few clearances that need checked (band apply pin, and probably a few parts that need endplay checked) and I wouldn't rebuild a 700 without checking all the clearances.

    In other words, do it "by the book" and for that, I'd use the ATSG manual.
     
  8. K5thatShmobs

    K5thatShmobs 1/2 ton status

    Joined:
    Sep 27, 2001
    Posts:
    353
    Likes Received:
    0
    Location:
    San Luis Obispo, CA
    I replaced all the lost fluid, and I still didnt have 3 and 4. Hell, maybe I could pick one up from a junkyard for 300 or 400 bucks. Its not a daily driver, so maybe Ill just take my chances. Damn, the salvage ones come with some pretty shi++y warranties though. Argh... I dont want to screw up this rebuild and have to take the tranny down a second time. Then again, rebuilding it myself would be the most cost effective route.
     
  9. ccox7

    ccox7 Registered Member

    Joined:
    Jul 24, 2002
    Posts:
    69
    Likes Received:
    0
    Location:
    Bayou State
    For starters i would drop the pan and check for metal on magnet , you may find chunks of metal which would be a bad sign.The sprag clutch which is a one way clutch are kind of weak.If you dont see a lot of metal etc. I would put a filter on it , seal it back up and top off fluid.Then I would add about 8 ozs of berryman B 12 and then do a road test.I have added Berryman B 12 to several transmissions here in our neighborhood and all of them are doing just fine.Good Luck , keep us posted.
     
  10. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    190
    Location:
    Roy WA
    If you don't mind having the vehicle down for awhile, have some motivation, and can really take your time, I don't think there is anything wrong with attempting the rebuild yourself.

    There are a couple of sticking points, but you can probably get a "standard" revuild kit for $2-300, which likely includes the most wear prone bushings.

    Best case scenario, all the internals are ok, just worn clutches (and hardened seals) and you are looking at your time/labor+ materials and you are on the road again.

    Worst case scenario, you put it together, it doesn't run right, and you get to pull it again, and perhaps buy more parts.

    Still...if you mess up one rebuild, and your time isn't worth anything, (can you justify the time with the experience you will gain?) you could buy another rebuild kit, some hard parts, and STILL be under what a "quality" rebuild will cost you.

    When my K5 fried the 700, it took some hard parts with it, and the total out the door was $1500.
     
  11. JAXSTER

    JAXSTER 1/2 ton status

    Joined:
    Mar 15, 2000
    Posts:
    181
    Likes Received:
    0
    Location:
    DFW, TEXAS
    I had the same delema! I have been wrenching for twenty five years and never cracked a tranny. I can and have done all; But! So I cracked down, bought a book and off I went. TH400 first. Sucess! Then a 700 R4: Again sucess! I figured if I lost I could count on my Lodge brother "At Longhorn Transmission", to Bail me out. But no avail. I did it, and the better man. "Iif you dont try you never learn! " School of Hard Knocks, Doctrine!
     
  12. Calclips

    Calclips 1/2 ton status

    Joined:
    Apr 4, 2001
    Posts:
    1,005
    Likes Received:
    0
    Location:
    Swartz Creek, Michigan/Flint while in school
    I'm 18, and have only been wrenching for a couple of years and I pulled off a th350 rebuild, and 2 th400 rebuilds. I'm fairly mechanically inclined and seem to have a good understanding of the way mechanical things need to go back together, but I think that ANYBODY could rebuild ANYTHING if you have the time to do it and a good manual. It took me about two weeks of after school tinkering and whatnot to pull, rebuild, and reinstall the th350 into my truck and it works fine. I need to take it back out and replace the front pump seal... but I just chalk that up to beginners mistakes /forums/images/graemlins/grin.gif
     
  13. Stroked72Blazer

    Stroked72Blazer 1/2 ton status

    Joined:
    Nov 9, 2002
    Posts:
    352
    Likes Received:
    0
    Location:
    Little Rock, AR
  14. doctor4x4

    doctor4x4 1/2 ton status

    Joined:
    Jan 22, 2002
    Posts:
    1,450
    Likes Received:
    0
    Location:
    Los Angeles
    Thanks for the raptor link !! are they as good as they say any experience with em ??? /forums/images/graemlins/ears.gif
     
  15. BobK

    BobK 1/2 ton status

    Joined:
    Oct 5, 2000
    Posts:
    1,604
    Likes Received:
    0
    Location:
    Petrolia,Ontario,Canada but working in Port Huron,
  16. doctor4x4

    doctor4x4 1/2 ton status

    Joined:
    Jan 22, 2002
    Posts:
    1,450
    Likes Received:
    0
    Location:
    Los Angeles
    thanks for the post i was gonna buy the parts from em but NOW that IRead how they treat people NO WAY IN HELL WILL I
     
  17. awdvkd

    awdvkd Newbie

    Joined:
    Jan 22, 2003
    Posts:
    1
    Likes Received:
    0
    If you choose to rebiuld it yourself be sure to take the time to find all the updates that are on the 700R4, I had a buddy rebuild mine and he stated that their are over 30 updates on the 700R4 since it first came out, we did all the updates, replaced the 6 ea. clutch pack to 10 ea. pack, put in a corvette servo, put in a shift improver and filled it up with mobil 1 AFT. It has been a really good transmission. When you do the updates the 700R4 is jsut as strong as the th350 and has a better 1st gear than the TH350. Just my 2 cents, GOOD LUCK! /forums/images/graemlins/thumb.gif
     

Share This Page