Polyurethane for subframe mount on MK5 Jetta

My transmission and engine bay has a lot of movement.

When driving, the shifter shakes about quite a bit, pressing lightly on the gas or releasing the pedal makes it move quite a bit.


My friend who isn't a VW/Audi Specialist diagnosed it to be the bushing inside the subframe, which the rubber was practically ripped.


Because he doesn't have the tool to replace it, he looked at scrap yards, found the entire subframe and replaced it. He also found other engine mounts to be in poor shape so he replaced those too.


But the Tranny and engine still have a lot of movement. Maybe a little less than before.


I brought it to a VW Specialist in Montreal, and they confirmed the same problem.


However even with the right tool to change that mount from the subframe, they said it's a pain in the butt and will do it next time I bring the car.
(they had the car for a number of tdi related troubles)







Here is what I want to do.


Since I have 2 subframes...


The one that is off my car at my buddy's place, I want to fill it with this


http://www.loctiteproducts.com/p/pl...hAk01MDVGHBzDdc3WWwmDOkxaQx5ktQakZ1JkvWuVPWdA


Let it cure for 4-7 days, and install it on my car as changing the subframe is a 30 minute job.


I picked the Roof and Flashing version over the usual Windshield urethane, or the PL Premium as those harden like rock... which I hear can add a lot of vibrations in the cabin.




Worst case senario, I have a spare subframe that I will bring to the VW guys in Montreal, so that they can change the bushing at their convenience.





My question is, if I did fill the sub-frame bushing with the solid curing urethane, would it transfer a lot of vibrations to the cabin?

VW makes the mounts somewhat "soft" so that it does not rattle the cabin. Putting polyurethane in the subframe mount will turn your ride into that of a tank. Might be fine for some people...it is really annoying in my opinion.

If the engine shakes a lot at idle, it may be that the center mass of the dual mass flywheel (if you have one) has gone off center or locked up between the two masses.

you can make your own poly mounts relatively easily!
I wold not unless you have a goal that requires it.
Stick with OEMs

The reason anyone would change the rigidity of the mounts is to get a more snappy response from the clutch and "more power"!
Its 99% a gimic and a scam auto part but the part stems from serious power builders who are trying to get ever 0.010 of a second out of the engine on the track. Some how someone though it would be cool to drive this car home and voila, harder mounts!
Are you drag racing? No, didnt think so, so stick with OEMs
IMHO either your a solid mount build or oem mounts, anything in between is a rice burning application or a necessity for some custom reason, like a custom mount for a swap and not enough clearance for a turbo when the engine bucks.

I have a single mass flywheel with an ACT racing clutch.


The engine is a BRM TDI 1.9 with 15% + injectors, PD140 turbo and stage5 custom Malone tuning.


I didn't have any problem with the transmission shifter shaking and moving about while I drive when the car was on the OEM Clutch. (which would slip with anything past 30% throttle)


I had someone who I thought was good take the Tranny out to change the clutch (and also do a weld on the casing as it had a crack)


I got the car back with tones of new issues which I didn't have prior... everything they touched was a F*** Up that needs to be fixed by someone else now.

Mongler98 said:

you can make your own poly mounts relatively easily!
I wold not unless you have a goal that requires it.
Stick with OEMs

The reason anyone would change the rigidity of the mounts is to get a more snappy response from the clutch and "more power"!
Its 99% a gimic and a scam auto part but the part stems from serious power builders who are trying to get ever 0.010 of a second out of the engine on the track. Some how someone though it would be cool to drive this car home and voila, harder mounts!
Are you drag racing? No, didnt think so, so stick with OEMs
IMHO either your a solid mount build or oem mounts, anything in between is a rice burning application or a necessity for some custom reason, like a custom mount for a swap and not enough clearance for a turbo when the engine bucks.

Click to expand...

From the details I just posted, it might look like I am into drag racing but no... I want this car to be a good daily driver. The clutch on it isn't that bad in terms of feel. I have had worse.
(I do intend to go to the strip and check out what I can do on the quarter mile... but that's at most once a year or 2)


So... my question is answered.



Ill use this on the bushing and see how it feels... It's not the rock solid type.
http://www.loctiteproducts.com/p/pl_...akZ1JkvWuVPWdA
I will see how it feels... I am curious.



The spare subframe will go to my vw specialist in Montreal (Heinz Garage) so he can put an OEM bushing.

Worst case scenario, ill have an OEM one ready to install in the future.

to be fair, i do have a stage 2 set from blackforest in my mk3, i hardly notice much of a difference though. Biggest thing is to make sure all the heat shields are installed on the mounts that are anywhere close to the turbo. the heat kills the mounts.

What issues are you having?
if you have issues after a mechanic, i would talk to them and make sure its fixed on their dime, or dispute the charges on your credit card, hopefully you used a credit card lol. i only use them for things like that where i might have to dispute a charge.

Mongler98 said:

to be fair, i do have a stage 2 set from blackforest in my mk3, i hardly notice much of a difference though. Biggest thing is to make sure all the heat shields are installed on the mounts that are anywhere close to the turbo. the heat kills the mounts.

What issues are you having?
if you have issues after a mechanic, i would talk to them and make sure its fixed on their dime, or dispute the charges on your credit card, hopefully you used a credit card lol. i only use them for things like that where i might have to dispute a charge.

Click to expand...

Lots of issues with this one, but they are the result of my stubbornness and stupidity.


I loved my previous TDI so much (with the exception of the green color), I figured ill spend more and make my new one exactly what I want it to be.


So I found the exact color I wanted, a white Jetta fully equipped, leather sunroom HID's... the works... but it was a 2.0 Turbo with a blown engine.


Long story short, first guy started off good but didn't care to properly finish the job. (fuel leak, cracked tranny, no rear view defrost, door lock, ac... long list of issues.


I brought it to someone else who was supposed to be good.... But this one who accepted the job even if he was working 16 hour days every day on personal things and the shop... well everything he touched he made worse. After him, Traction control which worked flawlessly, broken, Door looks needing to be programmed, instead he seized the locks, Driver mirror flasher dim, breaks the mirror and sells me a new one without the courtesy light, welds transmission, still leaking, broke subframe bushing which I know was perfect before they took the tranny out... Airbag light...


TO be fair, I can't blame all on him as some could have been due to the poor install and wiring of the first guy... but many of those things are 100% them.

It's been to long ago and not worth having a headache over it...



I have had my poor baby under 4 months in the last 14-16 months since the project started and the cost has been WAY over the cost of just buying one already TDI... Yet I am far too invested in to stop lol...


Lesson learned. Unless you are an actual mechanic, don't go for a swap to build a daily.

So a few things to say here,
I'ts not your baby dude, its someones shi77y build that your funding.
you want it done right, do it yourself or pay someone a crazy amount of money who does it right. Seems like you chose to stick to a budget?!

Do us all a favor and please review your posts and run them though a spell checker. it was painful to try and get though your post.

Mongler98 said:

you can make your own poly mounts relatively easily!
I wold not unless you have a goal that requires it.
Stick with OEMs

The reason anyone would change the rigidity of the mounts is to get a more snappy response from the clutch and "more power"!
Its 99% a gimic and a scam auto part but the part stems from serious power builders who are trying to get ever 0.010 of a second out of the engine on the track. Some how someone though it would be cool to drive this car home and voila, harder mounts!
Are you drag racing? No, didnt think so, so stick with OEMs
IMHO either your a solid mount build or oem mounts, anything in between is a rice burning application or a necessity for some custom reason, like a custom mount for a swap and not enough clearance for a turbo when the engine bucks.

Click to expand...

Mongler98 said:

So a few things to say here,
I'ts not your baby dude, its someones shi77y build that your funding.
you want it done right, do it yourself or pay someone a crazy amount of money who does it right. Seems like you chose to stick to a budget?!

Do us all a favor and please review your posts and run them though a spell checker. it was painful to try and get though your post.

Click to expand...

Hey "Gandma", what was that thing you were saying about spell check?
LOL

JETaah said:

Hey "Gandma", what was that thing you were saying about spell check?
LOL

Click to expand...

lol, thank you for that reply.

After putting my text through a spell checker I realized I didn't do many spelling mistakes.
However I do get what Mongler means.
It's how I wrote what I wrote, the excessive triple dots and so on that made it for an annoying read.
English is my second language and when I write about my experience, no matter how much I try to minimize the details, I get emotional about it and write as it comes to mind which can make for a poor read.

" Originally Posted by Mongler98
So a few things to say here,
I'ts not your baby dude, its someones shi77y build that your funding.
you want it done right, do it yourself or pay someone a crazy amount of money who does it right. Seems like you chose to stick to a budget?!
"


Yes it is someone else's poor build, but it is still my car and it's still my baby. I picked it to be exactly as I wanted. All good car guys get attached to their cars regardless of the headache.
I did want it done right, I did have a budget, which in term of the car value was a proper crazy amount. Sadly, my lack of fortune telling skills or crystal ball couldn't confirm the future.
So far I am at a loss 11000 CAD. I hope to turn this around and run it for a good 2-5 years with very limited future updates such as predictable maintenance.

Lets let the thread die out
I wanted to know if that specific engine mount/bushing at the subframe would make the cabin vibrate with solid Urethane and it's 110% confirmed yes.
As I have 2 subframes Ill try for the fun if it the polyurethane construction glue that remains somewhat elastic once cured... (I am curious and stubborn, I can't imagine it being any worse than what it is)
And Ill get the other subframe OEM ready for the near future.

Thank you everyone for your help.

JETaah said:

Hey "Gandma", what was that thing you were saying about spell check?
LOL

Click to expand...

so, i never said i did! thanks grammar naz! police

C00lit said:

As I have 2 subframes Ill try for the fun if it the polyurethane construction glue that remains somewhat elastic once cured... (I am curious and stubborn, I can't imagine it being any worse than what it is)
And Ill get the other subframe OEM ready for the near future.

Click to expand...

To my thinking, since you already have a second subframe that will be reconditioned with OEM bushings as a fallback and are committed to your experiment, I say go for it, you've got nothing to lose except the time to swap to the OEM-bushed one (the risk of having to do so you already said up-thread that you had accepted).

Please let us know how it turns out - initial and longer-term impressions, how it seems to hold up over time, etc..

After all, sometimes technology only takes a jump forward because someone tried something considered crazy, and as the saying goes, "sometimes crazy works".

Done, however the problem persists

This took a bit of time but it's done for now.


This is the subframe bushing that I filled with some flexible polyurethane.


https://plus.google.com/photos/phot...0710416139723298?icm=true&iso=false&ftu=false


https://plus.google.com/photos/phot...0866138314817458?icm=true&iso=false&ftu=false


I feel no vibrations at all within the cabin.
My only complaint is when I am stopped and idle, if I face a car or a wall, I see the light from my headlights have a bit of a vibration. This goes away the second the engine isn't idling.


Also, prior to this fix, sometimes sometimes when catching the friction point on first gear, I would feel heavy shaking/knocking as it grabs, this has not happened anymore with the filled bushing.

But my shifter is still bouncing around 1-3 cm as I accelerate or simply release my foot of the gas.


https://www.youtube.com/watch?v=T-ggQJjSAbg



Could this be caused by anything else ?

This started when a garage took my transmission out to weld a crack in the casing and change the clutch.


When they gave me the car back, I had this movement and 2 weeks later, I couldn't shift it to first or second. (I had to press down and go in between first and reverse)

I gave them back the car and they resolved the issue of not being able to properly go first but the movement was not resolved.
And even if the casing was welded it still leaked.