Usually a thoroughly cleaning of the aerial mast and a drip of WD40 from time to time keeps the automatic antenna working for quite a long time.
But as it is with things - one day they'll just give up working.

So did my aerial mast a few days ago. It just got stuck halfway down every time I shut off the radio.



Fortunately (and expecting the antenna to fail in the near future) I bought a replacement mast with my last order at Britishparts.co.uk.
(The aerial mast is available online for about 20$. Part No. is LNA4134AAX.)



The job of replacing the aerial mast is a fairly easy task but I thought an FAQ is always a nice to have.
So here it is...


The antenna mast should be fully retracted, so if it got stuck like mine try compressing it WHILE the motor is running.
(Turn the radio off, jump out of the car, wait for the automatic antenna to run and slowly push the mast down until fully retracted.)
Note that when the antenna motor is not running there is NO chance to move the aerial mast without damaging the inner parts of the antenna!

Remove the trunk floor boards and the right hand side inner trunk panel.




Using a 14mm spanner wrench undo the aerial top nut.




Remove the ball-shaped nut (grommet stays in place).




Inside the trunk disconnect the electrical connectors.




Remove the ground cable (Phillips head screw).




On the bottom of the antenna remove the 8mm bolt on the bracket.




With the drain hose still attached, lower the antenna and remove carefully.
Here it is, the famous Mexican-made Jaguar automatic antenna.




Remove 6 Pillips head screws and open housing.






Remove clear plastic drum-shaped housing.

 

Inside the drum there's the geared plastic shaft/cable/drive that engages the aerial mast.




Remove the white flat plastic cover.




Using a flat screwdriver carefully lift up the white cog wheel and remove it.








The geared wheel eventually will come apart but it's easy to figure out how the two parts belong together.




Pull out the aerial mast completely feeding the furled geared plastic cable through the antenna body.




The old mast removed.




Now's a good time to clean everything out and to put some fresh lubricant on all the inner parts.




Put some grease as well on the geared cable of the new aerial mast.

Fully extend the new mast and insert it by feeding the geared cable into the antenna body.

Reassemble inner drive parts an mount the black antenna body cover.

Place the reassembled (and extended) antenna into the trunk.




Turn on the ignition and the radio.

Plug the electrical connector into the antenna housing.
(Antenna motor will now start to run until antenna mast is completely extended.)

Hold antenna and have someone turn of the ignition/radio.
(Antenna will now retract fully - IF you did everything right.)

Disconnect electrical connector again and reinstall antenna.




That's it! - Aerial working!




David

 

Thanks, this thread will be added to the FAQ

 

Maybee I'm missing something, but the motor does not need to be removed to replace the mast. Maybee you disasembled it to clean out the inner workings?

 

How so?
Pls explain!

 

On most of the units I have worked on the gearing has a clutch that slips as it reaches both ends of travel with the aerial mast array held in by the top capture nut. The unit is timed rather than actually limit switches.

The replacement is to remove the nut and extend the array -- normally you have to pull the mast as the teeth are what strips out on the plastic whip. It will just pop out when it gets to the end - then you just pull the remaining out. Once it is out you feed the whip of the new array into the unit by turning off the radio -- the whip is then fed into the gears. You do need to be careful as you feed it in.


This is how I did it in my x300 -- the x308 may be different - But you do not normally need to remove the unit or open it up unless the whip breaks off at the very bottom. You can also normally just pull the small section out with needle nose pliers as the above mentioned clutch will allow the gears to move.

But this may be different in some markets.

 

One more thing I forgot:

The grease that was to be used on the replacement teeth of the whip was specific -- it was a white lube -- it was probably just a lithium grease like Lubriplate or what is often sold for garage door openers. It was designed to provide lubrication with out the high petroleum solvents of many products---that would damage the plastic whip.

The new plastic may not have this problem -- this was also why the mast was always to be cleaned with a non petroleum product. The fear was that a product like wd40 would leak down past the mast into the whip and both liquify the grease and weaken it.

 

Ah, ok, I see...

So it's basically remove the ball-shaped nut and let the antenna extend until the whole plastic whip comes out.

That's clever!

To insert the new mast I guess you just have to feed the new whip in the housing, turn off the radio and try to push it until it gets caught in the geared wheel...

Anyway, while removing the whole antenna and taking it apart I was able to clean an re-lube everything.
(And yes, I used the special white electrical grease.)

Thanks Guys!


David

 

Yes David -- that's basically it. You do need to position the teeth correctly so the new whip will catch.

I have run into a few different types. From your pictures the Jaguar supplied unit has some form of electronic control -- so maybe it counts the revolution of the motor like a memory seat to get the limit about right. The motor only looks to have two wires so the control is able to reverse the voltage. Many of them would run for quite some time after the limit was reached with the clutch inside clicking away until the motor stopped.

Years ago when all the cars had them it was a common repair -- and its important when you bend one to fix it quickly because that is when the forces tend to snap the plastic whip forcing you to open it up.

 

Great info!

Besides breakage, what is the most common source of failure for the antenna?

Is there are special lubricant that works best? I've been using white lithium grease.

 

Basically Shi*e building up on the mast and not being cleaned when the car stereo asks for it to be. This all jams up the mast & stuff. I keep these clean and polished so the dirt has a harder time sticking to it. I have the same type of Aerial fitted to my 71 Triumph Herald.
S.

 

hi fellas, i have a new mast to fit this weekend so thanks for the great, very detailed description of the task. i think i may strip mine right down for a proper clean out and re-lube. if nothing else, i love taking these things apart and maintaining them! do you think a waterproof, silicone grease would be ok to use as a lube or do i need the specific stuff you mention?......
thanks in advance,
dominic

 

I would take the old mast out and if the whole plastic whip comes with it like it should -- I would just put the new one in. The whole thing is plastic and you risk more problems taking it apart.

It only needs a little bit on it -- I believe it is a light Lithium -- but you don't need much.

 

I did this repair on my 01 XJ8 and had to take it apart to get all the broken peices out. Works great and is an easy fix.

 

I am doing this tomorrow. Is any one else's replacement mast black colored? I got a cheap one from ebay.

 

Well I did the job today. It is super tall, and it doesnt always go all the way back down flush with the body. Is this unusual? The instructions said it would "center" itself after the radio has been turned on and off a few times.

 

Sorry to hear that!

Did you compare the length of your old mast with the new one?
My guess is that the black one (never heard of a black aerial mast BTW) is not a good fit because it's longer than the original replacement part.

If I understand the mechanism right, the motor will retract the mast until there is enough resistance detected so the motor will stop.
(Same with extending the mast.)

Probably the motor is electrically limited to a certain amount of revolutions to keep it from turning and turning in case it tries to retract a broken mast with a ragged whip.
That could be the problem you just discovered - The motor simply hits it's limiter.

In my case the aerial mast got fully retracted after I electrically re-connected the antenna.
It worked as it should be right away.

David

 

The whips normally have a little taper on the end -- if the old one was jagged on the end when you took it out you may still have a section of the old one in the mechanism.

You do need to get a whip about the same length -- the number of sections does not matter - just the overall length and the length of the lower largest section.

The only ones I have ever encountered with any kind of intelligent timing/ limit control were older OE Mercedes units -- that sold for $500.00 25 years ago and are widely over engineered.

Most are set to run for a set about of time /revolutions -- with this setting longer than what would be needed. The units use a slipping clutch that just clicks away when the limits are reached - that is why you can have a the mast bend and jam and still do no harm to the mechanism.

If --when you activate the motor -- the mast begins to move immediately and does so smoothly (no clutch clicking/slipping) until the motor stops -- that is the full travel. If the mast has not fully extended -- then it is too long.


You can always remove the new mast and compare it with the old one - cut the plastic whip to match the length of the old one. Now the new whip will only extend as high as the old one and should work fine -- the new mast does not care that it is not fully extended.


A lot of euro cars had black masts in the 80's

 

Yeldogt,

IF the whip of the black mast would be cutted down, the only effect will be that the mast will extend until the whip slips completely out of the mechanism because there would be no resistance to stop the motor because the antenna is still not fully extended.
So I guess the mast will not retract any more at all after that "surgery".

And the geared wheel (picture posted above) has no slipping clutch.
Believe me, I took it apart! It just has some kind of a spring loaded mechanism to keep forces off the little white plastic wheels inside the aerial.

The electronics inside the aerial must detect the force/resistance of the mechanism and with increasing force at some point "reads" that data as "okay, here's the end" and the motor stops.

My only explanation of the symptom that ixj8it describes is that the aerial mechanism is limited to a certain amount of revolutions to keep the motor from spinning with a broken whip.

I wouldn't cut the whip...


David

 

Yeah I dont know if the drum is getting too full of whip, or if the thing is just "off track." I dont really care I am going to give it a day or two until I mess with it again.

I took it apart to pull out a piece of broken whip from the old one. It took the new cable in like a champ, but couldnt take it all before the motor timed out. I just kept experimenting with stabbing it at different times. I have never done one like this. Years ago I did one on a lexus rx300. I disassembled the motor and wound the cable on the drum myself. It worked perfect on the first try. Thanks for all the good info in this thread!