Topic: The Patience Project - my 1980 300SD

[avantbenz]

I'll use this post to update everyone on what's been done and what I'd like to do to slowly restore 'Patience,' my 1980 300SD.

Last summer I found myself in need of a good, realiable and safe daily driver and, while doing some research, I kept coming testimonails of reliability for these old Mercedes diesels. Now, I know those testimonials only refelect engines which have been well cared for but I was still impressed by the sheer number of people who praised these cars and decided to take a chance.

I found a few W116's on Craigslist and went to visit a few of them that looked promising. Two of them were in much worse condition than advertised but the third had a good looking interior, strong sounding motor, and only 167k miles. The biggest problem with contender #3 was a salvaged title due to a recent accident that required some bodywork to repair.

When I went to see #3 most of the bodywork had been done with the exception of the paint. The frame looked straight and during the test drive the alignment felt good. The biggest problems I did notice, however, were:

Window regulators (all four) were shot.
A/C didn't blow cold.

The seller seemed to know a fair bit about these old diesels and assured me he could take care of the paint job, window regulators, and the A/C. I wasn't looking for A+ work but just something to get me started so I'd have a decent base from which to work. I put down a sizeable deposit on the car and was told he'd have everything ready in a week.

That week turned into a seven month long nightmare. I recommend no one *ever* put down on a deposit on a car with a private seller unless you know them to be trustworthy. I was far too naive. I was able to get the title fairly early on so I wasn't worried about my ownership of the vehicle but I definitely made a lot of mistakes and gave him too much money for me to back out when it was clear that he wasn't in a great hurry to do the work.

I ended up taking posession of the car after completely losing faith in his time management skills. He'd completed a 'meh' paint job - it's good enough but not perfect and fixed the driver's side and passenger side windows. The rear windows will go up and down but sound so ragged that I simply don't use them because I'm afraid they'll stop at any moment. The A/C (surprise, surprise) still doesn't work - he told me to bang on the server with a small block of wood and see if that would fix it. The driver's side is also missing a small piece of chrome that he promises he'll get to me (one day).

The worst of it all is that he'd put on at least 800 miles driving it during the time he was supposed to be working on it. It could actually be more - the odometer which was working when I put down the deposit stopped working before I brought her home.

So, I learned a few valuable lessons about buying a used car from a private seller. In the end though I'm pretty happy with the price I paid (even without the work being completed).

I recently took it to an awesome mechanic who specializes in Mercedes (and has experience working with old diesels) he gave it an (almost) clean bill of health - her flex discs needed to be replaced ASAP as well as the two rear tires. I had expected both of these costs so it wasn't a huge blow although I'm upset that the money I put towards the flex discs and new tires could have been put toward fixing the A/C and/or rear window regulators.

I'll probably end up taking the seller to small claims court (I have all receipts, record of work to be completed along with written records of timeline shifts along the way, mechanics report of the car's condition when I finally took posession of it, pictures of the odometer and everything else when I first bought it compared to when I took posession) but I doubt I'll ever see a dime from this guy. If anyone wants the name and number of this guy so you can avoid him, please PM me.

So, onward to what's been done so far:

-Oil change using Shell Rotella oil and a Mahle filter
-Air filter changed (Mahle)
-Flushed and replaced power steering fluid
-Flushes and replaced brake fluid
-Replaced a few corroded fuses in the fusebox (I plan on replacing them all with newer fuses from Mercedes Source)
-Printed and affixed a copy of the fuse chart to the fusebox so I always have it handy
-Replaced transmission mount (it was completely disintegrated)
-Replaced flex discs (genuine)
-Replaced fuel lines with new ones (genuine, braided) 
-Replaced a couple worn out donuts that hold up the exhaust (still need at least two more)
-Retrofitted a magnetic mount using 3M tape for my phone (used an old one that was specific to my Audi A4)

And now for what I plan on doing, in the order of priority - funds are limited so it'll be slow going. This isn't a comprehensive list and until I get the important stuff out of the way I'm not even thinking of cosmetic improvements although new carpet and floormats are an absolute must. Open to other suggestions as well!

-Replacing air filter housing mount bracket with the beefier one found on Mercedes Source
-Replacing the seals on the elbow joint connecting the air filter housing to the turbo - the lower seal isn't holding up probably due to the vibration caused by the broken bracket and I'm worried about unfiltered air getting sucked into the turbo
-Replace the flexible hose for the air intake housing - it wasn't on the car at all
-Replace the air filter breather tube clamp
-Replacing pre-filter and screw-on fuel filters. Maybe check out the diesel tank fuel filter as well.
-Figuring out a way to unstick the front calipers - they aren't terrible but they're sticking every once in a while - I'll have to tackle the brakes soon anyway so it can wait a little bit
-Replacing weather stripping on all four doors (it's rotten and they let water in as verified during a car wash)
-Find all vacuum leaks and verify correct assignment of lines
-Fix the A/C system (bleh, dreading this)
-Lube up those window regulators to extend their life, maybe tackle the rear windows
-Re-calibrate the speedometer / rebuild the instrument cluster so the odometer and tachometer work

Problems I've noticed:

-If I lock the doors while I'm still in the car and go to turn off the engine, it won't shut off after I take the key out. It'll sputter and stop after about a minute. I'm almost positive this is somehow related to a vacuum leak.
-There is a slight hardness to the early shifts, especially while cold (even if I'm taking it easy and staying slow). I think it might be a vacuum leak to the transmission modulator or it could be a torn diaphragm within the modulator itself.

That's it for now! She'll be my daily driver and I don't have plans to get her into show-ready condition but I would like to make her look and run as nice as possible. I'll post some pictures soon but gotta get to dinner. This is a long enough first post!

[ptashek]

-There is a slight hardness to the early shifts, especially while cold (even if I'm taking it easy and staying slow). I think it might be a vacuum leak to the transmission modulator or it could be a torn diaphragm within the modulator itself.

Can't say specifically for a diesel, but on the petrol models (350 and 450 at least), the transmissions tend to be a bit on the harsh side, until warmed up fully. They're not harsh in a jerky sense, but the shift points are certainly noticeable.

Some adjustments can be made with the control pressure rod attached to the throttle linkage, and getting rid of vacuum leaks, but it's not going to be a night/day kind of difference.

Truth be told, the fully rebuilt, perfectly tuned 35k mile transmission in my 450 is just about as cultured as the much more modern specimen on my W124 (funnily enough, also partially rebuilt 40k miles ago). It seems to be a Benz thing

[avantbenz]

-There is a slight hardness to the early shifts, especially while cold (even if I'm taking it easy and staying slow). I think it might be a vacuum leak to the transmission modulator or it could be a torn diaphragm within the modulator itself.

Can't say specifically for a diesel, but on the petrol models (350 and 450 at least), the transmissions tend to be a bit on the harsh side, until warmed up fully. They're not harsh in a jerky sense, but the shift points are certainly noticeable.

Some adjustments can be made with the control pressure rod attached to the throttle linkage, and getting rid of vacuum leaks, but it's not going to be a night/day kind of difference.

Truth be told, the fully rebuilt, perfectly tuned 35k mile transmission in my 450 is just about as cultured as the much more modern specimen on my W124 (funnily enough, also partially rebuilt 40k miles ago). It seems to be a Benz thing

Hey, I just got finished reading through your goldilocks thread and browsed the blog! Love that plush green carpet - I need to lay down *all* new carpet on Patience soon.

How are you liking the performance of your infiniti speakers?

I've been reading the forums and also noticed a theme about the shifting. I do think inspecting the vacuum and replacing all the rubber diaphragms in this car will make a difference but I think you're right - it won't be night or day. It seems like there is a "Benz shift" which, seeing as how this is my first Benz, is new to me. I will say both of my Audi's had a stiffer shift into 2nd gear so maybe it's a German engineering thing. I'll see if I can capture it on a video and post a link.

This is a link to a flickr album containing progress pics of Patience - it seems like so many of the pictures posted on this forum aren't working anymore so I want to have a permanent repository somewhere else.

I chose Flickr: https://www.flickr.com/photos/154440914@N02/albums/72157666372064647

[ptashek]

Hey, I just got finished reading through your goldilocks thread and browsed the blog! Love that plush green carpet - I need to lay down *all* new carpet on Patience soon.

I got the whole lot from cabrio.de in Germany, both as a complete set ($450 delivered), and some extra in bulk at about $50 a running meter (WxL 59"x39").
http://cabrio.de/en/carpets/car-models-prices/mercedes-benz-2013-11-05/116-126-limousine/carpet-set-w116-detail
http://cabrio.de/en/carpets/carpet-materials/fine-velours

They also sell the profiled foam pads, but I haven't used those.
http://cabrio.de/en/carpets/car-models-prices/mercedes-benz-2013-11-05/116-126-limousine/profiled-pads-front-and-rear-db-116-sedan-set-4-pcs-detail

How are you liking the performance of your infiniti speakers?

Compared to the JBLs I have in the front, they're definitely better balanced in terms of tonality, but on their own tend to be a little weak in the lower range. I've biased the fader +2 to the rear, and have the equaliser set to bass +2 and that balances the front/back nicely - that's the setup you can hear in the video. I'd say they'd be perfect if supported with a dedicated subwoofer in the low-end, but that's more hacking then I was bothered to do I still tend to listen to the V8 as my main music track anyway.

[avantbenz]

Lessons Learned Changing Transmission Fluid

Tools

Ratchet wrench
Socket, 19mm
Socket, 10mm
Socket, 13mm
Open ended wrench, 19mm
Philips Head Screwdriver
Chamois / Leather cloth (I used paper but leather would be a better idea)

Materials

Heavy duty plastic sheet
Shallow container for catching used ATF
Lint free towels
Funnel with a small tip
1 gallon of ATF (I used Valvoline Dex/Merc Max Life Fluid - came in a red bottle at AutoZone)
Meyle transmission service kit (I purchased mine from MercedesSource.com). It includes a new pan gasket,  three washers, and a new transmission filter.

Preparation Work

1. Place chocks on back wheels.
2. Put parking brake on the vehicle.
3. Jack the vehicle up via the chassis bit behind the oil pan - I wanted a good amount of space to work under the car.
4. Place jack stands under the vehicle to secure it.
5. Remove the jack.
6. Place a large sheet of heavy plastic under the car. This is a messy job and I didn’t want to ruin the driveway.

I used Diesel Giant’s write up on changing Mercedes transmission fluid as a resource and, although it was helpful, it wasn't a true apples to apple comparison for my 300SD. http://www.dieselgiant.com/mercedestransmissionfluidchange.htm

The 1980 300SD only has four bolts holding on the pan and 2 screws holding in the filter (Diesel Giant’s pan had six bolts and 3 filter cover screws).

I placed the shallow container under the pan to catch the used ATF and then used the ratchet with a 19mm socket to remove the banjo bolt from the transmission pan. It was a mistake to use the ratchet because when the ATF came out, it spilled all the way into the socket and I had to spend a lot of time cleaning it before I could use it again. I would recommend using an open-ended wrench to loosen the banjo bolt.

After dropping the transmission pan and getting all the ATF into the container, I gave it a good cleaning using de-greaser, water and a soft brush. MAKE SURE THIS IS CLEAN! Diesel Giant  had his pan dry in the sun for 30 minute prior to re-installation. I did the same thing but was worried about small microscopic particles getting in the pan that I couldn’t see. Next time I’d take a blow dryer and dry it out just prior to re-installation.

DON’T USE ANYTHING TO DRY THE PAN THAT MAY LEAVE LINT OR OTHER PARTICLES. It needs to be spotless!

After I cleaned the pan I cleaned the fasteners that secure the pan with some degreaser.

After letting as much ATF drip from the filter as possible, I loosened the two phillips head screws to drop the filter. Just when you think there isn’t any more ATF fluid…there is more so keep that shallow container handy for this step.

Don’t waste much time getting that new filter on there - the more time it’s off, the more time contaminates can get into your transmission.

After getting the new filter installed, I re-installed the pan. Be careful not to over-tighten at this stage. I took my time and tightened one faster on one side, then went to the other side to tighten that one, then back again. It’s best to tighten things like this in as much of a star pattern as you can.

Even though the Meyle kit contained three washers, I only ended up using two because I couldn’t find anywhere the third (slightly smaller) washer would go - hopefully I didn’t screw up anything there.

The two washers I did replace were on either side of the banjo bolt and the fitting. It was difficult to remove the old washer from the banjo bolt. (I tightened the banjo bolt using the open ended 19mm wrench but when I went to put ATF in, it was leaking a little and I had to use a ratchet wrench to get enough torque to tighten it properly.)

After tightening the pan and the banjo bolt, replace the jack under the car’s chassis, remove the wheel chocks and jack stands and gently lower the car to the ground.

Procedure for Re-Filling Transmission Fluid

1. Locate your transmission fluid dip stick and remove. Place it somewhere where it won’t become contaminated with lint or anything else.
2. Using a funnel, pour about three quarts of transmission fluid down the dipstick opening.
3. Turn the car on and slowly pour a little more transmission fluid in the reservoir. Wait for the vehicle to get up to operating temperature (80-90 degrees celsius)
4. According to the Mercedes manual for the 300SD, the oil level is correct if, with the transmission at operating temperature, the oil level is at the max mark.

Tips on Re-Filling Transmission Fluid

Go slowly. It took a while for my engine to reach operating temperature. Even when it did finally reach operating temperature (which for me is close to 90 degrees celsius) and the oil level was finally sitting at the max line, I sat in the driveway and slowly moved through the gears with my foot on the brake pedal. I took about five to ten seconds before switching it to the next gear and made it back to park. The level seemed steady at max and I took her for a short drive around the neighborhood. When I got back, I checked the level again and now the level was sitting a little bit above the max level so I need to drain off some excess fluid before I drive her again. The whole process is kind of a pain but I’d rather do it right than deal with a damaged transmission.

Pictures Here: https://imgur.com/a/452NOIB

Personal Observations

Fluid was definitely on the darker side but it wasn’t burnt smelling and there weren’t any particles in the drop pan - comforting.  Both before and after the transmission fluid change my car slips out of gear from a standstill unless I’m coming directly out of park. A shame and my search for a solution persists. Details found here and copied / pasted below: https://forum.w116.org/mechanicals/question-about-shifting-problems-with-my-300sd/msg139940/#msg139940

I'm trying to diagnose an issue I'm having during shifting.

It doesn't seem like a serious issue and I've found a workaround but I'd like to get everything running well *without* applying my workaround.

The issue: If I start the car, put it in 'D', and drive she shifts fine. When I stop at a stop light or stop sign and put my foot on the brake long enough to come to a complete stop and then press the accelerator pedal it seems like the transmission slips. It feels like she's starting in 2nd gear but not really - there is a total lack of power. My workaround is that whenever I come to a complete stop I move the shifter from 'D' to neutral and then back again into 'D' and then proceed to drive with no issues.

Any ideas? Is it a vacuum issue? Throttle lingage issue? I just want to know what I should tackle first because it seems like adjusting the transmission shift points is a big deal. Also, I checked my transmission fluid and it seems like it's at the proper level although it looks a little dirty. I'll probably end up changing it and the filter soon but I don't know if this would actually have anything to do with the issue I'm experiencing.

[Harv]

Thanks for the info. Did Kents kit come with any instructions?

[revilla]

Nice detailed write up. Thanks.
The 3rd washer is for the torque converter plug. In fact, in order to change the full amount of ATF in the transmission the torque converter needs to be drained too. From memory, there are about 3 more liters sitting in there. Your gear slipping issue can probably be resolved by adjusting your modulator located on the right side of the transmission.  It worked for me.  There are many posts on that subject here in the forum.
Cheers

[avantbenz]

Thanks for the info. Did Kents kit come with any instructions?

Update: There are instructions from Kent! I just didn't realize it was a PDF download until after I changed out the fluid. Oh, well. No instructions from Kent on the transmission fluid change out which is one of the reasons I tried to go as in-depth as I did here. It was the first time changing my transmission fluid and I wasn't able to find one fully detailed write-up outside of Diesel Giant's which still wasn't as in depth as I was looking for - this is a write-up based on looking at other forums, other transmission fluid write-ups in general, Diesel Giant and my own experience.

Nice detailed write up. Thanks.
The 3rd washer is for the torque converter plug. In fact, in order to change the full amount of ATF in the transmission the torque converter needs to be drained too. From memory, there are about 3 more liters sitting in there. Your gear slipping issue can probably be resolved by adjusting your modulator located on the right side of the transmission.  It worked for me.  There are many posts on that subject here in the forum.
Cheers

Thanks for solving the mystery, Revilla! Maybe I'll get to that next time I change out the fluid. I'm going to try and change out the shift bushings today so while I'm down there I'll test the modulator and see if it holds vacuum. It probably doesn't but if it does I'll try adjusting it based on what I can find in the forums.

[avantbenz]

I've got some time on my hands so I decided to keep trying to diagnose and fix my transmission issue. I highlighted the issue here: [Question about Shifting Problems with my 300SD](https://forum.w116.org/mechanicals/question-about-shifting-problems-with-my-300sd/msg142899/#msg142899)

Summary of the issue: If I start the car, put it in ‘D’, and drive she shifts fine. When I stop at a stop light or stop sign and put my foot on the brake long enough to come to a complete stop and then press the accelerator pedal it seems like the transmission slips. It feels like she's starting in 2nd gear but not really - there is a total lack of power. My workaround is that whenever I come to a complete stop I move the shifter from 'D' to neutral and then back again into 'D' and then proceed to drive with no issues.

A few of you mentioned that it may be the kickdown switch so that’s what I’m trying to tackle (link to images at the bottom of this post).

Today I cleared out the area by the accelerator pedal to expose the mechanical kickdown switch. I made sure that there was nothing preventing the pedal from making contact with the kickdown switch.

When I depress the kickdown switch it makes a mechanical click sound so that’s a good first sign. I noticed that the plug was only halfway secured (but still enough that the points should make contact) and I fully secured the plug.

I then crawled under the car to find out where the plug leads. The wire appears to lead under the drivers side (left here in N. America) to the transmission. I cleared off the area where I believe the solenoid is located and see the part number 04 8532 00. I can’t seem to find anything related to this part number so I’m still not sure if it’s the solenoid housing or not but I hope it is.

There seems to be a sheath of some sort protecting the wires and it’s a difficult spot to work in but not impossible. I watched Ken’s video on how to test a kickdown solenoid ( [Testing a Mercedes Automatic Transmission Kick Down Switch - YouTube](https://www.youtube.com/watch?v=nzBBHwX41mY) ) but his seems to have a black housing and doesn’t look much like what is on my vehicle.

I’m assuming that the wire will be screwed down somewhere and that is where I can place a lead to test the solenoid. I’m waiting on a couple leads so I can outfit my battery booster in the same way and easily test this - I’ll do that hopefully within the next couple of days.

Does it sound like I’m on the right track? Is this the solenoid? Any tips?

I’ve posted images with commentary here: https://imgur.com/gallery/WgAQBZL

[daantjie]

On my transmission the kick down solenoid is on the passenger side (right hand side in driving direction from driver perspective).  If you are hearing it click then it should be OK.
How are your shifts otherwise?  You might need to adjust your modulator pressure.

[avantbenz]

On my transmission the kick down solenoid is on the passenger side (right hand side in driving direction from driver perspective).  If you are hearing it click then it should be OK.
How are your shifts otherwise?  You might need to adjust your modulator pressure.

Interesting that it would be on the right side. The transmission modulator is on the right side for me - is your kickdown solenoid near it?

I tried testing my transmission modulator to see if it held vacuum yesterday but I think my hand pump is faulty because even with my test hose plugged with a golf tee it won't hold vacuum. I'm going to pick up another hand pump tomorrow to re-test and make sure it holds vacuum. If it does, I'll attempt to adjust it for firmer shifts with an allen key.

I also need to make sure the shift linkage is properly seated but still learning what the proper way even looks like so I can go from there.

Picture of the transmission modulator on the right side is here: https://imgur.com/gallery/VJMUBlo

[daantjie]

Yes the solenoid sits in front of the modulator so if you look up at the transmission from the right hand side the solenoid sits above the pan on the top right corner if you can imagine now looking from above if that makes sense.

[avantbenz]

Yes the solenoid sits in front of the modulator so if you look up at the transmission from the right hand side the solenoid sits above the pan on the top right corner if you can imagine now looking from above if that makes sense.

Now I'm re-thinking this! Based on what you said I went back and looked at a few more pictures I had taken of the area surrounding the modulator and found something I think might be promising (at least I don't know what it is).

Does your solenoid look like this? I'll take a better picture when I'm under the car again tomorrow.

Pictures: https://imgur.com/a/zxez26q

[daantjie]

Yup that be the solenoid in the middle bottom of your pic.