new 1984 300SD owner checking in
 

Hello all,
I recently became a proud member of MB diesel family. Purchased a 1984 300SD in California, available with all records going back to 1984. Very low miles, 131xxx, one family owned vehicle.

I have studied this forums for the last three weeks. The wealth of information is amazing!
Since purchasing the car, I drove from California to North Carolina with no issues with exception of hot start I mentioned in my other post. Got 26-29 mpg on that trip!

So far I have changed the oil/filter, both fuel filters, replaced air housing mounts with new ones (added metal caps), replaced the whole tie rod assembly and did the brake guide mounts. Factory stereo was disconnected since the owner said it was draining the battery. Installed an Alpine HU, no issues with battery three weeks later.
Bought some of the parts right here!!
On the list of things todo are UCA (joint bushings are destroyed on each one),
replace trannsmission mount, figure out why both front power windows dont work, solve my starter issue, replace all belts and figure out whining noise from the transmission when in PARK or NEUTRAL.

Great car, great forum here.

Whoo Hoo!!

Keep us posted.

Welcome! from another 1984 300sd owner

Congrats
 

Hope you enjoyed the road trip. We want to see photos :D

Congrats Pics please.

Some pictures I have so far.

thankfully, the auto shop on base had a press to get the guide rods in.
About to go do both UCA's and replace transmission mount.

When I took the car to the dealer, one item on the list of things to fix i am not sure about:

"Modulator cap for transmission housing recommend replacing $93.28"

What exactly is that part? I'm not terribly familiar with automatics yet..

The M-Bs of that era use vacuum to modulate the transmission shifting based on engine load and speed.

On a gas engine the engine vacuum naturally happens based on throttle position.

On a Diesel you do not have a throttle so no engine vacuum. You have artificially produced vacuum from the vacuum pump. So on the fuel control linkage there is a device known as a VCV or vacuum control valve. That varies the constant vacuum coming from the pump into a signal that emulates what a gas engine would be doing at that point.

This goes to the modulator on the transmission to regulate the shift points.

The cap is the adjustment device for the modulator. It is inexpensive and easy to replace once you are under the car.

The hard part is tuning the new one properly. The correct way is to tap in a pressure gauge into the transmission fluid test port and tune it based on fluid pressure.

Lots of posts on here about this.

Go to startekinfo.com, on the left is MB workshop resources, click through a couple pages to the 126 service info, you have the entire shop manual for the car available online.

As a former '84 SD owner, I will say that it was my favorite of the 126's. Mine had all the best options, but not the trap ox (being a CA car). I think '84 was the best year for the OM617 powered cars. The gray interior is my favorite as well. The paint on mine was the only real problem, but yours looks really good. Enjoy your car, as I know I did when I had mine....Rich

Thank you for the info. I went to startekinfo.com, but only found manuals for 123 and 124 models. I did buy a Chiltons manual, maybe I'll find something there.

does anyone have a link to an official MB manual?

Thank you! I dont know why the 126 manuals wont show up from the main page.

Wow, that's a Beautiful car! GOOD SCORE!
no press is needed to install the Guide rod bushings, but it's easy with a press. they will press in by hand, or you can use the bolts to pull it in. glad you got it done! I love the wood shifter handle you've got, looks great.
is your leather interior grey or creme? it looks creme in the pics. UCA joints are a snap to install too.
you need to post more interior shots, include the center console, and some close ups of the gauges too! also, ENGINE SHOTS!!!

glad another NC resident has a great SD! enjoy her!

What a beautiful car! Don't sweat the mechanical stuff as all of it is easy to do and cheaper than something like a re-paint. I'm no good at cosmetic work, so I have to farm that out and it gets real expensive fast.

You say you are on a military base? What division? Thank you for your service!

The interior is grey, the hood and front fenders were repainted by the original owner couple years ago, the rest of the body shows appropriate wear on the paint. Will take some more interior pics soon!