Replacing flex discs - What do I need? - Page 2 - PeachParts Mercedes-Benz Forum

Stretch · #16 04-06-2015, 02:30 PM

Quote:

Originally Posted by Ceristimo

@Stretch
Oh, I was taught that everything can be used as a hammer. I have a big flat blade screw driver laying around as well to do some prying with. I'm sure I'll get off somehow.

And hey, who knows: it might not even be that stuck. A man can hope...:-)

Indeed we can hope! I have my fingers crossed that an Alaskan environment will not have been harsh on your flex discs...

Ceristimo · #17 04-06-2015, 02:58 PM

@Stretch
Yeah, I thought things up here in Alaska don't really rust. But boy, did my oil cooler lines turn into a struggle. Holy cr*p, those things were seized on. Especially the bottom one. Fought with it for three days.

And you know, looking carefully on the bottom of the car, I certainly have some rust going on on the Benz.

So....It's probably gonna be hella stuck.... We'll see. Parts will be here the 16th.

I can see a few tiny hair cracks on the front flex disc, but all things considered they really don't look bad. Especially if these would be the originals. Which they may or may not be, since I have exactly zero information about the history of this car. Literally nothing is known about the maintenance history.
I can probably drive it like this for months and be fine, but I saw some pictures of failed flex discs that scared me pantless, so....

And on a totally unrelated note:
I feel like I might be subconsciously putting off the "getting-the-car-ready". It seems I can keep finding things that cause me to tell myself I can't drive it yet.
I have a feeling it's because I don't fully trust this car. I don't know why. Just a nagging feeling.
I feel like I'm going to sink a bunch of money into it, drive it for the first time and have the timing chain break or the transmissions give out or something. There is no reason to believe it will. I just don't know at what point the car can be considered 'trust worthy'.

All things considered I did drive it home 350 miles over terrible snowy and icy mountain roads and did not have a single issue. Well, except with the headlights. They suck.
Anyway, being able to drive it for 8 hours without a complaint from the ol' Benz must mean something. But I parked it on Feb 14th, and haven't driven it since. We're almost halfway through April, so it has been sitting for two months now. The engine has been started three times since then, just to get it on or off my ramps under its own power. Runs fine by the way. Starts good too.

I don't know. Maybe I'm just an idiot or maybe I like complaining, or maybe I should've never bought a 32-year old car - since I might not be smart enough to fix it -, but I don't know how to give myself more confidence in this car. There just seem to be so many (small) things wrong with it, the list appears end-less.

I am not looking for advice. I was merely venting.

Ceristimo · #18 04-13-2015, 02:17 AM

Still waiting on my flex discs. Had to replace the windscreen washer pump on my wife's car today, so I needed the garage. Backed the Mercedes out of it for the first time since February.

Even though it currently isn't insured, I couldn't resist and drove it up and down our street a little. It's a cul-de-sac, so not too much traffic anyway.
When driving it around I noticed - again - that it's shifting a little late. First shift seems to happen around 25 mph.
Pulled over, popped the hood, and adjusted the bowden cable to where it has a tiny little bit of slack.

Judging by ear (my tachometer is dead) it shifts at much better points now. Not too early, but at least I'm not cruising at 20mph in first gear anymore.

I did notice something I hadn't noticed before, and that is that the transmission has a very feint whine in park and neutral. It disappears instantly when shifted into gear. The noise is so feint that you really have to listen for it, but it is noticeable. I hope that is not a sign of something else expensive coming up, but I was planning on changing the tranny fluid and filter anyway, and I'm hoping it will disappear then.

I paid some more attention to the play in the steering wheel, and noticed that it isn't really play, but more of a dead spot in the center. When I turn the wheels, there is no play at all. It only seems to be there when the front wheels are straight, and we're talking a good 3 inches, measured at the rim of the steering wheel. Not sure if I want to adjust the steering box, because I read at several places that is not a good idea. Then again, other folks seem to do it without a problem. The play in the steering wheel doesn't bother me all that much, it doesn't "feel" dangerous, as the car tracks straight and doesn't need much steering input in a straight line anyway.

After my little trip around the block (I'm sure the neighbors thought I was being weird, when I passed their house for the 4th time in 10 minutes) the Benz got parked in the garage again and as of now, it's still waiting for those flex discs...

Stretch · #19 04-13-2015, 07:01 AM

Still no spares? I thought service round here was bad...

jaw174 · #20 04-13-2015, 09:14 AM

This guy, Kent Bergsma over at mercedes source has a great video covering the whole drive shaft, including flex disk. Very informative.

https://www.youtube.com/watch?t=22&v=tmznEE7JRpI

Steve_in_NV · #21 04-13-2015, 10:42 AM

Ceristimo, I just replaced my flex discs the other day on a 85 300TD. The rear disc is ease, but you need to pry the drive shaft forward about an inch because of an alignment pin in the rear end (it's) easy. The front is a little more involved you need to remove the transmission mount and that means supporting the transmission with some sort od jack. Not on the transmission pan. Maybe spray the bolts with lubricant. 17mm wrench and 15mm socket for the flex disc bolts. Mark the drive shaft (propeller shaft) so you get it back in the same orientation. I was able to pull mine out the back, separating from the front shaft. I didn't need a 47mm, it slipped right out, their very tight. On the front I put the flex disc on the transmission then bolted on the front shaft. On the rear I put the disc on the shaft then mated it to the front shaft REMEMBER to mark the two shafts where they go together. It took me about 3 hours. As far as you tach mine didn't work either, did you check the over-voltage relay? Located passenger kick panel, there is a 10 amp fuse mine was blown, but that didn't fix it, I needed a new relay. That relay powers up another device that makes a lot of things work. FYI the relay I got was updated and I needed to cut a pin off for it to fit in the socket (that pin is not needed). Good luck and work safe.

Ceristimo · #22 04-13-2015, 12:15 PM

@Stretch
Spares for what? Not sure if I'm following...

@jaw174
Thanks!

@Steve_in_NV
Thanks for the information! Only three hours, huh? That's not too bad. I'm expecting myself to take at least 2 days, if not three. I've noticed things tend to take about 3 times as long as expected whenever I attempt them.

I had seen someone that jacked up the transmission with a thick piece of wood underneath it (pretty much the same process as jacking up the engine). If you can't jack it on the pan, can I ask how and where you lifted the transmission?
Thanks!

Stretch · #23 04-13-2015, 12:51 PM

Quote:

Originally Posted by Ceristimo

@Stretch
Spares for what? Not sure if I'm following...

...

I meant the flex discs still had turned up - spares as in - spare parts - the bits you need

Ceristimo · #24 04-13-2015, 01:33 PM

@Stretch
Ooh, gotcha...Yeah, things do tend to take their sweet long time to get here...

Ceristimo · #25 04-15-2015, 02:33 PM

Still waiting on parts. Got bored, surfed Ebay looking for fun W123 stuff.

I was looking for a replacement right rear light cluster (mine has a hole in it) and then I found this:

Mercedes W123 123 Brake Light Upgrade 300D 300CD 280E | eBay

It's a brake light upgrade, using the (unused) fog lights as brake lights. I bought it, so we'll see how that turns out.

I noticed the light switch in my US W123 can be pulled out 2 notches. I remember from my dad's W123 in Europe that when pulled out all the way the rear fog light would turn on. Am I correct in assuming that the second "notch" on the US light switches is just not wired up at all, and thus useless?

Also, my front fog lights only turn on with the head lights. Pretty sure on the European W123 you can run the fog lights (we always called them "wide beam lights" in Holland) without having the head lights on, but I'm assuming this was also not allowed in the US?
On my daily driver (Mazda) I rewired the fog lights so I can turn them on with just the parking lights. That was quite easy, but I guess it'll be much harder to accomplish the same thing on a W123?

TnBob · #26 04-15-2015, 10:45 PM

Surprised he didnt use LED's.

Ceristimo · #27 04-16-2015, 10:03 PM

The postman came bearing gifts today. A nice shiny box from Pelicanparts full of goodies.

For whoever reads this in the future: If you order the flex discs as OEM brand, they are in fact Lemförder. Nice!

Now to set a wrench-date...

Ceristimo · #28 04-20-2015, 03:58 PM

I'm going to attempt this repair this week, during the evening hours when I get off work. That'll give me roughly 3 hours a night (I go to sleep early, I need my 8 hours...) to mess around with this. I don't have time during the weekends for several weeks, but I don't want to wait any longer. I want to start driving this car.

I found a how-to right here:
Pelican Mercedes-Benz Tech Article - Replacing Your Front and Rear Flex Discs on your Mercedes Benz - 190E, W124, W126, W201, W123

It looks pretty straight forward, but I had three questions, since I'm not the most mechanically inclined person:
1) The flex discs look identical on both sides. The only difference is there is a number written on one side. I guess that side should face the drive shaft then? I've read other folks where the flex disc had "this side to driveshaft" written on it in German, but mine don't have that; they only have a small number
2) How can I jack up the transmission? Can I do this the same as I did when I jacked up the engine, underneath the transmission pan with a large piece of lumber to support it and spread the weight? Will the transmission pan hold this? The oil pan on the engine had no problems supporting the engine weight with a piece of lumber.
3) The how-to says to "lightly grease the fittings". What do they mean with "the fittings" and what kind of grease should I use for that? Brake grease?

Thanks!

I'll have the car on ramps; someone here mentioned that you can jack up one wheel on the lower trailing arm temporarily to rotate the drive shaft, and I'd rather have the car on ramps then on jack-stands. Just personal preference I guess; I feel safer with the vehicle on ramps.

SD Blue · #29 04-20-2015, 10:32 PM

Here is the FSM: Mercedes Service Manual Source, CD/DVD/Paper

The main thing to watch out for is how the flex disc is oriented in regard to the seating into the flange. Here is a thread that will help explain: Flex Disc Orientation, safety and durability issue.

When I did mine, I don't recall having to jack up the transmission. If you raise the rear end, with the suspension dangling, you should have plenty of clearance to remove the propeller shaft. However, if your working on ramps, you may have a time getting the shaft to compress enough. Personally, I would never jack on the transmission pan as I don't believe you can get away without bending/distorting it to where you will have constant leaks. It uses a rubber seal that I don't believe will hold up to jacking.

Grease the fittings is probably referring to where the raised boss of the flex disc inserts into the flange. If you don't apply a very small dab of grease, you may have a very difficult time of ever removing them the next time.

Ceristimo · #30 04-21-2015, 02:09 AM

Thanks for the information. That is very valuable!

See, I thought the orientation of the driveshaft doesn't change, regardless of whether or not there's a load on the suspension. I was under the assumption that the transmission and the differential were both fixed and couldn't move, so I figured that putting the car on ramps wouldn't matter.

But you're saying I have to jack it up? Well shoot. I currently don't own a jack and jack stands yet that I can use for the Mercedes. I have a small 2 1/4 ton jack and 2 ton jack stands. I've used them on my daily driver a bunch of times, but that little Mazda is not nearly as heavy as the Mercedes is.
That means I'll have to go buy a jack and jack stands. Bummer, that sets it all back a little bit. Really no chance this'll work just fine on ramps?

I do wonder how you're supposed to jack up the transmission like the instructions say if you can't jack it under the transmission pan with some wood to spread the weight. Someone else have a suggestion?