DIY: Upgrading/replacing transmission mounts

[vtl]

Does the exhaust on an N54 135i cause issues with access? Does it have to be removed? Hate when I find new parts to buy after already placing a big order to save on shipping haha

[vtl]

I just did the install today.

- Exhaust is not in the way at all, the only thing you have to remove is the middle and rear plastic undertrays
- I couldn't torque the top bolts down, only a ring spanner would fit in that area.

This is how I made sure the gearbox was settled:

- Removed transmission mount per DIY (I had all 4 wheels off the ground)
- Reinstalled all bolts finger tight
- Lowered jack
- Start engine and put into gear (wheels will be freely spinning).
- Gave it a few revs and changed gear a few times to settle all the components.
- Shut off car and tightened to final torque.

After my test drive I noticed zero change in NVH, feels just like stock to me.

I would not say the shift quality has improved much, only the lower gears its subtlety better. Revmatching from 3rd to 2nd is a bit easier. I have not tested WOT 1st to 2nd shifts yet which is what I hope this mod will improve.

Worth it? I am glad the mounts were cheap since the improvement was quite minor. The stock gear change on my 135i was actually pretty goo to begin with.

Maybe I will machine up a solid chunk of aluminium on my lathe and see how much a rigid mount will improve shift quality (and how bad the NVH would be)

[Dackelone]

Originally Posted by vtl

I just did the install today....

....After my test drive I noticed zerochange in NVH, feels just like stock to me....

...Worth it? I am glad the mounts were cheap since the improvement was quite minor. The stock gear change on my 135i was actually pretty goo to begin with. ....

WHICH transmission mounts did you install? e46 M3 ones?

[vtl]

Originally Posted by Dackelone

WHICH transmission mounts did you install? e46 M3 ones?

E46 M3 ones

[rhodesman]

for risk of sounding silly/stupid: is there any benefit for doing this on an AT?

[vtl]

Probably not, I felt the improvement was pretty subtle and minor on my MT. My stock mounts were in good condition though.

They're cheap enough that its worth a shot though. I think they're probably only worth upgrading if your stock mounts have gone soft.

[Joebie]

I put e46 M3 mounts on mine recently and I am in agreement with vtl that the improvement was minor. shifts may be slightly more crisp but nothing day and night.

Also this is a super duper easy DIY. Once you have the car up on stands it is a 5 minute job. Nothing is in the way, nothing is complex or tricky to get to. Just have the right size open end wrench and a socket and you're good to go.

[polskatomek]

Anyone know what the difference is (if any) between the E46 M3 tranny mounts and the 335is ones in terms of stiffness?

[Boosted_N54]

: i installed the m3 e46 transmission mounts and have not notice anything diffrent when shifting

[vtl]

If you want crisp shifts I think an upgraded shifter is probably the way to go. Transmission mounts imo didn't make that much difference.

Sat in a 1M with a modified BMW performance short shift kit. The gear level felt so tight with no slop at all. Felt very notchy but not in a bad way. Not sure if I want to upgrade it since I am actually pretty happy with the stock shifter.

[froop]

Couple years ago I used this thread to install the E46 M3 mounts. They made probably a mild improvement to shift feel with no increase in NVH.

Tonight, in preparation for installing AD Engineering poly motor mounts and turner solid diff mounts to go with my solid subframe bushings, I installed some UUC Blue isolated poly transmission mounts with Enforcer Cups. I reused the stock nuts rather than use the nylock nuts and washers supplied as per this thread. Torqued to 16ft/lb as per the UUC instructions and just too it for a bit of a drive.

Shift feel is improved dramatically. I have a BMW SSK with a MOTIV twin plate clutch and running Redline MT-90 and with the stock and the E46 M3 mounts, shifting into 2nd was a nightmare. Crazy notchy. The shifter feels much more direct and it slots in much easier. There is still some notchiness but its not annoying or difficult like it was before.

NVH - (Keep in mind my car is quite loud and I have a SMFW with twin plate pucked clutch) There is no noticeable increase in NVH at idle. During driving, there is some mild to moderate vibration noticed between 2-2.5k RPM but other than that it's smooth. There is maybe some slight increase in transmission noise but that's probably because of my flywheel and clutch.

All in all, I'd highly recommend the UUC Blue's with Enforcer Cups over the E46 M3 in a performance perspective, especially if you have a notchy transmission.

Once my motor mounts and diff mounts are installed, I'll see how it feels and then maybe install the UUC Red poly bolt-through mounts and see what that's like.

[ianc]

I did the E46 M3 mounts over the weekend. The increase is small but noticeable. Not as great as the improvement I felt from the Whiteline RSFB inserts for example. ECS had a good price with free shipping and shipped fast.

Still, easy job with no increase in NVH. Just Jack up trans to support it, remove x-member, unbolt old mounts, attach new ones finger tight, torque x-member back to car taking car to center the bolts in the holes and using a cross pattern, then tighten the four mount bolts. No issues...

ianc

[snub-nose 28]

I just returned from an hour thrashing my 128i manual, along rural byways after installing ECS trans mounts. I decided their 'street spec'red poly mounts for 1/2/3 series might meet my hopes.

This modification achieved more- much more -beyond improved shifting mentioned by others in this thread mostly using E46 M3 oem version.

Tight shifting, especially down shifts are vastly better! SSK for dd street car became instantly redundant, so I won't be doing that one.

Re: BMW hourglass mounts studying carefully those informative threads, one discovers minor improvements, better or competent shifting but lacking transformative improvement for our 1-series variants.

I am of the opinion the 'edge', the 'nervosa', has been filed off common BMW street cars, rightly so.

Going kinda rogue, I sought to re-energize exactly that nervosa, that edge, be re-introduced for my interpretation as I mod my street car ...getting it to where it should have been, if the world was less regulated, less soft.

ECS's red 'street mounts' utterly transformed the character, from benign, competent and civil...into an edgy, vocal, alive, awake and engaging 'civilized hulligan' street car. Kind of sounds like an oxymoron, I know.

Did N increase? YES, perfectly 'un-neutered'. Vibration increase? No. Nothing. Nada. Harshness increase? +5% to 10%.

Did it remain a commuter coupe? No. Become nearer to a sports car/touring coupe?
Definitely.

Adding the aFe full kit today contributed to auditory joy, plus, modest throttle response gain.

However, the character created by these mounts was totally unexpected, a serendipitous event wholly out of proportion to the two-digit expense!

Two thumbs up indeed. Crisp, precise shifts, music resonating with each extended howling upshift.

Bolt-action precision on downshifts. Gas mileage will be compromised-boot in it all the time now! Gentle throttle, 5th or 6th at 70-80mph... no discernable change.

Now it's closer revealing proper legacy BMW traits as a normally-aspirated raucous BMW in-line six. Or, when needed... a quiet tourer. All from trans mounts. Amazing.

RSFB tomorrow, and M3 LCA this weekend...

[dcaron9999]

Originally Posted by snub-nose 28

I just returned from an hour thrashing my 128i manual, along rural byways after installing ECS trans mounts. I decided their 'street spec'red poly mounts for 1/2/3 series might meet my hopes.

Are these the ones you bought ?
https://www.ecstuning.com/BMW-E82-13...nts/ES2859359/

I did the E46/M3 tranny mounts last year, and not completely satisfied with them on the track, with all the FBO power Im making and how much gear shift hunting Im struggling with powering out of turns.

I will probably go for the stiffer 80A durometer ones ...
https://www.ecstuning.com/BMW-E82-13...nts/ES2718367/

[snub-nose 28]

Originally Posted by dcaron9999

Are these the ones you bought ?
https://www.ecstuning.com/BMW-E82-13...nts/ES2859359/

I did the E46/M3 tranny mounts last year, and not completely satisfied with them on the track, with all the FBO power Im making and how much gear shift hunting Im struggling with powering out of turns.

I will probably go for the stiffer 80A durometer ones ...
https://www.ecstuning.com/BMW-E82-13...nts/ES2718367/

Yes, they are. Since you have a track focus, the denser ones will be recommended by ECS. Report back on how they perform...

[dcaron9999]

Originally Posted by snub-nose 28

Yes, they are. Since you have a track focus, the denser ones will be recommended by ECS. Report back on how they perform...

I installed the stiffer 80a durometer Ecs tuning mounts yesterday, and immediately noticed how these were stiffer than the e46/m3 mounts I was replacing. They required a little more manoeuvring of the cross brace and I had to slightly raise and lower the transmission a few times during installation for proper alignment.

Cons: This introduced a lot of NVH over the M3 mounts. I did not expect as much. The noise I can get used to, as my 135i is mainly used on the track and to drive to and from the track. The vibration is disconcerting at times when coasting. Occasionally, these introduce a huge vibration and resonance throughout the whole car. A little throttle application will stop this behaviour. Im wondering if the stock engine mounts might be tired, allowing for movement, and need to be changed.

Pros: Crisp gear shifts under normal and aggressive driving like I've never experienced. Downshifts and heal and toe driving are amazingly precise now.

I'm going to try these on the track this week and come back to this thread. I'm going to have to decide if I can live with the N+V or turn it down a notch with slightly softer 70 durometer mounts.

[desertman123]

I would love to hear how you like the 70 mounts, I'm looking to improve that 1-2 shift without too much NVH. Seems the e46 ones are good but not great for the money.

[snub-nose 28]

Originally Posted by dcaron9999

I installed the stiffer 80a durometer Ecs tuning mounts yesterday, and immediately noticed how these were stiffer than the e46/m3 mounts I was replacing. They required a little more manoeuvring of the cross brace and I had to slightly raise and lower the transmission a few times during installation for proper alignment.

Cons: This introduced a lot of NVH over the M3 mounts. I did not expect as much. The noise I can get used to, as my 135i is mainly used on the track and to drive to and from the track. The vibration is disconcerting at times when coasting. Occasionally, these introduce a huge vibration and resonance throughout the whole car. A little throttle application will stop this behaviour. Im wondering if the stock engine mounts might be tired, allowing for movement, and need to be changed.

Pros: Crisp gear shifts under normal and aggressive driving like I've never experienced. Downshifts and heal and toe driving are amazingly precise now.

I'm going to try these on the track this week and come back to this thread. I'm going to have to decide if I can live with the N+V or turn it down a notch with slightly softer 70 durometer mounts.

I've just returned from 1400 mi over-and-back thru the Montana rockies.
Fitting the M3 lca and aFe stage2 intake called for nothing less than a serious romp. Back to civilization-can also revisit this thread and my experience settling in after fitting ECS red mounts. More miles under the hammer reveals: character of the car was indeed transformed from soft compliance' (oem mounts) -easy DD- into a 3.0 CS with Webers, a connected-ness that is utterly addictive. Admittedly, my frame of reference is classic David Brown 60's-era Astons- I'm better understood as somewhat out-of-the-mainstream. The 1series is after-all, about that era, no?

Will your wife like these mounts? depends on who she is. Mine drove 190SL national show quality restorations as weekend car, no ps, drums all'round and dual Webers!, or, our 1973 911E Cpe (w)as her commute vehicle, and a 356B Cab, and another 356B Cab, so she would accept the intoxicating increase-minor, but magical-NV to get "that sound".

There is intake resonance, that was not there before the refit. I'm interested if that remains when the stage-3 intake DISA gets fitted this fall, w/reflash. I've adjusted to the fleeting but odd resonance at 2600-2700.

That's the one downside, by my standards.

I wanted to achieve that 3.0 CS essential character-recollections of a 3.0 CS and 4.0L twin-cam triple-Weber Astons have been recaptured 200%. With 1-series improved steering +brakes too!

[dcaron9999]

Just found out these specs from 034Motorsports, which might help other members make a choice:

The "Street Density" Transmission Mount is manufactured from solid 50 durometer rubber, which is stiffer than the stock hydraulic mount (45 durometer - with voids). ... ideal for daily use.

As a reference point, the ECS tuning mounts are offered in 70 and 80a durometer poly.

In addition to the 034M mounts, Im looking at the Rogue Engineering rubber mounts with a durometer of 55, as a compromise between the e46/m3 mounts and the 70/80a ECS poly mounts. http://www.rogueengineering.com/Rogu...nts_p_137.html

The ECS 80a mounts introduce weird vibrations when coasting, which may come from the mismatched softer OEM motor mounts.

The more I give this some thought and discuss with other track junkies, the more Im convinced that the motor mounts and transmission mounts should be replaced as a matched set. It's easy to go overboard, and choose tranny mounts that are too stiff and have no give, which become un-matched to soft OEM motor mounts. The drivetrain gets mis-aligned under hard acceleration followed by coasting, and you end up with nasty vibrations throughout the chassis. I dont mind some NHV, as long as it is constant and predictable.

The bump from the OEM 135i voided mounts to the solid E46/M3 was just right in terms of added NVH, but fell short or got softer and perhaps worn out with 1-2 year of track abuse. To add to the equation, I recently jumped from Extreme Performance tires (ZII SS) to semi-slicks (NT01), which contributed to even more mis-shifts and hunting for gear engagement. This occurs under the following conditions: hard braking, heal-and-toe, powering out of turns, even street driving to my great astonishment. When I first started tracking the car, I noticed this issue and I moved from stock mounts to e46/m3 mounts. Although this helped, I feal the m3 mounts have become unmatched to higher forces and tensions with the stickier tires and increased torque of the engine ...

Ahhhh, the slippery slope of mods and track use , and finding the right balance of making compromises in a dual-duty car, with a limited budget ...

[snub-nose 28]

Originally Posted by dcaron9999

Just found out these specs from 034Motorsports, which might help other members make a choice:

The "Street Density" Transmission Mount is manufactured from solid 50 durometer rubber, which is stiffer than the stock hydraulic mount (45 durometer - with voids). ... ideal for daily use.

As a reference point, the ECS tuning mounts are offered in 70 and 80a durometer poly.

In addition to the 034M mounts, Im looking at the Rogue Engineering rubber mounts, as a compromise between the e46/m3 mounts and the 70/80a ECS poly mounts.

The ECS 80a mounts introduce too much weird resonances for my taste. More unnerving are the akward and odd vibrations when coasting, which may come from the mismathced softer OEM motor mounts.

No durometer specs on the RE mounts, and I just emailed them to find out : http://www.rogueengineering.com/Rogu...nts_p_137.html


The more I give this some thought and discuss with other track junkies, the more Im convinced that the motor mounts and transmission mounts should be replaced as a matched set. It's easy to go overboard, and choose tranny mounts that are too stiff and have no give, which become un-matched to soft OEM motor mounts. The drivetrain gets mis-aligned under hard acceleration followed by coasting, and you end up with nasty temporary vibrations and resonances throught the chassis. I dont mind some NHV, as long as it is constant and predictable.

The bump from the OEM 135i voided mounts to the solid E46/M3 was just right in terms of added NVH, but fell short or got softer and worn out with 1-2 year of track abuse. This year, I jumped from Extreme Performance tires (ZII SS) to semi-slicks (NT01), and ended up with mis-shifts and hunting for gear engagement under the following conditions: hard braking, heal-and-toe, and powering out of turns. This is originally why I moved from stock mounts to e46/m3 mounts 2 + years ago which helped, but might have become unmatched to higher forces and tensions with the stickier tires ...

Ahhhh, the slippery slope of mods and track use; finding the right balance in a dual-duty car, with a limited budget ...

The other mounts in the equation is diff mounts. My car is a street car, with oem mounts thru-out but for trans. The tires in a track setting will induce strain in diff mts, and that slippery slope is well, a long one...

My goal achieved- I was hoping to add precision in shifting (did I contemplate SSK, yes), (did I contemplate opening the exhaust, yes!) and with a street spec car, I 'added' precise crisp shifts! without SSK. And the 'noise/music' is perfect without having to open exhaust.

I'm reminded of "it's alive, it's alive" from a vintage comedy. My 1er has indeed become alive...

[dcaron9999]

http://m3.madrussian.net/diy_re_tranny_mnt.shtml

[EndOfAnEra]

So for a daily driver 135i with periods of hard driving and possible future autocross, would one suggest the Rogue Engineering 55a mounts or the 70a ECS mounts?