Subframe Swap

[AndrewGray]

As a few of you already know I am hoping to carry out a subframe swap on my '95 A8 D2 4.2 Quattro

The car is currently up on axle stands and I have the full front end and engine bay partly stripped down


Plan of action is to:

• clear access to the 4 engine block lifting holes
• disconnect arb, wishbones so that all that is left is the subframe bolts.
• source suitable engine crane
• source straps and u-bolts
• remove bonnet

Questions:
How much does the Engine and gearbox weight?
What is a suitable rating crane to use?
What is the best method for lifting? A u-bolt through each engine block hole with a strap from each connecting to the crane?

Cheers
Andrew

[Conan_the_Librarian]

Andrew,

To answer the questions first:
Your engine weighs 195Kg dry
Gearbox is approximatly 60Kg dry
A half ton lift will do.
As for lifting its not necassary.

Here is what I would do to change my subframe.

Get a strong steel bar that will span the engine bay.
Get some wooden chocks and wedges.
Disconnect the 2 bolts to the engine resilient mounts from underneath the subframe, and the same for the tranny.
put a thick wooden pad under the engine sump to spread the load and using a jack lift the engine a couple of inches.

Put wooden pads on the suspension tops and lay the bar across.

Use chains from the 4 lifting points with either shackle bolts or just bolted and then wedge the bar up with 2 wedges either side so that the chains have the weight of the engine.
Put a jack under the end of the grearbox and take the weight of the gear box.

Undo the 4 main bolts and 6 rear plate bolts and drop the subframe.
Remove and replace with the new one.






Gotta go will finish this later. Work calling!

[AndrewGray]

Sounds like a good method, have you used it before?
I've just sourced a 1000kg crane aswell, looks like I wont be needing it anymore!
Now to source some sort of strong, thick metal bar

Scaffolding tube should be up to the job I'd have thought - that's what we used to use for lifting engines with rope before we could afford hoists/cranes

Mind you, they were only mini engine/box and cavalier engines, not quite as heavy as the v8 lump.

[Conan_the_Librarian]

Following o from above.

I haven't used the method but it's a variant on the Audi process when removing the tranny which requires the subframe to be dropped to let the tranny out. Audi have a special tool........



As long as the engine can't move and the tranny is held in place then the subframe should drop away.

You won't be able to remove the rear lower control arm as the bolt wont come out until the subframe is lowered. When you re-assemble on the new subframe put the bolt in the other way so you can strip the suspension down in the future without dropping the subframe.
Like this:


HTH

[A8 Doc]

It might be a 1000kg crane remember, but it you extend it out, it suddenley becomes 250kgs. Look at the crane arm and you will see.

You will most likely need it to extend out too!

[AndrewGray]

Finally picked up the crane tonight!

Should hopefully get some work done tomorrow, plan out how i'm going to do this and get it done asap

[AndrewGray]

Today I:
removed the front arb and 1 set of bottom arms.
Couldnt get the other set bottom arms as Conan stated above, you have to drop the subframe so that you can get into them.
I did get a small 18mm socket and rachet onto it and started to turn them but it felt dodgy, like it was about to burr or slip.
Are they 18mm bolts either side?

I disconnected the throttle setup to create room at the back of the engine so that I can get into the engine block holes.

I need to come up with how I am going attach the engine to the crane through the engine holes and buy whatever I need.

I started to remove the arch covers to create more room and to clean everything up while i've got the car stripped down.
Couldnt get the passenger side off due to being unable to take off two plastic clips that hold it on.
Looks like you need to pull the center of the clip out to release it. Usually you have to push them through and then they pop out.
Didnt have the right tool to get a good grab on it and pull it out so instead of destroying them like I did on the other side i've left them til I get a decent tool.


What is this foamy part, is it needed? Mine is thick with dirt and soaking wet.
Is that a drainage point above it?



picture of said plastic clip that I'm trying not to break.


bottom arm that I've not removed yet.


crane

as far as it will go in on lowest reach setting


what is this?
does it control the cruise control?
Trying to move it by hand but is extremely stiff

[Conan_the_Librarian]

Originally Posted by AndrewGray

Today I:
removed the front arb and 1 set of bottom arms.
Couldnt get the other set bottom arms as Conan stated above, you have to drop the subframe so that you can get into them.
I did get a small 18mm socket and rachet onto it and started to turn them but it felt dodgy, like it was about to burr or slip.
Are they 18mm bolts either side?

They are M12 bolts and nuts. Use open ended spanner and ring spanner inside the subframe

I disconnected the throttle setup to create room at the back of the engine so that I can get into the engine block holes.

I need to come up with how I am going attach the engine to the crane through the engine holes and buy whatever I need.

Go to a ships chandler and get a couple of 1/2 tonne bow shackles and a length of chain.

I started to remove the arch covers to create more room and to clean everything up while i've got the car stripped down.
Couldnt get the passenger side off due to being unable to take off two plastic clips that hold it on.
Looks like you need to pull the center of the clip out to release it. Usually you have to push them through and then they pop out.
Didnt have the right tool to get a good grab on it and pull it out so instead of destroying them like I did on the other side i've left them til I get a decent tool.


What is this foamy part, is it needed? Mine is thick with dirt and soaking wet.
Is that a drainage point above it?

It is and the foamy stuff is noise suppression and heat shield. Leave it be.



picture of said plastic clip that I'm trying not to break.

Drill a small hole in centre and use a small self tapper and pliers.


bottom arm that I've not removed yet.

Make sure you use a ring spanner on the nut inside the subframe.


crane

as far as it will go in on lowest reach setting

That's spot on for reach.


what is this?
does it control the cruise control?
Trying to move it by hand but is extremely stiff

That is part of the inlet manifold variable length inlet primaries. it is operated by vacuum and should move fairly freely. Will work seized but will effect top end performance


HTH

[AndrewGray]

Thanks for all the info Conan!

Is there a drainage point above the foam inside the inner arch?

I know my drainage points are blocked so it'd be good to clean them out while the car is in pieces.
The ones i've read about go from the scuttle down to either side of the gearbox - i've not found these yet, finding it very hard to see in about the scuttle where they should be.

For the "inlet manifold variable length inlet primaries part" can I safely degrease it all and regrease it?
What would be a suitable grease for it?

As for reach, do you think I should just attach it by the two block holes at the back of the engine or should I do all 4?