Wishbone Q's

[zcacogp]

Chaps,

The next big job on my S2 involves these things;

Yes, Bilstein, with home-made collars for the top of some replacement casings. I'm very excited!

BUT, I'm aware that there may be a lot of other bits that are worth doing while it's all in pieces. I have the parts to rebuild the strut tops (thanks to Kongdosoken on here!) and am now pondering the wishbones and wishbone bushes themselves. Both outer ball joints on the wishbones are in good order but neither are new - one wishbone is original (I think) and the other one was replaced by a second-hand unit about 4 years ago. The rear mounts are 968 items, done about 6 years ago. I have no reason to believe that any of these parts need replacement as they all seem to work well and have had no warnings at MOT time. However getting a car's geo right is a bit expensive and there is merit in changing a number of parts while it is all apart, particularly when the parts aren't new.

I am lucky in that I have a spare pair of wishbones. Sadly those have knackered ball joints on them, meaning that my options are as follows;

- Rebuild the spare wishbones and have them ready for a straight swap
- Re-use the wishbones that are already on the car and replace whatever parts as necessary while they are off

I think my questions therefore are;

- Are balljoint rebuild kits worth the effort? I'm aware that many people have opinions on this so I'm particularly keen to hear from people who have them fitted on their own cars and can give first-hand experience. Also, what kits are the best ones to buy? (I do recall that the metal-cup ones are much better than the plastic-cup ones). If I do swap the spare wishbones on then I'm much more likely to rebuild them myself than spend the £175 or so that Hartech want for rebuilding them unless the consensus opinion is that the kits are very likely to fail.
- Is it worth fitting new front wishbone bushes to the car or sticking with the ones that are on there? If I do replace them then is it worth using polyurethane ones or stick to rubber ones? What's the cheapest place to get the replacements? Powerflex have these:

https://www.powerflex.co.uk/road-series/product-details/Front+Wishbone+Front+Bush/293.html

... at around £40 (I presume for two), which seems to be about the going rate. Rubber ones are much cheaper.

For reference, the car is a daily driver (although is not used much). It's not a track toy.

Also, while asking about the wishbone bushes, I have dismantled the spare wishbones and noticed that the old bushes sit in steel sleeves inside the cast alloy of the wishbone itself. Do these sleeves stay in place or are they replaced with the new bushes? Photo here, showing the join between the two ends of the sleeve;

Thanks for any help you can offer.


Oli.

 

[Monkeythree]

Oli,
Quick reply (call me if you want more details):
1) Balljoint rebuild is straightforward. The hardest part is getting the circlip out. I re-used the original spring and the original cover plate as the ones in the kit seemed a bit flimsy.
2) I put powerflex black bushes in the front of my wishbones (i also have 968 rears) and I'm really happy with them. I was concerned they might make the front end a bit harsh and crashy but they don't at all. It's tight but really compliant and just makes the car feel up to date.
3) Those bush shells need to come out of the wishbone to fit powerflex but they take care to remove. Hacksaw (carefully) a groove and then they drift out with a suitable piece of steel engaging (just) into the gap in the middle of the two halves.
You are welcome to have a drive of my car if you want to feel how the black bushes feel.

 

[zcacogp]

Tom,

Thanks. That's as helpful as always. Interesting that you went for the Black Powerflex bushes rather than their 'regular' purple ones.

Where did you buy the balljoint kit from? Rennbay is the source that is always quoted but they are $185, which is a chunk more than I remembered from previous research. That's about £125. OK, that's for both sides but it makes the £175 for having the wishbone fully rebuilt for you look rather more reasonable!

Also, out of interest, who did you get to do the geo set-up on your S2?


Oli.

 

[u63af]

Oli
i used the rennbay kit for rebuilding the wishbones on my old turbo and found it was fairly straightforward. I went for the metal ones, didn't notice any compromise in ride. I had power flex purple ones, car felt good and once you get the old rubber ones out they are straight forward to push in. I will be rebuilding using this on my newer turbo aswell.
cheers
sandy

 

[bmnelsc]

Re Balljoint kits - I used the metal socket version vs the plastic ones and have had no trouble but only about 15k miles. Vertex in the US offers rebuilt arms and one of their options is to machine the end of the arm to accept a sealed ball joint assembly that screws into the arm. Supposed to be very good and "easy" to change them in the future when required. Seems to me I've seen similar on the websites of English suppliers. Sorry - I don't have any more/better info.

If you go for rebuilt control arms then the bushes are new also - Vertex provides choice of bushing - stock/stiff. etc. I would expect others would provide the option also.

 

[Monkeythree]

I bought my ball joint kits from Design 911. £50 each which I think is expensive for what they are.
http://www.design911.co.uk/fu/prod13104/Wishbone-Ball-Joint-Repair-Kit-Porsche-944-1985-Onwards/
I'm sure they are a generic kit so if you could just identify if it is common to a VW or Audi or something then I daresay it could be found cheaper elsewhere.

I got a full set up done at Centre Gravity. Made sense given that everything had been in bits. Chris asked me what I was looking for from the car and set it up accordingly. That meant that it ended up outside of factory limits but I'm comfortable with that as it just means that the handling is not compromised to be all things to all men.

 

[zcacogp]

Chaps,

Thanks for your answers. It's sounding like the repair kits are not necessarily to be avoided, which is heartening.

Tom, that's an interesting comment about it being a generic kit. My concern with the one from Design911 is that it looks from the photos like it has nylon cups for the ball to sit in. Is this the case?


Oli.

 

[colin944]

I used a Rennbay rebuild kit for my arms. One has performed perfectly and the other failed after about a year and 2-3 thousand miles. I did replace the bushes in the arms with poly ones.

 

[Monkeythree]

Chaps,

Thanks for your answers. It's sounding like the repair kits are not necessarily to be avoided, which is heartening.

Tom, that's an interesting comment about it being a generic kit. My concern with the one from Design911 is that it looks from the photos like it has nylon cups for the ball to sit in. Is this the case?


Oli.

Yes. Nylon cups. But the joints should be packed with grease so in theory the contact surfaces are permanently lubricated. The OE ball joints have plastic cups so it didn't concern me. You could always drill and tap the steel sealing plate for a grease nipple which would facilitate replacing the grease on a routine basis.

 

[zcacogp]

Tom,

I'm with you on the plastic cup thing in that it shouldn't be an inferior solution but it seems that there are more reports of the plastic ones failing than of the metal ones doing so. Colin's experience is not uncommon it seems, although it does beg the question of what was the difference between the two sides that caused one to fail after only a tiny mileage.

The grease nipple is another thing that is missing from the D911 kit. I'm tempted to stretch the budget a bit further and buy the Rennbay one - it seems like a better bet. Although it is even more expensive, annoyingly!

Thanks again for your help.


Oli.

 

[colin944]

The short of it is that I would probably buy good used or new arms the next time. I don't think I would buy a rebuild kit again.
Also there is no need to argue about turbo's and S2's. S2 is best the end...............

 

[zcacogp]

Chaps,

An update on this. I eventually bought the phosphor-bronze cupped balljoint rebuild kit from Rennbay and had it shipped to the UK. It was expensive. Shipping was also expensive. And I was then stung for Import Duty on delivery which made it even more expensive! The kit was nice enough and simplicity itself to fit (although getting the whole thing in the vice, along with a drift on the front and back, and doing it up, was a prize fiddle which would have been made much easier if I had had a third hand) but certainly didn't have the appearance of something that was worth the vast price it ended up costing. I sincerely hope that it lasts well.

I also bought the softer, purple Powerflex bushes for the front of the wishbone and was sent the black, harder ones. Time was such that I couldn't send them back and ask for the correct ones so I fitted them anyway. Thanks for the tip about cutting the shells out of the wishbone with a hacksaw Tom - it was very helpful. The bushes fitted dead easily, helped with the sachet of grease that came with them. (But - blow me! - I think the prices of these must have rocketed recently! Nigh on £75 for four bits of rubber and some stainless steel tube and a few washers! I don't recall the last set of Powerflex bushes that I bought about 8 years ago was that absurd!)

Here are some photos of the completed wishbones. Suffice it to say that the completed cost was a lot less than that of having them re-done by the likes of Hartech but not as much less as I had hoped. And, for reference, Max Schenker of Frazerpart is offering rebuilt ones now as well, and at a slightly better price than Hartech. Still more expensive than rebuilding them yourself though.

New Balljoints.

Grease nipples!

Bushes.

For reference, the hardest part of the job was fitting the new wishbones into the mounts with both of the washers in place as it was all very tight. However I am guessing that this tightness will mean taughter handling and it's not squeaking (yet), so I'm happy.

The car goes in for an alignment tomorrow morning with the new wishbones and Bilstein shock absorbers. It's (very) good already and I'm hoping it will be excellent once fully aligned.

Thanks for your help chaps. Particular thanks to Tom for the tip about cutting the steel shells out!


Oli.