Power Antenna - PeachParts Mercedes-Benz Forum

#1 09-09-2002, 01:18 AM

On my 78 300SD, my power antenna stopped working. The motor still works however the mast no longer goes up and down.

I understand that replacement masts are available, however, it is easy to install them.

The antenna stopped working 6 years ago. I said "As soon as the mast breaks I'll replace it". Guess what - won't break. Lost other power antennas over the past six years..oh well.

I have been working on this vehicle a lot lately. I have recently done radiator, climate control, aux fan, aux water pump, new front seat spring frames, replaced all dashboard lights and more.

The antenna is last on the list...

Thanks,
Richard

'78 Mercedes 300SD
'97 Mercedes E300D
'02 F-250 Powerstroke
'97 Lincoln Town Car
'89 Lincoln Town Car

haasman · #2 09-09-2002, 01:37 AM

The antenna masts are easy to do.

Have someone turn it on and off to help. Search this site using "replacing antenna".

Here is a good one: My Antenna!

RSH · #3 09-09-2002, 02:18 AM

You will need another person to help you on this one. There will be a screw-type collar right on top of the fender, the upper most collar, not the lower one that attaches the antenna assembly to the fender. Take a correct size wrench and unscrew this counter clockwise. While some one sits inside the car and turns the radio on, have your helper pull up with slight force on the antenna mast. The mast and nylon tail, (this is the bottom portion of the antenna mast that engages inside the assembly, and makes the metal portion of the mast move) will come out as a complete piece, If pieces have broken off inside, they have will have to be removed, take the antenna motor cover off and remove the broken tail pieces, replace the cover. Now to install new antenna mast, you basically perform the same operations in reverse order. Sit inside car and turn radio off. Have your helper at the same time, feed the nylon tail into the assembly while turning the tail back and forth. This is to enable the nylon tail to engage into the gear underneath. When the antenna tail engages and the motor completes its cycle and shuts off, screw down the mast collar, (clockwise direction). After this is done, turn the radio off and on a few times, (allowing the antenna motor to completely cycle each time). This will properly time the antenna mast to the motor.

goldenbear · #4 10-10-2002, 10:31 AM

Well, I finally got around to this job. It is one of the more simple DIY jobs I felt I would tackle with the SDL. I ordered the replacement antenna (smooth). Like a dummy, I did not check to see if the one I was replacing was smooth or toothed, but the individual who took the order said it wouldn't matter. The long of the short is I couldn't get the smooth tail to "take". Am I likely doing something wrong, or do I need to get the toothed version? Also, I'm unsure if I have any broken pieces on the inside, but would like to check. Is there a trick to getting the cover off the antenna motor? Thanks.

uberwagon · #5 10-10-2002, 01:24 PM

First, when you removed the old antenna did any of the old tail come out? If it did was it toothed or not? If nothing came out, you definitely have broken bits inside the motor you will need to remove.

When I was replacing the mast on my 300TE I couldn't get the tail to "take". After taking the motor assembly apart (again) I realized the tail was just getting caught on a little lip in the tube when I pushed it in and wasn't going in far enough. The trick was to bend the tail straight before inserting it so it would go down all the way to the gear.

Assuming it's a Hirschmann antenna, getting the cover off is easy. You'll probably need to remove the antenna from the car first. One side of the cover snaps on. Just use a screwdriver to carefully pry the snaps around the edge. You may find you have other broken parts when you open it up. I had a broken gear and belt. Fixed the gear myself and got a new belt from www.antennaworld.com.

Good luck.

#6 10-11-2002, 10:26 AM

None of my old tail came out. I have to remove the antenna from the metal housing. Once removed, I then took off the round container where the antenna is stored when retracted. I have to remove the broker tail manually. Once I reassembled the antenna, i put additional grease where the tail moves. Then I fed the new antenna in.

Richard

Tref · #7 10-11-2002, 03:47 PM

If you replace the mast and nothing looks wrong inside, is it possible that it needs adjsutment? I have heard that you could adjust the tension against the mast. Is this true, I took it apart and could not figure it out.

uberwagon · #8 10-11-2002, 04:28 PM

Tref,

This info is for Hirschmann 6000EL antennas. Looks like the 6000EL was used from the mid 80's on. Don't know how it differs from the older models (6000U?).

On the 6000EL there is a small wheel on the outside of the the curve, opposite the geared wheel that engages the "tail". This wheel provides pressure so the tail engages the gear. I don't think there is any way to adjust the pressure this wheel applies.

If you hear the motor running but the mast isn't moving, make sure that the tab on the top gear isn't broken off.

There are two large gears that sit on top of each other. The top one engages the worm gear driven by a belt from the motor. This top gear connects to the bottom gear via a tab that interlocks with a spring. The bottom gear is the one that engages the tail.

The tab on mine was broken. I was able to fix it by screwing the broken piece back onto the gear using a small sheet metal screw.

Also check for a broken belt or broken spring.

BoB

RSH · #9 10-11-2002, 11:05 PM

Tref,

The drive "clutch" is adjustable, bend the lockplate tab away from the large nut and turn the nut clockwise for more tension and counter clockwise for less tension, I would not deviate to much from its original adjustment (no more than +/- a nut flat or two).When I bought my 83 300SD the antenna did not operate, besides the kinked mast, the ratchet gear that controls the limit switch had a couple of broken teeth, I replaced that gear, then found the worm gear wheel that the motor worm drive mechanism engages was stripped, which was originally caused by the kinked mast and the "clutch" assembly not slipping enough to keep the drive componets from being damaged.I replaced the worm gear wheel and now have a completely functioning factory power antenna. The antenna in my car is the Hirschmann Auta 6000u.