custom motor mounts for type 3s with IRS

[ob_wan]

I'm going out on a limb to say this is for all type 3s with an IRS rear suspension but not sure(feel free to correct me). I did the work on my '69 Fastback. background on why I replaced them is in the following post(note: other than actually seeing the score marks on the underside of the rubber, I never would have guessed the original motor mounts were bad):

http://www.thesamba.com/vw/forum/viewtopic.php?t=553557


Parts list:
1. Energy Suspension part #: 9.4102G (comes with 2 complete bushings)
2. 1/2" diameter all-thread - make sure it's high grade thread, 6" on each side = 12"
3. qty 4 - grade 5 or grade 8 nuts
4. qty 2 - grade 5 or grade 8 lock washers
5. 1/4" plate steel, enough to make 2 mounts
6. re-use part of existing motor mount: "fingers"


I've used the following bushings before in another application and they seemed like they would be a perfect fit: Energy Suspension part # 9.4102G (they also have them in red if you prefer: 9.4102R or stiffer if you want 9.4101G or R)

Note: I did one side at a time to make sure I returned engine to matching height for each new mount(can adjust from there if you feel the engine was sagging from old mounts)

I took off the original motor mount and started measuring, then pulled out my compass and started making circles till I came up with the following template to match the new poly bushings inside diameter(1.25") with the outside diameters and bolt hole locations of the old mount:

I don't have a picture of just the custom made mounting plate but you can see it below. It took a lot of cutting/grinding/drilling/filing but it turned out just fine. very sturdy, I used 1/4" because that's what the bushings called for, keeps a nice compression on the bushings when everything is tightened down.

I went to the store looking for 1/2" dia threaded rod. Most all-thread is low grade(grade 2 or lower?) = soft. and grade 5 or 8 bolts around here don't have 6" of thread on them. Luckily I was able to find some heat treated all-thread, pretty heavy grade stuff at a local hardware store.
1. cut all-thread to 6" pieces
2. cut existing body mount below the rubber so you end up with about 1/2" of tube and the "fingers"(part that mounts to the engine cross-brace. note I cut it flush to the rubber aka 3/4+" of tube left, take a little more off to allow for more adjustability)
3. tap 1/2" threads in to the 1/2" tube(not necessary, only half of the thread is cut in to the tube, alternatively you could just grind a little thread off the all-thread so it will slide in, I did it to ensure alignment mainly)
4. screw/slide the all-thread in to the "fingers" tube till you can just see it peaking out the bottom of the tube(screw/slide in 3/4" or so) and weld it in place. I would not feel comfortable with anything short of welding the two together. I feel very comfortable tapping + welding.
5. screw one of the nuts down on to the all-thread almost all the way
walla! that's the hard part(mine's painted black but you can see where I welded the all-thread to the "fingers" tube):

All the parts ready to go together:

The way I assembled them, I wanted the majority of the bushing to be on top to provide cushion for the engine while it sits and coincidentally, I don't know if it would fit the other way around.

When I installed the new motor mount, I kept the bolts on the body loose to allow the mount to shift as needed, I used the adjustable nature of the new mount to first allow me to attach the fingers to the cross-brace(keep bolts loose), then screwed down the top nut on the all-thread until I had the engine at the height I wanted. When that was set, I tightened the bottom nut completely, tightened the "fingers" bolts, then finished off with the bolts that hold the engine mount to the body. very easy install.

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1969 Fastback, 4-sp, carb'd

[supaninja]

Very slick indeed, I am impressed.
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http://i5.photobucket.com/albums/y163/chucky1974/ninja.gif

Nick
Megasquirted Type 4 powered Notch http://www.thesamba.com/vw/forum/viewtopic.php?t=427890&postdays=0&postorder=asc&start=0
Blog of Doom http://supaninjanick.wordpress.com/

[Slow 1200]

impressive, does the car feel any different? more vibration? they are probably better than 40 year old rubber that's for sure!

[ob_wan]

[Brent]

Nice work.

I was going about this the same way with 911 mounts. But, when I was cutting the threads on the top portion it just wasn't turning out very nice. Probably the crappy VA die I was using. I saved the parts, maybe I'll try again using threaded rod like you did.

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69 Fastback Build
Berg5 Build

[Bobnotch]

[ob_wan]

I trust my welds but I know what you mean. It would definitely be a good added safety to toss some welds at the end of the allthread as well.

as for the nylock nut. good idea. Either I'll add a 2nd nut to the allthread to lock against the first or will buy some nylock nuts. lock washers are nice but constant vibration could work something loose, not worth the risk.
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1969 Fastback, 4-sp, carb'd

[TommyBoyGomes]

Ob_wan, I went 80% down the same road you did when I rebuilt my engine a couple years ago. I had everything I needed except for the polyurethane vibration isolators. I have an acoustics background so we deal with these day-in and day-out, but no one could give me a straight answer on whether it could sustain variable vibration Hz AND asymmetric vibration (which is pretty demanding for vibration isolation assemblies).

I ended up re-using my old original ones and they seem to be doing fine, but please let us know how these hold up long-term.

In case anyone is looking for an NOS VW engine hanger, I know fastback Don has one for sale as we speak.
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1969 Squareback, 1776cc
1990 Vanagon Multivan

[ob_wan]

[Bobnotch]

[joey1320]

Wooohooo!!!
I was planing on making some new mounts, now I have a how-to. Thanks!!!
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**1971 Super Project
https://www.thesamba.com/vw/forum/viewtopic.php?t=...mp;start=0

[Miyoji]

I used the method for building the Type 3 motor mounts described in this thread, but I did it slightly differently.

I took the idea to my mechanic and, for him, the hard part was creating a new mounting plate. So, we discussed ways to use the original plate and here is what we came up with. I hope this helps someone.

We used the bushing kit described above and modified the flange to work with it. We cut the bottom side of the flange flush:

Then I found a sturdy washer which fit into the top side of the flange. The hole in the washer was a little too small for the "nose" of the bushings, so my mechanic made the hole bigger. He then welded it into the flange:

Everything else, I did the same as the previous post.

My mechanic says if anyone else wants these and does not have the means to build it, he can build them for $400/pair.

[Absoluteyeti]

Interesting, i hadn't even thought about building my own set of these. I'll have to give these a try once the type 3 body work is done.

[Arizonasquareback69]

My question is, how much “squish” or compression should one put on the new mounts? Is engine weight good enough or should you tighten the top nut down a bit? I’m thinking of doing this soon.

[sub-hatchtim]

Have you guys looked at using 911 motor mounts

You can buy them in varying degrees of density

https://www.partsgeek.com/yq1c7ls-porsche-911-engi..._fEALw_wcB
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58' pg/sg silo fridge westy
58 Dove blue singlecab
76 911S

[cpaz5150]

Not to derail the thread or invalidate the latest questions, but just in case you all are not yet aware, ISP sells brand new mounts now:

https://vwispwest.com/type-3-irs-engine-mount-kit-311199301by/

I was going down the path of custom mounts years ago but thankfully these came out a couple years ago and have been perfectly good units from my experience thus far. Not that custom mounts may not be necessary again in the future, or be needed for other specific demands, but being able to open a package and simply install brand new items as intended is sometimes rewarding in itself. Good luck regardless of your pursuit!

[squaretobehip]