The Official Diff Mount Thread

[RhoadBlock]

One of the weaker links in the MS6 is the rear diff's bushings. You can buy replacement bushings, or if you're hardcore like all of us here on MSF, you'll just upgrade the whole damn mount! Because RACECAR!!

The rear diff actually has 2 mounts. Here are ALL the options you have for rear diff mount upgrades.

Bushing Upgrade:

$44.08 USD - Turbine Tech Bushings
Turbine Tech Bushings


Stock bushings for reference


"Rearward" Rear Diff Mount:

$255 - SURE Motorsports Dreadnaught


$269.00 - CP-E Rear Diff Mount


"Forward" Rear Diff Mount:
$245 - SURE Motorsports Juggernaut


$289.66 USD - Turbine Tech Differential Mount

[AtTheDriveIn]

My stock bushings were thrashed to oblivion. I have Street Unit's old school Stiff Diff mount. Shifts got a bit tighter. Just like the rear motor mount, this is a necessary upgrade for the MS6s.

[RhoadBlock]

Feel free to post your own pics & rants/raves of your diff mounts. The more feedback we get, the better we'll be able to help newer guys looking to upgrade theirs not have to ask too many questions.

[chuckms6]

is the full mount recommended or will the bushings suffice? also is a press needed for the bushings or can they be done by hand?

[Jh8909]

Also, for someone new at this, are any little tools helpful or any extra parts helpful that will/might break while doing the install like bolts sheard off or anything?

[arnobg]

Yes I also wanna know if the bushings are good enough and if a press is needed. The whole brace is expensive!

[RhoadBlock]

IMHO the bushings would *probably* be good enough, especially if it's mostly just a daily driver and you don't thrash it too hard on the weekends. I don't really recall seeing any snapped factory mounts. It was usually either torn bushings or sheared bolts.

I don't know if you need a press to do the bushings or not. I know I did my AWR bushings for my side motor mounts by hand so I couldn't imagine the diff bushings being much harder, but I personally didn't do the bushings. You'll have to do some searching on the forum for bushing install threads.

As far as tools, air would be great, phenomenal actually since you're gonna drop the subframe to get the mount out. But it's a pretty straightforward install with basic tools.

One note is to install a rear sway bar while you're at it, since you have to take the stock one out to get to the diff mounts anyway. 2 birds, 1 stone. 3 birds if you install both mounts at once too.

The price for the mounts actually are pretty good, but if you feel it's too much to swing, you can always check the for sale/classifieds section. Access is for VIP members only. You can find them in good condition for much cheaper every now and then.

Here's a pretty good how-to to remove the rear subframe to make life much easier to do the mounts: How-To: MS6 Rear Subframe Removal

[MS6FL]

Great sticky!

Just want to add for those of us that have trashed our rear.....


-Front Diff case-------------------------------Part#MA2727681

-Bearing--------------------------------------Part#996068206

-Oil Seal--------------------------------------Part#M05427165

-Front Diff mount bolts(the 2 that sheer off)---- Part#H26034037A (I Used 12mm 1.25 pitch Grade 8.8 bolts)

-Rear Axle Seals-------------------------------Part#M0A727238A

-Bolts (The ones that secure the front diff case to the rear)

-------------------------------------Need 2 of Part#M05327604 (Didn't use these as mine were a lil shorter. Dunno why)
---------------------------------------and 6 of Part#907812830 (Only used 4 as the SURE mount came with 2 long ones you need)


Pic of mount on the diff case:

[mazda_speed_6]

Originally Posted by MS6FL Great sticky! Just want to add for those of us that have trashed our rear..... -Front Diff case-------------------------------Part#MA2727681 -Bearing--------------------------------------Part#996068206 -Oil Seal--------------------------------------Part#M05427165 -Front Diff mount bolts(the 2 that sheer off)---- Part#H26034037A (I Used 12mm 1.25 pitch Grade 8.8 bolts) -Rear Axle Seals-------------------------------Part#M0A727238A -Bolts (The ones that secure the front diff case to the rear) -------------------------------------Need 2 of Part#M05327604 (Didn't use these as mine were a lil shorter. Dunno why) ---------------------------------------and 6 of Part#907812830 (Only used 4 as the SURE mount came with 2 long ones you need) Pic of mount on the diff case:

Is this everything that is needed for this install?

[KevinK2]

Originally Posted by mazda_speed_6 Is this everything that is needed for this install?

One thing I don't understand about T-Case reassembly is setting the lash at the bevel gears. This is typically done with shims, like at the rear diff. With correct lash, a bluing test would show contact at the pitch diameter of each gear.

At a minimum, there should be some type of lash specification. Hard to believe you can just bolt it together, when bevel gears are involved.

.

[Clark954]

Originally Posted by RhoadBlock IMHO the bushings would *probably* be good enough, especially if it's mostly just a daily driver and you don't thrash it too hard on the weekends. I don't really recall seeing any snapped factory mounts. It was usually either torn bushings or sheared bolts. I don't know if you need a press to do the bushings or not. I know I did my AWR bushings for my side motor mounts by hand so I couldn't imagine the diff bushings being much harder, but I personally didn't do the bushings. You'll have to do some searching on the forum for bushing install threads. As far as tools, air would be great, phenomenal actually since you're gonna drop the subframe to get the mount out. But it's a pretty straightforward install with basic tools. One note is to install a rear sway bar while you're at it, since you have to take the stock one out to get to the diff mounts anyway. 2 birds, 1 stone. 3 birds if you install both mounts at once too. The price for the mounts actually are pretty good, but if you feel it's too much to swing, you can always check the for sale/classifieds section. Access is for VIP members only. You can find them in good condition for much cheaper every now and then. Here's a pretty good how-to to remove the rear subframe to make life much easier to do the mounts: How-To: MS6 Rear Subframe Removal

i was thinking with the bolt issue, what if you get grade 8 bolts along with bushings you think that would help eleminate the shearing issue

[cletusb]

Has anyone compared the rear TT + CPE combo vs. the Sure Combo?

[06Speed6]

No because you arent going to break either of them and they are basically the same.

[cletusb]

I guessed as much, was more thinking in regards to whine etc as AFAIK no one has broken any of the upgraded mounts

[weakdog85]

Ok so yesterday I noticed while downshifting there was a clunk noise which felt like something hitting the bottom of the car. Gotta be a diff mount right?

I knew I should of done the diff mounts before AP but I want more Powa!!

So question is. Do I stock out go to dealer and have them fix it under warranty or just upgrade the mount now and avoid the hassle. I can just limp around until it's fixed right?

[DPFISUMS6]

Originally Posted by weakdog85 Ok so yesterday I noticed while downshifting there was a clunk noise which felt like something hitting the bottom of the car. Gotta be a diff mount right? I knew I should of done the diff mounts before AP but I want more Powa!! So question is. Do I stock out go to dealer and have them fix it under warranty or just upgrade the mount now and avoid the hassle. I can just limp around until it's fixed right?

i am in the same boat now, had the same holy shit i hit a huge pothole noise.
Had the sure mount on since i got the car just over a year now. Dissappointing to say the least.

I have a clicking type noice that changes with acceleration and if you pull up a couple clicks on the ebrake. Going in tomorrow. pretty sure it is the internals.

Fidelity extended warranty is about to get tested... worried they are goung to tell me to shove off because of what is in my sig below...

[MS6FL]

Could very well be. Just get under and take a peek at your bolts. I limped around for a bit but wouldn't recommend it if you don't HAVE too. Depending on how cool your service dept is maybe you can go in for warranty and give them the aftermarket mount to put on instead of that oem pos.

[Stealth01]

Definitely upgrade to something aftermarket rather than going with OEM.

[weakdog85]

Originally Posted by MS6FL . Depending on how cool your service dept is maybe you can go in for warranty and give them the aftermarket mount to put on instead of that oem pos.

Now that's a good idea. I'll check my local nator people and see what they say

[MS6FL]

Well I can tell you Fidelity is one if not the best extended warranty out there. On the other hand warranty direct can go fuck them selfs.

[SpeedRebirth]

Here are my videos on the stock mounts
Front:

Mazdaspeed6 Front Diff Mount movement - YouTube

Mazdaspeed6 Front Diff Mount movement - YouTube

Rear vs CPE:

Mazdaspeed6 Rear Diff Mount movement vs CP-E - YouTube

Mazdaspeed6 Rear Diff Mount movement vs CP-E - YouTube

[ESB Jiu JItsu]

what about diff straps always a viable option, been holding it down on my car for 45,000 miles at least!!!!

[DPFISUMS6]

Originally Posted by MS6FL Well I can tell you Fidelity is one if not the best extended warranty out there. On the other hand warranty direct can go fuck them selfs.

This makes me feel warm and fuzzy, but when it comes to them paying a lot off money to fix this car, and they see ehat i have done to it, will they leave me out in the cold?

side note, mazda thinks its the drive shaft ujoint, 1300 for a replacement. not e a rear diff issue, they think.

[speedtoz]

going to install my sure diff mounts and rear sway bar this weekend, a bit nervous. looked at the how to's. i dont want to mess up.

[Spiral1183]

For someone who is not a hardcore track guy and is just trying to prevent serious damage while having fun on the street, is the front or rear diff mount the more necessary purchase? I can always pick up the other down the road, but I'd like to know which of the two is considered more important to upgrade.

[xI Leveler Ix]

Hey guys, I installed the SURE Dread and Jugg Diff mounts yesterday. Everything feels freeking awesome!!! Much stiffer on the rear end! I love it.
Although...
While downshifting I felt a "Clunk" in the rear end. This is after I put on the mounts. I can recreate the noise every time. I've heard of clunks from the stock mounts, but not after the install. I drove it home from our NATOR house this morning and the car runs fine, no squeaks, no grinding, no odd noises other than this. (I swerved my car side to side to see if something was really loose, nothing out of the ordinary.)

Any thoughts on what it could be? I did disconnect my Sway bar (No funds for a new one.) I've read it could be the endlinks? or something else? Any help will be greatly appreciated.

I'll double check all the bolts to make sure they are tightened down again tomorrow.
@RhoadBlock @MS6FL - since you guys have quite a bit of knowledge on this lol

[Stealth01]

Probably end links IMHO. Did you get them reconnected right?

[xI Leveler Ix]

Originally Posted by Stealth01 Probably end links IMHO. Did you get them reconnected right?

Yeah I believe so! lol I'll check them out tomorrow. Thanks Stealth.

[dot584]

The top mount is more important that the front. I have just the Sure too mount and stock front and the difference from stock is amazing.


Sent from my ADR6300 using tapatalkreplace 2

[chuckms6]

i think this is a good place for this







went to the track one night, took off fine, shifted into 2nd, heard a boom and hit redline. quick systems check, hit the gas and kept going lol. took the left axle with it so the driveshaft shop replacement is on the way. its actually marginally cheaper than the oem after the core price...

[MATT DAMOND]

After doing roughly a dozen diff mount installs(I cannot remember the exact number), I'll share my opinions on the subject.

First off, the stock rear diff mount(the one with 2 bushings), should be upgraded on pretty much every MS6. Every mount I've pulled, even once on a MS6 with 14k miles, the bushings were completely shot. The OEM bushings of the rear mount are a poor design, and they allow for way too much flex of the diff. That's why ppl break the rear diff mount, front diff casing, or the front diff mount at the bolt holes.

For 90% of the MS6's out there, you really only need to upgrade one mount. The 10%(you know who you are), pushing lots of power, doing many launches, tracking, and hitting up the strip, it's better to have both of the mounts upgraded. But for the occasional launcher, daily driver, light track duty, 90% only need to really upgrade the REAR mount. Upgrading the rear mount, will pretty much take all the flex out of the diff, under high loads, launches, etc.

If you upgrade to just a front diff mount, you'll still get the diff to flex, since the OEM bushings in the rear are garbage. This could lead to the rear mount breaking, and the cases could crack.

As for which mounts are the best, the rears are all pretty much the same. They're all beefy as fuck, they have little to no flex in the bushings, and they cost roughly the same. I don't really recommend just adding the TT rear bushings, unless you don't plan on launching the car. They still use the rear cast mount, and it can still break.

For the front diff mounts, I'd recommend the TT FDM over Sure's FDM. Simply because it has more mounting points, and more effectively "wraps around" the diff. However, the FDM's are really only need for the 10%, and once the rear has been upgraded, adding either FDM will have the same effectiveness.

As for NVH, you'll barely experience any with the mounts upgraded.

[Stealth01]

Originally Posted by MATT DAMOND I don't really recommend just adding the TT rear bushings, unless you don't plan on launching the car. They still use the rear cast mount, and it can still break.

I would caution against any decisions based on whether or not you plan on launching the car. My front diff mount bolts sheared when my wheels slipped on ice, then caught on dry pavement a moment later. Same thing could happen with sand, water, etc. Same could happen with the rear brace.

[KevinK2]

Originally Posted by MATT DAMOND After doing roughly a dozen diff mount installs(I cannot remember the exact number), I'll share my opinions on the subject. ....

You bring up a lot of good points. It must be as you say, that once the rear mount is upgraded, the oem front mount sees less shock, but still sees prying at the bolts due to the full reaction torque equal to the torque at the wheels.

But, when they first started selling this special model, it was the front mount that had equal or more failures, due to BENDING FATIGUE of the 2 bolts at the 1st thread. These bolts DO NOT fail by SHEAR (see the smooth fracture surface in the next link). Once this happens, the contact surface at the two soft aluminum casing bosses were rounded off at the edges, allowing even more rocking at this interface after new bolts were properly installed:

Bolt Failures, front mount

Because this compromised fit of the front mount if a bolt failed in fatigue, and the multiple owners of many cars, I think for reliability, the front mount should be replaced with the Turbine Tech mount, that we both agree is the best choice. This front mount eliminates the critical bending loads on the 2 side bolts.

Note that this offset, one sided front mount was a design error by Mazda, that was corrected with the same AWD differential design for the Cx-7. They used symmetric left and right side front mounts, each with two bolts to the casing with vertical separation, and not the incorrect horizontal sepatation like the MS6.
Cx-7 AWD differential Front Mount

This setup is currently used in a custom AWD MS3, putting down 625 hp and 570 ft-lbs of torque to 4 wheels ... with oem mounts!.
pte-6466-awd-conversion


.

[dot584]

I noticed nothing different NVH wise with the rear different mount. If anything it felt smoother all around. I agree every 6 should have this even if you never plan to launch or go to the track. Shifting gets easier, less slop ect

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[93GTS]

For those who bought the SURE mount(s), which durometer of bushing did you buy?

[KevinK2]

Originally Posted by 93GTS For those who bought the SURE mount(s), which durometer of bushing did you buy?

There is no stated durometer difference. Just appearance.

.

[Mazdazilla6]

Turbine Tech and Corksport

[KevinK2]

From an engineering stand point, the CP-e rear mount is the only rear mount I would choose, tough steel design, and most important, 60 Duro bushings.

" ... bushings are 60-duro rubber inserts that positively locate the differential, but will not rattle your passenger’s teeth out ... "

The stiff bushings others use are for suspension arms or sway bars, where you want minimal deflection.

For the front mount, Turbine Tech for the best spreading of the attachment to the case on the driver's side (opposite side to the original 2 bolts). I had posted about this type of fix back before TT released their design. The Sure looks like a good 2nd place.

.

[Hargarbl]

Just an update, Turbine Techs website is broken. You have to send them an email with what you want and they send you an invoice.

[r3d]

Does anybody know / can find out what are the size of the bolts that hold front part of diff to the rear? I got TT front mount used and it didnt have any hardware, but in the instruction it says to use longer bolts, i need to know what are they, can somebody help?