A subframe question (just the beginning ...) - Page 10 - PeachParts Mercedes-Benz Forum

KarTek · #**136** 01-13-2011, 08:32 PM

Looking great so far. Way to go, sticking with it!

BodhiBenz1987 · #**137** 01-15-2011, 12:43 AM

Well, I got everything done today, almost, but ran into a hurdle getting the axle nuts and inner axle bolts torqued down. As in, I pretty much can't do it and I need clever ideas. I'm putting a lugnut in with a scissor jack under it, but the whole wheel just lifts up off the nut. I tried jacking up under the spring link, with another jack under the lugnut, and it still moved. The parking brake offers a lot of resistance, but not enough. The inner bolts, I have a double problem in that the axle is turning slightly when I really put torque on it and I also basically can't generate 100 nm of torque under there while also holding the top of the wrench to keep it from stripping the bolt head. I strained so hard I almost blacked out. I feel pretty pathetic to say the least. I was thinking about putting the car on its wheels to try those bolts (then moving it forward/backward to get to whichever bolts I can't reach) but that obviously won't work for the outer ones.
Ideas? Am I missing an obvious solution?

Edit: I had this idea but forgot when I typed this post ... is there any reason not to put the calipers back on and have someone press the regular brakes while I turn the torque wrench?

I also can't get those parking brake cable clips on, but I'm not freaking out over that.

gsxr · #**138** 01-15-2011, 10:29 AM

Hmmm. On my cars, the parking brake was adequate to lock the wheels to torque the inner and outer axle nuts... otherwise yes, you could have someone stomp on the brake pedal, preferably with engine running to provide vacuum & therefore power assist! The outer axle nut should be done with the tire mounted & wheels on the ground, that makes it much easier - leave the wheel center cap off to access the nut. For the inner axle bolts you cleaned the threads with a die, applied blue Loc-Tite, and oiled the contact surface - right? 100Nm isn't a lot, you should be able to do that, but I understand it's more difficult with the car on jackstands instead of a lift. It's a breeze when you can stand under the car!

BodhiBenz1987 · #**139** 01-15-2011, 12:51 PM

Quote:

Originally Posted by gsxr

Hmmm. On my cars, the parking brake was adequate to lock the wheels to torque the inner and outer axle nuts... otherwise yes, you could have someone stomp on the brake pedal, preferably with engine running to provide vacuum & therefore power assist! The outer axle nut should be done with the tire mounted & wheels on the ground, that makes it much easier - leave the wheel center cap off to access the nut. For the inner axle bolts you cleaned the threads with a die, applied blue Loc-Tite, and oiled the contact surface - right? 100Nm isn't a lot, you should be able to do that, but I understand it's more difficult with the car on jackstands instead of a lift. It's a breeze when you can stand under the car!

Wow, I forgot about the removability of the center cap ... that might work a LOT better. Thanks.

The inner bolts, I replaced all of them with brand new ones, which have a torx head that I'm actually finding harder to get a grip on than the XYN heads. The new bolts came with a little bit of blue loctite on them, and I added my own. I used the grease inside the bolt holes residual from repacking them to lightly lubricate the threads ... hopefully that was OK?
I know I can generate 100nm, I think it's just the challenge of doing it on my back, while also pressing very hard on the head of the wrench to keep the torx bit on the bolt ... it really wants to slip off. I guessing if I find the right angle and approach on one, the rest will be much easier. Thanks!

babymog · #**140** 01-15-2011, 02:17 PM

On the inner axle / CV joint bolts, I have installed two lug-bolts (the 126 double-headed type are best) and a pipe through them to the ground, keeps the hub from turning.

The big axle nut I have done with the wheels on the ground as Dave mentioned. Brake & wheel chocks seemed adequate.

BodhiBenz1987 · #**141** 01-15-2011, 07:50 PM

The good news is I got everything together, put it on the ground and got the axle nuts done relatively easily using the parking brake and a chock. The bad news ... I'm screwed on the inner bolts. I got one torqued done with the wheels on the ground, but it's basically impossible to get the torx bit to stay on the bolt head. I stripped one beyond use, so now I have to figure out how the &%^$ to get it out (I have several spare new ones). It may sound pathetic to you guys, but I can't generate 100nm with one hand while pushing in another direction as hard as I can to keep the torx bit from slipping (which is what I was doing when it slipped anyway). If the bit would stay, I could get at an angle to apply the force. I'm going to see if I can find a torx bit with a slimmer design, but I don't think there's anything wrong with mine, it's from Sears.
So basically just ticked. I'm so close, and now I have a monumental task trying to get this stupid stripped nut out and still find a way not to do it to the others.

I also have a migraine and majorly light-headed so have to take a break, but really want to keep working and solve this bugger!
Thanks for the axle nut tip, at least I got that done.

BodhiBenz1987 · #**142** 01-15-2011, 09:46 PM

On a more chipper note, it is pretty cool to see my car sitting on the subframe I put in:

(I know the second pic looks crooked, but I was holding the camera crooked

)

TylerH860 · #**143** 01-15-2011, 10:52 PM

B-E-A-Utiful.

ImBroke · #**144** 01-16-2011, 08:16 AM

Cecily, you are far from pathetic. Keep asking the right questions, and they'll keep providing the answers. She looks real good sitting on the wheels, not much longer now. You'll get it, I know you will.

BodhiBenz1987 · #**145** 01-16-2011, 01:13 PM

Quote:

Originally Posted by ImBroke

Cecily, you are far from pathetic. Keep asking the right questions, and they'll keep providing the answers. She looks real good sitting on the wheels, not much longer now. You'll get it, I know you will.

Thanks ...

... it's just so frustrating to be so close and then get puzzled. I did get three bolts torqued down last night so at least I know I can do it. Going to see if i can get a few more now before I have to be at work.

BodhiBenz1987 · #**146** 01-16-2011, 01:50 PM

Just to clarify ... when the FSM gives different torque specs for different sized bolts (in this case M10 and M12) is that referring to the head or the threaded part? Because it occurred to me the bolts that came out were M10 XZN, while the bolts in there now are M12 torx ... I was following the M12 torque setting in the FSM, but was thinking, shouldn't it be the same as for the old bolts? Now I'm worried I'm overtorquing them. Hope that question makes sense.

KarTek · #**147** 01-16-2011, 02:52 PM

Torque specs refer to the shaft size. You wouldn't want to put a M10 level of torque on a M5 bolt with a M10 head in other words...

If that makes sense...

Nice job anyway.

BodhiBenz1987 · #**148** 01-16-2011, 04:16 PM

Quote:

Originally Posted by KarTek

Torque specs refer to the shaft size. You wouldn't want to put a M10 level of torque on a M5 bolt with a M10 head in other words...

If that makes sense...

Nice job anyway.

OK, that definitely makes sense ... I'm not sure why it didn't occur to me earlier. Then again I'm glad it occurred to me after torquing down three bolts with 30nm too much torque rather than after torquing down 12 bolts that way. I checked the shaft size with Pep Boys' gauge and it's M10, so they only need 70nm ... so now I have to redo those three. Good thing I have about 20 extra bolts that came with various kits. On the positive side, when I start over, 70nm won't be that bad ...
Stuck at work for the rest of the night, but will resume the battle tomorrow.

BodhiBenz1987 · #**149** 01-17-2011, 05:40 PM

ALMOST DONE!!!!!

I was able to remove the three overtorqued bolts with the impact wrench and replace them with new bolts using the 70nm specified for the M10 shaft. I even got the stripped one out ... after first stripping it worse, I carefully hammered the torx bit onto it ALL the way to the base, then used the impact wrench, and it whirled right out. I was able to reach three bolts on each side, then jacked up each wheel, turned it halfway, put it back down and did the other three (marking the ones I already torqued with a Sharpie just to be sure I got them all). I ALSO checked the torque on all my flex disc bolts, because I wasn't sure if I had followed the right setting (in light of my mistake about interpreting bolt size) ... so they're all at the correct 60nm.
I topped off the diff fluid, then started putting the exhaust back together, but had to run off to work ... it's almost done except one of the old exhaust bolts stuck in the flange, which is working its way out with a punch and hammer. I also forgot the exhaust shield, though I'm pretty sure I can work it under there with the exhaust in place. Guess I'll try to finish that up when I get home from work at 1 a.m., since I scheduled to drop it off for an alignment tomorrow at 8 a.m.

I'm really nervous to start it up and actually drive it ... like there will just be some awful grinding sound when I go to move, or something will fall off. There's also a good possibility it won't start at all, as I didn't think to unhook the battery and my amp may have drained it a bit ... but that would be no big deal, I can just take it to the Advance down the street and get it rejuiced.

Assuming all goes OK and I can go to my alignment as planned: The shop I use is about 10 miles away ... should I try to stick to back roads and drive really slow since it's probably misaligned now? I did try to put the eccentric bolts in the same position as on the last subframe, but that might not mean much since all the old linkage was so worn. I probably could have picked a closer shop, but this one is really good, and handles a lot of older MBs (my indy uses this shop for his clients' cars; it's right down the block from his shop).

BrianCostello · #**150** 01-17-2011, 05:46 PM

I would not be too over concerned with the rear alignment being out for the 10 mile drive. It's the front that gets down right dangerous if way out of wack. .

been there, done that. .

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