IRS upper shock mount - Permanent fix

[Sox]

This has been cleared with forum admin.

Howdy all,
For some time now I've been aware of the dreaded IRS upper shock mount problem, as most of you blokes probably have.

The standard mount is quite a substantial metal unit, with a good portion of it vulcanised in rubber. There are actually 3 metal sections to it -

1 - A top hat which is the section that bolts to the underside of the chassis.
2 - The bottom part of the main body, which is vulcanised to the top hat.
3 - The spring saddle, which is press fit (into rubber) inside the lower section of the main body.

This unit is flawed in several areas IMO -

1 - There is an aluminium sleeve within the main rubber section which is able to 'float' within the rubber. The amount of float is determined by how much packing *(washers) sit between the rubber and shock fastener.
2 - The upper and lower sections of the main body are joined only by rubber which is vulcanised to both pieces. No other mechanical contact is in place.
3 - The spring saddle is lightly press fit into the lower section of the main body, however this is also lined in vulcanised rubber.

This amount of rubber is certainly beneficial for low NVH levels, however it does not benefit rear suspension control, or longevity.

Minor complaints have been noise from the top of the shock being a loose fit inside the aluminium sleeve.
Vagueness from the rear suspension, lacking feedback, due to the shock not being able to use it's full damping capability because of the amount of give in the rubber.
Extra sag due to the deflection in the rubber between the 2 sections of the main body.

It is not fully understood why the 2 main sections are joined by rubber, the only explanation being to reduce NVH. However the spring mount already contains a rubber upper spring saddle, and normal practise for upper mounts on shock absorbers is to use 2 small self locating rubber disks.
With the standard system we have 3 rubber isolation systems at work.

Many users change the units on a regular basis, having a fairly short life span.
If left long enough, complete failure could result due to rubber breaking down over time and the sections then separating.


I have designed an improved version of the mount, using the existing unit, totally disassembling it, and replacing 1 of the sections with 2 new parts.
The new unit has no flex, as the spring mount is fully welded to the upper body.
Isolation still exists for the spring via the rubber upper saddle, and for the shock via conventional rubber disks.

The new design is many times stronger, has zero flex, uses off the shelf user serviceable upper shock rubbers, and is inexpensive.
Considering it will outlast the life of the car, it is a very inexpensive 1 time purchase.

I have trialled a pair on my own AU3 XR8 220 over many months, with excellent results. No knocking, no slop, no vagueness, and no noticeable increased NVH.
The last point about NVH may vary from car to car, as my XR8 is already suspended with a sports bias, and louder than standard exhaust.
A Fairlane user with standard suspension and exhaust may notice increased NVH.

It should also be noted that this system can be tightened up a little further by using the conventional practise of fitting poly upper shock rubbers, with of course the associated increase in NVH.

If you poked your head underneath your car, or just know the AU suspension well, you would see that there is nothing revolutionary about what I have done, as it is essentially the same upper mount system as the Watts Linkage live axle, and even very similar to the front of the same vehicle.


I haven't worked out final pricing yet, as I have a few minor things to deal with to speed up the process, however it won't be a lot as 90% of the job is done by myself. Parts cost is small, as there is only 2 pieces of metal, 2 rubbers, and a washer.
I'm guessing somewhere in the vicinity of $200-$250 for a pair, with a small amount of that being donated to the AFF CHARITY CRUISE.

I can obviously only do this on an exchange basis as I need to re-use most of the original unit.
If anyone has old units they can donate to me, I will happily pay a small amount so I can have some on the shelf ready to go.
It is obviously beneficial for me to do many at a time, to save on part and labour cost.

I am also happy to assist with you making them for yourself, I'm not doing this for the money, I'm doing it to help a fellow Ford enthusiast.

We can make a list of interested people here, and then we can work out the logistics of gathering some mounts to do a run.
Several members from the T series section had already shown interest a week or so ago.

Photo 1 shows the standard original on the left, with the break up of pieces of the re-manufactured unit on the right.
Photos 2 and 3 show the re-manufactured units either side of a standard original.
.

[Ride]

Would there be any issues in using these with shock absorbers that are adjustable from the top aka Koni Yellows?

[Sox]

Originally Posted by Ride

Would there be any issues in using these with shock absorbers that are adjustable from the top aka Koni Yellows?

No issue at all, as exactly the same amount of the shock protrudes from the mount as before.

[Brooksby122]

Count me in for a set I'm very keen I'm actually replacing mine next week so I can send up my old mounts once I have them out if that helps.
Also thanks for coming up with a solution to a problem that I'm sure annoys allot of us.

[T3man]

Add me to your list for the first "run" you do please. Even though mine have given me no trouble now for several hundred thosand kms I am always looking for that "better mousetrap" and your solution is simple and will obviously be effective in prolonging the life of the upper mount indefinitely.

I will be in Sydney region at least a couple of times in the coming weeks so will work out with you where to drop a pair off.

[Sox]

Ok, so we have -

1 - Brooksby88 - 1 pair
2 - T3man - 1 pair

[Ride]

Ok, so we have -

1 - Brooksby88 - 1 pair
2 - T3man - 1 pair
3 - Ride - 1 pair

[TS50]

Ok, so we have -

1 - Brooksby88 - 1 pair
2 - T3man - 1 pair
3 - Ride - 1 pair
4 - TS50 - 1 Pair

[Fluffly]

Ok, so we have -

1 - Brooksby88 - 1 pair
2 - T3man - 1 pair
3 - Ride - 1 pair
4 - PROBLM - 1 pair

[TS50]

Ok, so we have -

1 - Brooksby88 - 1 pair
2 - T3man - 1 pair
3 - Ride - 1 pair
4 - PROBLM - 1 pair
5 - TS50 - 1 Pair

[DaveTE]

Ok, so we have -

1 - Brooksby88 - 1 pair
2 - T3man - 1 pair
3 - Ride - 1 pair
4 - PROBLM - 1 pair
5 - TS50 - 1 Pair
6 - DaveTE

[GK]

Sox, you are a champ and an innovator!

Makes me wish I had IRS! LOL!

Very well done and thanks for such a practical contribution to AUvians with IRS.

GK

[T3man]

Originally Posted by GK

Makes me wish I had IRS! LOL!

Easily arranged. I know of a complete IRS rear cradle sitting in a garage in Melbourne. It is cheap at $15k and will include the T2 TS50 that it's attached to.

[tkfd]

count me in aswell - tkfd

[zdenko]

I just had mine changed in November for new Standard ones.

Now I should still have my old ones (I think dad has the at work somewhere, will have to ask).
Would flogged out ones be able to be repaired?
They have 150000km's on them and were in an XR6 VCT. The centre is elongated.
They are worn to the point that the car sounded like a drum inside driving over the smallest bumps on the road.

[Ride]

Originally Posted by T3man

Easily arranged. I know of a complete IRS rear cradle sitting in a garage in Melbourne. It is cheap at $15k and will include the T2 TS50 that it's attached to.

Also have a complete IRS setup myself from the Ghia, all bits required for a conversion (inc. 3:45 diff)

[myts50]

Ok I'm in but dont have any to exchange at the moment

1 - Brooksby88 - 1 pair
2 - T3man - 1 pair
3 - Ride - 1 pair
4 - PROBLM - 1 pair
5 - TS50 - 1 Pair
6 - DaveTE
7 - Myts50

[Sox]

Originally Posted by zdenko

I just had mine changed in November for new Standard ones.

Now I should still have my old ones (I think dad has the at work somewhere, will have to ask).
Would flogged out ones be able to be repaired?
They have 150000km's on them and were in an XR6 VCT. The centre is elongated.
They are worn to the point that the car sounded like a drum inside driving over the smallest bumps on the road.

No problem at all, the major wear parts are totally removed and replaced with parts that will never wear out.
The only serviceable items in the modified unit are the smaller conventional upper shock bushes which cost a few dollars and will last as long as they normally do on any other car which uses that type of bush.

BTW, I'm not sure if you wanted to be added to the list, or you want to donate an old set of mounts to me?

To everyone, The bush can be modified no matter what condition it's in. Please don't throw your old ones away, I can use them to keep a few on the shelf on hand

1 - Brooksby88 - 1 pair
2 - T3man - 1 pair
3 - Ride - 1 pair
4 - PROBLM - 1 pair
5 - TS50 - 1 Pair
6 - DaveTE - 1 pair
7 - Myts50 - 1 pair
8 - tkfd - 1 pair

[GK]

Originally Posted by T3man

Easily arranged. I know of a complete IRS rear cradle sitting in a garage in Melbourne. It is cheap at $15k and will include the T2 TS50 that it's attached to.

Where the heck is 15K when you darn well need it? LOL!

GK

[tkfd]

Originally Posted by Sox

No problem at all, the major wear parts are totally removed and replaced with parts that will never wear out.
The only serviceable items in the modified unit are the smaller conventional upper shock bushes which cost a few dollars and will last as long as they normally do on any other car which uses that type of bush.

BTW, I'm not sure if you wanted to be added to the list, or you want to donate an old set of mounts to me?

To everyone, The bush can be modified no matter what condition it's in. Please don't throw your old ones away, I can use them to keep a few on the shelf on hand

1 - Brooksby88 - 1 pair
2 - T3man - 1 pair
3 - Ride - 1 pair
4 - PROBLM - 1 pair
5 - TS50 - 1 Pair
6 - DaveTE - 1 pair
7 - Myts50 - 1 pair
8 - tkfd - 1 pair

you should go to nearest wrecker and buy a whole heap. probably get'em for $50 a pair.

[POELWYK]

hmm will theres fit BA??

[zdenko]

Originally Posted by Sox

No problem at all, the major wear parts are totally removed and replaced with parts that will never wear out.
The only serviceable items in the modified unit are the smaller conventional upper shock bushes which cost a few dollars and will last as long as they normally do on any other car which uses that type of bush.

BTW, I'm not sure if you wanted to be added to the list, or you want to donate an old set of mounts to me?

I'm gonna say probably the donate option for now as long as my Dad didn't loose or throw the mount out. Should find out in the next week.
Will let you know once they are back in my hands.

[jeffb]

This is great! I have hated those strut mounts since I have owned my T2. I think I will give this a crack myself, are you willing to share a bit more info? Like the diameter and height of the pipe you used, is that a washer or did you cut it out with an oxy? How does the washer and top attach? Did you just weld the washer into the top of the pipe then sit the top on and weld from underneath? I notice that you chamfered the top of the pipe a bit, is that to help the top piece locate better? Any more photos?
Thanks in advance

[tkfd]

Hello SOX,

I have put my name down for a set.

How long until you think you will start doing them?

Mine are starting to go now, and was going to replace with OEM, but will hang off if not too long.

Cheers

[Reaper8]

hey sox, Im another that would be interested in the diy. Would be more than happy to pay cash for your time and charity for some diy instructions

[Sox]

Sorry guys, net has been down since storm on sat night. Will reply in detail soon as web is back.
This is from wifeys work iphone.

[Sox]

Rightio, I'm back on line.

POELWYK - As far as I'm aware, these will not fit the anything other than AU's with IRS.

JeffB and Reaper8 - I'm more than happy to give you details on how to make these yourself. The prototype you see in the photos have a 90mm tube of 4mm wall thickness. And the disk is 6mm thickness, and the diameter is the ID of the tube.
My plan was to make them from 100mm tube, as the 90mm is what I had at home at the time. 100mm will sit nicer on top of the spring saddle.
I did just oxy the the 6mm disk from some flat bar I also had at home.
I'm getting prices to have the disk profile cut, and the tube I'll have cut from the supplier.
When I have the new exact sizes, I'll pass them on, as they'll be slightly different to the prototype. I also made a jig for it all to sit in for speedy assembly. It could be don't with out a jig, but it will be harder.

tkfd - My aim was to do at least 10 at once, however I can start with 8 if everyone is willing to throw me their mounts ASAP.
Once I get going it should only be a couple of days turn around.

[tkfd]

Hello SOX, welcome back

I would have to send my set from Perth which might be pain. My car isn't a daily driver, but if I take mine out and send, then you send back, would be close to two weeks I reckon. Also, if I get the *****, and decide to have someone instal them properly, I can't drive my car there.

Are you able to source a s/h pair (maybe from a friendly FF member ), or alternatively, I could send you a pair from a wrecker at my end, (or actually it might be cheaper to send from a wrecker at your end)

have you come up with more definative pricing at all.

Thanks mate

[Sox]

Originally Posted by tkfd

Hello SOX, welcome back

I would have to send my set from Perth which might be pain. My car isn't a daily driver, but if I take mine out and send, then you send back, would be close to two weeks I reckon. Also, if I get the *****, and decide to have someone instal them properly, I can't drive my car there.

Are you able to source a s/h pair (maybe from a friendly FF member ), or alternatively, I could send you a pair from a wrecker at my end, (or actually it might be cheaper to send from a wrecker at your end)

have you come up with more definative pricing at all.

Thanks mate

I do still want to chase some from wrecking yards, I just haven't gotten around to it.
I understand about the turn around time.

I don't have firm pricing yet, but as said in the original post, between $200-$250.
How about I'll put a maximum of $250 for this first lot, and you'll likely get a pleasant surprise. It will likely be closer to $200.
I'll add the amount from the wrecking yards to the price of those that haven't sent me any, and will refund that amount on return of your dead ones.

Are you all happy with that?
If so, start sending me PM's with 100% confirmations, and I'll reply with postal details.

[TICK4D-TAS]

Im in sox, im 99% sure that i have a spare set here in the garage, i might even have the old ones from my XR8 if i look hard enough.