Don't like the adverts?  Click here to remove them

80 auto - replacing the throttle (auto box) cable

Chris

Super Moderator
Supporter
Joined
Feb 24, 2010
Messages
17,937
Garage
Country Flag
great_britain
There is a cable that runs from the main throttle bell crank over the top of the starter motor, down to the driver's side of the auto box. Contrary to popular belief, this isn't the kick down cable. Anyhoo, it seems that over time this cable gets a bit scratchy and has a tendency to stick. When on the throttle it pulls out, but on release it should snap back nice and smoooooth. But it doesn't. It drags and this can affect gear changes. There does seem to be a few of these popping up at the moment and perhaps it's a symptom of age. So, swapping it seems sensible. Well. be prepared for a shock as Mr T will require some eighty of your English pounds which is frankly ludicrous But what can you do.

I changed mine today and there is definitely a difference in response and throttle feel. But enough of that. This is just for the knowledge archives. Just for those who follow on, here's a hint that will turn a frustrating job into a simple one.

To start with you need to drain the ATF and remove the pan. Simple enough. You can see the cam where the cable is attached and disconnecting this end is not difficult. A pair of needle nosed angled pliers is handy. The cable can be pulled up out of the side of the box. You are supposed to thread the end of the cable through a small diameter socket so that you can push the plastic gland (which is barbed) up out of its hole. But mine was broken and as it's being replaced, who cares. Give it a good tug or a shove with a flat blade.

Now, what you will then encounter is a clamp placed fiendishly out of reach (to all but those with crippling arthritis) on top of the transmission. It needs a 12 mm socket. Here's the tip then.
Place a jack under the centre transfer box, undo the middle cross member bolts and lower the whole transmission about 4 inches. This gives you so much room on top of the box that you can actually get a 1/4 drive ratchet on there. This whole procedure took me less than 15 mins. There is a tie wrap too that hold the cable to a bundle of wires down there. I just snicked that and didn't bother replacing it.

Then it's a case of disconnecting the bell crank end, pulling the old cable out, shoving a new one through, reconnecting each end, cleaning and reattaching the sump plus a refill of ATF. Not really the nightmare that I thought it was gong to be when I first found the clamp!

Chris
 
Re: 80 auto - replacing the throttle )auto box) cable

Chris said:
There is a cable that runs from the main throttle bell crank over the top of the starter motor, down to the driver's side of the auto box. Contrary to popular belief, this isn't the kick down cable.
Any chance of a photo of where this cable runs from/to Chris.... I'm intreagued :think:
 
Re: 80 auto - replacing the throttle )auto box) cable

Not at this very second Paul- but I can later. It's not very tricky. The main engine throttle cable comes over the inlet manifold then movement is transmitted via a series of vertical linkages down to the injector pump. At the bottom of these linkages is another bell crank which takes the new cable off past the dipsticks and over the starter motor. It's in plain sight. It's been posted on before, but as I said, people mistake it for a kick-down cable, which it isn't. There is adjustment on it which is all covered in the FSM. Apparently it tell the auto box what the throttle is doing so it knows to do either soft gear changes - like driving in town or hard changes like a race at the lights. Without it, you get soft changes which create wear and shorten the life of you box considerably.

Chris
 
Re: 80 auto - replacing the throttle )auto box) cable

Thanks Chris, in my Jack Daniels fueled moment I was confused.... I thought this was an additional cable to the 'kick down' one.

In the sober light of day all is clear :thumbup:
 
Re: 80 auto - replacing the throttle )auto box) cable

Hi Chris, not sure if your aware but an old garden spray pump thingy majig is idle for refilling the box :lol: :lol: :lol:
 
Re: 80 auto - replacing the throttle )auto box) cable

Really Dave. Damn I so wish I'd had that idea first :whistle:

It's a winner so it is. Effortless. But in an emergency, a picnic wine glass with the stem cut off works well as a funnel. As long as you can find some ATF on a Sunday. Eh, Gav

Chrus
 
Don't like the adverts?  Click here to remove them
Re: 80 auto - replacing the throttle )auto box) cable

Here ya go,

WindowFrames014.jpg



Various443.jpg
 
Re: 80 auto - replacing the throttle )auto box) cable

Smashing. I knew someone had a pic from before. Now the interesting thing is that the little pip on the wire needs to be adjusted to a mm or so from the end of the shroud - yes? But on a new cable, the pip comes in a bag and you have to crimp it on. So where you do put it ad how do you know? I just set the cable so that there was very slight play meaning that the cam in the auto box would always return to zero when I let the throttle off. It does drive very differently. It has more power and when you boot it, it's got some of its old woomph back again.

I can understand it not returning when on the over run but why make a difference accelerating?

Odd one is that.

Chris
 
Re: 80 auto - replacing the throttle )auto box) cable

One of the key things when setting up the cable is to do it when the engine has warmed up otherwise the cold start device knocks the setting out.

There is a procedure in the manual for setting the position of the ring, although at a simplistic level you can always position it as per the original cable.
 
80 auto - replacing the throttle )auto box) cable

Lol, you make these things look so easy Chris. Tidy work :)
 
Hi Julian, the cable seems to be set. I followed the procedure in the manual including the paint mark on the cable. They say that full deflection should be 33mm. Well I get a lot more than that. Maybe I am starting from the wrong point. They say pull until slight resistance is felt. Do they mean until the cam starts to move, which is what I did, or do they mean when the cam starts to pull back on the cable. All a bit vague. I have it so that if I let the cable go, the cam in teh auto box hits the end stop. IE no tension on it at all.

Hi Matt. What are you looking at? Great work? You've been on that Amerulla again haven't you.

Chris
 
After I fitted mine I just went out for a drive and kept adjusting it until I had it was changing gear at the point I wanted rather than the manual setting. ;)
 
Rob it changes gear just fine straight off the drive. Been no prob, then suddenly ......

C
 
Rob80vx said:
After I fitted mine I just went out for a drive and kept adjusting it until I had it was changing gear at the point I wanted rather than the manual setting. ;)

What year is yours?

Chris' later box has the change points regulated by the throttle position sensor on the pump, the kick down cable has less effect.
 
Mine's a 94 vintage.


Chris
 
The 'kick down' cable on the electronic box controls hydraulic line pressure inside the box - how much clamping force is used on the clutches, so if your foot is down hard it uses enough clamping force not to slur the gear change or on a low power gear change there's not much clamping force for a nice soft change. If that cable is out of adjustment you get sloppy or hard changes but the change points are not affected, those are controlled by the electronic TPS on the pump like Julian says.
 
Going to attempt this on a mates 80, just got to find a new cable now.
 
Could it be worth trying to inject some lube down the cable as a PM item using something like the cable oilers you get for motorcycles?
 
No. The cable sits in a loop and water collects in there so it rusts. As it's a bowden cable, it starts to fray and spilt. It's gets stuck in the cable outer sheath and that's game over. Now as a preventative measure that would be a good one, spraying something down there would be an excellent idea. But it's not a cure.
 
I noticed my throttle seemed a bit heavy at times, so decided to investigate. Sure enough that gearbox cable is stiff to pull out, and doesnt go back in as it should. There was a loose loop where it wasnt going back in.
I spent the day filling it with light oil, and its better, but still doesnt retract on its own. The piece of cable you can see though looks good!
Anyway, took it for a run, and sure enough it pulls out about half way and doesnt go back in. But it doesnt seem to make any difference to the shifting. The throttle mechanism does have the electronic position sensor as well.
 
Back
Top