Subframe swap project

#81

Outboard bolts pointed in seamed the only logical way when I did it. If you hit a wall and bend a trailing arm wouldn’t your weekend be done anyway.

#82

[quote=“turbo329is” post=56126]If you hit a wall and bend a trailing arm wouldn’t your weekend be done anyway.[/quote]No way! It’s an easy swap if you carry a spare (and don’t turn the bolts the wrong way). :wink:

#83

I meant that you would have multiple other issues if you hit the wall.

#84

5hrs later the subframe is on. I put it on with the trailing arms attached (necessary) and the diff attached to the half shafts, but not attached to the subframe (very optional). What a bitch that was.

Lessons learned.

Jim was right about the subframe bushing bolts. Either you bang the subframe bushings back up into the passenger compartment or you remove the driveshaft. If you attempt to put the subframe in place with both the bushing bolts and drive shaft in place, the drive shaft will defeat you. You can get the driveshaft thru the subframe or you can get the subframe bushings to the bushing bolts, but not both. So one has to go. I banged the bolts up. It wasn’t hard.

Having the diff bolted to any part of this only makes it harder because there’ so much more weight to jockey around. Put the subframe on w/o the diff attached. What I did is to remove the diff from the subframe but leave it attached to the half shafts. I carefully supported everything and eventually overcome the obstacles, but I can’t recommend my solution. If I ever have to do this again, and I hope I don’t, the diff will be laying 20’ away when I put the subframe on.

There is a piece of steel below each subframe bushing. It acts as a washer for the subframe bolt’s nut, and it also “locates” the bottom of the subframe bushing. 2 bolts go thru the washer-locator to attach it to the body. Those 2 bolt holes on mine wouldn’t line up for money or love. After banging on the bastards for a while I decided that maybe the entire subframe was twisted. So I figured out a way to put an opposite twist on the subframe by jacking up on the big flange that supports the diff. Then the goddamned bolts holes finally lined up and I was able to fasten the subframe bushing to the car.

I still have to fasten the diff to the subframe, put the parking brakes back together and re-attach the brake hydraulics, but there’s light at the end of the tunnel.

#85

I keep saying and nobody listens. It is far easier to re-install the subframe complete with differential & trailing arms. There is a balance point under the diff, rather farther forward than it looks, that will lift the subframe straight up. And, driving the subframe bolts up and out should be the first step in dropping the subframe. It comes down easier and goes back in far easier if you do.

#86

What Jim said. CB

#87

Reassembly of the E-brakes is tricky. Without making your own “brake shoe f**king retaining pin inserter” by cutting a hex key short, reassembly is impossible. Now that I’m familar with our E-brake, I’m kinda surprised that the crappy ass things aren’t a source of problems. They don’t hardly look like they’d hang together. Mine looked so flimsy they might not stay together long enough for me to get a rotor on.

As long as I didn’t screw up the park brakes, all I have left to do is put the rotors and calipers back on, and bleed the brakes.

I would have to say that a rear end bushing swap is harder then an engine swap. And you just try to impress your buddies at work the next day…“yah, I swapped my rear end bushings”. It’ll be lost on them.

Any thoughts on how tight to fasten the subframe bushing bolts? Bentley says 56ftlbs, IIRC, and that ain’t much for such a big-ass bolt. Maybe the fastening torque was low because the OEM bushings are rubber? Or maybe it’s because the bolts heads are only fastened by knurling and sheetmetal? I couldn’t accept such a low clamping force holding on the rear end of the car so I did 70ftlbs. I’d a been happier with 90.

#88

56ft-lb on the subframe bolts is more that enough. All the bolt does is to bold the bushing tight to the body. The lateral loads are carried by the stub that sticks out of the top of the bushing.

#89

I figure that when a 14mmX1.5 bolt is spec’d at 56ftlbs, there’s gotta be a reason. Depending on plating, the school solution for fastening torque is 100-112ftlbs.

It’s the twisting moment I was thinking about, not so much lateral forces. Having said that, there isn’t much to the bushing’s little aluminum nub to resist those lateral forces.

The subframe bushings that I pulled off a couple weeks ago were installed by the race shop in VA that prepared the car. Those puppies were torqued on pretty tight. I’d estimate it took 120-130ftlbs to loosen the nuts.

#90

Scott, I’m from Richmond, VA. Do you know the name of the shop?

#91

DP Motorwerks.

#92

Rear rotors went on. One of them was a struggle until I figured out that an Ebrake cable wasn’t all the way inserted into the back of the brake so it was putting the cable under some tension. That was spreading the brake shoes enough that the rotor wouldn’t go on.

Made a rough adjustment to the Ebrake using the little rotary star adjuster.

I put the rear hydraulic brakes back on and put wheels and tires on all 4 corners.

Now I just have to do an alignment, and if all is well, bleed the rear brakes and put the exhaust back on.

And if all is not well there is always binge drinking.

#93

I set the rear toe last night. For the first time since I bought the car, the toe is perfect. I used a laser level against the rear tire and shoot it forward past the front wheel.

I’ll work on camber tonight.

#94

[quote=“Ranger” post=56349]I set the rear toe last night. For the first time since I bought the car, the toe is perfect. I used a laser level against the rear tire and shoot it forward past the front wheel.

I’ll work on camber tonight.[/quote]

It’s a beautiful thing.

#95

Ok, rear camber is done. For the very first time my alignment is exactly what I want. I need to make a wrench that will let me tighten the nuts on the rtab eccentrics tho. The thin wrench I’m using isn’t getting them tight enough and there isn’t room for a socket wrench.

One thing I noticed tonight is that there’s only a couple threads of purchase between nut and bolt. It would be better if the bolt was a tad longer, call it 5mm. If I ever have to take the damned thing apart, I might try to thin the eccentric on the nut side by 2mm. I’d need a lathe or a mill to do that, but that’s in the works.

#96

[quote=“Ranger” post=56378]I might try to thin the eccentric on the nut side by 2mm. I’d need a lathe or a mill to do that, but that’s in the works.[/quote]I don’t know which kit you used, but I think the Ireland kit simply uses the E39 eccentric/slotted bolt combination (bolt p/n 33306760591?). I believe they are plenty long. RealOEM shows it as an M10x66 size.

#97

I’ll check the bolt length. My kit is definately non-standard tho, the nuts are SAE. I bought some SAE wrenches today at HF. I’m hoping I can tighten the nuts a whole revolution and in so doing get another thread of purchase on the bolt. If I tighten them too damned tight tho, the threads on the bolt will strip. Half the threads on the bolts are already gone because of two “chords” cut out of the bolt-circle in order to go thru the eccentric.

I’m thinking maybe I need to take the nuts back off, hope the hell my precious perfect alignment isn’t disturbed, and get some locktite on them.

#98

Jim - I listened to you. Last night I started my sub-frame swap and within a few hours had it ‘done.’ Today I’ll do the alignment and button everything up. Thanks for your tips and advice.

#99

So would it be safe to say that Rob Levied it up instead of Rangered it up?

#100

It would be more correct to say that Rob “used the Force”. I’ll leave it to Patton to explain that…