Outer Limits 4x4 Board

Hey there everyone,

I have replaced the rear diff centre in my 84 HJ47, with what i was told was a centre from a newer cruiser, possibly a 75 or a 79??

It is a 4.11 ratio, the same as standard for the 47.

I had someone install it for me, and when i got the car home i noticed oil patches on the driveway, the oil was leaking out through the front of the pinion behind the circle cover that is behind the flange. (hope that makes sense)

Now on driving a long distance the pinion became extremely loose and yes the underneath of the car is covered in diff oil as it all came funnelling out! Diff also started barking a bit when i raised the right foot, probably because there was no oil to keep it lubed, and couldn't handle the backlash.

So i was going to take the tail shaft and axles out to drive it home in front wheel drive, and when i took the tail shaft off saw the nut on the front of the pinion was loose and that the nut had not been hit with the cold chisel to lock it into the section out of the bolt (forgotten what this nut is called).

So tightened it all back up and locked the nut in, filled it up with oil and even before driving it, it is still leaking out the front of the pinion where i indicated at first.

The housing for the centre looks different than the original that didnt leak, has different gussets etc and who knows could possibly be on upside down if that even works at all.

Anything similar happened out there??

thanks

It won't be up side down the diff centre can only bolt in one way.

What you were referring to was called pinion nut, so you were right

If the pinion was torqued up origionally it should not have come loose that quick, they have a fairly high torque setting

I dare say you have damaged the centre now, if the nut had come loose good chance it may have broken a tooth or chipped it. Really the diff should come back out, inspected for damage and if ok then reset back up and new pinion seal.

Also if it didnt have a solid pinion spacer (if its a factory built diff) then the collapsible pinion spacer is now no good (one use item)

Or just buy another one, pull it out and put the other one in

Brad

Yeah the pinion nut hadn't been broken into the thread to lock it so easily came loose.

Centre is probably on its way to being totally farked, there is alot more (like 30mm) backlash in the pinion now, but doesnt move sideways though.

just a pain with the oil leaking and coating the underneath of car!

thanks

The pinion nut mave have been loose , usually the main cause of the pinion nut coming loose is the spline is worn out in the pinion flange, its a bit of a mith that the collasable spacer is the main cause.