In the process of changing the subframe monuts. The only things keeping me from dropping the front axle carrier are the track rods. My tie rod removal tool is too big, the span is nearly as wide as the as the rod ends, so it is of no use. Careful persuasion with a drilling hammer yields no result. I'll probably swing by the parts house in the morning to see if they have a tie rod tool with a narrower span. In case I can't locate one, does anyone have any ideas on how to get the track rods off the steering knuckle in a pinch?

So far, outside of the track rods, the hardest part has been loosening the big bolts on the motor mounts. There isn't a whole lotta room to work, and it would be worse if the sub-mounts weren't shot, that's giving me an extra 3/4 to 1 inch working room.

Mike, Try loosening the tie rod nut and then giving the knuckle a sharp rap with your hammer. I like using a metal faced "deadblow" hammer, but I think a regular hammer will be fine as well, as long as it has sufficient weight. Size really does matter in this case. Just to clarify this a little more, the hammer blow is not trying to drive the tie rod out of the knuckle, it is against the side of the knuckle. I guess it provides momentary deformation of the taper joint and it just pops out! If this doesn't work, try it again with a pry bar putting some removal pressure on the joint as you rap the knuckle. Having removed many rod ends while a working mechanic (notice I didn't say professional!), I never had to use a "pickle fork".

Do you have to remove the brake flex line while doing this job? If yours have never been replaced, I would suggest doing it at this time. I have heard they tend to swell or break down internally, which happened to me. I bought mine while on the road at a Salt Lake City Dealership for $15 each (front only). There are three more in the rear.

Good Luck!

Mike,

Why are you loosening the motor mount bolts? It has been a while since I did subframe mounts on a 108 chassis but I know we did them one side at a time and I don't think we removed the tierods. We definitely used the weight of the motor to help drop each side. A jack handle also helped to pry down the subframe briefly for removal and installation.

If you have to remove the tierod there is a puller that will do it without tearing the boots as a picklefork will.

Steve,

My MB manual calls for loosening the motor mount bolts, so I did and have supported the engine. The Manual also called for removing the front coil springs, but I didn't since they are contained within the control arm and axle carrier and will move as a unit. It didn't look like I could drop the axle side enough with the tie rods attached.

As I just wrote that last line, it dawned on me that I'm looking at the tie rods with the front suspension totally relaxed. Once I put the jack under which ever side I'm changing, the suspension will come back under some load, the tie rods will level out, and there should be enough room for movement.

Deezel,

I tried good solid, sharp raps (gentle persuasion) with a 3 lb. sledge. No joy. I'll give a try with tie rods attached as Steve suggested.

The brake lines appear to be in excellent shape. Yes I removed them and they came off easily. The rubber is flexible yet firm, not soft or mushy, plus there was still a very faded part number label on one. So I would believe they have been replaced at some point. Judging by the color of the brake fluid, it has been several years though. The brake fluid came out looking like used motor oil, so I opted to completely drain the system and will flush new fluid through it while the whole car is up on stands.

I am taking pictures as I go, and I'll try to sum it up when I finish.

Thanks.

Mike,

You are going to a lot of extra work on this one. We always loosened the fan schroud and let the motor and subframe fall each side one at a time. Except for bleeding the brakes the whole job doesn't take more than an hour with experience.

Remember you should do a front end alignment afterward as the relationship between gearbox/idler arm is moving relative to the steering arm at each wheel.

"doesn't take more than an hour with experience", that's the key - experience. But I'm travelling uncharted waters for me, I don't mind taking the long way because I learn. Plus, I found that the left motor mount bolt was loose, at least now it will be tightened down when I'm done. The next time, in 30 years or so, I'll have the one hour procedure :).

The alignment will be done after the next step, I'll be taking the car to my local Tech Franz, for a steering box reseal.

One last question, before I grab a cup and start back to work. The book calls for torque of 10 kpm on the big bolt and 2.5 kpm on the 4 small bolts, according to the conversion formula I have that works out to ~70ft lbs and ~18 ft lbs respectively. Did I do my math correct, are the mumbers close?

Thanks for all the help.

Mike: Real close on the math. One kilogram meter = 7.23301385120989 foot pounds. I use the conversion link at http://www.convertit.com/Go/ConvertIt/Measurement/Converter.ASP

It works real well as long as you follow their format. For instance, the calculator doesn't want to see the phrase "foot pounds", it is looking for "foot*pounds" (foot times pounds). "Square feet" is ft^2, and so on.

Good luck with the sub frame work!!!

They're in!
 

Thanks Steve,

I listened to the experience, tightened the motor mounts and used the engine's weight. Did not have to pull the tie rods either. Once the subframe was lowered, it only took a little pressure on a pry bar to pop out the mounts, same for installing the new ones.

The old mounts were still intact, but the rubber had become very soft. This apparently allowed the axle to shift fore and aft, and this movement was wearing away at the axle suspension bolts.

Gonna get back to putting the pieces on, just wanted to let you know the hard part is accomplished.

As always, Thanks!

Mike,
Congrats! If I drive Suzanne back to Temecula, will you help me change mine?

Hmmm, now that I've been through it, we could knock it out in an afternoon. Let's see, 4-5 driving days (3 if minimal stops), a day to recuperate from copious amounts of Mexican food and beer, a day to work, another day to recuperate from another round of Mexican beer and food (and Franz does an alignment), then 4-5 days to get home (substitute weeks for days in Deezel's case). Piece of cake.

I still have to button the little stuff up, but came to a stand still thanks to Mother Nature. Even though the car is in the garage, it's cold and damp right now. I also decided that since I'm in there, I'm going to change out the brake hoses even though they seem to be in good shape on the exterior. It's cheap insurance.

While on the subject, I have owned my big torque wrench for nearly 20 years and only Sunday learned it was scaled in both foot pounds and Newtons. Never had a call to look at the flip side of the handle until I laid it down in it's case wrong side up. Dang I'm observant :o :) :D.

Deezel,

Sounds as if Mike just gave you the excuse you need to make the trip again. Remember, you shouldn't let Suzanne set up, she needs to be driven regularly.

Have a great day,