Rear Axle Refurb - Bushes?

[edh]

My car is going in for some work soon (clutch, fuel lines, some minor rust) & i think it makes sense to drop off the rear axle to replace bushes while we're at it.. I haven't seen any particular issues, but it would be sod's law that a bush would fail soon after everything is put back together. They are probably on borrowed time after nearly 240k miles.

It's a road legal track car, currently all rubber bushed, KWv3 suspension with clubsport spec springs. No cage, bucket seats & 3 point belts. That gives you an idea of the style of car - comfortable enough to drive across europe, but firm enough to go well on circuits.

There are a number of different bushes in the rear suspension that could be replaced - but with what? OE rubber? (Can the OE rubber bushes be pressed in easy enough?) Worth changing the spring plate cover mounts to solid? Just using this vendor as an example really... http://www.elephantracing...4suspensiondiagram.htm

Oh and before anyone dives in, my car is the best and fastest iteration of the transaxle range, and is near on perfect already with its judiciously selected modifications and weight reduction... []

 

[zcacogp]

... my car is the best and fastest iteration of the transaxle range, and is near on perfect already with its judiciously selected modifications and weight reduction... []

Great!

Why are you tinkering with it then?


Oli.

 

[edh]

"near on perfect".... (apart from the broken clutch & crusty fuel lines). This is just preventative maintenance

 

[Chrishazle]

If the fuel line run is like the 968, then the WSM way to replace them (from the fuel filter forward to the front wheel arch) involves dropping the rear axle anyway, so your thoughts about re-bushing are worthwhile.

 

[944Scott]

The rear axle will need to be dropped for the clutch change anyway. Poly bushes will give a firmer ride with a bit more road noise and they have a tendency to squeak at low speeds. At that mileage you might want to consider having the torque tube bearings refreshed at the same time in fact I think you might be surprised what needs attention and now would be a golden opportunity to get some awkward jobs out of the way. I planned to do a clutch change which has swiftly escalated into so much more, the list so far;

Exhaust rubbers.
Refurbish rear exhaust mount and hangers.
Fuel pump (impending failure imminent, terminal badly rusted)
fuel pipes (pump end)
Fuel line to top of tank.
Replacement filter.
Remanufactured transmission mount.
Corrosion treatment, cross member area.
Cross member refurb inc filter mount.
Refurbish tank cover and both straps.
Transmission output seals.
Transmission repaint.
Replacement short shift kit inc link arm (last one worn out after 4 years)
Refurbished torque tube.
Replacement clutch.
Replacement needle bearings.
Replacement crank seal.
Replacement flywheel pan head screws
Replacement reference sensors.
Replacement earth strap.

I think that's everything so far, I'm sure there will be some more parts I end up ordering.

 

[bmnelsc]

I understand that rubber is the way to go with street/road cars - the poly-bronze bushes bring a harsh ride and lots of noise (vibration as well as the squeaking you mention). Porsche has two specs of bushings - soft and hard - probably soft for "standard" and hard for M030/sport suspension. I believe it is in the workshop manual where they specify where to use soft and where to use hard on the S2s...there was a mix - it was not all one type.
As you enjoy using your Porsche on road trips (as do I) I think the way to go would be hard rubber to maintain decent NVH while possibly sharpening the handling a little (especially is Porsche specified soft for the trailing arm bushes).

 

[edh]

The rear axle will need to be dropped for the clutch change anyway. Poly bushes will give a firmer ride with a bit more road noise and they have a tendency to squeak at low speeds. At that mileage you might want to consider having the torque tube bearings refreshed at the same time in fact I think you might be surprised what needs attention and now would be a golden opportunity to get some awkward jobs out of the way. I planned to do a clutch change which has swiftly escalated into so much more, the list so far;
......

Thanks Scott - very useful and lots to ponder. I have addressed a fair few of these over the past few years - the car has been in bits a couple of times

 

[924Srr27l]

4000 Miles so far with Elephant Racing Poly & Bronze Torsion tube bushes, which have grease nipples
fitted and have been re applied with ZX1 grease 2 times so far, with no squeaks or excessive vibrations.

Only this and the chassis / arm bush is using Poly, the rest is all Rubber (Trailing arms / Wishbones ARB's etc)

R

 

[edh]

I understand that rubber is the way to go with street/road cars - the poly-bronze bushes bring a harsh ride and lots of noise (vibration as well as the squeaking you mention). Porsche has two specs of bushings - soft and hard - probably soft for "standard" and hard for M030/sport suspension. I believe it is in the workshop manual where they specify where to use soft and where to use hard on the S2s...there was a mix - it was not all one type.
As you enjoy using your Porsche on road trips (as do I) I think the way to go would be hard rubber to maintain decent NVH while possibly sharpening the handling a little (especially is Porsche specified soft for the trailing arm bushes).

Looks to me from the WSM that they have standardised on a mix of hard/soft now - you can't choose...

 

[edh]

4000 Miles so far with Elephant Racing Poly & Bronze Torsion tube bushes, which have grease nipples
fitted and have been re applied with ZX1 grease 2 times so far, with no squeaks or excessive vibrations.
Only this and the chassis / arm bush is using Poly, the rest is all Rubber (Trailing arms / Wishbones ARB's etc)

R

Thanks - I think I will stick with a maintenance free option Can't get spring plate bushes or trailing arm bushes supplied separately from Porsche but can get rubber versions from Elephant racing
I think I will go with solid upper mounts (they are also much cheaper)

 

[924Srr27l]

4000 Miles so far with Elephant Racing Poly & Bronze Torsion tube bushes, which have grease nipples
fitted and have been re applied with ZX1 grease 2 times so far, with no squeaks or excessive vibrations.
Only this and the chassis / arm bush is using Poly, the rest is all Rubber (Trailing arms / Wishbones ARB's etc)
R

Thanks - I think I will stick with a maintenance free option Can't get spring plate bushes or trailing arm bushes supplied separately from Porsche but can get rubber versions from Elephant racing
I think I will go with solid upper mounts (they are also much cheaper)

WPO Shop Germany also do some rubber Trailing arm bushes 30% Stiffer

http://www.ebay.co.uk/itm/Rubber-bearing-Bushes-for-Porsche-944-968-Axle-guide-Control-arm-rear-Rear-axle-/391808350221?hash=item5b3998f80d:g:2SoAAOSw9NdXrziH

I've got 2 brand new OE Rubber bushes for the torsion spring / chassis arm (In the third photo, post 8 right hand side)
I couldn't get these to fit even with a press, but you can have them if you want for £20 inc postage?


R

 

[PAUL RUDDY]

http://www.ebay.co.uk/itm...-944-968-/262644079590

 

[edh]

http://www.ebay.co.uk/itm...-944-968-/262644079590

Thanks Paul - that's useful info - in fact, that's a great shop! impressive range and prices. They sell a new spring plate + bushes for £140...Porsche want £400

 

[Monkeythree]

I converted the upper beam mounts to solid versions with a bit of fabrication and a few minutes welding. No noticible NVH issues and cost basically nothing to do.

 

[PAUL RUDDY]

http://www.ebay.co.uk/itm...-944-968-/262644079590

Thanks Paul - that's useful info - in fact, that's a great shop! impressive range and prices. They sell a new spring plate + bushes for £140...Porsche want £400

They do the full kit including the bolts, I plan on using these eventually, all my spending is engine related at the moment.

I have bought other items from the seller without any problems.

cheers

 

[edh]

They do the full kit including the bolts, I plan on using these eventually, all my spending is engine related at the moment.

I have bought other items from the seller without any problems.

cheers

I think you will probably need to steer clear of my thread as I don't plan to be using any toothbrushes in my project.... [] it will be purely functional [] Apologies in advance... When we get the axle off we can take a view on what exactly needs doing

My mechanic thinks he can fab the fuel lines from cunifer, which should save me money but lose me concours points.. He builds race cars so is quite good at improvising.

 

[edh]

WPO Shop Germany also do some rubber Trailing arm bushes 30% Stiffer
http://www.ebay.co.uk/itm/Rubber-bearing-Bushes-for-Porsche-944-968-Axle-guide-Control-arm-rear-Rear-axle-/391808350221?hash=item5b3998f80d:g:2SoAAOSw9NdXrziH

I've got 2 brand new OE Rubber bushes for the torsion spring / chassis arm (In the third photo, post 8 right hand side)
I couldn't get these to fit even with a press, but you can have them if you want for £20 inc postage?

R

Part no 477 501 069A? I'm interested but you don't fill me with optimism that we will fare any better though?
Racers Edge do a solid bush set for $129

 

[924Srr27l]

WPO Shop Germany also do some rubber Trailing arm bushes 30% Stiffer
http://www.ebay.co.uk/itm/Rubber-bearing-Bushes-for-Porsche-944-968-Axle-guide-Control-arm-rear-Rear-axle-/391808350221?hash=item5b3998f80d:g:2SoAAOSw9NdXrziH

I've got 2 brand new OE Rubber bushes for the torsion spring / chassis arm (In the third photo, post 8 right hand side)
I couldn't get these to fit even with a press, but you can have them if you want for £20 inc postage?
R

Part no 477 501 069A? I'm interested but you don't fill me with optimism that we will fare any better though?
Racers Edge do a solid bush set for $129

I can't find any part on them apart from 102? They were from an OPC, I should have the Invoice somewhere
I really am unsure how they heck Porsche fitted them! So yes your right it could be the same scenerio for you..
Hence why I ad no choice but to fit 2 piece Powerflex Poly.

R

 

[Monkeythree]

The main beam mounting OE bushes are practically solid so I am not surprised they are difficult to fit. I wouldn't be surprised if a polymer replacement was actually softer and allowed more movement of the beam than the OE bushes.

 

[924Srr27l]

The main beam mounting OE bushes are practically solid so I am not surprised they are difficult to fit. I wouldn't be surprised if a polymer replacement was actually softer and allowed more movement of the beam than the OE bushes.

Not a chance ! the shore grade on the Purple Powerflex must be x1.5 than rubber, the downside as all poly bushes is they will wear
and elongate a lot quicker than rubber.

The reason they are hard to get in the hole is getting the end pieces in...



R