Mercedes-Benz Forum banner

1 - 20 of 251 Posts

·
Moderator
Joined
·
9,038 Posts
Discussion Starter #1
If you can link to or post repairs, please do so in this thread. I will be "polishing up" the thread later to make it easy to follow.
 

·
Registered
Joined
·
4,021 Posts

·
Registered
Joined
·
56 Posts
RE: Do It Yourself (DIY) repair thread

Nice topic about Cruise Control Amplifier. Also quite often Clutch transistor going bad - CC start hesitate and then quit... If you look at the board from top and 14 pin connector on a left - clutch transitor located by 8001-501 chip on left lower corner it is 40c part....
 

·
Registered
Joined
·
1 Posts
AC expansion valve W126

I did a writeup on this job. This is a true (not a cheapo) R134a conversion that has held and worked nicely in hot&humid Washington, D.C. for two full seasons now. I'm not talking about the conversion - all I am explaining is how to replace the expansion valve (which is the first thing to go after a doubtful conversion) yourself for about 90 bucks in parts in one afternoon. This is a job that was quoted to me at several places at over $1,250 (yes, with the r134a conversion already done, so the quote means the refrigerant for the entire system only cost me $15 at Target...).

http://www.funnyyouasked.com/Mercedes/W126/ExpValve/removal_and_replacement_of_expan.htm
 

·
Registered
Joined
·
173 Posts
How To : change wiper blades

having done a search here & looking at the owners manual i was none the wiser in changing the rubber wiper blades...

having bought the wrong set of blades, i then went to a mb spare parts & garage and bought the correct bosch 4224 22inch blades... (AUD$18.00 each - even though they came in a pair packet - maybe the garage priced them that way to make it easier for them when replacing only one on customer's cars)

i removed the old ones and correctly fitted the new ones, but realised they didn't look right - as in the manual... there were no 'metal' strips in the rubber blades... so, i took the metal strips out from the old blades and , , , voila, , , success!!!

so, just in case, another benzworld and car newbie doesn't know "how to" change things, i thought i'd post this as well as attach a pic of the correct bits :)

safe and happy motoring

kindest
~m
 

Attachments

·
Registered
Joined
·
1,155 Posts
Wheel fitment thread

Below is a list of links that will answer most questions about what rims will fit on a W126. the single most important thing to remember is that an offset (ET) of 25 or less is what the car calls for.


Anyone wishing to add to this thread please do.





Wheel fitment links

http://benzworld.org/forums/forums/thread-view.asp?tid=1253232&posts=7
http://benzworld.org/forums/forums/thread-view.asp?tid=1253713&posts=4
http://benzworld.org/forums/forums/thread-view.asp?tid=1249823&posts=2
http://benzworld.org/forums/forums/thread-view.asp?tid=1248573&posts=8
http://benzworld.org/forums/forums/thread-view.asp?tid=1247774&posts=3
http://benzworld.org/forums/forums/thread-view.asp?tid=1246617&posts=6
http://benzworld.org/forums/forums/thread-view.asp?tid=1245906&posts=2
http://benzworld.org/forums/forums/thread-view.asp?tid=1245593&posts=4
http://benzworld.org/forums/forums/thread-view.asp?tid=1244092&posts=2
http://benzworld.org/forums/forums/thread-view.asp?tid=1242571&posts=2
http://benzworld.org/forums/forums/thread-view.asp?tid=1242366&posts=15
http://benzworld.org/forums/forums/thread-view.asp?tid=1241700&posts=15
http://benzworld.org/forums/forums/thread-view.asp?tid=1240225&posts=25
http://benzworld.org/forums/forums/thread-view.asp?tid=1240055&posts=3
http://benzworld.org/forums/forums/thread-view.asp?tid=1239304&posts=16
 

·
Registered
Joined
·
1,155 Posts
RE: Wheel fitment thread

Here's a list of wheel widths and offsets that I wanted to add last night but couldn't get to format right. I think Talbir is the one to thank for the original list.
 

Attachments

·
Premium Member
Joined
·
6,225 Posts
RE: Do It Yourself (DIY) repair thread

POOR IDLE

quote:
48hp - 3/4/2006 1:33 PM

Per Factory Service manual V-8 Engine 116..96 & 117.96:

Checking electric activation of idle spead adjuster (ICV)

Engine - operating temperature.
Ignition switched on.
Pull coupling from idle speed adjuster and measure voltage.

Readout approx. 12v then

Checking regulation of control unit

Engine at idle at operating temp. Plug on couple at idle speed adjuster in a manner that voltage can be measured on plug.

Readout 5v +-1 then

Check idle speed adjuster

Engine at idle.
Simulate coolant temp <42 degree C, for this purpose pull coupling from temp switch and bridge. (located at rear passenger side on top of manifold)

Idle speed increases to approx. 750/min.

End of test

Any other values then those described above suggest a faulty control unit (located at firewall)

If a faulty control unit is found, nowhere within the Mercedes Manual does it suggest this method but others have suggested this and it worked for me. Remove the control unit cover and lightly twisting from side to side while engine is running. Idle should drop to normal speed once twisted in a manner that effects the potential poor solder union. Heat each and every connection, adding a bit of solder to each point. My idle is now on the money.

Hope that helps.
 

·
Premium Member
Joined
·
6,225 Posts
RE: Wheel fitment thread

Here are a couple more:

http://www.mbnz.org/forums/forums/thread-view.asp?tid=1166576&posts=9
http://www.mbnz.org/forums/forums/thread-view.asp?tid=191006&posts=6
http://www.miata.net/garage/tirecalc.html

link didn't work for this page but here's the info..

Wheel Offsets

There are two basic offsets. The early cars had a small offset:
Pontons, Fintail, 108/109, 114/115, 116, 126, 123 and 107
More recent cars had the larger offset:
201, 124, 202, 140, 129, 210, etc, etc.
As offset change with rim width there are heaps of differant offsets.

The Late Ones The Early Ones

5.5 X 14 ET35 6.0 X 14 ET30
5.0 X 14 ET50 6.5 X 14 ET30
6.0 X 15 ET49 6.5 X 15 ET30
6.5 X 15 ET49 7.0 X 15 ET25
7.0 X 15 ET44 8.0 X 16 ET23

ET44 is the dimension in mm front centre of the rim to the face where the hub bolts to the rim.
So ET25 is quite small (25mm from the centre of a 7" rim). The later cars were something like ET44, that is a lot further from the centre. So if you put a W124 rim on a W126 the inside of the rim is in danger of fowling on the steering arm and maybe even the brake lines - this is known in the trade as "a real bad thing".

The stud pattern has remained the same over the years, just the offset changed. Regarding spacers: check with the local regulatory agencies first. They're illegal here in Australia.

John Greene

Some actual offsets of various Mercedes chassis
W126
6.5" - 21.5mm
7" 25mm
201 and 124 Mercedes offsets

The '84 201s came standard with a 14" 15 hole alloy 5" wheel (looked like the 15" wheels used on 124/126 from '86 on but was 14"). It had a unique lug bolt (not used on ANYTHING else that I know of). Part way into '85 they switched to a 6x15" wheel (changing to the same lug bolt used on the 124s). Except for not fitting on the 190E-16V sports cars, in '84-'86 you could swap these 14 and 15" wheels around. The introduction of the 190E 2.6 and 190D 2.5 turbo, both with vented front rotors and a larger caliper assembly (in MY '87 I think) the 15" wheels were redesigned and while none of the standard measurements changed listed in the specs changed, the newer wheels cleared the larger brake assemblies fitted to the more powerful of these newer cars where the older ones didn't clear! All of these wheels had 48-50 mm offset. The later wheels could be used on all of the earlier cars. All the US sold 124s thru the '80s used 6.5x15" wheels with ~49 mm offset (though the sportlines in the mid '90s MIGHT have used a 7 or 7.5" wide wheel - I have NO wheel listings for '90s 124s). None of these wheels should be fitted on any 123/126 even if they MIGHT physically fit! The '86+ 126s used either 6.5 or 7 x 15 wheels with 21.5 or 25 mm offset respectively. THEY can be fitted to older 126 and 123 cars but NOT to 124/201s

Marshall Booth
 

·
Registered
Joined
·
5,646 Posts
How to test the OPV (Overload Protection Relay)

It is a good idea to first check/replace the fuse in the relay.

Remove from car. It is held by a single 8mm nut and then unplugs.

set the multimeter to diode mode. Positive test probe to terminal 31 and neg to term 30

norminal value is 0.4V to 1.5V
 

·
Premium Member
Joined
·
1,905 Posts
After a crash course by Axel Wulff and Horst K, the light finally went on in regards to tire sizes...here is a link with a calculator to see which tires are permissible to maintain suspension geometry and how much your speedometer will deviate due to changing tire size.

http://www.avtogumi.com/index_en.php
 

·
Registered
Joined
·
1,830 Posts
To replace the shifter bushings:


You will have to get under the car and disconnect the shifter lever at the trans. Put the shifter inside the car into position 2. There is a bolt holding the lever onto the shifter shaft. Once you slide the clip off the shifter rod, the lever will come off. The NSS has a moveable lever on it and it has to line up with the hold in the shift lever. The NSS is held onto the transmission with two 10 mm bolts. The electrical connector has a twisting locking ring so rotate it, can't remember which way, and pull it off. Replace the NSS with the new one, align the NSS lever with the shoft lever hole and put it back on. You may want to replace the shift bushing while you're in there. The rear bushing is a PITA but can be done from below but is best done from above by removing the center console and shifter mechanism.
 

·
Registered
Joined
·
18,534 Posts
Brake Pad Replacement

It’s best to put the front of the car on jack stands and remove both tires at once. That way you can turn the steering wheel and the calipers out for easier access. The procedure is the same for the rear brakes, simply delete the wear sensors.

Tools/supplies:

Textar pads
Bottle of DOT 3 brake fluid, do not open as it may not be needed.
MB anti-rattle paste
Anti-rattle spring a.k.a. cross spring
Four pad wear sensors
Channel lock pliers
Brake fluid bleed screw hose and fluid container
(a Mity-Vac is best)
3/8 in bleed screw wrench
Hammer and punch
Assortment of rags and large and small standard screw drivers

Using the hammer and punch remove the retaining pins. A small screwdriver will work as well. The pins are held fast by the cross spring. When enough of the pinhead on the inside of the caliper is exposed remove the pin with pliers.

The cross spring can be removed when the pins are out. Note that the pins pass through the corresponding loops on the top of the pad. Remove the bleed screw nipple cover and place the bleed screw wrench on the bleed screw and attach the hose over the bleed screw nipple. The connection needs to be air tight as to not get air in the system. The small container at the end on the hose will collect the excess brake fluid when the caliper pistons are retracted. Open the bleed screw. Remember you’re working backwards – as you’re facing the caliper you’ll turn clockwise to loosen, the screw opens with very little effort.

Resist the temptation to pull both pads at once! Do one pad at a time, do not have the caliper ‘padless.’

Using the channel lock pull the pad away from the rotor and against the caliper and piston. This should free the pad enough to remove. It is common for the pad to be hard to remove; being very gentle and careful use the large standard screwdriver to coax the pad out, gently moving it back and forth until it’s free. Pull it out with the pliers when you can.

Open the channel lock all the way, place one jaw on the outside of the caliper and the other on the solid metal part of the piston. Note the dust shield on the outside of the piston, make sure the plier's jaw is clear of the dust shield and very gently push the piston back into the caliper – DO NOT PUSH TOO FAR or you’ll damage the caliper. As you retract the piston you see a small amount of brake fluid drain into the hose and container.
Spread a thin amount of anti-rattle paste on the back of the pad where indicated in the image below. One packet can do an axle. Insert the wear sensor and install the pad.
Repeat the process for the other pad and again the other caliper.

Close the bleed screw and remove the hose, replace the cover over the bleed screw nipple. Place the cross spring in the caliper and insert the retaining pin through the brake pad loops. Using the punch drive the pin into the caliper so the pin is secure, you should see the point of the pin sticking out of the caliper pinhole just as it was before the job.

The brakes may feel a little light when you first step on them but they’ll firm back to normal on the second or third application. With new pads the pistons do not need to extend as far for the pads to contact the rotor, thus less fluid is needed. The amount of fluid bled will be equal to the greater thickness of the pads. If the low brake fluid light come on add some fluid to the reservoir

I recommend checking the pads once a year and replacing them when half worn, to wear to the brake pad sensor is too low in my opinion and forces the pistons to ‘hyper-extend’ to compensate. I believe this adds stress to the caliper and may cause leaking and a premature rebuild or replacement of the caliper.
 

Attachments

·
Registered
Joined
·
18,534 Posts
M103 Motor Mount Replacement

The mount replacement for the 300 SE/L is the same as the V8 cars, the mounts are chassis, not engine, specific using the same basic w123 part number with different p/n’s for the left and right mounts.

Left/LHD driver side: 1232415013
Right/LHD passenger side: 1232415213 (under protective shield)

As correctly noted in a recent thread get the mounts from the MB dealer only, do not use after market as they can fail too soon. In this case the extra expense of the dealer is worth it.

Engine prep: detach lower part of engine shocks, fan shroud, snorkel, and disconnect the battery.

Tools: 6 mm Allen key, 8 mm Allen/hex socket bit, 3/8 wrench with extension, bottle, floor, or engine jack, large block of wood for the oil pan (see bottle jack/wood block image below).

The mount is attached to the cross member by two 6 mm Allen bolts and to the engine by one 8 mm Allen bolt. Remove the 8 mm bolts first to free the mount from the engine and raise the engine enough to gain access to the 6 mm bolts. The 8 mm bolt is accessed via the cross member passthrough under each mount. Take care removing the 8 mm bolt: make very sure the hex bit is snug in the bolt hex recess otherwise it may get stripped. A breaker may be needed for your ratchet and an extra pair of hands is a good idea, one person to turn and the other to make sue the hex bit remains snug in the bolt recess. For the passenger side mount protective cover there is an arrow pointing forward for correct replacement. With the 8 mm bolts off the protective shield can be turned to access the 6 mm bolts.

Using the 6 mm Allen key remove the two bolts holding the mount to the cross member. You may raise the engine more for better access. When the mounts are out clean the cross member where the mounts rest of debris, it can be considerable over the years and will fall in your face when installing the new mounts. As you introduce the new mounts take care in raising the engine, raise the engine only enough to insert the mount and clear the engine foot. Attach the new mount to the cross member and slowly lower the engine on the mount. Secure the engine to the mount with the 8 mm bolt.

The two most difficult parts of mount replacement were breaking free the 8 mm bolts and aligning the mounts to the engine ‘s 8 mm bolt and cross member. This requires raising and lowering the engine to make sure the 8 mm bolt is connected correctly to the threads in the engine foot to avoid stripping the thread.

Below are pics of my old crushed mounts in the middle with new mounts on either side, as you can see there is a considerable difference in engine elevation. In my case the passenger’s side mount (second from left) was torn and the top part of the mount resting on the cross member. When I replaced the fan shroud I had to adjust it a little higher from the original placement with the engine at its proper height.
 

Attachments

·
Registered
Joined
·
18,534 Posts
Changing the ATF and Filter

Tools and Supplies:
8 quarts of Dexron III ATF
AT filter
Pan gasket
Ramps and chocks
Torque wrench
Funnel that fits the dipstick tube
27mm socket/wrench with extension
5mm Allen key
Phillips screw driver
8 quart (minimum) drain pan
Lots and lots of rags

Ramps are the safest way to work under the car if you don’t have a lift, imo. First, remove the axle cross member (6 16mm bolts) to access the torque converter drain plug vent. Attach the 27mm socket to the crankshaft bolt and turn the engine clockwise until the converter drain plug can be seen through the vent. Open the plug with the Allen key and let it drain.

Using the Allen key remove the drain plug on the AT pan and let the fluid drain. One option is to let it drain overnight. The lower part of the AT and filter are submerged in ATF in the pan sump and will drip forever when you drop the pan and the filter. Letting it drip will avoid much of the mess. If you elect to drop the pan and replace the filter right away make sure you’ve got lots of rags around. DO NOT WIPE ANY PART OF THE AT WITH RAGS. Even the smallest fiber can damage the system. There are three Phillips screws holding the filter to the bottom of the AT. Remove the old filter and replace with the new one. Clean the AT pan.

Remove the old pan gasket and replace with the new one, reattach the pan to the bottom of the AT.

Add four quarts of ATF to the transmission through the dipstick tube using a funnel. Start the car and run the gear selector through all gears. Add more ATF up to less then one quart of ATF to avoid overfilling. For example, if your AT takes 7.9 quarts of fluid add seven quarts. Drive the car and get the ATF hot. On level ground run the gear selector through all the gears again and check the ATF level. Add more fluid if needed.

Pan bolts torque to 8 Nm.

Pan drain plug and torque converter drain plug 14 Nm.
 
1 - 20 of 251 Posts
About this Discussion
250 Replies
94 Participants
Michael Pillay
Mercedes-Benz Forum
BenzWorld.org forum is one of the largest Mercedes-Benz owner websites offering the most comprehensive collection of Mercedes-Benz information anywhere in the world. The site includes MB Forums, News, Galleries, Publications, Classifieds, Events and much more!
Full Forum Listing
Top