Front Control Arm

[fioravanti]

Hi Guys,

Firstly, let me introduce myself. I am the owner of a 2000 2.7 Boxster, and I'm living in Dublin, Ireland. I have luking around the forum for the last 6 months, looking at bits and pieces regarding the Boxster. I must say, this is an excellent site, with a wealth of information for Porsche virgins. It has enabled me to fix many issues my car has developed, and diagnose other issues which led to prompt diagnosis by my garage.

I have had all the usual issues with my car in my last 8 months of ownership (coils, MAF, door locks, coolant cap failure & subsequent tank failure, top mounts, clutch, CV joint failure), which has cost me dearly!

Sick of paying the garage mucho €€€ to fix it, I have recently replaced all four disks, all the pads, and the rear trailing arms (forked control arms). I have the parts to change out the front control arms, but reading the Bentley manual, I find the following...

"Retaining bolt at transverse control arm must be torqued to specification with vehicle on ground, and suspension loaded with weight of vehicle".

Exactly how am I supposed to do that without a pit? Is this a job for the garage? Am I out of my depth?

Any feedback appreciated!

Thanks

[geoff]

Exactly how am I supposed to do that without a pit?

Ramps? Like Rhino Ramps

[greerj1]

I used cribbing,(blocks of wood and a 12 in wide plank at the top) to get my car high enough to remove the transmission. The wheels were on the top plank, about 2 ft off the ground. It took a while to get it up and down but the car was level and the suspension was equally loaded on all corners. If you use a ramp, you will get the cosine effect where the rear wheels will be supporting it's normal load plus the normal weight of the front end x the cosine of the angle the car is at. The Boxster wheel base is 2415 mm. If the front end is 250 mm in the air the cosine of the resultant angle will be .11. The weight of the car is (1356 kg) since the Boxster weight distribution is nearly 50:50 this holds true. The load on the front suspension of the car will be (1354 kg/2)= 677 kg, and 677 kg on the rear. At the cosine of .11 the front will have a load of (677 kg)-(677kg x .11) = 602.5 kg. The rear will have (677 kg)+(677 kg x .11) =751.47 kg ; 751.47+ 602.5=1354 kg. This is a difference of 75 kg from flat and level loading of the car. Also, fill up the petrol.

You are not out of your depth. These cars are very easy to work on. If you use the ramps, Get the rear end level with the front and all will be well.

James Greer

[fioravanti]

Thanks Geoff and James. I wasn't expecting a response so quickly!

James, that is about as complete an answer as could be imagined! I think this work is meant to be carried out using a Pit, or a lift that can raise the car by the tyres (I have seen one at national car testing centres). That would make this into a very easy job indeed! I don't feel like investing €20,000 into buying one, so, going by your meticulous calculations, I am assuming that a ramp with a 12" rise will suffice to torque the bolts to an acceptable standard. Oh, on re-reading your post, you state that the rear must be in line with the front, so that would mean 4 ramps...I might just bottle it and get my local indie to tackle it...They don't have a pit either though...

[timbo]

Not long did mine, same year and model. You'll find there is a raised mark on the control arm which lines up with a mark on the chassis, I lowered my front hub onto a block and let the hydraulic jack down slowly till they lined up, then tightened the bolt. It's so the rubber bush isn't under torsion when the car is standing at rest.

[fioravanti]

Not long did mine, same year and model. You'll find there is a raised mark on the control arm which lines up with a mark on the chassis, I lowered my front hub onto a block and let the hydraulic jack down slowly till they lined up, then tightened the bolt. It's so the rubber bush isn't under torsion when the car is standing at rest.

Thanks for the response Timbo. That makes perfect sense to me, and saves a huge amout of hassle during installation. I have, however, booked it in to get the garage to do it, as I can't raise the car enough to remove the undertray without some considerable risk (I have jack stands, I just don't trust working under the car with so little clearance). That and the fact that I would like to 'keep in' with them should I ever need more complex work carried out. You would think it is enough that I give them money, but it is important to keep up relations.

It's a pity that the Bently manual doesn't explain the reason the control arm has to be torqued whilst the car is on the ground. Your explanation clarifies why. I have found the Bentley manual to be lacking in comparison to some of the quite excellent DIYs on renntech and other Porsche forums.

Thanks again!

[timbo]

Just as a matter of interest, I managed to do mine without takeing the undertray off, just removed some of the fastenings to allow access for a socket.

[fioravanti]

Just as a matter of interest, I managed to do mine without takeing the undertray off, just removed some of the fastenings to allow access for a socket.

You know what Timbo...I think I might give it a shot tomorrow! I'll let you know how I get on. Thanks for all your help!

[fioravanti]

Just as a matter of interest, I managed to do mine without takeing the undertray off, just removed some of the fastenings to allow access for a socket.

You know what Timbo...I think I might give it a shot tomorrow! I'll let you know how I get on. Thanks for all your help!

Just to wrap up this thread, I had another look, and realised that there was no way my Jack / axle stand combo could get the car high enough to get a torque wrench in to tighten up the arm once the job was completed, so up to the Garage it went!

I am now the proud owner of a squeak and rattle free Boxster.

Thanks for all your imput guys, I really appreciate it.