Towing My w124 300D - PeachParts Mercedes-Benz Forum

oilslick · #1 07-04-2015, 11:57 AM

I've towed them before BUT they were always non-runners. I've always disconnected the drive shaft of them too. This one is in running condition. I'm towing it less than 125 miles. Is it okay to just let it idle while it's being towed? I want to avoid disconnecting the drive shaft if at all possible. Thanks!

Kevin

P.S. Before it's brought up that "it's a running automobile so why don't I just drive it" question, we are moving and I will be towing this car behind the truck.

ROLLGUY · #2 07-04-2015, 01:38 PM

I have a friend that tows these cars all the time without removing the driveshaft. I always thought that it was a bad idea, but he has towed MANY MB's with automatics behind his car (300TD) without issues. On the cars with the 722.4XX, they have a secondary pump that supposedly will lubricate the needed parts. The 722.3XX and earlier trans' don't have the secondary pump, so I wonder what might happen to the trans if a car was flat towed. As far as my friend is concerned, nothing. It still makes me wonder though

jay_bob · #3 07-04-2015, 01:49 PM

I thought it was the other way around, the 722.3s have the rear pump and the .4s did not.

ROLLGUY · #4 07-04-2015, 01:53 PM

Quote:

Originally Posted by jay_bob

I thought it was the other way around, the 722.3s have the rear pump and the .4s did not.

I do know that my bro's '91 300D has (had) the pump, as I removed it! I am sure it is a 722.4.

97 SL320 · #5 07-04-2015, 02:06 PM

A running engine gets you lube for the gear train however, the planetary gear sets will be spinning at speeds not normally seen when the car is driving. A planetary type auto trans in neutral really isn't in neutral from a gear train standpoint. Would you put a manual trans in 1st gear , hold the clutch pedal to the floor then tow at 65 MPH?

oilslick · #6 07-04-2015, 02:15 PM

Quote:

Originally Posted by 97 SL320

A running engine gets you lube for the gear train however, the planetary gear sets will be spinning at speeds not normally seen when the car is driving. A planetary type auto trans in neutral really isn't in neutral from a gear train standpoint. Would you put a manual trans in 1st gear , hold the clutch pedal to the floor then tow at 65 MPH?

Nope! Thanks!!!

pawoSD · #7 07-04-2015, 02:42 PM

Quote:

Originally Posted by jay_bob

I thought it was the other way around, the 722.3s have the rear pump and the .4s did not.

You are correct. 722.4 deleted the rear pump.

My 190d (1993) has the 722.4 in it, can't roll start it due to no rear pump.

My 1989 420sel has a 722.3, can roll start that one. (on a BIG hill)

Wodnek · #8 07-04-2015, 05:51 PM

If it were me, I would rent a Uhaul car trailer. I have a few times, and it isn't that expensive.

BillGrissom · #9 07-05-2015, 01:56 AM

I flat-towed my 1985 300D 600 miles to San Diego last August to deliver to a son. I disconnected the driveshaft, but re-attached 30 miles from the destination (Walmart parking lot, they seem understanding to RV's and towers). I towed it the rest of the way with the engine idling (to be safe). If I did again, I would leave the driveshaft connected and engine idling the whole way, since disconnecting it isn't fun w/o ramps (pulled up on a curb). I could have driven the car, but nicer to ride in one car, plus saved much fuel. You couldn't even tell it was behind our Chrysler minivan, other that on steep grades, and a few times I briefly wondered why some idiot in an old M-B was tail-gating.

Hardest part was making brackets to bolt in place of the front bumper, but now have them for next time. I don't suggest connecting to the front bumper. I did that once, drilling holes in the bottom of bumper of my 1985 to tow home when the engine failed, and broke one of the bumper shocks. Probably bottomed-out the tow bar (upward direction) going up the driveway hump.