Morello

Hey all

I was all set to install my poly diff mounts today and the guy who was helping me press them in thought it'd be a bad idea... he mentioned hitting curbs and such with poly diff mounts can break the diff housing? Has anyone heard of or experienced this? I'm not opposed to the mazdaspeed rubber ones, but I already have the energy poly bushings...

Thanks

gooflophaze

Hitting a curb breaks the diff mounts, poly or no. There a weak spot on the diff housing to break away in an accident.

The biggest problem with poly diff is gear whine increases in the cockpit, along with typical nvh.

Gee Emm

Any data to go with statement?

M2Ken

Look at the notch on the diff mounting arm...

matrussell122

iTrader: (1)

Im running delrin diff bushings and been fine. Many others here are running poly or delrin without issues as well. Dont worry about it and put in the poly.

dleavitt

iTrader: (1)

I run delrin, no issues.

I haven't heard of anybody having issues breaking a diff mount just running over curbing.

Morello

I think the fear is more hopping curbs (think turn 3 at Road Atlanta) or riding really tough curbs (turn 10 road Atlanta) but I wanted to be sure I wasn't crazy for thinking they'd be fine.

concealer404

iTrader: (3)

I think the guy who was helping you press them in doesn't know much about cars.

flier129

iTrader: (7)

Like we discussed yesterday, I've had ES poly in my diff for ~7 years. Along with many RA T3 curb jumpings, diff has not broken yet. You good fam

concealer404

iTrader: (3)

Marcus jumped my car with delrin diff bushings. I don't think the diff broke, but i haven't looked. On the other hand that was 2 years ago and i imagine i would have noticed something.

gooflophaze

Sorry - I was imagining a street curb. But the statement stands - if it's a strong enough jolt to break a mount, it won't matter if it's poly or rubber.

matrussell122

iTrader: (1)

Dont hit curbs

concealer404

iTrader: (3)

Do you even drift, bro?

Morello

You willingly let Marcus drive your car? Lol

So, poly diff bushings it is. Thanks all.

Your Drunkle

Always hit curbs (on the race track)

Gee Emm

So, no data.

I know about the notch. I raced for years with poly diff bushes, using the kerbs aggressively - no broken diff. The only broken diff I know about first hand happened when a car got rear-ended and the diff was hit by the other car.

k24madness

iTrader: (6)

Someone explain to me how hitting a curb is going to snap the carrier housing? That is not a moving part of the suspension.

I can see having crappy OEM engine mounts that allow the weight of the engine/trans to load the diff carrier when fitted with Poly/Delrin. Not a good situation indeed.

FWIW I ride curbs all the time with Delrin diff mounts. Never had an issue. Then again I run BFW drop mounts. Prior to that I was on AWR mounts.

Savington

iTrader: (31)

I hit a kerb and broke the diff carrier once.

Physically hit the kerb.

As in, I dropped a wheel and physically struck the bottom of the diff, with a kerb, with the full weight of the car, plus any additional force from inertia.

Any kerb that can be hit hard enough with the tires to damage the diff carrier is going to **** up so many other things first that the diff carrier will be an afterthought in your repair plans.

Morello

My thoughts exactly...

sharkythesharkdogg

Most of the broken diff carriers we've seen come from bump drafting that became something closer to ram drafting.