Started front end on 115
 

Now that I've gotten into things, I have questions.

I started with the front subframe mounts, haven't gotten any changed yet but noticed the steering box is leaking down onto the drivers side rear mount. Should I Not replace the mount until re-sealing the box?
I plan to do the entire front end so maybe I should plan on dry docking the car until all of it is done instead of doing it bit by bit.

Also plan on replacing front brake pads, noticed the rotors have a small lip on the outside edge. The rotors look good other than that, there are no unusual grooves otherwise. The lip is about a millimeter deep. Are they shot?

Thanks for the help.

Your call on the steering box -- the oil won't help the mount any, but you can cover it maybe till you get the box done.

It will take some time for the deterioration to get very bad.

Get new rotors, chances are they are several mm thinner than new, and the safety of good brakes greatly outwieghs any savings for me. You won't need new ones again for about 60,000 miles.

No one said these were cheap cars to maintain, did they?

Peter

Seems I need to separate the brake hoses and tie rods to get the sub frame to drop enough to get the mounts out. Going to replace the tie rods anyway. I should just get all this junk out of the way and make the whole job easier.

You're right, discs aren't expensive, I hadn't looked at it like that. Only 30$ each on Fastlane. I think these pair have 150,000 miles on them.

Are the brake hoses reverse threaded? They wont budge. I've got the counter hold on the brake line while trying to move the brake hose lefty loosey but nuts are starting to round. Ugh.

Is there anything bad from lowering one side at a time that can happen to the drivetrain? Seems like an odd angle for things to be at that aren't used to twisting that way, like driveshaft U-joints and exhaust lines.

No reverse threading - use Kroil or PB Blaster + time, and proper brake/fuel line wrenches - not a box-end.

Good luck.

No need to remove anything to replace the front subframe mounts, but for the second side you will need a sturdy pry bar. First side will be easy, the wieght of the engine will drop the subframe down enough to get the mounts out. With the new mounts in on that side, though, you gotta pry down pretty hard to get clearance on the other side.

Since you have the car up on jack stands, the wheels can move around on the tie rods.

Peter

Plan of attack
 

If I'm going to remove the steering box, is it necessary to remove the brake master and booster? They look old and crusty and I've been considering rebuilding them anyway. Should I make this a one time big project and get front end, steering box and brake system all at once?

I'm not too worried about cost and time, this 115 has been in my family since I was 3.

Thanks

CT, did you use all the tools in the front end kit from JC Whitney? (Just wondering if I should try getting pieces individually)

Are you sure that some kinda snake oil plus genuine steering fluid instead of tranny fluid might not fix the leak. I think the steering box will be massive chore. Uncoupling the pitman arm and steering shaft?? Plus you might as well reinforce the fender well with sheet metal drilled for the mounting bolts.

Btw, 123's are notorious for having weak and sloppy steerage. Retro-upgrade to 114/115 steering box is on my list for the 240D.

I've never heard of a brake booster going bad, and it might be an involved process to replace where it hooks up to the pedal. I just repainted the casing of mine when doing the master cylinder a few months ago.

It always seems like old frozen rusted bolts are toughest part of working on these cars. Good idea to marinate *everything* with penetrating oil. For suspension kit I'd think about a ball-joint separator, 3 foot pipe extension for 1/2" drive break bar, small sledge hammer and propane torch.

I used two or three pullers/spreaders. But the set was so cheap it was still a good deal.

The only special tools I've used on the front ends on these cars are a "pickle fork" for ball joints and a Klann spring compressor to do the front control arm bushings and a press for the ball joints. I suppose you would need a puller to get the pitman arm off. Otherwise, just regular toolbox stuff, most of it is very easy.

Master cylinder would be a good idea, particularly if the brake fluid is totally black and cruddy, but if the brake booster works, leave it alone except maybe to paint it.

While you are at it, I'd go ahead and plan for brake hoses, new fluid, and brake caliper rebuilds. Not necessary to do all this at once, but definitely flush the brake fluid before winter and rebuild the calipers when you do the next set of pads -- 30+ year old rubber seals are gonna give you trouble sooner or later, and this is a very easy job on calipers that aren't seized yet!

Bet a sway bar bushing kit while in there, it makes a HUGE difference in the way the car drives.

Peter

Yes, I've got the sway bar kit. I heard the pass. side mount is a PITA.
I'm going to get the bell, wedge and pitman arm puller individually (sorry CT, it didn't add up for me, but I did follow the link in your signature and dug the pictures :o ) and borrow what else I need from my mechanic. He's really cool about that sort of thing but won't lend out his Klann spring compressor anymore. Another indie in town borrowed his old one and used an impact gun on it. Next time he went to use it he said he nearly got killed. :(

Think I will do the master, calipers and steering box, but not the booster. Had to stop for now as the rains are hitting hard this week and can't stand to leave the Finback outside.

The mount bolts on the passenger side are box, with very limited access. Yes, it's a big pain.

Most likely the rubber is gone at the control arms, too, or at least bad, and I've even lost the head of the long bolt there on the 280SE. Had to saw the other one off, the sleeve between the control arm and sway bar bush sets was frozen on something terrible, I just cut the bolt with a hacksaw.

You shouldn't have any other problems, on the W115 the bolt is long enough to fit right up, as I remember. On the 280 I had to use a floor jack to compress the rubber enough to get the nut on the thread! Tighten down only to where the is a nut's width of thread showing or a bit less -- equal to one or two threads showing out of two nuts (the new ones are all locker nuts, not the origianl twin nuts). You can screw it down a whole lot more, usually, but you will compress all the spring out of the rubber and it will ride hard. Ditto on top shock mounts as well, the are often greatly overcompressed.

Peter

I've got the rear wheels up on ramps, had the front tires off with jack stands under the frame rails just aft of the firewall. It is amazing how much the body flexed when I lowered the jack from the subframe. I didn't care for that so I raised it back up a little and put some other stands under the outside edge of the LCA. Just in case, there are the stands under the frame rails with slack and the jack just below the subframe also slack. The weight is resting on the LCA's with less flexing noted in the body. Will not be able to work on it for about a week. Now that I think of it, it's stupid that I started today since the fintail will be expelled from the garage for no good reason.

Steering box looks daunting. Fluid loss in the resovior is minimal but there is play in the wheel. Suppose the coupling is bad. Is there an adjustment on this box? Should price a rebuild before removing it. :o

Check the coupler, it's common for it to loose it's bushings, makes the car wander and the steering wheel will rattle on rough pavement -- clack-clack noise. Watch the coupler while someone move the wheel, if the rear half of the coupler moves independent of the front half, replace it.

Should tighten the steering up quite a bit.

Peter

Coupler
 

Hey PSFred,

On the coupler, my 115 has a lot of slack. Can I replace the bushings or do I need the entire coupler? part # M502015324

Any hints to make the job easlier? It looks like it will be a little hard to work on.

Sorry, not trying to hijack this thread.

Joshhol
On the steering box leak, Lucas makes a power steering stop leak that says "Guarenteed to stop all seal leaks or your money back" .
Well, it may not work for a bad leak but I have had very good results with all their products I have tried.

Thanks,
Brian

Brian:

If there are spring clips on the ends of the "pins", you can replace the bushings. If not, you must replace the coupler. MB changed from a rebuildable one to a non-rebuildable one sometime around 1972 (the W108 is fixable, the W115 is not). Same part fits both, later # is swaged together.

Peter