Installed Polyurethane Dogbone Mount on my Focus

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After enjoying the difference in the car from replacing the hydraulic passenger side mount, I decided I'd go for a polyurethane dogbone mount aka "Torque Restrictor".

The engine/trans do not rest on this mount, but it helps stop the 'rocking' motion that happens with transverse engines and transaxles. The stock one is known to allow a lot of rocking.

I have heard claims that it helps with shifting and clutch engagement. Never really believed it. The thing that bothered me, and the reason I replaced it, was I could feel the engine rocking around (to an extent, less than before) when taking off from stoplights or shifting. I never cared for it.

I bought the polyurethane dogbone mount from "Techstar Massive" engineering. It's just polyurethane bushings pressed into a 00-07 Focus factory dogbone. While they aren't designed specifically for racing, they do provide some improvement for street driven Focii.

Once it was installed, I noticed a HUGE improvement with the driveability of the car.

  • I can "feel" the clutch engage. When taking off from a stoplight, I no longer have to give it a bit of gas or stay on the clutch longer than I'd like; I let the clutch out and go.
  • Shifting is much more precise. I'm not entire sure how, but I did some "spritied" driving (never above the speed limit) but upshifting and downshift are completely different. I can tell EXACTLY where the gears are and where the clutch is going to engage. Before, I'd have to feel where the gear was when trying to accelerate quickly.
  • No more wheel hop! The car used to wheel hop horribyly; even taking off from a stoplight quick I'd occasionally get some wheel hop. Now it either hooks up or just spins the LF tire.
  • Engine/trans no longer feel like they are flopping around when driving.
  • Engine doesn't shake at lower RPMs any more. This one really surprised me. But if I'm in traffic and need to idle along in 1st gear, or even hold the brake a bit ... no more shaking.

The downside? Noise. Lots of it. If the engine is pushing on the mount hard, at low RPMs (such as going 30 in 5th gear and trying to accelerate), you'll hear it. It isn't like a cabin vibration like the bad passenger side mount ... but it sounds like the car has an intake. It's a strange one, really.

Original compared to poly.:
rRgS3rc.jpg


Install instructions say 45 minutes ... Not so much. More like 3 hours.

To remove I had to:
- Remove two bolts from factory mount - bracket and frame end
- Knock out original dogbone. Woo - out in 10 minutes!

This is where things got tricky. The new mount was so stiff it couldn't just be punched in. So to install:
- Bolt dogbone to bracket (attaches to transaxle), slide assy. into the frame
- Bolt dogbone to the frame
- Line up two lower bracket bolts, bolt bracket in with 2 lower bolts
- Separate dogbone from bracket, rotate engine and transmission forward (this has to be done because the top bolt interferes with the steering rack)
- Bolt top bolt back in the bracket
- Bolt dogbone back into the bracket.
- Enjoy!

This is something I should have done when I was driving primarily in the city.

On the way back from my parents, I took the state road through small cities. Hoping to hit stoplights. Of course, I didn't hit a single stoplight.

I have heard they tend to tame out after a while. I hope that's the case.
 
Originally Posted By: Colt45ws
When I put the poly mount in my old Cavalier, you could REALLY tell when the A/C was on due to the additional vibration.


That's what is kind of odd. I was expecting it to be bad with the A/C compressor on. It's quiet at idle, with and without A/C. Only time it's obnoxious is when cranking the engine (sounds kind of cool, actually) and lugging the engine.

As long as I keep the revs above 1500 when pulling hard, it's not too bad.
 
That OE mount looked a little tired, eh?
Transverse applications are particularly finicky with regards to the HVH vs. drivetrain dynamics equation.

Swapped in some manufacturer-supplied ‘factory motorsport division’ (~75A durometer replacing ~55A durometer) mounts into my Miata.
Negligible increase in vibration although enjoyed dramatic improvements in tip-in and shifting control.
 
Wonder if you could do a hybrid mount with poly for the big bushing and standard rubber for the small one. If Im not mistaken, the big one is the engine and the small one is frame side. Seems the big on is what takes the beating from the looks of the OE mount.
Though, what would likely happen iwth such a hybrid mount is the small bushing would get beat to tar having to take all the load.
 
Originally Posted By: splinter
That OE mount looked a little tired, eh?
Transverse applications are particularly finicky with regards to the HVH vs. drivetrain dynamics equation.

Swapped in some manufacturer-supplied ‘factory motorsport division’ (~75A durometer replacing ~55A durometer) mounts into my Miata.
Negligible increase in vibration although enjoyed dramatic improvements in tip-in and shifting control.


I ordered the 95A ... Should have got the 76A mounts.

Originally Posted By: Colt45ws
Wonder if you could do a hybrid mount with poly for the big bushing and standard rubber for the small one. If Im not mistaken, the big one is the engine and the small one is frame side. Seems the big on is what takes the beating from the looks of the OE mount.
Though, what would likely happen iwth such a hybrid mount is the small bushing would get beat to tar having to take all the load.


Thought about that. Guess it depends on how long this works. The style of the purple one is for 00-07 Focii and a lot of companies sell bushings for those. I could even press in a lighter bushing. Oddly enough the big end is the frame end.
 
IndyIan said:
Well thanks for posting your experience, I'll probably get the 76A one someday. I do wonder how even the 76A will do in winter? [/quote

I think the reason I may have had trouble with the factory dogbone and the passenger side mount is I did get the car stuck in the snow ... really good once. Didn't have a shovel and there was no one nearby to help push.

So, I'd rev up to 4000 in 1st and reverse and sidestep the clutch. Got me out ... but probably hurt things.

The 95 are quieting down quite a bit now. Unless I'm lugging it hard in 5th gear going 30 it's not bad at all. Keep the revs above 1500 when pulling hard and you'd never notice.

I suspect they are noisier in the winter.
 
I lucked out; I was able to install the E-Focus rear mount/roll restrictor on my 2007 Mazdaspeed 3. It was only $59.97 shipped from Tasca Automotive Group. There was virtually no increase in NVH compared to the OEM mount- but it's more than adequate for my purposes, since my engine is only making @300 hp at the crank. I was a bit surprised to find that my OEM mount was still in pretty good shape- even after nearly 145,000 miles:
RMMComparo_zps67950ca7.jpg
 
That was my next thought too, the euro version of my Focus couldn't have been sold with the NA rear mount. I just haven't got around to searching that out.
 
Just to avoid any confusion, the "E-Focus" I'm talking about is the Electric Focus- and that same mount has been retrofitted per a Ford TSB to the early Focus ST and is now the OEM mount for that car.
 
I've known a lot of people over the years who moved to poly bushings when the rubber was tired, or when trying to upgrade performance. The best "driver" mods do tend to reduce the smoothness and quietness of things, but gain feel, control, and precision.
 
meep speaks the truth.
I installed a poly bushing top engine mount in my car over the objections of many.
They were right. It was UNBELIEVABLY SHAKEY.

Last week I installed poly bushings into the lower control arms of the same car.
THAT'S WHERE YOU WANT 'EM.

It tightened up the action of the arms a small but noticeable bit and will far outlast the original rubber ones.
In a control arm, I'd recommend them.
I should note that my car has 177,500 miles. The original bushings were shot and needed replacement. Kira
 
For those interested, the part number for the E-Focus mount is: CM5Z-6068-A

If you are installing it on a Mazda you will also need a new horizontal mounting bolt: W500545-S900 The reason for the new bolt is because Mazda uses a fine thread bolt and the E-Focus mount takes a coarse thread bolt.
 
Originally Posted By: meep
I've known a lot of people over the years who moved to poly bushings when the rubber was tired, or when trying to upgrade performance. The best "driver" mods do tend to reduce the smoothness and quietness of things, but gain feel, control, and precision.


That's exactly what I did. The clutch and shifter feel like a different car.
 
I had a pretty poor experience with polygraphite bushings once. I've used them here and there, but with varying degrees of satisfaction. I put a complete polygraphite bushing set in my '84 Cutlass and 100% hated it. There was a lot of binding somewhere. You could set the car down from a jackstand and the suspension would remain at full droop (even with the weight of the car on it) until you drive it into a driveway ramp or something to compress it. The ride was unbearably stiff and they squawked bad in cold weather. It's possible the shop installed them wrong. A few years later, I paid to have new rubber put back in; problem solved.

I used polyurethane bushings on the front stabilizer bar of my '97 Dakota...and rather liked them on that. I also had some R/T front springs on it and it rode nice...firm, but planted. On the flip side, I put some polyurethane bushings on the rear stabilizer bar of my CR-V a month or two ago because I had the bar off anyway to replace the sagging rear springs and and I actually put the factory rubber bushings back in because it was too stiff with the polyurethane.

I don't think I would like a polyurethane engine mount; the noise would pretty quickly wear on me. My CR-V has a very similar lower dogbone to the Focus here, and I imagine that it, too, has some pretty compliant rubber.
 
Even a few days in it is still quieting down. And it's colder than normal, so that makes it bad.

It's really only obnixous or noticeable when lugging the engine < 1500 RPM and pulling hard.

It's getting traded with the car, that's for sure. My shoulders still hurt from changing it!
 
I have polyurethane bushings on my Mazda's JBR rear bar, but the bushings/mounts are fitted with zerk fittings. I hit them with Super Lube Grease every 7,500 miles when I change the oil. They are dead quiet.

TruTorsionBrackets_02.JPG
 
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