Rear subframe replacement
Discussion
Assume 4 of the 8 bolts will shear when you try to undo them. Therefore buy a stud extraction kit and high tensile drill bits to drill them out. Then a tap & die kit and/or Timeserts/Helicoils, with new bolts to go in.
You will probably have to burn the trumpet seat cups out with a gas blowtorch. Wait for the seats to cool before fitting the new ones.
Other than that, it's easy peasy (!), but make sure handbrake quadrants, radius arms, etc, are well greased and the new subframe is well anti-rusted.
Most of all, good luck.
You will probably have to burn the trumpet seat cups out with a gas blowtorch. Wait for the seats to cool before fitting the new ones.
Other than that, it's easy peasy (!), but make sure handbrake quadrants, radius arms, etc, are well greased and the new subframe is well anti-rusted.
Most of all, good luck.
Two bodies best but eminently possible single handed - go banzai with the penetrating oil for a few days beforehand, the whole job is surprising straightforward (remove exhaust & battery cable terminal, undo the brake line, move tank out of the way, take shocks off, unbolt & drop - strip the old knackered frame & fit up the new one - to use the time honoured Haynes quote - reassmebly is the reverse of removal...yeah right!) the only real problem area is the intact removal of the four bolts that attach mounts to the heelboard - be VERY VERY gentle sometimes you'll get lucky - my 81 city had never had a new sub - it was 24 years old (must be some kind of record) yet these came out with no problems whatsoever - invariably however they'll be stubborn as hell - if you get some movement gently go fore and aft in increasing measure and eventually they'll come out (or use some heat) - most useful tool for the job is a hefty plank at about 5 foot to support the body on axle stands whilst sub out - failing that it's none too technical a few ½" spanners & sockets, a new battery positive terminal (if sub not previously replaced - if it has been you'll probably already have a screw on replacement) pair of decent axle stands and a cheapo 2 ton trolley jack and a brake bleed tube. Take the opportunity to replace the mount bushes too (unless race car the std rubber bushes are absolutely fine & have a close look at the radius arms for wear too) The debate over gen / heritage vs aftermarket frames reges on - but I've dont 6 or 7 over the years and never had a problem with the cheapo's bar one captive nut tha broke free on reassembly couple of mig spots and all was fine.....
Don't lose heart if a bolt snaps there are ways & means of getting them out and even if the heelboard a bit shot (not unusual) you could always bash the hole in weld a captive nut to a large penny washer & weld that back in (lining it up a litte tricky though!)
Enjoy! - not the most pleasant of jobs but it comes to us all and I'd far rather do it myself than entrust to a bodge it garage (said with due sense of irony in view of suugested bodge above....)
Don't lose heart if a bolt snaps there are ways & means of getting them out and even if the heelboard a bit shot (not unusual) you could always bash the hole in weld a captive nut to a large penny washer & weld that back in (lining it up a litte tricky though!)
Enjoy! - not the most pleasant of jobs but it comes to us all and I'd far rather do it myself than entrust to a bodge it garage (said with due sense of irony in view of suugested bodge above....)
I have replaced 2 and have had no problems with the bolts so I must be very lucky.
My 1st was 15 years old, the second 20 years old.
I did spray penetrating oil onto the bolts for a few days before and was, as previously mentioned, really careful when loosening.
Did one on my own with the help of a trolly jack and axle stands. Hard work but this was 20 years ago so didn't mind spending a weekend stuck under a car. Definatley better with 2.
My 1st was 15 years old, the second 20 years old.
I did spray penetrating oil onto the bolts for a few days before and was, as previously mentioned, really careful when loosening.
Did one on my own with the help of a trolly jack and axle stands. Hard work but this was 20 years ago so didn't mind spending a weekend stuck under a car. Definatley better with 2.
Whenever I've sheared the forward facing bolts I've MIG-welded nuts onto the stubs. The heat from the welding has always freed off the stubs. Then I just run a 5/16" tap down the threads and use lots of copper grease on re-assembly.
Don't forget to check and set the rear wheel camber afterwards. New subframes seem to all have positive camber which makes for extremely bad handling. Use a big absolutely square piece of plywood, stand the car on a flat smooth surface and hold the wood against the side of the tyre in a vertical position. The distance to the lowest part of the wheel rim must be the same or slightly less than the distance to the top edge of the rim. If it isn't you must remove the location bracket, file the hole into a slot and keep on re-trying until you have zero to 1/16" difference between top and bottom, with the 1/16" being at the top. Then fit a big flat washer and lightly MIG weld it into place. The camber is then set and is correct. This job normally talkes about half an hour each side, but it's really worth it in handling terms. For really good handling you file the hole in the bracket to give 1/8" toe-in on the rear wheels as well, but that is more difficult to check.
Don't forget to check and set the rear wheel camber afterwards. New subframes seem to all have positive camber which makes for extremely bad handling. Use a big absolutely square piece of plywood, stand the car on a flat smooth surface and hold the wood against the side of the tyre in a vertical position. The distance to the lowest part of the wheel rim must be the same or slightly less than the distance to the top edge of the rim. If it isn't you must remove the location bracket, file the hole into a slot and keep on re-trying until you have zero to 1/16" difference between top and bottom, with the 1/16" being at the top. Then fit a big flat washer and lightly MIG weld it into place. The camber is then set and is correct. This job normally talkes about half an hour each side, but it's really worth it in handling terms. For really good handling you file the hole in the bracket to give 1/8" toe-in on the rear wheels as well, but that is more difficult to check.
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