A-A-ron

So after reading tons of posts on here I've decided to contribute a little myself. I did a pretty thorough rebuild on a 95 993 4x4 with about a quarter of a million miles. Most of the parts were worn out so the car got an engine rebuild, power steering rebuild, pretty much any rubber bushing or mount replaced, and all the drivetrain parts were removed and cleaned.

First off are thanks for the online folks at Rennlist, P-car, and Pelican for providing some outstanding guidance.

I'm going to skip over a lot of the how to's since they already exist and jump straight into some of the additions I found.

Engine:
1. Piston Oilers:
a. Don't soda blast the case, it will clog the oilers. Sounds obvious but I thought it was OK.
b. Make sure the oilers are sealed into the case. They are holding back ~90 psi of oil. You want them to seal at idle oil pressures. I used Loctite 680 which is OK for oil environments and is for slip fits. I'll let everyone know how it works in 10 years if I have to take the motor apart again.

2. Oil system/sealing the case:
a. Be sure to put sealant on the bearing webs, they hold back ~90 psi oil that feeds the oilers and main bearings. Just make sure to use something that cures under compression, that way you don't have to worry about clogging oilers etc. I used Curil K2, it will only harden under compression.
b. The cam boxes only go on the case ONE WAY, they are mirror copies of each other. Check the orientation of the SAI ports before you put em on.
c. Prep the cam chain housings/covers well. The magnesium cases on my motor had tons of pitting. I used RTV anywhere the magnesium touched a gasket.
d. Head position is slightly important. They should all be the same height after the machine shop so you can mix them up. But the exhaust stud direction is specific to the left/right side of the engine. I had to add in some extra studs once I got the motor back together.
e. Don't push the RMS too far into the case. I made a tool to push it in the required 2mm after messing it up once. Is this something anybody would be looking to buy?
f. Antiseize. Use it a lot. I had a lot of corroded/stuck bolts on the heads/cam boxes.

3. Pulleys
a. I had to make my own pulley holder for the crank and cam wheels as they are installed at 100+ flt lbs of torque. Is this another thing a lot of other folks are needing on their rebuilds?
b. FYI the crank pulley tool works for the power steering pulley as well.

Suspension:
1. New bushings
a. The 20T HF press is not adequate for these. I broke one of the cast plates in half when trying to push them in. I had to go to a friends shop and use a 50T press to get it done. I replaced rear subframe and front control arm bushings.

2. ABS sensors, use an impact gun to get the bolts out. I had one snap that I tried to remove by hand and had to weld a bit of another bolt on to get it out. Antiseize is your friend for reassembly!

Front CVs:
1. You can actually take both inner and outer carriers off of the axle. The outer CV (wheel side) has a circlip hidden in the grease. You can use a brass hammer to remove the outer joint, just hammer on it until it falls off.
2. I had trouble finding band clamps for the front outer CVs, they are really big. I used some generic ones from o-reileys. So try to buy a kit with clamps if you can.


Misc:
1. Front accessory fan resistors; buy resistors for them on the internet. You can get some nice aluminum heat sink resistors from digikey.com for about 15-20 bucks a piece.

2. Buy some tripple square bits from the internet or your local auto store. They start at about 20 bucks for a whole set of them. Don't strip your expensive bolts! These are standard tools, not Porsche tools.

3. My favorite way to clean parts: 1 small can of mineral spirits and 1 small can of acetone (~1qt each). You can slosh parts around in the two cans so they clean nuts and bolts really well. You don't have to waste much cleaning solution. The acetone as a final cleaner leaves parts residue free!

Hopefully this stuff may help some folks out on their own build!

e3photo

Thanks for the post. Always interesting to see what someone else encountered on their restoration.


Emerald

Mike J

Good suggestions!

Another alternative : For the front A arms, I usually just use heat to remove the inner metal pivots, a sawzall to quickly cut the rubber out, and a hacksaw (in my case air powered) to just slice through the outer sleeves - then knock them out with a hammer. They usually go out pretty simply. For the subframe bushings, you mean the four pillows that support the subframe from the body? They seem to come out pretty easily with an air chisel - i have done them while the frame is in the car (with the engine in) and that seemed to work.

I was going to use my press once I machine the exact colors to fit for the A arm bushings, but I suspected I needed a lot of pressure - thanks for the confirmation!
My shop press is too small....

Cheers,

Mike

Top-Gun

Just did my front A-arm bushings, I found two tools invaluable for this. The first was an air saw (as Mike mentioned above). I used this to cut the rubber out from the sleeve, and then to quickly slice through most of the sleeve in two places. I used a hand hacksaw to finish the cuts to prevent damage to the control arm bores. A chisel and hammer will then easily knock the cut chunk out and the sleeves come right out.

The second was an air chisel/hammer. This thing is a wrecking machine and you have to be careful with it, but it makes short work of the flanged bushings. I used a hand chisel and hammer to carefully bend the flange away from the arm in two opposing spots. Then the air chisel can grab the bent part and drive the bushing right out in one piece.

A-A-ron

Hey Mike and Top-Gun,

You guys are spot on with the air gun/sawzal/heat methods to remove the old bushings. I did the same thing and it worked great!

It was the install that proved more difficult. Most of the new bushings went in fine, but one of the rear subframe bushings (pillows) and one of the front control arm (T-shape) bushings wouldn't go in all the way with the 20T press. It may be worth getting some rolled steel plate instead of the cast plates provided so they will bend instead of cracking.

Don't put the smaller front control arm bushings (T-shaped) on wood or anything soft to push them in or the washer portion will separate from the center metal piece. Make sure the metal bushing is contacting flat metal on both sides. I'm not really sure why they were so hard to put in, they were all clean, any burrs from my removal were filed or cut down, and they had a light coating of grease. I may have just been a little unlucky with the fitment of parts I received because it sounds like most people haven't had many issues with the install.

Aaron

Steve Weiner-Rennsport Systems

Hi,

While I cannot comment on everything, I would tell anyone who reads this to NEVER to use any RTV on these engines. You would never believe where that stuff migrates to and in most cases, has caused component damage when it clogs spray bars, crankshaft oiling passages, and main oil galleys.

Porsche's recommendations on sealants are really very well thought out and in the majority of applications, the ones to use.

A-A-ron

Hey Steve,

Good point. Do you have any suggestions for engines where the chain covers and housings have a lot of pitting? Do you just use the standard gaskets or would you apply some kind of surface treatment first? Those covers and boxes are really expensive...

Here's another guy with a similar predicament.
http://forums.pelicanparts.com/911-e...seal-leak.html

Thanks,
Aaron

Steve Weiner-Rennsport Systems

Aaron,

If I determine that the sealing surfaces are too pitted/corroded to seal and I cannot resurface them in the milling machine, they get replaced.

Standard gaskets for me, only.

bcameron59

This from PP engine rebuild forum, echoes Steve W's concerns with RTV but with some qualifiers...

See post #260 at bottom of p. 13.

http://forums.pelicanparts.com/911-e...thread-13.html

Elsewhere in the same thread threebond 1104 seems to be the popular choice for chain case sealing. Pitting on the chain cases seems to be very common if not universal and some state they come from the factory like that. I've never seen a brand new one so I couldn't say either way. If you have access to milling equipment Steve's solution is the optimal one, if not you'll have to decide what's the lesser of many evils...

A-A-ron

Hey Guys,

Thanks for the input. Steve's approach is by no doubt the best from a mechanical/reliability standpoint.

Unfortunately these pieces would be real hard to mill. The covers are curved (so you need a CNC). It would work to machine the flat surfaces on the box as long as they don't require too much material removal. The seal for the camshaft needs to stay in roughly the same location.

I'd imagine debris from sealant is more a problem on the 964 as it does not have a filter between the pump and high pressure lines leading into the engine. So I'll have to take my chances at this point.

Optimally, you'd want to use something similar to the case sealant that doesn't actually harden unless it's under pressure. Maybe give the Curil stuff a shot, but I'm not sure if it will harden under the pressure of the rubber seal. Has anybody else used Curil to supplement rubber gaskets?

Maybe the folks at Loctite will have a suggestion too...

Just finding an appropriate sealant saves $2500 in parts.

Aaron

bcameron59

Curil T is non-hardening:

http://www.elring.de/fileadmin/Datei...il_T_en_01.pdf

Used it only on cylinder bases to case (to supplement metal ring seals), haven't tried it on rubber seals. Would try it before I'd try silicone grease eg Dow 50 in the chain case application though.