Z3 diff mount vs. OEM E30?

[mtech325]

I think Nando is right, the iX diff bushing is solid rubber as opposed to standard rwd e30 diff bushing (at least that's what RealOEM shows after checking part numbers).

That being said, I've actually had the Z3M, the soft AKG 85A poly bushing, and now the solid rubber e30 iX version in my car at one point or another. Aside from the Z3M one developing a tear in the rubber upon inspecting it, I can't say I noticed any discernible vibration differences between any of the bushings (street driving only though). The poly one didn't squeak either, it just had the benefit of easier installation.

[nando]

a soft poly bushing is fairly pointless IMO. If you put anything stiffer than stock, it's going to be pretty nasty (I had a delrin bushing in for a week - never again). if it's not any stiffer than stock, it's just a waste of time.. my original ix bushing looked perfect at ~125k, although that was a lot of years ago.

[TrentW]

I just pulled the original dealer invoice from July of 2010 when I purchased my Z3M bushing and it was $42.55 with my CCA discount.


Crazy.

[varg]

I wouldn't do that unless you like vibrations

I've been driving a car with a full set of solid UHMW bushings in the rear for several years now and plenty of E30 owners have ridden in my car, none of them have remarked that it vibrates. I'd say the only drawback is that you can hear the differential whining where you wouldn't with stock bushings, but it's not loud or shrill so most of the time the ample wind and tire noise that is part and parcel of driving an E30 overwhelms it.

[digger]

I'd say the only drawback is that you can hear the differential whining where you wouldn't with stock bushings, but it's not loud or shrill so most of the time the ample wind and tire noise that is part and parcel of driving an E30 overwhelms it.

that is what he means

[LowR3V'in]

god damn even the ix one is expensive as frick.
ive had it btw. Very soft still.
https://www.ecstuning.com/b-genuine-...g/33171134802/

right now i'm using a stock e36 cover with the little solid rubber bushings.
waaaayy stiffer setup and the only way i could tell is it has a louder diff noise. very slightly but i can hear it if i try.

i imagine the z3 one is as stiff as the stock e36 ones at least.
Can't even find them for sale on ebay new.


dooooddde.

buy this cover and press it out.

https://www.ebay.com/itm/2001-2002-BMW-Z3-Roadster-Coupe-3-0i-M54-3-0L-Differential-Carrier-Rear-Cover-OE/223270636705?epid=1626305476&hash=item33fbf78ca1:g:E14AAOSw4vpcBtCZ:rk:10:pf:0

[rturbo 930]

Wow, I got my Z3M bushing years ago, I don't think it was more than about $60-70. Crazy how much they've gone up in price.

[varg]

that is what he means

Barely audible under most driving conditions, inaudible at highway speeds, so probably a non-issue for all but the most noise-sensitive drivers. Well worth the immense improvement in rear end feel over stock rubber.

[nando]

yeah, I'm not sure your solid diff bushing is as solid as the one I ran for a short while. The vibrations were so harsh it would rattle the fillings out of your teeth. No thanks. Couldn't tell any difference in handling either over rubber or polyurethane.

[D.Martijn]

Ow wow, seems there is also a difference between the iX rubber as I can't find the pn33171134802 here in Europe.

33171134802 for US models (solid)
33171135244 for EU models (open)





Any idea why the difference? More bad roads in EU?

[Zambuzan]

Barely audible under most driving conditions, inaudible at highway speeds, so probably a non-issue for all but the most noise-sensitive drivers. Well worth the immense improvement in rear end feel over stock rubber.

I'm planning to go 80a rtab and subframe bushings on my car, and OEM diff bushing. This a daily driver for me. Thoughts?

[Northern]

Barely audible under most driving conditions, inaudible at highway speeds, so probably a non-issue for all but the most noise-sensitive drivers. Well worth the immense improvement in rear end feel over stock rubber.

Same experience with AKG's 75D diff bushing here. A little diff whine and you can hear the wub-wub during tight turns, but I think the extra clutches are more to blame for that.

[slippery]

My factory ‘87 325is bushing was solid as well.

When I bought a replacement one a few years ago I noticed the new one was not solid anymore.

[reelizmpro]

You'd think the Z3 bushing would be improved but I don't think so. I've never had a problem with E30 bushings but as I soon as I installed my 3.15 Torsen Z3 diff I got a clunking noise and it appears the bushing has cracked and is allowing movement. It could just be coincidence but why not make it solid to begin with? Now I have to pull the cover and install Garagistic's 80A polyeurethane bushing.

[packratbimmer]

You cannot use the iX bushing in a RWD - the hole is at a different location.