4kq differential locks ?s

[Ryan Moon]

Okay, so for the light to actually come on when you turn the dial 
switch, the diff has to lock?

I did a rear differential drain and fill, Sunday, and found the lines 
to my rear actuator rotted off, so I replaced them, and found the 
actuator to work. The light still doesn't come on, on the dash due 
which I figure is due to the switch being broken and disconnected (the 
one to the upper rear of the differential.)
--
I seem to think the front differential is locked, but the light only 
comes on when I turn the dial switch in the cab. I'll have to lift the 
front up and check... just turning one wheel by hand would tell me 
right? If unlocked the opposite wheel should turn the opposite way? 
Thus, if locked the wheels would both turn the same way ?

Ryan
On Apr 26, 2005, at 10:45 AM, Robert M wrote:

> The actuators are all plastic, except for the rod.  They're a 
> two-chamber design, and depending on the position of the switch vac is 
> applied to one side or the other.  If you're getting odd lock 
> function, you could have a hose problem (not uncommon IME, these hoses 
> are going on 18+ years old :) ) or an actuator problem (again not 
> uncommon, see above).  The mech can also get sticky, and is likely to 
> be so if one of the other elements fails and the mech goes thereby 
> unactuated.
>
> On my first 4kq (an 86 with 195k) the rear mech was just frozen up.  
> Shooting it with PB Blaster and working it by hand 200 times was all 
> it took to get it to work, and trimming the actuator hoses back about 
> an inch to eliminate the split zone helped also.
>
> On both my 4kq's (my current is an 87 that I bought a couple years ago 
> with 65k on it :) ) there was physical damage to the front actuator.  
> In both cases I was able to remove it (I think it's on the pass side 
> though*...), clean it, and JB weld the cracked area.
>
> IME the lights work well.  I've not had one burn out (aren't they 
> LEDs?) and on my cars they were a very reliable indicator of actual 
> lock status.  I checked them by hand with all 4 wheels off the ground. 
>  Have a helper sit in the car and sing "ON!" when the light lights.  
> Turn a wheel, and then actuate the lock by hand.  On my cars the 
> actual lock even coincided perfectly with the light coming on.
>
> *getting the front actuator out is a pain- as I recall it's mounted to 
> the back side of a protective shield that will be caked with 
> ~0.33"/18+ years of accumulated road grime.  10mm bolts I think, three 
> of them.  No other parts have to come off, but you'll have to pull 
> some wild contortions to get it all out.  MAKE SURE YOU KNOW WHICH 
> LINE GOES WHERE BEFORE PULLING THEM OFF :).  Write yourself a note...
>
> Difflocks rule!
>
> hth,
> Robert
>
>> From: Shawn Manny <shawn.manny at gmail.com>
>> Reply-To: Shawn Manny <shawn.manny at gmail.com>
>> To: Ryan Moon <moon at velaru.net>
>> CC: quattro at audifans.com
>> Subject: Re: 4kq differential locks ?s
>> Date: Tue, 26 Apr 2005 10:39:47 -0500
>>
>> They nipples on the actuators are only plastic, they may break off and
>> if they break when the diff is locked it'll stay that way. IIRC the
>> center lock is on the drivers side (us spec cars) ontop of the tranny
>> under the tunnel. The rear lock id on the drivers side as well on the
>> pumpkin. You may also have a short or bad connection making the light
>> stay on. Grab your bently and start tracing vac lines, look for broken
>> plastic chassis lines and shot old rubber under body lines.
>>
>> On 4/26/05, Ryan Moon <moon at velaru.net> wrote:
>> > I'm curious about the diff locks. They are activated by vacuum, but 
>> is
>> > it possible for them to stick or stay locked ?
>> > Is the front lock mechanism is on top on the transaxle towards the
>> > passenger side, where you'd have to remove some of the exhaust to 
>> get
>> > to it ?
>> > The lights on the switch panel in the passenger compartment are
>> > activated by switches similar to reverse light switches ? So meaning
>> > the light would only come on if the diff is locked? Or the light 
>> would
>> > stay on if the diff doesn't unlock?
>> >
>> > Thanks
>> > Ryan Moon
>> >
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