Rear Sub Frame Refresh

[Dpicariello]

Dan, are you leaving the Diff and prop attached and dropping the subframe, wishbones and arb?

If you are leaving it on the car so to speak, then you need to crack off the rear diff mount bolt which depending how it looks might be easy or a nightmare as they get well cruded up...I'd soak it in some penetrating fluid or plusgas etc?

Failing that you'll need to disconnect the vac lines x2 and then remove the inner driveshaft bolts and the 6 cap head bolts on the rear cv of the prop...which will mean you need to tie up the prop or risk messing up the universal joint. of course then your well into 'i could replace the centre bearing on the prop......can of worms

David,

I'm planning on removing the diff still attached to the sub frame as I would like to clean that up/check it over. If the prop centre bearing is accessible then I will replace it, there's a BMW equivalent isn't there?

If you are taking off the diff then make sure to decide how you are locking the prop/driveshafts to undo the bolts before you remove to many parts.

What's the best way of locking the propshaft?

I think I may start this sooner than later!

[s2driveruk]

in gear or wheelbolt through one or two of the hubs with handbrake on from distant memory. theres not much torque in the capheads so no worries on stressing anything but well worth cleaning the capheads before you start and getting a decent 6mm (from memory) bit. They can have a habit of rounding so a decent extraction bit would be useful for the back pocket too

[Error404]

My top tip: the two vac lines to the diff lock come in really handy for tying the prop out of the way

[s2driveruk]

hmm just remembered, the diff bolts are torx or multi-splined actually..anyone confirm, been a while since i have been underneath

[Error404]

tri-square 12 point spine IIRC. **** them with a hammer first they always round out IME

[andy10v]

Get the bit seated/shock the bolt.

Allen key bolts on the prop, tri square splines on the driveshafts (on my 3B). Don't confuse the tri square with torx.

Make sure you use good tool bits.

I used the handbrake/in gear to undo the bolts, much quicker with an assistant, saves you running about to let the handbrake on and off to get at all the bolts.

Couple of bolts through the hubs and a bar works as well if you don't have brakes on etc.

[willg54]

I ended up putting a prybar through the propshaft UJ and holding it against that...into my hip anyway.

[Dpicariello]

Thanks for all the tips lads, there's a few things that I had no idea of so thank you!

I have ordered OEM wishbone bushes and the 3 diff mount bushes from Quattro Corner. I'm still umming and arring over solid sub frame mounts. Will it be too harsh?
Using the car this week so not gonna get much 'prep' done.

I am going to do the prop bearing and just found this beauty of a thread (as well as David's)

http://www.s2forum.com/forum/showthread.php?t=7823&highlight=prop+centre+bearing

[Dpicariello]

Diff mounts and wishbone bushes arrived from Pete @ Quattro Corner. Not that he needs it but I have to recommend Pete again as he is a top bloke and gets the right stuff out very quickly and reliably.

Had a couple of hours under the car this afternoon and managed to remove all of the 12 point spline bolts from the inner cv joints. They came out fine (good recommendation on the 12-point as the heads were a bit gungy and I probably wouldn't have noticed) although they were ******* tight!

Gonna split the prop from the diff tomorrow and that should be everything to remove the sub frame. So far so good.

[willg54]

Once you've undone the diff-prop bolts, it'll feel like its still bolted to it...
Use a precision engineering persuasion tool (decent hammer) and give it a good tap. Watch it doesn't drop on your head! I had a spare axle stand ready to hold it.

Good luck!

Ps they're just allen key heads not 12point on the prop....on mine anyway

[Error404]

Looks like you might want to replace the output flange seal on your diff matey

[Dpicariello]

This job has been a fine example of how a few hours prep can make things go so smoothly! Got the entire subframe dropped in two hours and that was only because it took me about half an hour to split the prop and the drive shafts from the diff.

The bottom ball joints on the wishbones (into the bottom of the struts) are being a pain. The pinch bolt is completely out and despite heat and a crowbar they have only dropped a couple of mm, not out!

Will keep going tomorrow. I had to cut a track rod end off as the nut was completely seized on the last few threads. Annoying as the track rods looked fine and was hoping to re-use them.

Two new track rods added to the shopping list!
I also need to add some wishbone ball joints as the boots have split and are dry as a bone.

[willg54]

Good stuff Dan I had many bolts that stuck on the last few threads...hours of WD40, back and forth with the nuts, wirebrushing won many battles!

[Fat Audi 80]

This job has been a fine example of how a few hours prep can make things go so smoothly! Got the entire subframe dropped in two hours and that was only because it took me about half an hour to split the prop and the drive shafts from the diff.

The bottom ball joints on the wishbones (into the bottom of the struts) are being a pain. The pinch bolt is completely out and despite heat and a crowbar they have only dropped a couple of mm, not out!

Will keep going tomorrow. I had to cut a track rod end off as the nut was completely seized on the last few threads. Annoying as the track rods looked fine and was hoping to re-use them.

Two new track rods added to the shopping list!
I also need to add some wishbone ball joints as the boots have split and are dry as a bone.

If it was all brand new it would be a piece of piss, because its old and rusty it can be a bloody nightmare. All I will say is, once you have done the rear, the front is a piece of cake.

Did you go for supaflex subframe bushes in the end? I have just replaced the front with supaflex subrame and powerflex wishbones and the car feels amazing.

Best of luck Dan.

Cheers,

Steve

[Dpicariello]

I've got supaflex/powerflex subframe bushes from Will and then OEM diff bushes and wishbone bushes from Quattro Corner.
I've made myself a tool to press out the old bushes so will do that tomorrow.