300D Wheels locked while towing - PeachParts Mercedes-Benz Forum

OldSchool300D · #1 05-22-2006, 05:06 AM

hello all,

I just inherited a 300D from my grandfather and we had a little bit of trouble getting it home...

The car made it to the highway just fine, but my father accidentaly left the oil cap off and the engine initiated a safety shutdown right there on the interstate. Initially, we didn't realize what the problem was, so we got a friend to come give us a tow.

While the car was being towed, the rear wheels locked up and sent the car off of the road (I wasn't there to see, no details on the condition of the truck) and into an embankment. Directly after leaving the interstate, the wheels were rolling again and the car began coasting down the hill it had been being towed up. The brakes appear to be faultless now, and the car still drives like a dream. I am sold on keeping the car, but I would very much like to know if you guys have any feedback about any possible reasons for it locking up like that.

The car is an auto, and we have toyed with the idea that it possibly slipped from neutral due to gravity on the incline - it is a very smooth, easy shifter - but that doesn't really seem feasible.

also - I am not sure of the year of the car, I was told it was a 75, but I read on wikipedia this evening that Mercedes didn't make a 300D until 76, any ideas?

t walgamuth · #2 05-22-2006, 08:25 AM

no, but your idea of it getting into gear is the best i can see.

sorry you are having problems with it.

they are really good cars, though and after you get accustomed to its idiosyncricies you will find it easy to work on and logical in its design.

good luck

tom w

sixto · #3 05-22-2006, 12:23 PM

Quote:

Originally Posted by OldSchool300D

... my father accidentaly left the oil cap off and the engine initiated a safety shutdown right there on the interstate.

I don't think there's any safety feature that shuts-off the engine because the oil filler cap is off. The engine will seize if it runs out of oil. That's not a safety feature.

How fast were you towing the car in neutral? The transmission front pump is not driven by the output shaft so some internals are not lubricated when the car is rolling with the engine off. Hence the factory recommendation against towing with the rear wheels on the ground in excess of 15-25mph or some such crawling pace.

Sixto

Rashakor · #4 05-22-2006, 02:15 PM

not to be pessimistic but i think you probably caused grat deal of damage in both incidents.
First, you ran out of oil and the engine is probably seized. and then you towed the car on its rear wheel and the transmission locked? so it is seized as well.

Well if the car is well cosmetically it is good for a complete engine/tranny transplant.

t walgamuth · #5 05-22-2006, 06:07 PM

Quote:

Originally Posted by Rashakor

not to be pessimistic but i think you probably caused grat deal of damage in both incidents.
First, you ran out of oil and the engine is probably seized. and then you towed the car on its rear wheel and the transmission locked? so it is seized as well.

Well if the car is well cosmetically it is good for a complete engine/tranny transplant.

unfortunately this could be true. i hope it is not.

tom w

slarson80 · #6 05-22-2006, 09:54 PM

Quote:

Originally Posted by OldSchool300D

The brakes appear to be faultless now, and the car still drives like a dream. I am sold on keeping the car, but I would very much like to know if you guys have any feedback about any possible reasons for it locking up like that.

So you've driven the car since the incident?

OldSchool300D · #7 05-22-2006, 10:14 PM

hay guys,

thanks for the quick attention.

I HAVE driven the car since the incident, and the entire drive train seems to be working very well. I had it up to 50 (then the road turned... it isn't licensed yet so I don't want to take it out on the actual highway) and there were no incidents at all.

When the engine died, the oil cap was left off, and it sprayed out a lot of oil, the engine didn't lock up, it actually just died and the car coasted. I had heard that a large number of old diesels had a fuel shutoff valve on them which would shut down the engine when oil pressure got low, and I assumed that was what happened.

The comment about the tranny lube seems to be the most practical idea so far. I am not sure how fast the car was being towed, but I would assume it was over 25 since it was on a major interstate. Does anyone have any idea how I would check to conferm something like that and that the tranny is ok? you know... other than using it to failure.

#8 05-22-2006, 10:32 PM

If it's driving ok now, then it's probally going to be ok for a while.
However I would go through and change all the fluids and filters...

OldSchool300D · #9 05-22-2006, 10:42 PM

yes, I had already planned to go through and change everything as soon as I finish cleaning up the outside (headlights kinda got owned in the highway escapade) I am worried that I am going to have trouble getting parts for a car so old though, can I just go to O'reileys and pick up all the normal maintenence stuff?

Nate · #10 05-22-2006, 10:58 PM

Get some pictures, and the radiator support codes... Check the drivers side door jam (should be a emmissions sticker)

Lots of pictures.

For oil, since it was abused, use moble one delvac... 10w40 ($25 for a gallon, you need 6 quarts)

Theres no safety shut down, just a fuel system that runs dry, and is a PITA to bleed (and dont bother with the old style primer)

For transmission fluid, use synthetic (whatever type you need)

The hays/chiltons manuals suck for theese rare cars (114/115 chassis)... They made the 115 style 300D for 2 years (75 and 76)

DONT hack up the dash for a radio/speakers, because a regular DIN sized one fits... a pair of 4" speakers on a box ontop of the stock opening works pretty good (kinda hokey looking, untill you get used to it)

The stock (hard to find) speakers are 4x8... Theres a cutout under the rear shelf for another one (if it had "stereo sound", theyre will be a rotting carcus allready in there)

~Nate

H-townbenzoboy · #11 05-22-2006, 11:14 PM

Quote:

Originally Posted by Nate

For oil, since it was abused, use moble one delvac... 10w40 ($25 for a gallon, you need 6 quarts)
~Nate

I don't think just because it was abused that it calls for synthetic motor oil to be used. In all probability, this car has been running conventional motor oil for it's 30 years over the road, and a sudden switch to synthetic is just asking for possible problems with seals leaking. Just use a good diesel rated conventional motor oil like Shell Rotella or Mobil Delvac 1300, and change it every 5,000 miles. The two aforementioned motor oils can be found at your local Wal-Mart.

vstech · #12 05-22-2006, 11:20 PM

since mobil 1 dropped 5W and 10W 40 I am thinking of going to delvac 1 or Rotella synthetic...
what is differant with this old a MB diesel? my 82 had been runnign on dino oil when I got it, and since I switched to Mobil 1 I have had no additional leaks. I thought the leaky seal synthetic thing was an old rumor? not true?
eh whatever.
John

Nate · #13 05-22-2006, 11:27 PM

yes, old rumor

I'm running synthetic in my winterbeater... Its leaking LESS then before.

Since i knew id only put on <500 miles last summer (no lisance), I put in dino. No additional leaks (allways had synthetic)

Theres better conditioners in a full synthetic then in CS dino...

BTW, its an old benz, it WILL leak something. Some say its marking its territory

~Nate

H-townbenzoboy · #14 05-22-2006, 11:28 PM

vstech, Delvac 1 is essentially the same as the discontinued and now hard to find Mobil 1 5W-40, so try that.

Nate · #15 05-22-2006, 11:30 PM

btw, SCREW WALMART...
We're selling some of our mobile one products at a LOSS, and were still not as cheap as them... Makes you wonder how/why they can get it that cheap...

Go to a place where they know what they're talking about, and for Gods sake, NEVER trust them with your MB (i wouldnt trust my truck in their hands)
Find an independant shop whos into them. Search high and low, but youll find one... if they're good, ALLWAYS go there, even if it means spending an extra $10 on oil