Help with replacing seals and other "While you're in there" stuff

[Por_sha911]

Found this:


Just finished this (first one):


I've got it down to a short block and I'm going to have a shop replace the head stud, Oil Return Tube seals, and Pilot Bearing (if I do the clutch).

Questions:
1) I want to replace the RMS (aka flywheel seal). Do I need a special tool? Any suggestions?

2) I have to replace the front seal on the G50. Do I really need a special tool or can I just use a deep socket?

3) I've pulled the clutch and the rubber center looks great. The flywheel has a lot of media left on it and a little scorching (but not bad at all). I know that a spring centered clutch is on the to-do list but can I get away with putting it off till I take the trans out and redo the sychros? (2nd gear is a little notchy and I can go down to first below 10 mph) If so, should I do the clutch fork upgrade now or wait? (The clutch has felt great with NO problems whatsoever. If I do a clutch/press plate/TO bearing, fork upgrade... can I resurface the flywheel?

4) I plan on also replacing the CHT Sensor (using homemade tool from cut deep socket), Oil breather gasket, Oil Cooler seals, Oil Pressure Sending Unit and gasket.

The car has 55k, had valve guides done at 35k, runs great, used about 3/4 quart of oil every 4-5000 miles, no oil leaks that I can find (other than trans front seal). Valves and plugs look perfect.
Is any of this overkill? Am I forgetting anything? This is not a money is no object project. I've been searching the forum but haven't found a firm answer on the above.

[Por_sha911]

Monday bump. Help.

[Por_sha911]

OK, am I on everyone's blacklist or does no one know anything about `87-89?

[KTL]

Originally posted by Por_sha911


I've got it down to a short block and I'm going to have a shop replace the head stud, Oil Return Tube seals, and Pilot Bearing (if I do the clutch).

Questions:
1) I want to replace the RMS (aka flywheel seal). Do I need a special tool? Any suggestions?

2) I have to replace the front seal on the G50. Do I really need a special tool or can I just use a deep socket?

3) I've pulled the clutch and the rubber center looks great. The flywheel has a lot of media left on it and a little scorching (but not bad at all). I know that a spring centered clutch is on the to-do list but can I get away with putting it off till I take the trans out and redo the sychros? (2nd gear is a little notchy and I can go down to first below 10 mph) If so, should I do the clutch fork upgrade now or wait? (The clutch has felt great with NO problems whatsoever. If I do a clutch/press plate/TO bearing, fork upgrade... can I resurface the flywheel?

4) I plan on also replacing the CHT Sensor (using homemade tool from cut deep socket), Oil breather gasket, Oil Cooler seals, Oil Pressure Sending Unit and gasket.

The car has 55k, had valve guides done at 35k, runs great, used about 3/4 quart of oil every 4-5000 miles, no oil leaks that I can find (other than trans front seal). Valves and plugs look perfect.
Is any of this overkill? Am I forgetting anything? This is not a money is no object project. I've been searching the forum but haven't found a firm answer on the above.

If you've come this far you can do the oil return tubes. They're not hard at all. Do a search for some tips if you want but there's really nothing to it. Crush the old tube to get them out and expand the new two piece ones into place. Just be sure to lube the new o-rings really good so the tubes will slide apart easily. The new o-rings are notorious for being a tight fit and not allowing the tubes to move apart easily.

The rear main seal is not hard either. Just need the proper 12 point triple square socket to get the bolts off the flywheel. The old seal gets crushed at the access notch with a flat screwdriver and a hammer, then carefully pry out. The new one goes in with some oil on the inner lip and also on the outside diameter to let it slip in better. Alternating taps with a mallet should wiggle the seal into place. I'm never very good at that so I use the spendy $100 P234 Porsche tool to press it in perfectly. Whatever you do, don't put the green Curil T stuff on the seal. It tends to pop out when you do that.

Pilot bearing is not something you need the shop to do. You pop the old one out of the flywheel by tapping it with a hammer. Press the new one in to the same depth (flush with the outer face of the flywheel bore) with a hammer and an appropriately sized socket that is the same size as the outside diameter of the pilot bearing.

The trans input shaft seal is kind of a bugger. The first step is to get the guide tube out of the way by removing the two pan head screws. I strongly recommend using an impact-style screwdriver with the LARGEST philips bit that fits in the screw. This will help avoid stripping the soft 4.8 class screws that are in there.

When you get the guide tube off, the seal is your next opponent. You're going to mangle this sucker pretty good so just be careful not to damage the trans case bore or the input shaft (shaft is hardened steel and quite damage resistant but be careful nonetheless) when prying out the seal. I found a good tool to use is a typical parts store seal remover with the handle cut short to fit inside the trans. bell housing.



Here you can see the mangled seal and a screw I had to drill out when the head stripped.



The clutch disc may still be good but you'll want to inspect the rubber center closely for cracking. Try putting the disc in a vise and twisting the center to check the rubber for fine cracks. If you find some, replace with a spring disc. Do a search online for discs and you'll find some cheap, some expensive. For street driving, you can live with a cheap spring disc. If you drive hard, consider getting a stock Sachs disc (75-77 930 Turbo disc) or something like a Spec Clutches disc. If you stick with the rubber disc, you should not resurface the flywheel because the clearances between the disc rubber damper and the clutch housing can be too close and there will be interference. With a spring disc, there is no potential for interference and a resurface of the flywheel should definitely be done.

Shoot us a picture of the clutch fork and shaft and we can better decide if you should do the upgrade ASAP. Gut feeling says no since you say it works fine. The condition of the shaft will better tell us what to do. The parts for the old style shaft are still available, but the wise thing to do is the Pelican/Weltmeister bronze-bushed shaft update (have you seen this in Pelican's catalog?) because it is much less prone to clutch lining contamination with the bronze bushings, vs. the needle bearings that Porsche uses.

The CHT replacement is wise if your sensor is one wire. The two wire later sensor is said to be more reliable.

The clutch work (like the disc and the flywheel) may be overkill with such low mileage. But since you've got scorching, maybe the previous owner(s) slipped or abused the clutch alot. If the disc lining is still well above ALL the rivets then you should be able to reuse it if the rubber center is still intact and not showing age cracking.

The seals you plan to replace are not overkill since they're relatively cheap insurance against future oil leaks. You say the oil pressure sending unit is being replaced, but do you mean the oil warning light sender atop the engine next to the internal thermostat housing? That one is notorious for leaking and should be replaced. So should the o-ring that seals the internal thermostat.

Any more questions, ask away!

[Por_sha911]

KTL:
Thanks for the input.
I was hoping that a deep socket could be used for the RMS. I sounds like it has to be aligned perfectly or it leaks.
I'll twist the rubber center to look for cracks but as far as I can tell it looks perfect. I'll see if I can get a pic of the fork. What is "well above the rivets" in terms of depth? I can measure the thickness of the clutch itself if someone can tell me the total thickness of a new clutch or the depth above the rivets.

[KTL]

A deep socket for the RMS? That seal is huge! You're better off with a large plumbing pipe fitting

I'll check the min thickness above the rivets in the service information I have. The new thickness is not that much, so if you've got a good depth of lining (0.5mm or more) above ALL rivets you're fine.

[darkbeer]

thanks Kevin....I'm doing the same "while your at it" routine while I'm switching form my current 2.7 (with worn guides) to my "new" (to me) 2.7 with low miles & good guides....I'm fortunate to have two 2.7 motor's, one to drive, one to work on....

[KTL]

According to Wayne's engine rebuild book, the G50 and 911 Turbo disc has a new thickness of 10.1mm +,- 0.3mm and the min. thickness is 8.5mm