better berg 5 transmission mounts?

[181]

Hello guys! In the past I used CB Rhino mounts, Mohr mid mount with urethane pucks between the bar and frame horns, and CSP trapese bars for my 4 speed swingaxle. Later I changed Rhino mounts to HD (Type 2) rubber mounts and replaced the urethane pucks in the mid mount for rubber bumpers. As a result of this I decreased the noise significantly, but at the end I think I broke the mount for clutch tube inside the tunnel.

Now I do not intend to drive the car for long distances anymore and I can go more radical in transmission mounting. I´m having a 5 speed Berg built, and I would like to use Rhino rear mounts again, with Berg mid mount and here is my question: I understand you can have the 5 speed mount either with rubber mounts, or solid mounted. Has anybody experimented with urethane pucks for the Berg mid mount?
I already asked CB if they know the hardness of ther Rhino mounts but I could not get any definite answer.

This would be a good way to experiment right: https://www.revshift.com/product-p/ptm-bt.htm?

Also I will add Berg traction bar to stiffen things up even more.

Thanks for opinions :-)

[Joel Mohr]

First, thanks for the props...I drove my Puma for several years complaining before I read the instruction section that states "With the Berg 5 speed, you MUST use a traction bar". I can't put a traction bar on the Puma, the glass would just crack...So, I'm experimenting with different mid mount inserts. First, I drilled out the Berg rubber pucks, and put a bolt all the way through. This was much better, but transferred vibration. I just installed urethane shift coupler pucks with a through bolt (4 stacked fits nicely) and I'll let you know...

[glenn]

I'm using a Berg 5 speed mount with rubber mounts, Genuine VW Type 2 rear mounts and a Berg rear engine support bar with a rubber puck. Noise is minimal and I have no sound insulation in the car.

[j-dub]

I have experimented a bit with the berg mid mount on my car. First for context, I have a oval window bug with a 4 speed trans using the berg 5 speed front mount so that I can move the trans a bit forward. The front, mid and rear mounts are all rubber mounted and it is very quiet and livable however the trans moves around quite a bit. Joel, thanks for pointing out the berg 5 speed kit requires the rear bar, that I did not know.

I have tried the aluminum mid mount inserts with the through bolts and they were more noisy but not too bad really. Fine for a weekend car, too much vibration for a long road trip.

Next I whipped up a set of inserts out of derlin, I tried both through bolts and threaded inserts. I was hoping for a in between of the rubber and the aluminum however they provided vibration that I did not like. I am not sure if it was a high pitch or what it was, the aluminum may have dampened that frequency.

Currently I am back to the rubber inserts but I have used some hose clamps around the rubber to somewhat limit the compression and deflection. This did prove the be a decent compromise.

In the future I would like to try a higher durometer rubber or polyurethane similar to what 181 linked to. I am also curious how the stack of poly mounts Joel used worked out.

I am trying to avoid using the rhino rear mounts but I do have a set I can try if need be.

[181]

its an interesting idea to sleeve the rubber mounts. I can make some thin alu or urethane sleeves quite easily, to wrap them around Berg 5 rubber mounts!

[j-dub]

The sleeve idea came from the BMW or volvo guys, they make a cup that bolts in and surrounds the lower and upper 1/3 of the rubber bushing.

I have not done anything to the front bushes yet, they are small and right next to the nuts to the nosecone mount and not a lot of room. Maybe a similar solution could be used.

[Joel Mohr]

The urethane is only marginally better than the rubber...I love the sleeve idea, I'll do that next...

[j-dub]

Guys, bump for any new ideas for better bushings for the Berg front and mid mounts. I have been scouring the www.mcmaster.com site and have installed different bushing for both front and mid positions. The mid position is definitely firmer than the Berg units, the front units are bigger however I can't be sure they are firmer. I did have to grind a bit on the front rubbers to clear the frame horns and to allow me to get a wrench on the the front mount bolts. More testing is still needed to see if this is a win or not.

Front mount P/N: 9213K74, quantity 2
Mid Mount P/N: 9213K74, quantity 2

Mid mount had the wrong thread size so I had to get inserts to go from 1/2"-13 to 3/8"-16
10 pack of threaded adapters P/N: 90259A144, quantity 1

On the front mount, the original bushes were 3/8"-24, the new bushes are 3/8-16.

Jeremy

[Martin S.]

Any pics of these?

[pupjoint]

curious to know why a Berg 5 would require the rear traction bar.

I am getting a Berg 5 built too, have the CSP brace bar already but my Wasp exhaust makes it difficult to mount the rear traction bar.

[j-dub]

curious to know why a Berg 5 would require the rear traction bar.

Because the elimination of the traditional nose cone mount causes the engine and trans to teeter totter on the cradle mount. The five speed nose cone does not allow space for a traditional nose cone mount so Berg developed small bushes to help support the noce cone along with the mid mount bushes. These new bushes are very soft and squishy so they require the additional support of the traction bar. The traction bar is a good idea on its own to prevent the frame horns from flexing.

 In the posts above we are discussing ways to improve the alternate bushes in the case that you don't want to or cannot run a traction bar.

[j-dub]

Any pics of these?

Not the best pic but here you can see the front snubber bushes that I have replaced compared to the originals. Note that I had to clearance them to clear the frame horns and to allow for getting a wrench in there. Also note that I changed my mind in the placement of these so I had to then grind away a bit more. Also these are 7/8" tall where the Berg ones are 1" tall so I have added a 1/8' washer. This is okay with me as it allows some degree of fine tuning.

Also displayed near the bottom of the image is a sample of the aluminum mid mount spacer, a derlin spacer I made up and spoke about above and the Berg rubber bush. The Berg bushes have hose clamps as an attempt to provide additional rigidity.
Not pictured are the replacement mid mount bushes I got from McMastercarr that I provided the part number for above. I can assure you they are quite a bit stiffer than the Berg supplied versions. They also are a touch shorter and I again used a 1/8' washer to take up the space.

[Martin S.]

Thanks for the pic!
Years ago when I needed a replacement rubber for my Berg midmount, I got it from Acklands-Grainger.
I remember them having different rubber densities although now they all seem to be 50 durometer rubber.
Take a look and maybe give them a call.
https://www.acklandsgrainger.com/en/category/Mounts-and-Vibration-Control/Material-Handling/c/2223?isWildCard=false&q=%3AtopSeller&pagesize=48