Idle time is the devil's workshop: Hacking the front rear differential mount...
11-23-2008, 10:03 AM
#1
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Idle time is the devil's workshop: Hacking the front rear differential mount...
So I've got a good sized order list that I'm about to pull the trigger on including the <A HREF="http://www.avalonmotorsports.com/images/Rear-diff-mount-2-for-web.jpg">Apkiol</A> front rear diff mount. However, last night while a couple of friends were over, new owners of my other friend's old C4 A6 and who also share a passion for playing around with old Audis, I decided to take out the front mount for the rear differential and effectively do the same thing that a Stern Power Ring would do.
One of my favorite things for DIY stuff is this nylon like material that you can get from any store that sells 2 part matrix epoxy. It is the stuff in the black tube and says 3,500 lbs test strength, dries in a cream color. The stuff sets up like tough nylon plastic in about 10 minutes or less. I find it works just as well if not better than any flavor JB weld and it dries so quickly even the parts not exposed to air are all set up in 10 minutes too. In fact once before a race back in the day when I broke a rear derailleur hanger on my road bike I was able to use this stuff to hold the old broken one back together and still do & win the race! The cast I made around the old hanger with it shifted just like a new hanger would have. So always keep a tube or two in the car tool box if you are smart as it can work magic.
Back to the car... I also used a piece of neoprene I had laying around for the part that contacts the body. Well results are very impressive over the OEM one after 133K. Do I even want to spend the $250 on the Apkiol now? I'll drive it a few more days in all conditions to make sure but man this was a nice cheap upgrade. Afterward we took a long drive with all 4 of us in the car and didn't notice any extra vibrations. I went out for a nice drive on the highway by myself this morning and still no vibrations so win-win all around so far. I also filled in a few of the voids on the other side as well with the same nylon/epoxy.
<img src="http://farm4.static.flickr.com/3280/3053738252_ff2f9a3595_b.jpg">
.
One of my favorite things for DIY stuff is this nylon like material that you can get from any store that sells 2 part matrix epoxy. It is the stuff in the black tube and says 3,500 lbs test strength, dries in a cream color. The stuff sets up like tough nylon plastic in about 10 minutes or less. I find it works just as well if not better than any flavor JB weld and it dries so quickly even the parts not exposed to air are all set up in 10 minutes too. In fact once before a race back in the day when I broke a rear derailleur hanger on my road bike I was able to use this stuff to hold the old broken one back together and still do & win the race! The cast I made around the old hanger with it shifted just like a new hanger would have. So always keep a tube or two in the car tool box if you are smart as it can work magic.
Back to the car... I also used a piece of neoprene I had laying around for the part that contacts the body. Well results are very impressive over the OEM one after 133K. Do I even want to spend the $250 on the Apkiol now? I'll drive it a few more days in all conditions to make sure but man this was a nice cheap upgrade. Afterward we took a long drive with all 4 of us in the car and didn't notice any extra vibrations. I went out for a nice drive on the highway by myself this morning and still no vibrations so win-win all around so far. I also filled in a few of the voids on the other side as well with the same nylon/epoxy.
<img src="http://farm4.static.flickr.com/3280/3053738252_ff2f9a3595_b.jpg">
.
11-23-2008, 11:49 AM
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Tell me about it:
Little project I started this weekend:
<img src="http://i23.photobucket.com/albums/b385/tebenson/IMG_3839.jpg">
<img src="http://i23.photobucket.com/albums/b385/tebenson/IMG_3840.jpg">
<img src="http://i23.photobucket.com/albums/b385/tebenson/IMG_3839.jpg">
<img src="http://i23.photobucket.com/albums/b385/tebenson/IMG_3840.jpg">
11-23-2008, 12:21 PM
#4
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=)
you must just love change in general too!? drives my wife crazy but I'm never happy not tearing into something when the ideas start to strike ;-)
A month or so ago I just finished the last room of about 900 sq. feet of a continuous bamboo floor that covers our entire living space minus kitchen and master bathroom. All that is left is the trim work now!
A month or so ago I just finished the last room of about 900 sq. feet of a continuous bamboo floor that covers our entire living space minus kitchen and master bathroom. All that is left is the trim work now!
11-23-2008, 12:35 PM
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I was tempted to use calk or silicone but I wasn't that patient =)
I can always drill and rip this stuff off with minimal problems if I need to.
What do you have for the rear bushings on the rear of the differential and how do you like the results with silicone?
If I really wanted to get crafty I could have ground some rubber up and mixed that in with the nylon epoxy to give it more flex. So far so good though with what I did. FWIW, I'm gonna pass on the $250 Apikol part pretty sure...
What do you have for the rear bushings on the rear of the differential and how do you like the results with silicone?
If I really wanted to get crafty I could have ground some rubber up and mixed that in with the nylon epoxy to give it more flex. So far so good though with what I did. FWIW, I'm gonna pass on the $250 Apikol part pretty sure...
11-23-2008, 04:47 PM
#7
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I used a 3M windshield Urethane
I've done the bottom voids of my spare diff mount with this stuff from 3M and will do the area that the Stern Power Ring fills soon.
3M Window-Weld Super Fast Urethane (Caulking Tube)
Item# 8609
Regular price: $17.63
3M Window-Weld Super Fast Urethane (Caulking Tube)
Item# 8609
Regular price: $17.63
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11-23-2008, 06:14 PM
#8
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So I experienced the "U" effect today.
just because a little is good more is not aways better; I really do know this! But those that just can't leave well enough alone know this effect well and repeat it over and over is my guess.
So after doing the "power ring" effectively as shown in my pic above and partially filling some of the voids with this hard as iron nylon stuff I decided to see what it would be like if I filled them in just a tad bit more today. Well after that extra bit was added driving at highway speeds I got some vibrations and while not all that bad I'd prefer to only feel the positive effects of this when standing on the throttle and hard down shifts, etc.
So I cracked all that stuff off and put a new mixture on. I mixed some plain old white caulk with that same nylon acrylic epoxy stuff and recreated the ring again. While the ring I had 1st made wasn't the problem I felt it didn't need to be as stiff. Then I filed the rest of the voids on the other side with black silicone. Going to be stiffer than stock when standing on the pedal but my hope is that by using the flimsy silicone it will take out 40% or more of play/travel but not polarize the shock/vibration waves into the car body as much like a stiffer unit would. Since it is so easy to remove I don't mind the extra time and the learning experience on making my own compounds.
I'm going to pick up a can of that stuff you mentioned to and see how it goes using that on the front tranny mounts. Plus after reading about it in the tech section here I cut out the aluminum bearings/rods from my old rear diff bushings so my goal is to cast those in some mix of urethane/nylon epoxy to use on my wife's car for the rear cross member similar to the Stern ones you can buy.
Anyway, this stuff is fun for me but probably not everyone's cup of tea...
So after doing the "power ring" effectively as shown in my pic above and partially filling some of the voids with this hard as iron nylon stuff I decided to see what it would be like if I filled them in just a tad bit more today. Well after that extra bit was added driving at highway speeds I got some vibrations and while not all that bad I'd prefer to only feel the positive effects of this when standing on the throttle and hard down shifts, etc.
So I cracked all that stuff off and put a new mixture on. I mixed some plain old white caulk with that same nylon acrylic epoxy stuff and recreated the ring again. While the ring I had 1st made wasn't the problem I felt it didn't need to be as stiff. Then I filed the rest of the voids on the other side with black silicone. Going to be stiffer than stock when standing on the pedal but my hope is that by using the flimsy silicone it will take out 40% or more of play/travel but not polarize the shock/vibration waves into the car body as much like a stiffer unit would. Since it is so easy to remove I don't mind the extra time and the learning experience on making my own compounds.
I'm going to pick up a can of that stuff you mentioned to and see how it goes using that on the front tranny mounts. Plus after reading about it in the tech section here I cut out the aluminum bearings/rods from my old rear diff bushings so my goal is to cast those in some mix of urethane/nylon epoxy to use on my wife's car for the rear cross member similar to the Stern ones you can buy.
Anyway, this stuff is fun for me but probably not everyone's cup of tea...
11-23-2008, 06:59 PM
#9
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Others AW people have used the urethane on various mounts,wasn't my idea
Its very cost effective. Any quick set window channel or windshield urethane will work from parts stores doesn't have to be 3M .
11-23-2008, 07:57 PM
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no I'm certain it was Al Gore who first used this method ;-)
BTW, this new version of the mount works perfect, no vibrations at all. I'm sure the center filled top caulk side and bottom silicone side are not fully cured yet but they have caps made out of the acrylic epoxy so they are effectively sealed in there like a dual density gel center. All the play is gone but none of the bad vibrations are back.