How To Install Bolt On Sub-Frame Connectors

Discussion in '1994 - 1995 Specific Tech' started by davis3, May 31, 2008.

  1. the purpose of sub-frame connectors are to stiffen up the chassis,reducing unwanted flex,and give you more predictable handling.

    before we start,i'm using BBK bolt in sub-frame connectors.these are much better than none at all.Weld in full length sub frame connectors are the #1 choice for sub frames.i chose the BBK's because i don't know how to weld yet,and i pefer to do as much work myself as i can.the BBK's can aslo be welded in,and at first i was going to have them welded after i bolted them up.i'll see how they feel first before i make my decision.

    ------------------------------TOOL'S NEEDED------------------------------------------------
    1-set BBK bolt in sub-frame connectors W/seat supports($129.99,about $155 shipped in california)
    4-jack stand's
    3-3/8 drill bit's
    1-3/8 ratchet
    1-1/2 ratchet
    1-1/4 ratchet
    1-22mm combo wrench
    1-9/16 combo wrench
    1-long 1/2 extension
    1-small 3/8 extension
    1-18mm,1/2 deep socket
    1-1/2,3/8 deep socket
    1-11/16,3/8 socket
    1-9/16,3/8 deep socket
    1-9/16,3/8 standard socket
    1-10mm,1/4 socket
    1-small plier
    1-small block of wood

    STEP #1.
    raise car,support on jack stands as level as possible with the suspension loaded.up front,place stand under control arm,at the spring pocket.

    at rear,under axle tube as far at the end as you can get it.

    should be level with the ground at these point's(arrow's.i measured at these point's,and from the ground to the top of the wheel opening at both front and rear,before and after install.i got all the same measurement's after i was done,so i ASSUME this is how your supposed to level everything.).

    STEP #2.
    we'll need to unbolt the cat back exhaust to make room for the drill.were just going to unbolt everything and let it hang there,not totally remove the cat back.using the 3/8 ratchet,and 9/16 deep socket,remove the four nut's connecting the cat back to the h-pipe.

    next disconnect it from it's rubber hanger,remove the little washer thingy with small plier,and slide out of hanger.

    STEP #3.
    remove the h-pipe.first,with 1/4 ratchet and 10mm socket,loosen clamp at the air tube.

    disconnect O2 sensors at both sides.(there are only two)

    now with 22mm wrench,remove passanger side O2 sensor.

    remove the four 18 mm nuts that connect the h-pipe to the headers.use your 1/2 ratchet,long extension,and 18 mm deep socket.disconnect rubber hangers at tranny crossmember.(passanger side shown,same for other side)
    ***one of my nut's was frozen up,so i could not remove the h-pipe.i got it loose enough to move the h-pipe around.

    STEP #4.
    DRIVERS SIDE FRONT sub-frame install.
    using two 11/16 nylon lock nut's and your 3/8 ratchet w/11/16 socket,place sub frame connector on car,attaching at the seat support.snug nut's up.

    with slanted side to front of car.Drill holes,front first
    A.with your jack and a small block of wood,apply pressure from below to bring sub frame connector as close to the frame as possible.
    B.with the 3/8 drill bit.drill first hole,then place bolt in first hole.drill second hole.
    HPIM2543.jpg from under car.drill out the holes on the other side.(sorry,no pic)
    D.after all hole's are drilled,using supplied large washer on bolt,slide bolt in from outside the frame rail,place split lock washer first,followed by the nut.tighten everything up using your 3/8 ratchet,9/16 standard socket,and 9/16 wrench.thats it for the front,lets move to the rear.

    STEP #5.
    same procedure as front. jack w/wood under sub frame connector,apply pressure.
    B.using drill w/3/8 bit,drill out the two outer holes.go slow and apply even,medium pressure.there's a lot of metal to go through here.take your time.change drill bit as necessary.
    ***you will be drilling at an angle,it's O.K.when we drill the other holes from under the car,use the drill to line up all the holes.

    C.from under car,drill inner holes.with drill,go all the way through to outer holes to clean them up and line up the holes.

    D.install bolt's.from outside frame rail,slide large washer onto bolt,insert in hole,place split lock washer on bolt,finally the nut.with 3/8 ratchet,9/6 standard socket and 9/16 wrench,tighten everything up.

    E.with hacksaw,cut off excess threaded portion of bolt,as you can see it's a tight fit(in hindsight,i guess i could have installed the bolt in the other direction and skipped this step)

    STEP #6.
    PASSANGER SIDE sub frame install.
    ***********repeat drivers side procedures for passanger side************

    STEP #7.
    after passanger side sub frame connector is all buttoned up,reinstall h-pipe.snug up four,18 mm nuts,reconnect h-pipe to rubber hangers at tranny crossmember.tighten up the four,18 mm nut's

    connect air tube,tighten 10 mm nut at clamp.

    reinstall passanger side O2 sensor.tighten with 22 mm wrench.

    reconnect both O2 sensors.

    reconnect your cat back,snug up the four 9/16 nut's,but dont tighten yet.

    place cat back in rubber hanger,reinstall the washer thingy.

    adjust your tailpipes.make sure they are even at the bumper.also ensure they are not touching the body anywhere under the car.

    tighten up cat back to h-pipe nut's

    go over everything,make sure every thing is properly connected

    tighten up all sub-frame connectors bolts.

    STEP #8.
    lower car.that's it.when i drove the car home,it felt much more solid.also did not creak when making turns.

    here are some pic's of everything all buttoned up.
    on the ground.

    pic's of some up coming projects.i'll try to take pic's if i'm not too lazy:p.

    Exlporer intake.soaking in engine degreaser,getting ready for a scrub down.

    Mishimoto radiator,manual(#80201,94-95 GT/V6/COBRA).$225,

    Goodyear.upper(#62149,$10.99),lower(#62150,$10.99),and by-pass hose(#63726,$15.99:eek:)Autozone.not normally stocked.two days from time ordered,delivered to store.
  2. How you like them, I was thinking about a set of bolt in ones too just because I would like to take off any part that I didnt want later. Also what are you doing, doing this and not putting on those gt40's tsk tsk on u lol.
  3. Nice looking setup, especially the radiator.

    Not intending to rag on ya (I see your reasoning, bolt in sfc's are better than nothing), more for general info. About the bolt in sub-frame connectors, you'd be much, much better off with them welded in, especially with full length ones. With the bolt in setup, the bolts are placed in shear (well double shear actually, but that is besides the point). Bolts don't like being in shear, its not what they are intended to do. This is just speculation, but I'm guessing over time that the bolt holes will auger themselves out, reducing their effectiveness until it will be almost like you had no sf connnectors to begin with.

    My two cents, find/make a buddy that can weld and give him a case of beer for his time. If you are sitll on the fence about subframes, I'll tell you that there was a pretty noticable improvement switching from standard lenth welded in subframes, to MM XL subframes. I can only imagine the improvement in switching from a bolt in setup to a full length welded setup.
  4. Thank you for posting this, as it was something I had always wondered about.

    While discussing the shear issues (something I also feared with bolt-in connectors), don't newer Stangs (i.e. the Bullitts, Mach's or something else) have bolt-in connectors? I believe they do. I wonder what provision they have for not hogging-out the holes (something like a threaded insert through the frame perhaps)?
  5. GTA_V6_Mustang,:rlaugh:my plan is to install the intake when the radiator goes in,need to get an intake elbow for the sub frame's,it's a very noticable more sqweak's and creak's when i turn to pull into the parking lot of my apt complex.if i have any problem's with them,i'll be sure to report back ASAP.

    Mr. Hawver,as stated in my post,i'm well aware that weld in full length sub frame connector's are top's.i've looked into the pro's and con's of bolt in connector's.bottom line is i pefer to do the work myself.i think this was a good little project to undertake.i like to gain knowledge and experiance with a particular part.that way i can help somebody out with my first hand info on how a part performed or did not perform and not just speculate.when i learn how to weld,out come's the bolt in's and in go the weld in's
  6. $225 shipped for the Mishimoto? They must have just increased the price- I paid $200 shipped about a month ago.

    Good how-to :nice:
  7. ALthough this post doesnt help me (already with Subs) Im giving you TWO :nice: :nice: and one :hail2: for the write up .... as usual!
  8. here's an update.i've been driving mostly around the city.rough roads and lots of bumps and pot holes.i went for a couple of drives in the foothills,near the lake i always go to.has some pretty twisty roads.the car held the road alot better,stayed very flat and level through the turns.i could carry more speed through the turns without the car feeling like it would roll over.overall the car feels more planted.(the roads i drive i'm very familiar with.though i was driving at a bit higher rate of speed,i was very cautious at turns and around other traffic,i'm always aware of others in public and will not take unnecessary risks-be careful when driving or testing your Mustang on public streets:))

    car still feels much better than before the sub frames.the ride is solid,still no creaking into turns like poping,rattling or squeaking from the sub frames.i'll try to get under the car this weekend to check all bolts for any abnormal wear and tear.
  9. Nice write up!, I have the same subframe connectors and like them alot, thery are very good quality. I was lazy and just paid the shop I use the 40 bucks to have them welded in because I don't have a lift and can't weld very good:D
  10. Thats what I did too (50 bucks).

    :nice:Awesome write up! Every time I worked on the car I thought about doing this but I tend to get angry easily and I'd probably spike the camera after a while. Can you use these subframes bolted in as a place for a jack?

    What kind of drill bit did you use for this?

  11. Nice job with the BBK subframe connectors. I'm tempted to do the same.
    Can I ask you one small favor? Could you put your Mishimoto radiator on a bathroom scale and tell me how much it weighs?
  12. is there a reason why took the o2s out of the pipes rather than just unplug them and leave them alone? your better off leaving them in there to avoid touching the ends and getting your greasy fingers on them.

    great write up. very very detailed.
  13. Great post!

    As said by others, welded in subs are the best way to go and usually at a cost of $40 to $50 to have a shop do the work. MM full length subs would cost more and take a bit more time to get done correctly. I've got Kenny Brown subs and they made a big difference. Eventually, I may ditch those and go with the long MM subs to go with the rest of my suspension.

    On a similar note, I can't imagine anyone removing subs to just not have them anymore. Maybe there is a reason, but not that I can think of at the moment. Subs should be a great upgrade, no matter what kind of driving/racing is done. Most people with bolt on subs wouldn't be interested in welding them in themselves, but obviously you've got those plans in mind.

    Thanks for the write up!
  14. hissin50-thank's

    black95gts-not sure,have not tried.i just used a regular 3/8 bit.

    bullitt95-sorry i can''s already in the car.

    prokiller-i took only the passanger side o2 sensor was in the way of one of the h-pipe-to-header nuts

    carnut-i just like to do the work myself.when i learn how to weld,i'll take these out and put in the MM full lengths.
  15. yeah i kind of figured that was why, but wanted to check. i usually just use a swivel attachment
  16. here's a little update.since i installed these connectors,the passanger side muffler would rattle against the rear connector bolts.

    i put the bolts in the wrong way:rolleyes:and was too lazy to get back under there and turn them around:nonono:.

    the nut is too thick,that's why the muffler would rattle against it,as you can see.
    here's where it rubbed against the muffler.
    i took the bolt's out and turned them around.first i checked them for any abnormal wear.they looked good as you can see.
    i checked the hole's to see if they were elongated,they were not.the bolt still fit snug.
    reinstalled them with the head of the bolts on the inside of the frame rail.
    drove home after and no rattle:)
  17. Bumping this from a long time ago.

    I'll be putting these in on my car in a few weeks. This writeup is awesome. Thanks a bunch!
  18. Honestly, I seriously doubt there is any difference between weld ins and bolt ins. As long as you crank those bolts down balls ass tight, there is very little difference. Welding on the sub frames actually weakens the metal. I wouldn't even bother welding them.