Case Bolts & Washers

[Dennis Vogel]

Reassembly the case halves today, and ran into a couple questions:

5. What is the correct length of the case through bolt (aka tensioning device) 616.101.171.00? Ours Verbus labeled bolt looks right at first glance, but after threading it through the case, it is too long (230mm).
11. I have discovered some part number inconsistencies. The case perimeter bolt washers are listed in the Porsche printed parts catalog as 900.028.010.01 , but the PDF catalog download they are listed as N.012.241.1 When I look up the later, it is listed at most parts vendors as a 912 oil cooler or fuel pump washer. Are these interchangeable? Pellow mentions in his video that the M8 case perimeter washers have a larger diameter than normal, but doesn't say how much. It's also not specified in the parts catalogs.
* Can spring washers (i.e. wavy) be safely reused?

Thank you.

CaseBoltsWashers.png (151.99 KiB) Viewed 1610 times

[Ron LaDow]

"5. What is the correct length of the case through bolt (aka tensioning device) 616.101.171.00? Ours Verbus labeled bolt looks right at first glance, but after threading it through the case, it is too long (230mm)."
Perhaps there's a T4 VW case bolt which is longer and has the shoulders and the proper hex head, but I've never seen a through-bolt which was longer than required. How much too long does it seem to be?

"Can spring washers (i.e. wavy) be safely reused?"
When I was much younger, poorer, and they were harder to find, it turned out that they were reusable about half the times I did reuse them. Feel good: Buy new ones.

[Martin Benade]

As a slight hijack, what’s the thought on reusing pushrod tubes? I always have in the past, but now wonder if that is a good idea or not.

[Vic Skirmants]

Back in the OLD days, when the tubes were made of a more flexible material, I did re-use them most of the time. Today, they appear to be made of a more brittle metal, and I do NOT re-use them.

[Bill Lawless]

F.Y.I.
https://www.ebay.com/itm/VERY-NICE-USED ... SwzBJafkX6

[Alan Hall]

I believe there are 911 through bolts which look similar to the 356 through bolts but are not correct. I don't recall what the differences are but perhaps that is what you have,

[Dennis Vogel]

How much too long does it seem to be?

I'd estimate 10 mm too long.

Porsche356-CaseThroughBolt.jpg (315.68 KiB) Viewed 1517 times

"Can spring washers (i.e. wavy) be safely reused?"
Feel good: Buy new ones.

Does anyone offer a washer kit that would cover most of the engine needs? I've found hardware kits, but they appear to include lock washers (not wavy).

I'm assuming that the PDF part listed as N.012.241.1 is correct for the perimeter bolts even though it comes up as 912 fuel pump washer? It is at least 8mm x 14mm. The other 900.028.010.01 part shows as 4mm x 9mm which is too small.

[David Jones]

Wavy washers are available at hardware stores including Ace, Home Depot and Lowes. Cheap and plentiful. I keep a stock of most sizes ready and waiting.

[Dennis Vogel]

Wavy washers are available at hardware stores including Ace, Home Depot and Lowes. Cheap and plentiful. I keep a stock of most sizes ready and waiting.

I assumed, perhaps erroneously, that like a lot of things Porsche, these were "special". Pellow mentions in his video that the M8 case perimeter washers have a larger diameter than normal, but doesn't say how much.

[Paul Lima]

Btw, the Porsche 356B parts catalog has this p/n for the through bolt: 616.101.171.00

[David Jones]

If you want specific sizes go here and buy.
https://www.belmetric.com/zinc-form-a-s ... 4_36_1106/
I know the 8mm case half washers were a slightly larger OD but I have been using stock size washers for 40 plus years for case halves and never had one case fall apart.

[Martin Benade]

I thought wavy washers were a DIN thing, not American. Time to learn!

[Dick Weiss]

Hi Dennis,

The long thru-bolt is 209.5mm (8.25") long.

Yes, the spring (wavy) washers can be reused, but there are different OD and thickness sizes; The 10 x 14mm ATF nuts
should have the larger diameter used on the earlier cases until the 13mm ATF nuts were introduced & their thicknesses
are around 0,8mm.
The 8 x 13mm nuts can use the large washer for the case bolts, but the thinner 5,0mm thick nuts on the late aluminum
rocker arm shaft assembly uses the thinner spring washers of 0,45/0,50mm thick, and don't over-torque them which
creates shaft-ends out of round which prevents easy removal of the rocker arm from the shaft. Follow the torque specks.

Finally, if the 13mm x 1,00 fine thread valve adjusting lock nut is over-tightened, it'll tend to jam the screw's thread @ the
oil hole relief and the screw must be cut for removal; The rocker arm threads can't be re-tapped due to its hardness, but
re-threading the adjusting screw (if removed in 1-piece), it may be saved; "What's in your wallet" to just replace it?

Another situation about the 3-10 X 45 X 15mm ATF bolts to mount the aluminum rocker stand--they're NLA, but having the
same #, they have a 16mm ATF and the spring washer should have the same OD and 0,8mm thickness discussed above
(not the thin one). Reason? The 10 X 47 X 17 ATF bolt and the large spring washer won't quite clear the side of the aluminum intake shaft support block and the large spring washer (mentioned above); You might see some interference to the bottom
edge of the block--that's why the 15mm ATF was used. Also, if the bolt is over 45mm (like 47mm) long, it'll bottom out
before tightening; I recently had one stuck during a teardown and was tight onto the aluminum rocker stand during removal!

Dick

[Dennis Vogel]

I recently acquired some original KARRO 8G 14mm ATF case perimeter bolts. I was fortunate that they came with washers and nuts. Assuming the washers were original too, their dimensions for reference were:

• OD: 17 mm
• ID: 8.86 mm
• Thickness: .75 - .8 mm

[Martin Benade]

Is your car early enough that it had 14 mm perimeter nuts? I think 13mm came in approximately with the T6 body.