When replacing the steering rack is replacing the flex disc recommended?

[MC Hammered]

I've searched and couldn't find a definite answer.

I'm going to replace the steering rack with an e46 unit, so does it make sense to replace the 25 year old flex disc (part #3) while I'm in there? Or do I leave it alone it it looks fine?

[jeffnhiscars]

I've always reused mine since they looked good..unless you want to replace it with urethane

[MC Hammered]

thought to upgrade with urethane and wondered if it was worth it for a street only car.

[ELVA164]

I'd just leave it. Mine looked fine when I put my E36 rack in, and I don't have any negative side-effects. That said, my rule of thumb with my car is to leave things rubber for the added cushion. It's a fun car, not a race car.

[cactusjacks1]

Winston, replace it with a urathane one as long as your right there - you will have a little play in the original one, even if you can't feel it in the wheel. Upgrading it now (with your rack) will help you get a crisp steering feel. Available at http://www.iemotorsport.com/bmw/E30-...-steering.html

[MC Hammered]

So a urethane disc won't cause any NVH as it will be going into my vert and this is my only concern stepping up from rubber.

And if I were to upgrade who to order it from?

[cactusjacks1]

So a urethane disc won't cause any NVH as it will be going into my vert and this is my only concern stepping up from rubber.

And if I were to upgrade who to order it from?

See edit in my above post. I put one in my vert & it works wonderful.

[jeffnhiscars]

So a urethane disc won't cause any NVH as it will be going into my vert and this is my only concern stepping up from rubber.

And if I were to upgrade who to order it from?

It's my understanding that every time you replace a piece of rubber with urethane you increase NVH.

[SkiFree]

It's my understanding that every time you replace a piece of rubber with urethane you increase NVH.

That's a bit like saying all BMW drivers are prats.

Traditional rubber and urethane are made in varying hardnesses, to the point where they can overlap on the shore hardness scale.

THEN throw in that rubber and urethane can be reinforced internally and externally (with cords in the case of the coupler). For example the E24/E28 rear trailing arm bushes are a stiff rubber molded inside a steel sheeth, it's actually equivalent to 90a-ish on the shore scale (which is moderately stiff urethane territory).

[jeffnhiscars]

That's a bit like saying all BMW drivers are prats.

If they werent then why do we have a thread for used prats FS :roll:

[MC Hammered]

Thanks guys for your input. Spoke with IE and have their flex disc on the way and I'll report back on the 'feel' after the swap is completed.

[camshaftgsxr]

too late, but akg and ie's flex discs are hard poly, and you will feel more of the road through the steering wheel, there will be vibrations and harshness, nothing to make your hands numb but its there.

[TrentW]

What's the verdict MC?

[MC Hammered]

Unfortunately I have no verdict as the stock flex disc was left in place.

Since the knuckle was not modified to complete the installation, there was no reason to swap the disc out.

[butters]

I did the IE poly coupler while I was in there a couple years back. I would definitely recommend it, the NVH is not terribly higher and besides, the steering is where you want to feel the road. I have GC coils but kept rubber bushings everywhere else, so the steering is the only poly part so far. I wouldn't call it harsh.