huskeric

For those that have removed/replaced their REAR lower control arms, need some advice. I was able to get the rear wheel carrier bolt out, the rear sway bar/shock bolt out, and the rewards eccentric bolt out; however, I am stuck trying to remove the last 18mm bolt/but on the forward control arm connection. I can surely get a wrench on the front of the bolt, but no means to get a wrench/socket on the rear lock nut, as it's hidden under the rear subframe and gas tank. I tried an 18mm universal, angles 18mm wrench, straight 18mm wrench, and a variety of other options to no avail. As a result, I had to put it all back together, though not can't even torque that same last nut down... I have the Porsche service manual, but is not helpful in this regard (actually, the OEM manual shows a FRONT lower control arm in their problematic repair sequence, which is even less helpful). I already replaced all the rear upper control arms (#8 & 9 below) with refurbed units with new poly bushings.

The REAR lower control arm is item #10, with nut #15 near the center of the diagram in question.

huskeric

Here's a better diagram of the rear subframe where the rear LCAs connect. I am having the issue on the highlighted upper left/right bolts on the L/R LCA near the upper arrows...

Marcus13190

You need to comme down the small chassis where the control arm is connected to access to bolt

chassis

If I understand what the above post suggests, the rear subframe/cradle needs to come out, at least partially, to allow access to nut #15.

chassis

Is this what you have? Note the cast hole in the aluminum subframe for the lower control arm forward bushing.

huskeric

Yes, this is what I have and I do see the area in the subframe where that pesky nut lives... sadly, lowering the subframe is a larger project than I had envisioned, but may be the only way to access.
Many thanks.

creeksider

That is disappointing. That’s a lot of effort for control arm replacement. Do you have performance issues or just know it needs replacement?

huskeric

Although my '15 PTT 'only' has 52K miles, appears all the original bushings are in very poor shape. This journey started with the typical clunking in the front end, which was worn out sway bar frame bushings and SB links. I was quite surprised the poor state they were in... yes, I realize it's a 4K pound car, but they were really trashed and the car has always been babied... So, I also have the upper/lower front arms, but that's for another day.

With the above in mind, decided to check the rear as well and just finished the rear SB frame and link bushings, and again, they were really in a bad state. Due to this, I also replaced the trans mount, which was also showing stress fractures on the rubber bushings... So, I opted to bite the bullet and replace the balance of the bushings as I suspect they are in equally poor shape and always looking for the next project.

I think the heart of the problem is the relatively soft OEM rubber bushings throughout the car... so, I opted to purchase poly bushings from a source in Poland to replace the front/rear U/L control arms bushings, as well as the rack bushings. We have all heard the horror stories of how harsh/noncompliant poly bushes can be, but, I chalk that up to cars that also had coffee-can sized exhaust hanging out the back with massive amounts of wheel camber. When properly engineered and in the right application, I have had very positive results using poly bushings. ( I installed poly bushings throughout my '89 944 Turbo S and is only mildly stiffer than the original bushings - also, all the slop and 'disconnected' road feeling are gone.)

In regards to the rear, I was able to replace/install the rear upper control arm bushings (12 in total - three arms per side x 2 bushings) and then started this challenging matter of the rear lowers, which is my current headache. I was able to source a number of cool tools (swivel-head socket wrenches, l-shaped wrenches, etc) in hopes I can get to that silly bolt without dropping the subframe.

Once I get the time, I will better document this journey as I realize others have expressed interest in poly bushings.
https://turboworks.pl/eng_m_Suspensi...ra-423523.html

rick

chassis

Think about removing the four rear subframe bolts and rocking the front of the subframe down until you get access to the nut. This avoids removing the entire rear axle+suspension system.

This suggestion might take 2 or 3 jacks/jackstands depending on what you have access to. Best case one jack aft of the axle and one jack under the pinion bushing. Lower the forward jack while keeping the rear jack in place. Lower the rear jack only to the extent needed.

With luck there is sufficient free play and compliance in halfshafts, propshafts, hoses and cables to allow this.

huskeric

Great advice indeed and this may create just enough room to remove - many thanks. I plan to re-engage on this project tomorrow after my latest tool purchase arrives.
Again, appreciated and I will ensure to post my progress for those also considering this job.

creeksider

Hey thanks Rick and chassis. Loosening the assembly could be a great approach if you can get in there. I’ll be right behind you…., well after the air suspension.

Maybe a tranny jack will be helpful?

None of my rears have been replaced yet but there is a lot of tire back there and I can pretty much feel the lateral stress on these soft bushings when I corner. I live in the mountains and drive twisty routes daily. They just repaved one of the roads recently and every time I drive it I feel like God reallly loves me lol

all the best Rick, refreshing the suspension should yield a car that drives like new.

Marcus13190

It's possible too replace chassis bolts OEM by longs threaded rods. After, you can lower chassis.
For change engine mount it's the same process.