How in the f--- do you get rear trailing arms off?

[djmcmath]

I'm stymied again. Rear trailing arms need to come off so I can replace the bushings. My bolts, fortunately, were inserted from outboard towards centerline, which should help. Theoretically speaking, all I need to do is apply an appropriate amount of torque with a pair of 22mm wrenches, but I'm just not getting it. Aside from Kroil/PB-Blaster, anyone have any good tips? I'm this close to dremmelling the nuts off and just replacing these two bolts. After all, how expensive can they be?

TIA for any thoughts,

Dan

[Joe Bob]

Trailing arm cover bolts on MINE were 17mm. Took all four off, pulled the cap, pried off the arm with BFScrewdrivers, then pound on the t-bars to loosen.....removed them and cut off the old crappy bushings.

I DID have to spray some PB Blaster in the tube to get the inside spline to release. On Dan Byers we ended up cutting the t bars in half as the end was welded on tight with rust and we were replacing the t bars anyways....

BTW,
The caliper needs to be removed as well as the shock bolt at the bottom.....then there are three 19mm bolts holding the axle tot he swing arm......

I got REAL good reindexing the rear of the 356 with out adjustable spring plates...took that SOB after five times on each side to get it right.....

The 911 was a breeze comparitavely....

[ishmeal]

Tie Shadowfax to the fence, and with a prybar, pry those horseshoe off. Make sure he doesn't kick you in the process.

Be careful, I think the torsen rod will kick too. (I think) As to how to do it. I haven't done that one yet either, I'd like to know too.

[jpnovak]

They are well torqued. Keep soaking in PB and maybe some heat. Watch out for the wiring harnes that exits near there. A section of pipe over the wrench or a large breaker bar will help a bunch. Try bumping the wrench with a deadblow hammer to break them free.

[djmcmath]

The torsion bar cover 4 were relatively easy. So were the camber and toe-in adjusters, and the shock bolts, and the sway bolts. It's the 2 m14x1.5 (?) bolts that actually mount the trailing arms into the pick-up points underneath the backseat, near the transmission.

I've attempted the impact method -- but I managed to sheer the socket off the bolt-head, because I couldn't figure out how to apply counter-torque in that tight location. When the breaker bar came off the bolt, I managed to push it straight into the torsion bar tube, which looks like it's been hit a couple of times before. (sigh)

You had to use PB to get the t-bars out? Crikey, that's rotten.

I'll keep working at it. BTW, on the off-chance that I have to remove these buggers with a dremel, does anyone happen to know the part number for these nuts and bolts? I may end up replacing them anyway, as they look like they've been abused even before I started. TNX,

Dan

[Jim Sims]

For 1975 through 1989: M14 x 1.5 x 75mm long, 10.9 strength class, hex head cap screw; PN 900.082.064.08. Pelican can order them for $5.22 each. The M14 x 1.5 nut (special locking type) is 900.084.014.02 but this part doesn't come up correctly on Pelican's part index. You have my sympathy; I found this job difficult even with the engine and transmission out due to all the other lines, wires and fittings in the vicinity of the screws/nuts. One caution about cutting the screw head off with a cutoff wheel; you will need to get to the nut to cut it off too if the screw head is gone. Good luck, Jim

[djmcmath]

Jim, thanks for the PNs. I'm very likely to just cut them off, for $5.22 each. Roger the problem with cutting the nuts off, too; Actually, I'll probably apply my tungsten carbide cutting bit to the nut, which would free the bolt as well, with less cutting. Now to find those silly buggers... It sounds kind of bad, BTW: "I'm going out to the garage to cut off my car's nuts."

Dan

[yeuporsch]

I used a long flat head screwdriver at the hex of the nut and pounded with a hammer to loosen it. Then, used a prybar to pull the nut off. This was the longest and toughest part. My was a 72 and the bolt was the opposite way.

John

[oneblueyedog]

The spring plate bolts (eccentric and clamp bolt) are torqued on at a huge amount. I got mine loose by using a floor jack as suggested by a poster. Breaker bar on the nut, jack on the end of breaker bar, pump it up. The weight of the car helps you.

I only did one this way though. I had not loosened one side on the car and tried to get it loose clamping it into a vise and using a breaker bar. No luck. I took it to a shop with a big compressor and that didn't work either. I then used a 24mm box end extension on the end of the breaker bar and it finally came loose.

The jack method to loosen it was simple and quick.

These bolts are expensive so try not to destroy them, although I doubt you will.

Lee78sc

[john walker's workshop]

a pair of 7/8" (22mm) wrenches usually get them. probably not rusted on a '86, just tight. gethold of the inner nut with one, and push with your foot on the other. or get longer tools for more leverage. you just have to loosen them initially and then it won't be so bad. hooking the box end of one wrench over the open end of another extends the wrench for more leverage.

[djmcmath]

Just got off the phone with Tom at Pelican, who helpfully admitted that the online catalog is sometimes wrong, and proceeded to dig around on the Porsche microfiche for me. These are the PNs that he came up with, which corresponded to parts that looked reasonably correct in the catalog search:

Rear trailing arm to body bolt 900-082-092-02
Associated nut 900-910-055-02

Parts ordered...

Dan

[Jim Sims]

Good to know the M14 nut part number; the screw number (900.082.092.02) Tom quoted is an 80 mm long screw. The '73 and '74 steel arm cars used a 77 mm long screw and the '75 and later aluminum arm cars have a 75 mm long screw listed. I wonder if Porsche rationalized the parts at the next longer 5 mm length or if the 80 mm length will be a tight fit? Jim

[Randy Webb]

Spray with Kroil or pb Blaster. Then put the wrench on and tap with a steel hammer over & over again. Repeat 10x. The [small] impacts help the penetrant get down in there. Keep doing it for 2-3 days. If that doesn't work you can try renting air impact stuff, heat, cutting it all apart. This is probably not a good time to tell you I had no problems with mine...

[djmcmath]

Jim -- I'll let you know if the 80mm one is the right length. It seems like there's enough room in there for an extra couple of mm, though it'll be fairly tight. Tom was quite certain about the size and number of the bolt, which was encouraging. If it's too long, I have a hacksaw and a set of threadfiles, which is a lot faster than waiting for a 75mm replacement part to arrive.

Roger the penetrant usage routine. I'll try tapping it with a hammer as long as I can manage to put off pulling the sucker. In addition to the usual PB Blaster, I've been applying some unusually coarse language; the foul vocabulary worked great for the wheel studs, but doesn't seem to have any impact on the trailing arm bolts. That is what you mean by "impact" tools, right?

(ahem) I have an electric impact wrench, but there isn't enough space to get it in there. The best heat I have is a heat gun, which is usually inadequate. Next step -- tungsten cutting bit! Whee, I love cutting my car apart!! I think I'll refrain from destroying the still functional parts that are currently installed until the replacement bits arrive. Pelican says it's a special order item, which may take up to a week to ship out. (sigh) Oh, well. Thanks for the help,

Dan

[Randy Webb]

Mapp gas torches are cheap - just a propane head and a can of Mapp gas.

Sorry to hear about the elec. impact wrench - use the hammer. Maybe a BFH...

Cursing has always worked well for me - it sometimes scares off girlfrineds tho. Good luck.

[Zeke]

Yeah, get the MAPP gas and the swivel torch tip. It seems to have a smaller point to the flame and you can focus it better on your target.

MAPP gas should get most things hot enough for the heat method of breaking frozen parts loose. Sounds like you've got a couple days until your parts arrive, give the wrenches another try.