6.9 Strut Disassembly

[TJ 450]

The myths and legends of 6.9 struts are about to go beneath the hammer.

In the name of research and development, PB donated a stuffed rear strut to the cause.

I have got to removing the upper cap and piston/shaft.

Removal...


Upper Cap with Orifice and O-Ring for cap and cylinder tube...


Cylinder Bore...


Piston Ring and profile detail...


Detail of piston top...


Detail of piston/lower and strut stop...


Detail of piston/lower and washers...


Tim

[robertd]

Good stuff Tim,

I acknowledge the time and effort that goes into this sort of thing.

Regards

Robert

[WGB]

Thanks Tim for the photo's.

In the mining business they rechrome the parts and re-build them - must be possible to do the same with a 6.9 strut.

Bill

[TJ 450]

Thanks Tim for the photo's.

In the mining business they rechrome the parts and re-build them - must be possible to do the same with a 6.9 strut.

Bill

I imagined that to be the case.
The piston ring is metal and all there is at the base of the strut is the o-ring for the lower cap, a ring similar to an oil ring on an engine piston and a nylon-looking ring above that. Both of these rings are sealing against the strut shaft.
I'll look at the leak-back line orifice in detail tomorrow.

Tim

[s class]

Wow.  We are are truly grateful for this.  Can you see any obvious wear in the components?  Is the main cylinder bore still good?

[koan]

Great work!

Would be interested to see the components of the disc valves either side of the piston and if there is any sign of wear.

koan

[oscar]

Hang on, how did you open it up?  Does the top just screw off and how did you get the piston out?

[TJ 450]

Hang on, how did you open it up?  Does the top just screw off and how did you get the piston out?

The top does indeed just screw off and providing the balljoint is removed, the piston just pulls straight out. I used the disc from a harmonic balancer puller and an allen key to hook over that protruding part to undo it without damage, as in the first pic.

The bore is still in excellent condition.

I'll attempt to pull the piston apart at some point.

Tim

[Big_Richard]

So far it doesn't look like a device designed by rocket scientists, it certainly looks remanufacturable, rather cheaply.

Perhaps TJ can obtain some glue, some $1.50 parts and sell them rebuilt for $500 each  Bargain!

[WGB]

What was actually wrong with the strut that took it out oif service PB.

Bill

[Big_Richard]

it came with the car when i purchased it, I've never used it. However when we changed over my gators, i stuffed one of my balljoints and used the spare one off the 3rd spare strut to complete the job.

I believe this strut was leaking and the previous owner replaced it for that reason.