P80 P2 Subframe Bushing installation with pictures 3507923

[BlackBart]

Done, thank you. Pushing the two front ones in this morning. It’s still cool, it’ll be 94 today.

[BlackBart]

I SURE wish I had not disconnected the steering shaft from the steering rack. Now I’m jamming my arms up in there from the bottom trying to pull the u-joint down onto the shaft to engage the little pinch bolt. Way less room now that it’s buttoned up.

77 ft-lb + 120 degrees, on your back, oof. Got the 4’ pipe out for that.

[Blacklab467]

Good Job, sounds like you're almost done!

[BlackBart]

I had planned on adding my experience to Blacklab's excellent write-up on this task.

It was tough, I made mistakes, it took too long, I feel like it knocked me down many pegs on the MVS mechanical aptitude chart, but oh well. So here are the steps I followed and some of the mistakes I made, if that helps others.

Just FYI, I supported mine from just behind the rear subframe brackets. There's a reinforced part of the floor where they attach. then I could move around anywhere forward of that.

I borrowed an extra floor jack to multi-task. Since it was coming all apart anyway, my plan was to combine the subframe bushing job with new IPD sway bar & links, replace the RF axle and dust seal, replace the angle gear oil, and replace all the motor mounts. Maybe bit off too much and was out of a car for a week.

So, mark the bushing orientation, mark your new bushings. Drill out the plastic shell in a couple of spots then collapse the bushing with a chisel or big screwdriver.

That led to my first major mistake. You want to drill out near the perimeter to catch the plastic ring, but not so far out that you gouge or score the steel ring on the subframe. I heard it and should have stopped right away.

There is an upper and a lower steel sheet with a gap inside the bore.
Doesn't look too bad, a scratch, clean it up with a round file and continue.

Aside - my HF impact gun did not break the subframe bolts loose. I used max leverage...

Always replace the subframe bolts - for stretch and for corrosion... (this is actually the axle bolt - replaced)

I used the 2x's on a jack method to push the new bushing in. Thought I had to be doing it wrong. It's not pushing parallel to the frame. Use large hammers on a 2x. What I didn't realize is that the little notch I put in the subframe hole was catching the edge of the bushing and grabbing it. It buckled out and wouldn't move. I pushed the frame back up and got a bolt to thread, but it was jammed. I shaped it back to round, tried again. Flipped it 180 to avoid that spot. Wasn't going in.

[BlackBart]

THIS was the whole problem. The force of shoving the bushing up split that groove into a crack in the rim, and the upper edge caught the bushing no matter what.

So I busted out the big files and reshaped the hole to eliminate the upper ledge and hook in the metal.

After the reshaping, I tried a different strategy. I used a cheap HF bearing press set I had in the closet. Not sure what car I bought it for, but it was like $30 on sale. I also filed down the plastic ridge on the bushing as well as the rubber where it overlaps the plastic. Eliminate ledges. I watched this poor sap in the UK on youtube fighting this without drilling them out or any of the tricks in this thread, and he used dish soap instead of grease on the bushing and steel. "Washing-up liquid" he called it. I will now forever call it washing-up liquid. It works, very slippery.

That giant tall nut on the top of the tool will rear its head later, and of course it's an Imperial size like 1 1/8 I don't have, so I held it with a vice grips and used a big Channellock pliers. But you can see the bushing creeping up into the hole. Everything nice and straight.
This worked until the top of the bushing hit the tool's washer.

So I took it apart and used the nut trick to make some room.

And BOOM, it bottomed with a little pop!

Pop on your o-ring, and Bob's yer uncle.

[BlackBart]

I did the backs first because I was already dragging the sway bar out the back and I had the exhaust loose and the subframe way down - which led to other problems later with the steering rack and motor mounts.

That supertall nut on the tool JUST cleared the left rear big location pin on the chassis. I'm sure I could find a normal one, or cut this down. (precision channellock marks on the bolt head)

But easy peasy, it went right in.

RF.....

On the LF, the factory location pin wouldn't allow that press tool in at all, so I went back to old school, but filed the bushing smooth, got everything nice and parallel, then washing-up liquid and a jack!

...and suck it up with the bolt and serious leeeverage....

A few spots, it looked like there was bare steel showing on the chassis, so I greased it up.

[BlackBart]

Workmanship. When I had it all back together and looked around, one of the o-rings is hanging a bit off the side of the subframe...
It's in place, but not all the way around - must have gotten bumped while I was cranking the bolt. I do have another set of bolts , I could loosen that corner, pry it down, straighten out the o-ring, pop in a new bolt. There's no noise, it's "probably fine."

[BlackBart]

Not to distract from the subframe topic, but I did several other things which made the whole exercise more difficult for me. The RF axle and seal was actually very easy - bolts all came right out, no damage to fix, popped in the seal with a big socket, slid the axle in, fought the strut, new axle bolt, bolted it all together. "I'm doing great, this'll be EASY!" Filled up the angle gear with a syringe (from the kitchen, shhhh)

So I dove into subframe bushings, which hit a standstill until I figured that out, wrestled (literally) the sway bar through the chassis and bolted it down. That required the exhaust supports loosened or removed, the subframe rear hung way down, and the steering rack and plumbing loose from the subframe. As long as it's hanging, the motor mounts should be easy, huh?

You've got three major chunks to support - the body, the engine/trans, and the subframe and everything hanging off of that. The front and rear motor mounts are hard to get to, and big heavy cylinders that won't clear the frame and pan, so you keep separating the subframe and engine farther. You rock the engine left to right, rotate it fore and aft.. pretty soon nothing lines up and it's all off.

Was there really anything wrong with this? At 150k miles and 20 years, might as well. The top strut and the bottom drag link mounts are easy. The right side / end of the block mount was accessible once the engine and subframe came back together.

Jack this, lower that...

I snapped off the tabs that support the crossover pipe, everything was cranked so far forward..

You'll need this to access the motor mount nut, kneeling on top of the engine... but then change that to a wobble socket at the bottom...

The rear motor mount actually bolts to and bears on the steering rack, so they have to be separated. But why won't it drop, why can't I get it loose?? Ohh, I forgot the steering shaft coming through the floor, and the subframe is hanging off the U-joint. DOH!
And why won't that come loose? Because the bolts are under a huge load and they're all bound up - stop hitting them with a punch! Stop trying to spread the U-joint clamp, it's a pinch bolt, dummy!

So...I finally got the shaft disconnected in the interior behind the pedals, dropped it through the floor, and the steering rack dropped down. Once I had the mounts out and replaced, I couldn't get the steering rack linkage back together because there was aluminum corrosion and I had scored it earlier and the pieces wouldn't slide back together. Lots of tiny files, laying on your back, some grease, and I got it back together. Now I'm thinking, "have I bent anything doing all this?" But I managed to wiggle and jack and push until everything either dropped down or lifted up from below and aligned. Some careful crowbarring. Went through each system to make sure all the hardware was back in and the plumbing and cables connected. Everything torqued.

And somehow, the SS Betty rolled out of drydock a week later. Alignment wasn't off by much, drives great. Next project - rear sway bar.

[Blacklab467]

Excellent write up!

[BlackBart]

Haha...postmortem? Oh, wait, the patient walked out of the clinic, it's a miracle!