Subframe swap project

#21

The subframe is now out. Had to play games with jackstands to get the car off of the scissor lift so I could remove the exhaust. That’s what I should have done when I (with help from Jim, Fred & Al) replaced the clutch in a hard 8hr ordeal last year.

The left subframe mount didn’t want to come free for money or love. But I kept at it and eventually wore it down.

One thing I learned last night is that one shouldn’t touch 25yr old brake lines without a torch. If you try to separate a brake line without getting some heat on it, you’ll just round the nut. Then you’ll have to buy a new hard line and they don’t sell those pre-bent anymore. You have to bend it yourself. Won’t that be a treat.

#22

If you’d have sprayed them with Kroil a day or so beforehand you wouldn’t have run into that problem.

I might have those pre-bent lines on my parts car. I’ll check for you tomorrow.

#23

[quote=“87isMan” post=55718]
I might have those pre-bent lines on my parts car. I’ll check for you tomorrow.[/quote]
Thanks, but I don’t need them. I hosed one up over the winter when I was replacing something or other. That’s when I had to go buy a replacement pipe and to my surprise it arrived without bends. Ultimately I didn’t install it because I’d pressed on and attached the line back together even tho the nut was damaged. But the new pipe will have to go on the next time I fool with that line.

The mistake I made when I hosed that brake line up is that I didn’t pull out the torch until I’d fought the connection a bit, and of course, chewed it up some. It doesn’t take much to round those things. This time I was smarter and I grabbed the torch before I grabbed the crow’s foot wrenches, or whatever those things are called.

#24

Several companies make wrenches specifically designed for those fittings…never try to remove one without them. They come in open and crow’s foot…its nice to have both. CB

#25

When figuring out what was up with my subframe bushings I had to go after the lines as well. Used penetrating spray and heat and still had an issue with one. Also the previous owner totally chewed up the two lines that connect to the soft-lines at the subframe so they went on the list for replacement. Also was not happy when straight pipes arrived. Still need to bend them up but I know how much of a PITA that is. Maybe tomorrow I will tackle that.

Good luck.

Chuck, can you post a link to the wrenches you are talking about. I would love to find an alternative that works better than a standard crows foot wrench.

#26

Here is the link to one of the sets I have. CB

http://buy1.snapon.com/catalog/tools.asp?tool=hand&Group_ID=572&store=snapon-store

#27

[quote=“cwbaader” post=55727]Here is the link to one of the sets I have. CB

http://buy1.snapon.com/catalog/tools.asp?tool=hand&Group_ID=572&store=snapon-store[/quote]

Those are a lot nicer then my wrenches. Mine are all Harbor Freight.

Made it thru some challenges today. Getting the bushing out of the diff took some work. I kept at the steel ring that surrounds the rubber with a beat up old hack saw blade and eventually I got thru it. I was concerned that the aluminum diff bushing would be a bear to get in, but with a bit of oil and gentle taps it went in pretty easily.

I pressure washed the new subframe and old trailing arms and then painted them with Chassis Black.

The real bear of the day was getting the old subframe bushings off of the big subframe bushing stud that sticks down from the body. The plastic? parts came off easily, but they left an aluminum cylinder around the threaded stud. Getting those off was brutal. Heating them up wasn’t enough. I had to use a pipe wrench with 3’ cheater bar…we’re talking 5’ of leverage.

#28

Well, I really screwed up. The subframe has it’s rtab bolts installed from outboard to in, and I failed to recognize that those bolts needed to be removed before I banged in the aluminum subframe bushings. So now the bushings are in and those bolts are stuck there.

Jim Levie’s ideas are to cut threads in a bushing and put a bolt in it. Then bang out the bushing from the other side. The problem with this is that it will widen the interior dia of the bushing and I’m concerned that it will allow the bushing to move. Which was not the objective when I decided to go to Al bushings.

Jim’s second idea was to cut off the head of the bolt. But I’ve taken a good hard look at it and the eccentric that is fastened to the bolt is going to make it really hard to cut it off w/o damaging the welded on ear.

Maybe I’ll thread the bushing, bang it out and buy new bushings. Man how that’s a pisser.

#29

You missed a step when removing the subframe. The first action is to drive the subframe bolts up and out of the bushings. You can get the subframe off with out doing that, but getting the subframe back on is almost impossible with the bolts in place.

#30

I didn’t understand that.

Bentley doesn’t seem to cover subframe removal. I guess I should check out the BMW service manual.

#31

The bolts stick down from the body, oh about 5". Dropping the subframe off the bolts isn’t that difficult. But trying to raise it in place over the bolts is a lot more difficult you have to keep the subframe square to the bolts and coerce both sides up evenly. If the subframe cocks left or right or forward or back it will jam on the bolts. You can’t but a lot of force on with with risking bent subframe bolts.

The solution is to drive the bolts up and out of the body. They have a knurled head that fits into a pocket, so it takes a good whack to free them. Once they are out of the way you only have to deal with stubs on the bushings that fits into the pocket in the body. Lots easier to only have an inch or so deal with that 5" or so of bolts.

#32

Ok, I understand now. Once I overcome my goatf**k and get my subframe bushings back out, I’ll try to install the subframe on to the car as you described.

When you install the subframe, do you do it with trailing arms and diff already attached to is? If so, what do you do to maneuver the ~200lb assembly up and into place?

#33

I tried today to get the 3/4" tap and the right size drill bit. That would let me thread a bolt into the subframe pushing and knock it out. Couldn’t find the necessary 21/32nd bit tho. I think tomorrow I’m going to take it to a machine shop and let them figure out how to unscrew it.

My Kirkey seat comes tomorrow so I can play with that for a while. That will give time for my frustrations over the subframe to abate.

#34

Ranger,

You need one of these:

http://www.harborfreight.com/450-lb-capacity-transmission-jack-39178.html

Not only is it for transmissions but also rear end work!

I’m finishing up the same rear subframe activity as yourself.

I have a piece of plywood that the rear subframe with assembled trailing arms fits on. I have the tranny jack centered under the plywood and its load. It lifts straight up, get the bushing holes aligned and voila, lift a little more and you’ve got enough stud available for throwing a nut on.

Works the same for the diff. Just lift it up, line up the holes and get the bolts started.

Oh yeah, it’s on sale right now for $79.99.

KB

#35

I just got done with my rear subframe this weekend. I removed the subframe with the diff and the trailing arms attatched with the car up on jackstands (with wooden blocks to spead the weight across the pinch welds) using just a floor jack to lower is down. The biggest issue for me was that the aluminum peice of the subframe bushings was seized in the body of the car and I had to drill, cut, chisel, hammer, and curse at it to get it out. I replaced the subframe bushings with AKG 75d poly with the 12mm spacer to raise the subframe. Replaced the diff mount and trailing arm bushings. Did new brake lines (bent myself), and SS lines to replace the rubber. I feel that removing everything and reistalling it as a complete assembly makes it easier. The diff ballances it all nicely if you put the floor jack right under it. I also did the rear sway bar reinforcemnt from TMS. Eventful weekend. Can’t wait to get this car done and get on the track!

#36

Admittedly, I have only done the drop-and-reinstall routine once, but it was actually pretty easy with the Horrible Freight trans jack mentioned above. I left the subframe studs attached to the tub. I am imagining that trying to crawl in the back of a caged car and single-handedly coax those studs down through aluminum bushings will help Ranger plumb new depths of despair.

Aluminum bushings: eliminate that last 2% of deflection in exchange for 1000% increase in installation difficulty.

#37

Re. Tranny lift. That looks handy. I fetched a 20% discount coupon and I’ll get one tomorrow.

Re. 2%. Probably less than that.

#38

Can you not just use a 2 jaw puller to remove the newly installed bushings?? I think with a puller, a threaded rod, a piece of flat steel drilled to allow said rod through, and a nut this would work

#39

Nothing to grab for pulling. And nothing to push against.

#40

Nothing to grab for pulling. And nothing to push against.[/quote]

I edited my last post to elaborate on my idea. So the bottom part of the bushing is not larger in diameter than the inside of the subframe like every other subframe bushing?? I’d have to have a lip!!

Is the bushing one piece?? who did you order them from?