Driver side upper engine mounting bolt

[Cusser]

Question: does your engine case actually have the captive nut there? This is a press-in nut. Note that you may need to remove the two "tins" on the hidden side of the doghouse fan shroud to see this, take your 10mm wrench with you (one small bolt and one small nut).
Engine Case Nut Insert Captive Nut press-in nut
https://wolfgangint.com/case-components/2883-engine-case-nut-insert-111199102.html
Part #111 199 102

If so, the driver side/upper left engine bolt is 10mm x 1.5mm x 70mm Ace has an allen head bolt this size, takes 8mm allen socket, which is what I use.

The passenger side/starter bolt is 10mm x 1.5mm x 110mm and typically has a D-shaped head.

If there is no captive nut there, you can always use a regular 10mm x 1.5mm nut and 17mm wrench to install that while those tins are removed.
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1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[scubasteve321]

Bay Guy here checking in on this thread due to the topic covered as well as detail

I am missing the driver side upper engine mounting bolt on my 71 Bay, dual port

I read that a 70 mm should work BUT it definitely isn't reaching the captive nut, while a vanagon bolt reaches but is too long to bite down

Going to my (fourth) hardware store tomorrow looking for the 110 mm length

Typing this out I think I figured out part of the issue; is the 70mm is for the non upright dog house engine configurations, whereas the 110mm is for BOTH the starter and the upright dog house engine configurations....

or am I missing something more than just the bolt?
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1971 Campmobile Tin-Top
1971 Campmobile Pop-Top
1974 VW Bus

[bomberbob]

Lots of discussion on this bolt. I tried J-B welding a nut to the case, but it didn't seem to hold. Maybe I didn't glob enough over the nut. So now I just leave off the ductwork on the oil cooler dog house until after I get the bolt through, and a nut on it and tight. There is access (in a bug) to reach around with a wrench and tighten. when motor is secure, I finish up installing all the remaining ductwork. I looked into one of those inserts and what I would have to do to the case to press it in, and abandoned the idea in favor of installing the motor and moving on with business. Can the car drive with only three bolts? Sure.
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1968 Beetle (storage)
1990 Jetta GLI megasquirted, burning E85 (currently in heavy maintenance)
2004 Jetta turbo GLI
Marion, Iowa

[hvactaylor]

Thank you for the response, Cusser. The noise and vibration were so bad that I thought the engine was going to jump out the back of the car. I never did let the clutch out all the way in reverse. Going forward was smooth as butter. CV joints look good. Brakes OK.. No other major problems except the shocks need to be replaced.

I really can't complain. I got a running 73 Super Beetle in very nice shape for a couple hundred bucks. It was "restored" in Italy in the late 90s and the replacement engine was put in in San Fransisco in about 2005. Now it's being made right in Kansas. What a journey.

[Cusser]

[hvactaylor]

I recently dropped my engine (first time in my newly acquired 73 Super) to assess the clutch. Got under it and took off the two lower nuts. Got to the top and BOTH bolts were missing. Long story short, the clutch was fine. I was getting a really loud thumping noise only in reverse when clutch was released more than about 15%. I've seen two posts describing the same symptoms to a tee and both posters said the clutch was shattered. I'm hoping it was the lack of top engine mount bolts and not a transmission problem, as I haven't looked that deep yet. Anyone seen anything like this before? Could the lack of support at the top of the engine cause this shuddering, thumping noise only in reverse? I'm probably not that lucky so I'm going to get the transmission out and send it to the shop.

Anybody recognize this problem? Serious replies only please. Thank you.

BTW, I was told by the PO that he had the motor put in 40,000 miles ago and did little to no maintenance. It then spent nine years in a garage. Of course, it ran perfectly when he parked it nine years ago. I'm convinced the bolts were never there for those 40,000 miles.

[Raymond73]

[Wayne S. Johnson]

[bluebus86]

[Cusser]

Advice I saved from somewhere:
"This captive nut came on all dual relief cases. This is because with a doghouse cooler it is near impossible to get a nut off or on once the engine is in unless you add the small shroud tins afterwards. If you're putting a dual relief case on a transmission that took a single relief case, make sure you grind off the locking boss for the bolt on the clutch arm side before you put the motor in. Be careful not to crack the case when installing. Rig up a pipe that has a notch to match the notch on the flywheel side of the case. Draw the nut into the case with a bolt."
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[Raymond73]

Many thanks for the link, Cusser.
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'70 Auto Stick Beetle
113 905 205AD
30 PICT-3

[Cusser]

[Raymond73]

[Wayne S. Johnson]

I'm installing an access panel for the left engine bolt access, adjusting the clutch cable and starter changes. Others on the Samba have made the same improvement.

See more pics and ideas for the project.
https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

Pics of factory access panel.

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Additional products https://www.thesamba.com/vw/classifieds/search.php?username=Wayne+S.+Johnson
Additional products with Bluetooth http://www.thesamba.com/vw/classifieds/detail.php?id=2097231

[Cusser]

If I understand your post, you're reluctant to use a long bolt and the press-in threaded insert for the left upper mount.

Guess what?? You can use a regular bolt and nut there, and then just install the two small doghouse tins after that. I've done that on someone else's engine, not tough.
_________________
1970 VW (owned since 1972) and 1971 VW Convertible (owned since 1976), second owner of each. The '71 now has the 1835 engine, swapped from the '70. Second owner of each. 1988 Mazda B2200 truck, 1998 Frontier, 2014 Yukon, 2004 Frontier King Cab. All manual transmission except for the Yukon. http://www.thesamba.com/vw/forum/album_page.php?pic_id=335294 http://www.thesamba.com/vw/forum/album_page.php?pic_id=335297

[Raymond73]

An update to my thought experiment.

One thing I didn't consider in the press-in insert/pin is how soft the case material actually is. I'm in the process of installing the doghouse oil cooler after much delay (translation:laziness). Since the studs for my offset cooler are slightly larger than the non-offset type, drilling was required. Completely do-able, which gives me more to ponder.

Sure what follows is not the scientific method, but I'm cool with that considering my limited resources. The pin, even with a close fit, is still much harder than the surrounding material. Without sufficient clamping force it's free to move and there's a definite possibility of enlarging the hole /cracking the flange after enough time. How much time it would take, I'm not sure. It might take days to decades depending on factors such as engine tune, driving style, etc.

Thinking back to my original..., well, thought, is a quick release pin and three bolts likely to cause more damage than just running with three bolts or are they equally bad, but just in different ways? Even with the softness of the material I still end up trying to think in percentages of effectiveness. If each of the four bolts provide equal clamping force and torsional resistance each bolt position is required to contribute a minimum of 25% of the load to max out at shared 100%. Dividing that requirement for 25% in half for each bolt hole position (12.5% each for clamping and torsional) that would mean that 3 bolts is 75% effective compared to 4 unmolested bolts (100%), and 3 bolts+example quick-release pin is 87.5% (i.e quick release pin lacks the clamping %).

Another thought is how much drilling and pressing damage the surrounding flange? Probably very little if done correctly. Still, to be fair, maybe half a percentage can be deducted compared to the original 100%. So, as a guesstimate for 4 bolts w/one press-in insert might be 99.5%.

To summarize assuming proper torque, no bolt/nut metal fatigue, crossed threads, etc:

75% for three bolts
87.5% for three bolts and example quick-release pin
99.5% for four bolts using press-in nut
100% for the original four bolts

If my crude thought experiment can be taken with a grain of salt, there are two distinct winners of the four options. Additionally, factoring in the theoretical damage the quick-release pin might cause, I'm comfortable in thinking that it would degrade in effectiveness over time. Eventually it would reduce from 87.5% down to 75% to equal only having three bolts.

One clear unknown to me is at what percentage (under 100%) does it fail to provide sufficient clamping force /torsional resistance to keep the engine and transmission happy? If it's 90% then it's clearly a bad idea to choose the first two options. If it's 80% then the third option is adequate, but probably not sustainable over time. If it's 70% then all options are viable.

However, considering that equal distribution is better than not, maybe the first option really isn't 75% effective after all. It's possibly less so I'm surmising that 75-80% is the minimum adequate clamping/torsional effectiveness required to stay operating. My rudimentary thinking is that the engineers chose 4 bolt equal distribution rather than 3, 5, or 6 for a reason. Losing a single bolt in the 3-configuration would result in 66% effectiveness, in the current 4-configuration 75%, in the 5-configuration it's 80%, and in the 6 configuration it's 83%. Overcompensating as the numbers increase. My 75-80% is based purely on economy as the 3-bolt option would likely be woefully inadequate during a failure. the 5 and more bolt options provide way more security, (most likely unnecessary considering the humble nature of the Beetle) but requiring more engineering and parts.

All that aside I realize that, yes there are four bolts and they are clearly better. If there were three bolts and a stud/hole then maybe the quick release pin given as an example would have more merit. For a theoretical example, drilling a broken stud and inserting a pin in its place.

Disclaimer: If you read this far, but missed my initial post in this thread, I'm neither championing the idea of running three bolts alone or relying on the pin. However, I still think that if the need arose, the quick release pin still seems to be adequate as a temporary measure to get you home.

If I missed something in my reasoning please don't hesitate to contribute.
_________________
'70 Auto Stick Beetle
113 905 205AD
30 PICT-3

[Raymond73]

[Cusser]

[Raymond73]

[Raymond73]