924Board.org

[jacobroufa]

Finished up the axles and transmission today. This feels like a huge step as it's been out of the car two years now!

Axles are nice and fresh. I had to get a special pair of retaining ring pliers and larger clamps than what came with the kit, but they turned out decent. One of these days I'll get a sandblaster and be able to really refurbish things to a higher degree..



Trans with the front case off, but 1st/Reverse assembled. Everything shifts fine. Looking forward to this very much!



I put the front case on and sealed again with the Curil K2 sealant. I will refill the gearbox oil once I'm ready to install it in the car. 924.org transmission page states "Approx 2.64 qts hypoid oil SAE 90 GL5". Per an earlier discussion I got some Redline 75W90NS for that.

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So after these things, my buddy and I turned our attention to my water pump, which I wasn't able to get a good seal on the last time I tried.. This stupid thing was so finicky to install and also get that lower hose on. So it got removed and we cleaned up the area, flushed the coolant passages as much as possible, and reinstalled it.



This is one of those areas where a 931 is a totally different beast than a 924. The designers of this car were truly masochists. We ended up putting the lower hose on securely before pump installation and this helped a great deal with the frustration level. I ended up installing the lower hose from the 924S and will trim the radiator end to fit once I complete that installation.

So naturally then comes the 924S/944 radiator mod. Per Dan's instructions, sheet metal screws work to install the fan and brackets. This didn't quite work out for me, as one of the sides ended up pulling out of the clip when I was hanging it. I could not get it to fasten satisfactorily so they came off.



I'll go to the store tomorrow to get some "u clips" with a threaded end instead of punched for sheet metal screws. I'll look for some that are M8 threaded and roughly the same size. These are 16mm square with a 2mm spread. There's about 7-8mm behind the panel where they can fit, so hopefully I can find something shallow enough. I will be much more satisfied with the fit on some metric bolts though, than sheet metal screws, considering these were meant for hanging the fan shroud on the radiator, not the whole radiator assembly itself!
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1980 Porsche 931
1981 Porsche 924 Weissach

[jacobroufa]

So I got some u-nuts that seem to work! Lowes had them, Home Depot did not. YMMV. I think I saw them on Autozone's website as well, but the hardware stores have a larger selection of fasteners overall so that's where I went.



Looks about right, though they are thicker than the old ones. That might cause the fan shroud to stand off the radiator slightly. I doubt that's anything to worry about.



They only had 1/4-20, not the M6 I was looking for... but I'll take what I can get. They will work!



Seems to fit OK on a test of one corner..



I've got 3/4" bolts in there, and they clear on the inner portion of the tab! This will hold MUCH better than the ones designed for sheet metal screws.
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1980 Porsche 931
1981 Porsche 924 Weissach

[jacobroufa]

A tab on the radiator broke off as I put the u-nut on... I attempted to use JB Weld on it but that failed.. I will get it welded soon. So radiator is on hold temporarily.

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So, on to the transmission! I wanted an access hatch to be able to more easily secure the top two bolts as well as the shifter linkage. I recall a guy talking about this at the track when I mentioned I have a 1980 931. I cleaned off the insulation on the top of the hump between the rear seats then had at it with a cutting disk.





Installed!



Plenty of access to the bolts here:



And from underneath, so happy to see this back in its spot!



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To wrap this up, I have to reinstall the axles and exhaust, seal the access hatch I made, and then install the radiator. Then to bleed coolant and brakes and I should be good to go.

For the trans tunnel access hatch, I am going to weld 1-1.5" strips around the edge and seal it to the body. I have thought about a couple ways to seal it; 3M window weld or some other sort of sealant/gasket maker. May not even need to screw it down, just apply the sealant, lay something on top to apply pressure, let it cure.. I don't intend to have it be opened often, but to be perfectly honest, I don't ever want to install this transmission without it again. Even with my friend helping and that additional access, it was a pain in the butt.

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So now I wait on shipping again. I have ordered a couple bits for the exhaust: new sealing ring and a couple rubber hangars. I also had to order new clips for the shifter; I could only find one up at the front of the car.

Getting really close to being able to drive this thing again. After two years this feels really good to do.
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1980 Porsche 931
1981 Porsche 924 Weissach

[Fifty50Plus]

That access port is exactly what I did on my race car for easy access to the linkage. Hayes and I both had the secondary shift rod (the one with the bushing that goes on top of a ball socket on the top of the torque tube) come off on our (snailshell tranny equipped) race cars this year which caused us to totally lose shift capability. I cut a second access port on the tunnel above the ball socket to put it back on. Tie wraps kept it from popping off for the rest of the season. Better fix coming this winter.
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1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

[jacobroufa]

That's awesome to know! I'm glad to have this idea validated. Even with the cut out it was a pain but at least it's something that is physically possible now without being a contortionist with 2-3 swivel joints on a 3ft long socket extension!

Thankful I don't have issues with that ball joint (that I am aware of!) but this car being more of a finicky beast than any other I've owned, I wouldn't put it past it to happen sometime in my care in the future..

When you reattached the piece you cut out, how did you accomplish this? I'm wondering if my "weld a lip around it and then RTV/windo-weld it" is a valid thought or if I should install some captive nuts and bolt it in. Trying to just get it back on the road, not make this facet a whole other project.. But my desire to get things right is cramping my thought process as per usual.
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1980 Porsche 931
1981 Porsche 924 Weissach

[Fifty50Plus]

Jacob, remember that I'm talking about a race car chassis with a full roll cage and no interior. When I built the car, I made the cut that you did and just covered it with a bent piece of aluminum and a couple sheet metal screws. When I lost the shifter at the track this year, I immediately thought that the coupling bolt had fallen out. I pulled the plate and all was intact. Using a mirror and looking back up the tunnel I saw that the ball socket didn't have the rod attached to the top of it. Remember that this is on the top of the torque tube and inaccessible from the bottom of the car. I had a brainstorm and borrowed a dremel and cut out another piece out of the tunnel above the ball socket. I replaced the shift rod on the ball socket and put a couple tie wraps around the torque tube and shift rod to hold it from popping off again. The finishing touch was to racer tape the piece of cut out tunnel back onto the tunnel. I suppose I could make another aluminum cover and screw it back on but.....
The ultimate fix will be to cut off the ball socket, weld a bolt on the torque tube and use a heim joint on the shift rod. The ball socket keeps the rod from moving front to rear and allows it to slightly wiggle side to side. The heim joint would accomplish the same thing. Unfortunately, it's best done when the torque tube is out and on the ground and there is easy access for cutting and welding. I'm not sure I want to try that in situ. Hmm...now that I think about it, I could just make the access hole larger, do the work and cover it with another aluminum plate.
_________________
1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

[jacobroufa]

Ok, that's good to know.

Being that your car is a race car with a roll cage.. I was warned that possibly C pillars can suffer cracking on pre-81 cars and in general later cars received more internal bracing in the chassis design.

Should I be seriously considering at least a roll bar? I do want to run this car on a track eventually, and definitely want to drive it hard regardless.

Do you think my cut out could have a detrimental effect on chassis stiffness? Is there a way to measure this possibility? I tried to cut behind the rolled and reinforced section but I would rather be safe than sorry.

And I guess further, if I am looking for a cage, the two simplest options are either the Autopower weld in roll bar (comes in street, street sport, and race with ever-more bracing) or a Weichers roll bar (looking at Model B, steel, to weld in). I will need to do some more reading here. I wonder if the Weichers bar is worth the premium or what would be my best option here.
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1980 Porsche 931
1981 Porsche 924 Weissach

[jacobroufa]

Looks like for a roll bar, if I intend to expand it to a full cage, it makes more sense to go with custom fabrication. I am now looking for a fabricator in my area to help with this.

Trying also to thread dig as much as possible for more learning as I go.
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1980 Porsche 931
1981 Porsche 924 Weissach

[Fifty50Plus]

I don't know how much stiffness was impacted by your cut or both of mine but a roll cage more than compensates.
When I first bought someone else's 924 with a cage, it had one of the bolt in cages but was considered SCCA legal. The problem (besides weight) was fit. The bar from the rear to the front was not close to the roof and with a stock seat mount, my helmet was being pushed towards the center of the car by the bar. I unbolted the cage and sold it locally while having a custom cage installed. The bolt in cage was fine for street driving but with the helmet on it was no good. Spend the time now to do it correctly for the future.
_________________
1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

[Rasta Monsta]

That brake line, though!


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Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[jacobroufa]

[Fifty50Plus]

I've made the cut around the brake line three times now. The cars still stop. Porsche has a habit of routing the line above the tranny ever since the 911/912 but not the 356.
_________________
1979 924 NA race car
1982 924 NA race car - Sold
1982 924 Turbo almost a PoS
1981 924 Turbo a real PoS, new engine
1982 924 Turbo nice body, blown engine
1972 911 E race car - going to Vintage
Various 944s to become IT-S race car

[jacobroufa]

I have started researching cages and will be starting discussions with a couple fabricators in the area this week. TBD on that, as I don't have a ton of room in my budget at the moment, but we will see what happens.

I will probably weld that piece back in for the time being.

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Yesterday, got the axles reinstalled as well as the exhaust..

I also finished making brackets and installing the radiator, which a stock 924S/944 radiator with a 3-blade fan setup. I may upgrade to 6 blade fans in the future, but I am also looking hard at that newly announced CSF radiator and fan setup which definitely matches or bests stock new rad/fan prices.

So I've got to plumb up the radiator and reinstall the air box, then bleed coolant, and bleed brakes. Alignment is roughly correct, so I will just deal with that in the spring, unless I end up able to do roll cage fab this winter.

Waiting on shifter clips still.. I will have everything but that ready to go by the time they arrive. Then I will take it on a test drive around the neighborhood, and... park it under a cover for winter.

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I'm super happy, all told. It feels good to have this car back together after a long 2.5 years..
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1980 Porsche 931
1981 Porsche 924 Weissach

[Cedric]

i wouldnt recommend a full cage in a car thats street driven, it brings along lots of safety issues. Half cage/roll bar types are great for that anyway.

didnt know about the CSF solution, if its not welded by monkeys out of chinesium like the ebay ones(i have one of those) it could be a nice solution. though quite alot of money with 25%tax+11% custom charges to order one here :/
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1980 924 Turbo
www.instagram.com/garagecedric/

[jacobroufa]

I appreciate the candor, Cedric! I was thinking of going with a roll bar at first, to gauge my commitment to driving this on track as HPDE, and if I intend after that point to get more serious to go with a full cage. Since I am possibly going to upgrade in that way, as Fifty50Plus recommended a few posts up it is worth spending the time/money to do it correctly now.

I see in my latest post I wrote "cage" not "bar" though I meant the latter.

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I have one of those cheap eBay radiators, which I got before picking up a stock used item, and would highly recommend everyone stay away. They may or may not be good and waterproof but if the insides are anything like the outsides...

The tabs on this one were so crooked I literally could not get them to fit the stock fan shroud no matter how I manipulated them. I would need to cut them off and grind back the stubs, then re-weld new tabs in order to fit it. Which is a waste of time and money that I already spent on the item and then subsequent fighting to get it in place..

I would expect CSF to do a better job on quality control though, as they are a respected company. At least in the US the cost comes out to be very close to a brand new OEM radiator, so value proposition could be there.
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1980 Porsche 931
1981 Porsche 924 Weissach