Coupe GT front suspension

84CoupeGT · 19-07-21, 04:43 PM

Afternoon all

I'm currently going through the front suspension on my pre-facelift Coupe GT (KE engine). I'm not an expert mechanic, so bear with me....

So far I've removed, stripped, painted and re-bushed the anti-roll bar, drop links, control arms and subframe. I've got new bolts for the subframe and control arms (part no. N90556902), however they are fully threaded, whereas the bolts that were on the car were all part-threaded (I think it's likely at least the subframe ones are original as the bushes were). Does anyone know if fully threaded are ok please? I thought probably yes for the subframe but not sure about for the control arms... Also, the new nuts for the control arms, ball joint bolt etc are the serrated collar type rather than nyloc, they are one of the part numbers given on the Audi catalogue for those... Anyone know if those are ok or can I re-use the nyloc ones?

Normally I wouldn't worry too much, but keen to avoid anything undoing itself or breaking for obvious reasons...

Anything else I should look at doing while I have the subframe off? Gearbox mount?

Many thanks.

mikes2 · 19-07-21, 05:01 PM

Those fully threaded bolts will be fine. I've fitted them to a few of mine now both to the subtame and to the wishbones. The only issue with them is that some of them come with a 18mm hex head - there isn't as much room for the larger tools when refitting and some tool kits might not have a suitable 18mm socket

The shouldered nuts are quite useful when fitting the wishbones to the subframe as the swan neck spanner will slip over a normal nut. These are usually 16mm which verifies they are replacements and not originals when all your torque settings get checked.

Are you fitting new ball joints ? Makes sense to if it's all in bits. I usually replace the ball joint lock plates and pinch bolts at the same time - obviously new locknuts also.

I'd only replace the gearbox mount if it shows signs of cracks / splits.

84CoupeGT · 19-07-21, 05:26 PM

Cheers Mike, that is helpful. I'm pretty sure the bolt heads were the same size as the originals, however I did notice they were around 1cm longer. Hopefully that doesn't cause any issues.

Yes, I forgot to mention I've got new ball joints and tie rod ends to fit as well. I've got the pinch bolts but not the locking plates, they look ok but I notice Autodoc have got them at a ridiculously cheap price so will probably order those in with my next order from them.

Gearbox mount visually looks ok, but the outer tabs feel a bit dried out. I haven't looked into how much of a job it is. Would it make much difference to the drive if it's hardened/worn out?

Cheers

droopsnoot · 20-07-21, 10:29 AM

Quote:

Originally Posted by 84CoupeGT

Anyone know if those are ok or can I re-use the nyloc ones?

As I understand it, strictly speaking, you should never re-use nyloc nuts.

84CoupeGT · 20-07-21, 11:42 AM

Quote:

Originally Posted by droopsnoot

As I understand it, strictly speaking, you should never re-use nyloc nuts.

Yes, I think Audi/VW spec is to replace every time too. Reusing would probably be OK at a guess but when new nuts are cheap there's no reason to take any risk so I'll use the new serrated collar ones I've got and get some new nyloc ones for the drop links

mikes2 · 20-07-21, 01:08 PM

If the gearbox mount is worn, it will allow it to move around more. Since it's bolted to the engine the whole assembly will feel looser.

You would notice it most when going off power to accelerating again and during changes

84CoupeGT · 20-07-21, 02:00 PM

Quote:

Originally Posted by mikes2

If the gearbox mount is worn, it will allow it to move around more. Since it's bolted to the engine the whole assembly will feel looser.

You would notice it most when going off power to accelerating again and during changes

Thanks. I've never driven it other than a very short distance on the driveway as it's not been on the road since 1996. Moving through the gears when it's stationary, it often doesn't want to go into gear but I'm guessing that is more likely to be due to lack of use, hopefully things will ease up once it's been driven a bit.

Can the gearbox mount be changed without removing the subframe, i.e. just removing the one bolt that goes through the subframe and gearbox mount? Or does the tightening sequence mean you have to remove and replace all the bolts again?

Cheers

mikes2 · 20-07-21, 04:11 PM

There's 2 mounts. There's one in the subrame and there's also another which mounts to a bracket.

The one in the subframe is best replaced off the car.

The other one is held on the bracket by a couple of bolts so if you undo the big main bolt, the 2 small bolts should be easy to remove and you'll be able to remove it - gearbox needs to be supported or it won't line up afterwards.

84CoupeGT · 20-07-21, 10:03 PM

Quote:

Originally Posted by mikes2

There's 2 mounts. There's one in the subrame and there's also another which mounts to a bracket.

The one in the subframe is best replaced off the car.

The other one is held on the bracket by a couple of bolts so if you undo the big main bolt, the 2 small bolts should be easy to remove and you'll be able to remove it - gearbox needs to be supported or it won't line up afterwards.

Good info, many thanks.

Sorry, I have another question! I've replaced the wishbone to subframe bushes like-for-like with what was on the car... Pic of these below:
[IMG]

[/IMG]

I've just been looking at the Audi parts catalogue on OEM EPC online and noticed those bushes (part number 811407181) are for 81/82 model years and seem to go with the non-sided wishbones. My car is 84 and has the sided wishbones and drop links, which according to the catalogue seem to go with different bushes with a metal casing on the outside for years 83-87, part number 857407181 (see pic below):
[IMG]

[/IMG]

Anyone know if the bushes are interchangeable? I'm confused now, I thought getting the ones that were on the car was the right way to go, but the catalogue seems to say otherwise. I supposed a previous owner could have had the wrong bushes fitted?!

Any help appreciated! Many thanks.

mikes2 · 21-07-21, 10:01 AM

No problems with the questions.

If you've gone to the trouble of fitting them, I'd be inclined to use them although they may not last as long.

Those bushes are slightly softer - they're used on the early 5 cylinder models which also had a different anti roll bar setup

The metal caged bush can also be 8A0 407 181 - they have a slightly larger flange on them.

19-07-21, 05:01 PM	#2
mikes2 4 ring whore! Classic Audi Club Member Join Date: Nov 2007 Location: Polmont Posts: 2,617	Those fully threaded bolts will be fine. I've fitted them to a few of mine now both to the subtame and to the wishbones. The only issue with them is that some of them come with a 18mm hex head - there isn't as much room for the larger tools when refitting and some tool kits might not have a suitable 18mm socket The shouldered nuts are quite useful when fitting the wishbones to the subframe as the swan neck spanner will slip over a normal nut. These are usually 16mm which verifies they are replacements and not originals when all your torque settings get checked. Are you fitting new ball joints ? Makes sense to if it's all in bits. I usually replace the ball joint lock plates and pinch bolts at the same time - obviously new locknuts also. I'd only replace the gearbox mount if it shows signs of cracks / splits. __________________ 1991 90 quattro 20v sport 1991 90 quattro

20-07-21, 01:08 PM	#6
mikes2 4 ring whore! Classic Audi Club Member Join Date: Nov 2007 Location: Polmont Posts: 2,617	If the gearbox mount is worn, it will allow it to move around more. Since it's bolted to the engine the whole assembly will feel looser. You would notice it most when going off power to accelerating again and during changes __________________ 1991 90 quattro 20v sport 1991 90 quattro

20-07-21, 04:11 PM	#8
mikes2 4 ring whore! Classic Audi Club Member Join Date: Nov 2007 Location: Polmont Posts: 2,617	There's 2 mounts. There's one in the subrame and there's also another which mounts to a bracket. The one in the subframe is best replaced off the car. The other one is held on the bracket by a couple of bolts so if you undo the big main bolt, the 2 small bolts should be easy to remove and you'll be able to remove it - gearbox needs to be supported or it won't line up afterwards. __________________ 1991 90 quattro 20v sport 1991 90 quattro

21-07-21, 10:01 AM	#10
mikes2 4 ring whore! Classic Audi Club Member Join Date: Nov 2007 Location: Polmont Posts: 2,617	No problems with the questions. If you've gone to the trouble of fitting them, I'd be inclined to use them although they may not last as long. Those bushes are slightly softer - they're used on the early 5 cylinder models which also had a different anti roll bar setup The metal caged bush can also be 8A0 407 181 - they have a slightly larger flange on them. __________________ 1991 90 quattro 20v sport 1991 90 quattro

19-07-21, 05:26 PM	#3
84CoupeGT Grown up member Join Date: Nov 2020 Posts: 309	Cheers Mike, that is helpful. I'm pretty sure the bolt heads were the same size as the originals, however I did notice they were around 1cm longer. Hopefully that doesn't cause any issues. Yes, I forgot to mention I've got new ball joints and tie rod ends to fit as well. I've got the pinch bolts but not the locking plates, they look ok but I notice Autodoc have got them at a ridiculously cheap price so will probably order those in with my next order from them. Gearbox mount visually looks ok, but the outer tabs feel a bit dried out. I haven't looked into how much of a job it is. Would it make much difference to the drive if it's hardened/worn out? Cheers