Installing a Power Antenna Unit on a MkII

(See also: Replacing antenna mast on a 92T)

Overview

Although this is a very straight forward procedure, I found that I ran into a few quirks during the replacement of my antenna so I decided to put together this guide.

Tools Required

10mm socket wrench
Small flat blade screwdriver
Trouble light (or flash light)

Materials Needed

Unfortunately, Toyota views the power antenna as a non-fixable unit, therefore they don't sell internal parts for it and you are forced to replace the whole unit. The first problem I ran into is that there are two different units depending on whether or not your car has a rear spoiler. The only difference between the two units is a small plastic extension on the end of the aerial mast for the spoiler-only model. This extension allows the mast to span the height of the spoiler side-wing (which the mast passes through) so that the base of the mast is at the top of the side-wing.

The following are the part numbers for a 1991 MkII, check with your Toyota dealer for the proper unit for *your* MR2.

86300-17100 Antenna (without rear spoiler)
86300-17110 Antenna (with rear spoiler)

Time Required

No more than 30-45 minutes depending on how good your back is :-) (There is a bit of bending-over required)

Removal of the Power Antenna Unit

Remove the four clips holding the trunk lining to the engine firewall. These clips have a center portion which you can push in using the small flat bladed screwdriver. NOTE: Do not push too hard on the center of the clip or you'll push it right through and lose it!

Carefully peel back the lining from around the trunk-lid hinge which will reveal the antenna unit. There are two snap type fasteners near the rear of the lining which you can unsnap to get better access to the antenna.

Disconnect the wiring harness from the top of the antenna unit by pushing on the left side (as viewed from the rear of the car) where the clip lock is located. Use the flat blade screwdriver if you can't get your fingers in there.

Disconnect the shiney black aerial harness that connects the radio to the aerial. This connector is a simple push-on, pull-off type so don't worry about breaking clips if it doesn't come out quickly.

Using the 10mm socket wrench, remove the nut holding the antenna unit to the body. The unit will not drop down or move when you do this as it's being held in place at the top of the unit.

This next step only applies if your car has a rear spoiler. Skip to the next paragraph if this doesn't apply to you. The second problem I ran into during this procedure is that the top of the antenna is held in place where it runs through the body panel by means of a two peice rubber gromment and a screw-on collar. On a car with a rear spoiler, this collar is inside the right "side wing" of the spoiler. To gain access to the collar, reach under the lip of the inside rear-fender panel near the rear of the spoiler side wing and you'll feel a nut on a stud. Now feel forward of the trunk hinge near the middle of the side wing to locate the second nut. Remove these two nuts using the 10mm socket wrench. At this point I was able to carefully lift up the rear of the side wing enough to gain access to the collar without actually removing the side wing. There is either a third nut or most likely some sort of clip on the front of the side wing but I was unable to determine this due to the size of my hands/arms as this spot is quite deep in the panel. I decided to NOT attempt to remove this last clip/nut for fear of not being able to get it back on afterward.

Using the small flat blade screwdriver, carefully unscrew the silver collar by pushing on one of the four slots in the collar. NOTE: Be careful not to let the blade of the screwdriver slip and scratch the paint!

Locate the black hose hose that runs from the bottom the antenna unit through the floor of the trunk and pull it up out of the floor. I also removed the rubber gomment in the trunk floor which this hose passes through as my new unit included a replacement.

Remove the antenna unit by pushing in on the unit to allow the stud to clear the body panel and lower the unit at which point you should be able to get the rubber gomment and the screw-on collar from the top of the body panel.

Installation of the New Unit

Installing the new unit is just a reversal of the above removal procedure so I won't go into detail about this.

Preventing Future Replacements

In the inspection of my failed antenna unit I found that the plastic gear that connects to the motor's gear had been stripped. I believe this happened due to a build-up of dirt on the aerial causing it to put strain on the motor and ultimately stripping the plastic gear. I plan on cleaning the antenna mast on a more regular basis this time :-) Also, lubricating it with something like WD-40 propably wouldn't hurt either.

Geoff Seeley

Replacing antenna mast on a 92T

From: ajrystad@mail2.quiknet.com (A.J. Rystad)
To: validgh!mr2-digest@uunet.uu.net
Subject: Replacing antenna mast on a 92T
Date: Tue, 30 Apr 1996 21:05:52 +0000

The weather finally became stable enough to where I felt comfortable enough
to fix my ailing power antenna.  The procedure is similar to the one Geoff
has on the web site (the removal part) with the following additions.

Once the antenna is removed from the car, turn on the radio to extend the
mast to it's fullest (it's already broke, don't worry about breaking it
further!!!).  

After extending the antenna, unscrew the 4 corner screws on the spool
housing and the center  nut and bolt.  Also remove the screw that is holding
the mast housing in the spool housing.  Remove the relay box from around the
housing (bend the top tab a bit to get it to clear).  You can leave the wire
to the motor attached, but it's not necessary.  LEAVE THE RADIO ON! (it'll
be obvious later, but turn down the volume).  Unplug the radio to antenna
wire from the housing.

CAREFULLY open the spool housing.  There shouldn't be any portion of the
nylon string left in there wound up, but you never know. :)

Once open, remove the spool holder and metal plate (remember how they fit!)
and remove the smaller plastic gear, then the large one.  Yes, it's greasy
in there!  Once both gears are removed, extract the antenna from the spool
housing and mast holder.  Clean out any of the nylon line that might have
broke (that's what happened to mine, about 5 inches off the end snapped,
antenna goes up, not down!).

Now for assembly...

Put the large plastic gear back in the spool housing. Place the new mast
(part # 86337-17110 MKII w/spoiler) in the mast housing collapsed and feed
the nylon string into the spool housing until it passes the metal pin on the
left (you'll see it) of the housing and past the water drain (where the back
hose connects).  Put the small gear back in and reassemble the spool
housing.  At this point you've got the housing assembled with the nylon
string partially in the housing with a lot of it out and the antenna in the
trunk (or on the engine hood, which is better for what's next.)  Pull the
ENTIRE package (housing, and new mast) onto the passenger side of the engine
hood with all the wires hooked up.  The radio is still on, right?  Now turn
it off from the passenger side of the car and guide the string and mast into
the spool housing (and you thought that you'd need to feed it in by hand!).
The motor will stop when the antenna mast housing is seated in the spool
housing. DON'T TURN ON THE RADIO TO CHECK YOUR WORK!!! The string will come
all the way out of the housing!  Wait until the antenna is mounted in the
car, the threaded sleeve w/ the 4 notches is what keeps it in. Replace the
screw that holds the mast housing in.  The rest of the install is the
reverse of removal.

$41.06 is a LOT cheaper than replacing the entire package.  And they even
had it in stock!

Hope this helps someone out there.  It's nice not having to beat on the top
of the antenna to get the teeth to engage the gear!

Geoff, feel free to post this on the web site.

A.J. 
'92T

Date: Tue, 22 Jul 1997 15:36:17 -0700
From: Jeffrey Ho See (jhosee@artemis.davd.com)
Subject: Re: MkII: Doh! Busted power antenna!

I just wanted to thank AJ's and Geoff's cool instructions
on the web site.

This past weekend, I repaired the power antenna in about
2.25 hours (w/ clean up)

The only comments I think could be added are :

1) It's messy (greasy) inside the housing. Wear gloves.

2) Carefully disassemble the unit. A bunch of parts fell
   out when I opened it up on car (but I saw where
   they came from)

3) I was todully spooked about moving the rear wing spoiler
   high enuff to get to the antenna mounting nut. I did get it
   on/off though. Just be careful not to tweak the locked
   in front end. 

4) Let the gears feed the new mast into the housing. Good tip
   AJ!

Impressions : the grease inside the unit had turn
a disgusting shade of brown-black. Clean
your antennas faithfully. I repacked
it with a liberal dose of grease.
It performs SILENTLY now. Previously, it was noisy.

My mast had broken off inside the housing, the big gear
looks robust enuff.

- Jeffrey
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-=-
  Jeffrey Ho See mailto:jhosee@artemis.davd.com
  http://www.geocities.com/MotorCity/7153/
  ^-- Tuned on July 17, 1997
  Desktop : http://wwp.mirabilis.com/761260/ 
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=--=-=-

From: Trevor Johnston (nzfab@es.co.nz)
Date: Fri, 10 Oct 1997 18:33:29 +1200
Subject: Re: MKII Replacing Antenna Mast...

I have *Just* finished installing a new antenna mast on my '90 Turbo. 
My Previous one broke in the Carwash after I forgot to put it down 
when I was playing my CD's- Duh!.

Anyway I just wanted to say a big thankyou to Geoff and the 
Participants of the MR2 website. Yet again it provided invaluable 
insight to my 'how to?' questions. We as MR2 owners should feel proud 
to have THE best Resource of it's type on the net.

I also thought I'd add a little to the Existing text: 

 "On a car with a rear spoiler, this collar is inside the right "side 
wing" of the spoiler.
To gain access to the collar, reach under the lip of the inside 
rear-fender panel near the rear of the
spoiler side wing and you'll feel a nut on a stud. Now feel forward of 
the trunk hinge near the
middle of the side wing to locate the second nut. Remove these two 
nuts using the 10mm socket
wrench. At this point I was able to carefully lift up the rear of the 
side wing enough to gain access
to the collar without actually removing the side wing. There is either 
a third nut or most likely some
sort of clip on the front of the side wing but I was unable to 
determine this due to the size of my
hands/arms as this spot is quite deep in the panel. I decided to NOT 
attempt to remove this last
clip/nut for fear of not being able to get it back on afterward."

This is Not a problem at all. The third fixture is a clip, which looks 
unbreakable (don't hold me to that!) and the whole side wing can be 
easily removed after taking off the above 2 nuts and *gently by 
firmly* lifting upwards. This makes it ALOT easier to work on. 

Hope this is of some help.

Elliot Johnston