Ra4 1994 Centre Diff Is Locked & Wont Unlock....help...!

[seanmcgrath]

Yippeee.!! The diff lock has disengaged. ill try+explain what the problem was. It was realy hard to get to as well, I must be double jointed.!! Cumin out of the diff is a 90 degree bar that locates threw a hole in a bar that cums out of the servo. When the diff locks + un-locks these move together one way or the other. But it wasnt doin this becos the 90 degree bar had !Removed! out of the hole + instead was jammed up against the end of it. I ad to get the bottom bolts un-done from underneath the os wheel arch which hold the bottom of the servo. Then the top 2 bolts from the top of the engine between inlet manifold + bulk head which hold the top of the servo. I cud then pull the servo back slightly + then pulled the shaft out of servo as far as it wud go. I cud then hook the hole in the shaft back onto the 90 degree diff bar. I hope this helps sumone in the future shud they av the same problem. Thankyou to everyone for all the help + advise uve been great. Im goin to post a new thread now as ive !Removed! across another problem this time its the engine.!

I've just spent the last 5 days looking on the net , for this info as I'm haveing the same C-Diff locked problem on a Rav4 Mk1 which I bought last week....

Thanks it will be very helpful...

Sean

[seanmcgrath]

I've noticed ...if I press the C-Diff lock button in & out repeatedly I can hear a CLICKING sound ,its comeing from the back of the engine some where under the inlet manifold....is this sound the actuator trying to disengage/engage..

sean

[seanmcgrath]

The Vacum hose that goes to the Actuator....where does it come from...so I can follow the hose back to the actuator,as I dont know what I'm looking for...

sean

[anchorman]

Sean

There is an EP (electro pneumatic) relay on the bulkhead with wires and pipes going to it They chaged the position form one side to the other about half way through production. If you get somebody to work the switch while you look under the bonnet you should hear it clicking.

[seanmcgrath]

Sean

There is an EP (electro pneumatic) relay on the bulkhead with wires and pipes going to it They chaged the position form one side to the other about half way through production. If you get somebody to work the switch while you look under the bonnet you should hear it clicking.

Yeah...I can hear something clicking...Still haven't found out where it's comeing from...

Will have another look today.

[seanmcgrath]

Sean

There is an EP (electro pneumatic) relay on the bulkhead with wires and pipes going to it They chaged the position form one side to the other about half way through production. If you get somebody to work the switch while you look under the bonnet you should hear it clicking.

Cheers Don...Found it.....

Followed the pipes down to some thing behind the drive shaft, think it's the Diff . . .

I've had a look a the link , but cann't work out what's what...

http://www.toyotaownersclub.com/forums/index.php?app=core&module=attach&section=attach&attach_id=5774

sean

[anchorman]

The chamber at the top right of the picture is the servo. When you switch the diff lock on, the EP valve allows inlet manifold vacuum through to the survo and that in turn affectively sucks the diapragm and the selector fork attached to it moves to the right engaging the diff lock.

Leggyloo had the gearbox out and got something jammed when she put it back. She managed to free it with the gearbox installed but it was tricky by all accounts. Try disconnecting the outlet (servo side) pipe at the EP valve and with the engine running switch the diff lock on and see if it is sucking as it should. If that is OK the EP valve is working and your problem is either with the servo or the selector fork.

When the diff lock is switched off, a buzzer should sound until the diff lock fully disengages. If it doesn't stop buzzing just rock the car back and forth to allow it to "unbind" and drop out.

[seanmcgrath]

Cheers Don...

I've been busy today...the buzzer is driveing me MAD....the EP valves are working fine getting presure from there,it's sucking good'o' . . .undid all the pipes,drove it back and forth still did not disengage, refitted the pipes still did not disengage....

went up to my friend house to do the rav....

lifted the front of the Rav up off the ground, had front drivers wheel(UK) off again...

What I did find was on the back of the servo ?? theres a bracket that bolts on to the engine,well there was two bolts missing,that bolt that bracket on... could only find one bolt on the lower left side of the servo next to the drive shaft....could not pull the servo off, still another bolt some where , but I couldn't see /find it...

So when we where pressing the C-Diff lock button on/off the whole servo thing was moveing back and forth...

Put two new bolts in the bracket,,,what a pain in the rear that was...but got there in the end...

........3 hours later............................all back together

C-Diff still locked....

Drove it home again,with that !Removed! buzzer going off,,thank god I've a loud stereo...

wont have any time now till next weekend...what along week this is gona be,

I hate when a job is not done there and then....

''just rock the car back and forth to allow it to "unbind" and drop out.''

will try that before the week is out...what gear do I leave it in??

any one got a foto of a engine that been taken out of a Rav, so I've a idea where this other bolt is on the servo thingy..

Sean

[anchorman]

There might not be another bolt. If you look at the picture you will see the selector shaft is cranked and the bracket on the engine side is to stop it straightening out and binding. I can't see how it attaches but the wire from the buzzer is attached to that switch screwed in just a bit further along towards the gearbox. Just disconnect it and the buzzer will stop.

Now, having said that you should be aware that if you really are running it with the diff engaged then you are running the risk of damaging it as it is under excessive load while you are "on highway". You need to determin that is not engaged or sort it out quick before you bggr it.

Just rocking it back and too from 1st to reverse should be enough to work it free if it is only hung up on the gears. It is the same as trying to push it into neutral with the clutch engaged - it just sticks.

If you read Leggy's post she said you have to remove the servo, hook the hole in the servo shaft over the pin at the end of the selector then fix the servo back on.

[seanmcgrath]

thanks Don

Will have a go at the rocking back and forth tomorrow...

[seanmcgrath]

Still no joy....with the rocking back and forth....

But luckly have found a local garage(cartrader.ie) that will hopefully sort it out for me...

Sean