Lower Balljoints (alloy arms) - and MOT

[zcacogp]

Chaps,

OK. My S2 passed it's MOT today. Which is good. Usual complimentary remarks from the tester, and 12 months ticket. Life is good.

Well, not quite. Life is OK. It had advisories. New tyres on the rear. And front lower balljoint on the off-side. In fairness, that last one was mentioned last year but wasn't a formal advisory, and really needs doing now. So, given I want to do both sides (one side only is not a good idea for anything suspension or brake related) ...

The options seem to be Hartech at £175 per side, plus VAT, plus postage, plus return postage for sending your old wishbones back. Total would be around £410, plus postage both ways, so not much change from £450. Link here: http://www.hartech.org/parts.html

Or Rennbay, from the states. Their super deluxe kit (with metal cups rather than nylon ones) is $134. Plus postage. That's about £88. OK, there may be some tax to pay when it's imported, and the postage will be a bit, but that's a LOT cheaper. And, having read their instructions (here: http://www.rennbay.com/info_pages.php?pages_id=13), there is nothing that sounds too terrifying. Link to the kit is here: http://www.rennbay.com/super-deluxe-ball-joint-kit-p-82.html?osCsid=1494c9327101c3b7417a8b4386cdbe87

Now the Hartech kit is clearly quality stuff, bulletproof, and you can be sure it will work well and it's easy - replacement wishbones, swap 'em over, job's a good 'un. BUT, £350 buys quite a lot of faffing around in my book, and I'm seriously interested in the Rennbay option. It seems that of all the DIY rebuild kits the Rennbay is the best; who has used them, and what was your experience? There are a few threads on here about them, but I'd like as definitive an opinion as possible ...

First hand experience of the Rennbay kits? Let me know.

Thanks.


Oli.

P.S. For those who are watching my "cam belt and chain change" progress with interest (which I am sure you all are ... please say you are ... Oh. That'll be no-one then []) ... the parts arrived this morning, the day after I wanted to do the job, due to some less-than-stellar performance on behalf of a courier whose name sounds like a form of explosive. I'll be tackling that one some time next week.

 

[Alexw]

Wasn't the problem with the rebuild kit that if the alu in the arm itself has worn then the rebuild is useless or even worse - dangerous as the whole arm snaps under extreme pressure? Or am I thinking of someone elses rebuild kit? I don't think this happens often but I thought I'd mention it - I hadn't realised the cost of the Hartech ones after postage and stuff! Then again I'm only 45mins from them so I'd just deliver it myself. I've heard good things about the Hartech stuff but nothing on the rennbay, probably more info on them on rennlist

 

[pauljmcnulty]

Wasn't the problem with the rebuild kit that if the alu in the arm itself has worn then the rebuild is useless or even worse - dangerous as the whole arm snaps under extreme pressure? Or am I thinking of someone elses rebuild kit? I don't think this happens often but I thought I'd mention it - I hadn't realised the cost of the Hartech ones after postage and stuff! Then again I'm only 45mins from them so I'd just deliver it myself. I've heard good things about the Hartech stuff but nothing on the rennbay, probably more info on them on rennlist

Seconded. I don't know what brand of rebuild kit the issues were with, but I've not heard of anyone having trouble with the Hartech arms (or the Dave Gilmore service, if it's still going).

Although, I think it was Baz who pointed the potential problems out! [][][]

 

[pegasus]

Hi ,I would only replace the worn arm,we are not talking about the need to balance the system as in shockers and pads. If the good side has no excess movement due to wear you will achieve nothing by throwing it away,put the money saved towards the hartech arm, you will find that suspensin balljoints very seldom wear at the same rate. If the other arm needs replacing in a few years do it then,all the best John.

 

[sawood12]

Hartech and Rennbay are both good options. The Rennbay ones are well tested by many people in the states - even some racers. The advantage of the Hartech route is that Baz will check for wear in the arms socket which can happen as the nylon bushes don't last long at all from new (another good reason for the Rennbay kit wiht the Phosphor Bronze bushes). If Baz finds evidence of wear and it is not too severe he will machine the socket to re-establish its shape so you wont get accelerated wear when you repair the joint.

I bought the Rennbay kit and got Baz to fit. But the car was off the road anyway so wasn't an issue being without the arms for a few weeks. Baz's comments were that he was quite happy with the kit, though the kit came with a fully circular circlip which Baz didn't install as he didn't think it was as good as the standard normal circlips - though this is one of Rennbays selling point as they say their circlip provides support around the full circumference.

Another plus point of the Rennbay kit is that it incorporates grease nipples so you can replace the grease at service time. No better feeling than squiring nice new grease into a joint and seeing old dirty grease being squeezed out.

If your concerned about how safe the Rennbay kit is i.ve seen a photo of the results of a offside head-on smash on Rennlist and the car was fitted with Rennbay's geometry correction kit with a longer spindle that looks way too long and thin - but after the crash this spindle was bent and the alloy arm had snapped about half an inch up from the socket - so they are plenty strong enough.

Installation yourself doesn't seem too hard so if you've got the confidence i'd say go for it. There are plenty of doom-mongers out there who will say don't touch it yourself, but from what I could see from the installation intructions it didn't involve any special tools or special skills. The only reason I got Baz to instal was I wanted him to check the socket geometry and correct if required - in my mind that is an important part of this repair.

I agree with you Oli - anything suspension and brake related then always replace as an axel set even if the other side appears to be fine.

 

[andy watson]

Oli,

I agree saving a the £££'s would mean another job or 2 could be done, would I like to risk a "kit" on something quite as important especially from abroad when if there was a problem you would then end up with a lot of grief?

Everything I have replaced on my car has been done so with genuine Porsche parts, my theory being if the parts have lasted this long then the replacements I have fitted should be good for another 20 odd years

Just my opinion and as you do the work yourself you are already saving £££££££££[][]

Cheers
Andy

 

[DivineE]

I bought the kit, probably still in a box somewhere. Looked at the components when they arrived and then thought, to hell with this and bought the hartech ones. I'm sure someone with a bit more dedication could make it a good option but the hartech unit is a safe bet and comes with all the bushes replaced not just the front ball. I just liked it for the peace of mind.

 

[pauljmcnulty]

I'm sure someone with a bit more dedication could make it a good option but the hartech unit is a safe bet and comes with all the bushes replaced not just the front ball. I just liked it for the peace of mind.

Again, seconded. It's not doom-mongering, but more a genuine safety thing. If you are a very experienced mechanic, then you can re-furb to the same standard as the guys who do it for a living. Personally, I couldn't even attempt it, and have seen the pictures of one failing on track. On road would have been more serious.

If you feel confident in both your ability, and the quality of the kit, then it's a saving. To me, it's not an option as I don't know one end of a screwdriver from another. I do think, however, it's a very small saving in the scheme of things, compared to a pretty big potential failure.

 

[BlackMagic]

I fitted the Renbay kit a few months ago. It is as easy as they say and the kit is beautifully made. Including removing and refitting the arms the first one took 4 hours and the other side 2 hours.

The only tricky bit is getting the old circlip out. I found that drilling a small hole (1.5mm) through the circlip (which you have a replacement for in the kit) enables a small pointy tool to lever it out.

I wasn't too worried about the change of circlips as they just hold the bottom plate into the arm but don't carry any serious suspension loads. Given that the suspension is a McPherson strut, virtually all the load is horizontal not vertical.

Also, Im not sure what Hartech use as material for the cup liner, but phosphor bronze is the material for me. When you take the old joint apart and see what has happened to a nylon liner its not pretty!!

The car's off to Jon Mitchell next week so I will see what they say.

 

[sawood12]

A word of warning for anyone considering the Rennbay kit. Check your car has not had 968 arms installed at some stage in its life. It was quite common for cars to have the arms replaced by 968 arms if the original 944 arms needed replacing due to ball joint wear. Mine had a 968 arm on one side and a 944 arm on the other. The Rennbay kit cannot be used with the 968 arms - in fact i'm not sure the 968 arms ball joints can be replaced. Baz exchanged my 968 arm for another 944 arm that hadn't yet been repaired.

 

[zcacogp]

Chaps,

Thanks for your answers. It looks like I have, however, fallen into the (self-inflicted) trap of asking a bunch of people for their opinions and then realising that many of them conflict! Hartech is the safe bet but Rennbay is excellent ... changing the side that is OK is a waste of time and money but it is good practice to do both at once ... the Rennbay ones are very strong but failure could be catastrophic (did I spell that right? Too much dalwhinnie is bad for the typing ... )

FWIW, the only thing that is bothering me at the moment is that the wishbones may be worn beyond repair. How do I know if they are? If I dismantle them, will it be obvious? For my money, and the saving involved (McNulters is right, the saving is small in the greater scheme, but it is still significant), I think the super whizz-bang Rennbay kit is a good choice. However, I will probably play it a little safe and buy some replacement wishbones, then rebuild the replacements and swap them onto the car. That way I can carefully inspect the replacements before doing the rebuild on them, and the car is off the road for as little time as possible.

Thanks for your input chaps. It rather seems as if this year is going to be an expensive one for my S2. Belts, cam chain, possible waterpump, tyres, wishbones ... the list goes on. Hmmm. Just have to hold onto her for some years to come to make it all worth it!


Oli.