Final Drive Discussion

[BRZoomTX]

Originally Posted by Mild2Wild

I'm at 500 already, so there's only one way to go... But I don't use the car for hard launches. Spoke with Weir today and he didn't think the m85 was any stronger than the stock unit; he suggested that I find a 3.73 from the non-locking diff and send it all to him for a refurbish.

Oh, well one thing I can guarantee you is that a m85 is much stronger than the stock BRZ rear. I know guys who have blown up the stock rear end who switched to m85's, and have yet to have problems (all 400+ range).

[Bobster]

Bump! Anyone running Weir performance FD? Are they quiet enough for a daily?

[RichardJ]

I have weir's 4.88 on my AT.
There's an audible whine around 50-70kph while decel.
It is not disturbing and it is quite subtle.
I love the sound tho

[fika84]

Originally Posted by Bobster

Bump! Anyone running Weir performance FD? Are they quiet enough for a daily?

Definitely quiet. Most of that depends on who installs it though. I did it myself and can vouch for the need to take it to someone who knows what their doing and takes the time to measure out the bearing preloads and gear contact patch. If preload or contact patch aren't within spec you'll get noise and premature wear.

[jcw99]

my 4.56 is quiet on decel and a bit noisy the rest of the time--there are a number of members who have posted having no noise at any time

[Bobster]

Anyone know whats causing the noise?

Is the M-Factory quieter?

[kingkenny]

Originally Posted by Bobster

Anyone know whats causing the noise?

Is the M-Factory quieter?

Pinion clearance need to adjust with proper size shim to minimum the noise , but it is rotation noise you can never get ride of it completely , generally shorter the FD ratio and louder noise .


After a year running the FD , I upgrade the LSD and install Cusco Distance Collar with Nissan shim set and the diff. is much quiet than before .


I notice a few thing when I did these , oem distance collar(Pinion Spacer) can compress a bit by torque it down more less , therefore easier to adjust clearance but the Cusco one is a different case and it simple don't change any when I torque it down . If I do it again , whenever I open the diff. , I would upgrade Pinion spacer again , I suggest anyone doing the FD or LSD should have it .

[#my86build]

I just had my Cusco 4.556 installed a couple of weeks ago. Here are the parts my local shop used in the installation. No new noises to report on mine. That could be the due to fact that it is a Toyota part, it could be the shop that installed it or it could be both. I would also recommend shopping around. I believe FT-86 Speedfactory has theirs marked up $200 USD more than where my shop ordered mine from.

1) Toyota Diff Washer Plate $13 CAD #90201-35518
2) Toyota Diff Case Seal x2 $15.40/per CAD #90311-38070
3) Toyota Diff Shims x2 $18.92/per CAD #90564-46043

[jefri91]

Originally Posted by RichardJ

I have weir's 4.88 on my AT.
There's an audible whine around 50-70kph while decel.
It is not disturbing and it is quite subtle.
I love the sound tho

So it's a nice sound? Not something like that'll give you a heart attack everytime you gear?

Got an auto and thinking of also doing the weir's 4.88. How are you liking yours?

Sent from my HTC 10 using Tapatalk

[SpectreRT]

I've got a Weir 4.56. It can get noisy. Shop (@PTuning) spent a considerable amount of time to get it as perfect as possible. Its louder than OEM because of the type of cut in the gear, and its thicker/stronger than OEM.

I'll get a recording later today if you're interested.

[RichardJ]

Originally Posted by jefri91

So it's a nice sound? Not something like that'll give you a heart attack everytime you gear?

Got an auto and thinking of also doing the weir's 4.88. How are you liking yours?

Sent from my HTC 10 using Tapatalk

Yea it's personally a pleasant sound lol. Nothing too bad I think.
Driving around town is improved with more wheel torque. When I full throttle in 1st gear I have slight wheel spin with 245's all around.

[Icecreamtruk]

Originally Posted by SpectreRT

I've got a Weir 4.56. It can get noisy. Shop (@PTuning) spent a considerable amount of time to get it as perfect as possible. Its louder than OEM because of the type of cut in the gear, and its thicker/stronger than OEM.

I'll get a recording later today if you're interested.

Weir 4.88 also has a small sound to it. 18 months of street driving and 13 track days (2h to 3h of track time per track day) tells me that the sound is normal, since oil doesnt come out with metal pieces and the sound hasnt changed at all during this time.

[Teseo]

Originally Posted by SpectreRT

I've got a Weir 4.56. It can get noisy. Shop (@PTuning) spent a considerable amount of time to get it as perfect as possible. Its louder than OEM because of the type of cut in the gear, and its thicker/stronger than OEM.

I'll get a recording later today if you're interested.

As long dont fall apart, im ok with sound/noise.
Video will be helpfull if you have time for make it

[fika84]

Originally Posted by SpectreRT

I've got a Weir 4.56. It can get noisy. Shop (@PTuning) spent a considerable amount of time to get it as perfect as possible. Its louder than OEM because of the type of cut in the gear, and its thicker/stronger than OEM.

I'll get a recording later today if you're interested.

The type of cut is the same as OEM. Look at them side by side, exact same cut, different number of teeth to create different ratio.