Major DIY repairs to my 964

RedCoupe · 08-17-2015, 11:12 AM

This won't be a build thread as I'm not modifying or changing my 1990 964. But, I am tearing it apart to fix the major oil leaking that's been going on for far too long and give the engine and transmission a thorough going over. Thought I'd post it here in the 964/993 thread because we don't have too much of this sort of thing here.

Here the fun begins:

Now the engine and transmission are being pulled out:

RedCoupe · 08-17-2015, 11:25 AM

I went ahead and removed both rear axles as well as the heater ducts as it gave better access to such things as the clutch slave cylinder and the starter wires. Here are some more pictures.

The clutch cross shaft has to be removed before the transmission and engine can be separated. The shop manual gives no guidance on how to do this, but found that there is a threaded hole in the end of the shaft. I put a bolt, I believe it is a 5mm bolt, into my slide hammer and screwed it into the end of the cross shaft. A couple of easy taps with the slide hammer and the shaft came right out.

Here is the transmission after pulling it off of the engine. The G50 is pretty heavy so I used my engine hoist to pick it off of the jack. I was amazed to find that one side of my clutch plate was worn all the way to the rivets as I haven't had any slipping or shuddering. Just a heavy pedal.

RedCoupe · 08-17-2015, 11:41 AM

Got the engine up on the stand last night. Used one of those adapter rings for a generic engine stand that was purchased here at PP. Fit nicely, but I not sure it would give sufficient room to keep the flywheel on while on the stand. Now, the real work of cleaning, removing, cleaning, and organizing everything begins.

964TargaC2 · 08-17-2015, 12:02 PM

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wesleyc · wesleyc's Garage

Keep em comming ! I love this stuff! ! Resealed my 993 last winter. And put in a new clutch. Mucho education to be had.

RedCoupe · 08-17-2015, 08:24 PM

I got around to examining the clutch disk, pressure plate and dual mass flywheel tonight and all is not well. On the positive side, I have been noticing very high effort to disengage the clutch lately and was worried that the cross shaft bearings had siezed up. They were fine. So was the release bearing and the pilot bearing. But, the clutch disk had worn so much that it had scored both the pressure plate and flywheel.

I assume that the high effort was just a result of the pressure plate fingers operating at a steeper angle than normal due to the badly worn disk. But, I'll still check everything else before it goes back together including pedal bushings and the hydraulics. I know you aren't supposed to reface the dual mass flywheel, so I'll have to decide whether to just replace it with another DMF or something else. Just for giggles, I think I will clean it and let my son see if there's a way to securely chuck it up in his lathe to clean up the face. According to receipts I got from the PO 11 Years ago, this particular flywheel is the car's third one and has about 50k on it. Anyway, there is much in front of me, so none of this has to be decided now.

bazar01 · bazar01's Garage

What I will do next time I plan to do this kind of repairs is to gather all the parts I anticipate I will replace to spread out the cost over a year maybe. My funds are limited. The reasoning here is that I tend to think the same way you do. Salvage as much old parts I can.

Replace all the clutch components and be done with it. You don't have to worry about it for another 50-70k miles.
Good luck!

RedCoupe · 08-18-2015, 04:47 AM

Quote:

Originally Posted by bazar01

What I will do next time I plan to do this kind of repairs is to gather all the parts I anticipate I will replace to spread out the cost over a year maybe. My funds are limited. The reasoning here is that I tend to think the same way you do. Salvage as much old parts I can.

Replace all the clutch components and be done with it. You don't have to worry about it for another 50-70k miles.
Good luck!

We're on the same page. Didn't anticipate needing a flywheel, as the current one only has about 50k on it. Planned on replacing pressure plate, disk, release and pilot bearings. For me right now, time is at least as precious as the $. I run a small business, am a Rotary Club president, and have an elderly father in assisted living who needs some of my time every week. Basically, I have most of Sunday and perhaps one evening each week for wrenching.

ischmitz · ischmitz's Garage

Take the flywheel to your local machine shop. It might be OK to just have it re-surfaced it if the grooves are not too deep. That's a lot cheaper than buying a replacement.

RedCoupe · 08-22-2015, 09:04 PM

Quote:

Originally Posted by ischmitz

Take the flywheel to your local machine shop. It might be OK to just have it re-surfaced it if the grooves are not too deep. That's a lot cheaper than buying a replacement.

Because it's a Dual Mass Flywheel, I think it needs special attention if it's going to be resurfaced. If you chuck up the whole unit, I not sure that the wear face would stay rigid enough for a precision cut. So, if I decide to reuse it, I may see if I can take it apart and just chuck up the piece with the wear face. On the other hand, this is my car's third flywheel. The total mileage on the car is 145,000, with about 50k on this flywheel. Perhaps it's false economy to try to reuse something that could be failing soon anyway. If I replace it, I may switch to a single mass unit. Not sure at this time.

tominizer · 08-23-2015, 09:31 AM

Watching this thread ..... good stuff.

RedCoupe · 08-23-2015, 08:13 PM

OK, got a little bit of strip down accomplished this afternoon. Found a bolt that had long ago broken on top of the right cam carrier, but fortunately it only attaches the cooling shroud. The good news is that looking in every intake port, everything looks pretty happy. Pretty much just nice grey color and no carbon buildup indicating oil pumping through the valve guides. I'm sure I'll wind up replacing all of the guides, due to the car's mileage, but it's nice to know that the old seals and guides appear to still be functioning okay. Lots of crud and oily buildup on the outside, however.

Also, it's disappointing how much rust there is on the engine tin, considering the cars never been exposed to road salt.

RedCoupe · 08-23-2015, 08:21 PM

Here's looking in one of the intake ports.

And here's the broken bolt on top of the right cam carrier. The bolt has a couple of threads proud of the aluminum, so think I'll try welding a washer onto it and if that's successful, I'll weld a nut onto the washer to unscrew it with. We'll see how that all works out, and If I have any other broken bolts or studs to deal with. (Knock on wood!)

RedCoupe · 08-24-2015, 07:41 PM

My valve covers have never leaked, and last time they were off, they were nice and flat. However, they look awful! The plating or coating is flaking off, so must come off.

My valve covers are magnesium. Does anyone know if soda blasting would remove the factory finish, but preserve the mag? Also, can powder coating stand up to the hot oily conditions inside of the valve cover? As you all know, the pockets underneath the valve cover that surround the spark plugs are open to the atmosphere. I think that at least these pockets should be coated or painted to prevent the corrosion of the magnesium. But a powder coating shop will want to just completely coat both sides, without worrying about whether the sections are closed or open to the atmosphere. So, anyone know if this will hold up over the long term?

porterdog · 08-25-2015, 03:48 PM

On the valve covers, tbh I'm not sure soda would touch it. There's primer under the coating and it is tough tough tough. Took me a long time to blast it all free.

Regarding PC; should be a non-issue if you choose your powder carefully. IIRC the epoxy flavors especially are fuel/oil resistant.

RedCoupe · 08-25-2015, 08:13 PM

Quote:

Originally Posted by porterdog

On the valve covers, tbh I'm not sure soda would touch it. There's primer under the coating and it is tough tough tough. Took me a long time to blast it all free.

Regarding PC; should be a non-issue if you choose your powder carefully. IIRC the epoxy flavors especially are fuel/oil resistant.

So what did you use to blast them with. I'm hesitant to use sand blasting because of the magnesium, but maybe I shouldn't be concerned.

RedCoupe · 09-14-2015, 12:23 PM

Haven't been able to do very much on the old 964 lately as I had a quick trip to Fallon, NV to crew for an off-road race that my son was driving in and then I got bogged down with work and other life events when I got back. Nonetheless, I managed to get the engine flipped over and the heat exchangers removed yesterday. Fortunately, no studs broke in the process. I had removed one of the HE's a couple of years ago and used anti-seize on the studs when I replaced it, so that one came off quite easily. The other was wasn't quite so easy, and all but one of the studs unscrewed out of the heads instead of the nuts unscrewing off of the studs. But, I do feel fortunate that I'm not having to remove broken studs!

Next step is to flip the engine back over and begin some cleaning before I do more disassembly.

RedCoupe · 09-14-2015, 12:36 PM

I also got the crankshaft pulley bolt removed. Not hard at all with the air impact gun. But, I'm having a difficult time finding the necessary 16 x 1.5 bolt to make the pulley removal tool out of. 16.0 x 2.0 is the common coarse thread size, and those are readily available around my town, but the fine thread 16 mm bolt isn't easy to find.

mikedsilva · 09-15-2015, 03:32 AM

great thread.. glad you are doing this, as we have the same year car.
My engine is fairly clean compared to yours, but am curious if you know if your engine has had the updated head gasket mod done?

If not, are you planning to do it?

Mike.

RedCoupe · 09-15-2015, 05:14 AM

Yes, my engine is very dirty. It's been leaking for many years. I have receipts going back to when the car was new, and no major engine work had ever been done. So, I presume it has the early cylinders with no head gaskets. My plan is to remove all the cylinders and examine and measure. If the Nikasil coating is still intact on all of them and the clearances are okay, I plan to take them over to Ollie's and have them machined for wire rings. If they show wear or damage, then I will replace them. I am planning on replacing all valve guides during the valve job, but there sure isn't sign of oil pumping through the guides when you look into the ports. I will be splitting the case, as I expect that the intermediate shaft bearings will need replacing. So, a lot more ahead of me!