Front lower arms... Am I missing something?

B4-Andy · #1 22nd June 2018, 07:35 PM

So 1 arm on each side of my S8 needs doing, but I reckon it’s probably just as well to do all 4 while I’m there. The tops are all fine.

My quesiton is... Are they really easy to do? It seriously looks like there’s 2/3 bolts to just pop off and on, then wrestle the arm out and new one in. Is it actually really difficult to do or is it as simple as it looks?

Also any advice on where to buy would be appriciated, struggling to find decent quality ones. Except one guy in Poland who appears to be selling the whole front end.

MikkiJayne · #2 22nd June 2018, 08:31 PM

They are a bit of a pain tbh, mostly due to the stupid way the rear arm is assembled.

The inner bolt is put in from the rear by the factory so you're supposed to drop the subframe to get to it. What most people do is cut the head of it off and push it in to the subframe, and put the new bolt in backwards from inside the subframe.

The outer balljoint is a complete pig to get loose on the aluminium uprights because its blocked by the CV joint. If you have steel uprights (PF or FL with 20") then a solid whack on the outside of the taper with a hammer is usually enough to pop the joint loose, but that doesn't work on the aluminium ones as they have a steel insert to form the taper. I've not yet found a balljoint splitter that will fit round the chunky uprights and so the best way (I've found) to get them out is to remove the CV joint from the upright so you can get a socket and extension bar square on the nut and then beat it out with a lump hammer. Often the balljoint is seized in the tapered insert so so the insert comes out of the upright with the arm. You then need a bearing puller to get the insert off which you can hammer back in to the strut.

The front arm is relatively straightforward by comparison, but bear in mind its supporting the whole weight of the upright and brake assembly on the suspension strut so when you remove it take care to support the brake disc otherwise it will drop and tear the upper bushes apart. Its also worth doing the ARB links while you're at it, since you have to take them off to get the front arm off anyway.

Lemforder / TRW are OEM, but if you have factory 20" wheels the only option now is Meyle HD as the genuine ones are NLA from TRW.

I have Meyle HD on mine and they're working nicely so far, although I on;y have about 12K on them. Murray's Direct on ebay is has been the vendor of choice for Meyle, although there are a few others now with slightly better pricing. Meyle have an online catalogue so you can find part numbers from that and then put them in to ebay and see who has the best price. The nice thing about Meyle arms is they come with all new hardware which makes everything nicer to reassemble, especially if you've cut the heads off the rear bolts

B4-Andy · #3 22nd June 2018, 10:25 PM

Ah, things like the direction of the bolt and the steel taper are thugs you don’t immediately see on a visual inspection so thanks for the info. The only arm that urgently needs done is on of the rear ones. Balljoint separation and cutting bolts off sounds like ball ache. It’s a final edition on 20” with the alu upright.

Thanks for the info, not the 30 minute job I was suspicious of! ��

I'm also assuming if CV is being popped I best order a couple of hub bolts.

Would a puller get the insert off the ball joint?

Adrian E · #4 23rd June 2018, 07:14 AM

Hi Andy

The upper 4 arms are all Meyle HD and have been on there a number of years, so should indicate how good the quality is by now

One of the arms that’s specific to 20” factory wheels is, I think, only available as an OEM part

Pretty sure I changed the ARB links with OEM parts not that long ago. They need to be angle tightened past an initial torque setting, so I made some paint marks to judge how far to turn them - probably long since rubbed off!

MikkiJayne · #5 23rd June 2018, 09:00 AM

If its Adrian's FE then the front upright should be steel, and as Adrian said, the lower rear arm is specific to the 20" suspension. That, alas, is the obsolete one so Meyle HD is the only option.

Steel uprights do at least make the job a tad easier since you shouldn't have to pull the CV joint.

B4-Andy · #6 23rd June 2018, 02:25 PM

Audi love a stretch bolt. Every Audi I have ever worked on had stretch bolts all round the arms so all of the bolts will be replaced as needed. The upright I’m 90% sure wouldn’t hold a magnet? If they are steel and that makes the job easier then that’s fine but I thought the uprights were ally to offset the additional weight in the wheels on the 20”? I may have the wrong end of the stick there!