Sway_NV

iTrader: (3)

Just dropped my car off at the shop to have the rear gears swapped but I won't be able to pick it up until late this week... What was your suggested break in for the gears? I heard you need to keep it under 60 for the first 100 miles... But I have a 112 mile trip home from the shop soooooo that worries me :/

chuckie311

iTrader: (3)

where did you hear that!
I drove mine just like I always do..
make sure you change out the gear oil after 500 miles
are you putting in whiteline bushings as well?

Sway_NV

iTrader: (3)

" Vehicle speeds should stay below 60 mph for the first 100 miles. Drive the vehicle 10-20 miles, stop and let cool for 30 minutes. Repeat this process at least 5 times before driving the vehicle at highway speeds. Do not abuse or dump the clutch or do any hard acceleration, let the ring & pinion bed-in gently. If you take it easy on a new ring & pinion and perform regular oil changes it will last much longer. Use caution when letting out the clutch, as aggressive high rpm clutch dumps can fatigue parts and may lead to eventual failures." - that's basically what I was told, quite via google result for rear gear swap break in...

Yes, I got the 4.083s, the seals and bearings, and whiteline bushings... Thought about SPL solid mounts but ended up getting whitelines since my car is my DD

Roadrash666

iTrader: (1)

[QUOTE=Sway_NV;3938734]" Vehicle speeds should stay below 60 mph for the first 100 miles. Drive the vehicle 10-20 miles, stop and let cool for 30 minutes. Repeat this process at least 5 times before driving the vehicle at highway speeds. Do not abuse or dump the clutch or do any hard acceleration, let the ring & pinion bed-in gently. If you take it easy on a new ring & pinion and perform regular oil changes it will last much longer. Use caution when letting out the clutch, as aggressive high rpm clutch dumps can fatigue parts and may lead to eventual failures." - that's basically what I was told, quite via google result for rear gear swap break in...

No. Gears do not 'bed in'. Drive it like you stole it and change the oil after 500 miles like chuckie311 said.

chuckie311

iTrader: (3)

You'll love the gears!! and you hear a bit more noise with the whiteline bushings but it's normal.. Once you get the car back and drive around a bit chime in for a review

PongSanity

iTrader: (5)

I just drove my car like normal. I didn't race or do any burnouts for a min but I didn't measure my driving distance nor speed. I swapped my bearings/seals for some fresh ones and added white line bushings. The white line bushings is the no wheel hop mod.

Sway_NV

iTrader: (3)

Glad to know I have nothing to worry about then, I think I'll still take it easy for the first 500 miles just to be safe. Then after I change the diff fluid I'll let it rip and definitely do a full review! I'm excited about this swap because ever since I put those heavy yet beautiful 20" Vossens on the car feels a good bit more sluggish. I'm hoping these rear gears will make up for that... How is swapping the diff fluid in our cars? Easy DIY job or no? I mean I'm not a mechanic, but I can change oil, spark plugs, install an intake, install rotors/pads etc...

chuckie311

iTrader: (3)

Super easy to drain and fill..their might be a DIY on here or the370z site fill plug is on the top right and you'll need one of these to fill the fluid back in..

WillCo1

I heard nothing or read nothing about a break in period.

Specialty-Z never mentioned it. And they have done many gear/pinion installs.

Either the gear and pinion, all the bearings and seals are installed perfectly or they're not.

If the exact needed shims aren't used and the proper lash isn't set, then you could get gear whine and even worse - diff failure.

Specialty-Z filled my diff with Redline Synthetic Gear Oil so I think I'll be good for a while before I change the oil again.

After my install I drove straight home from Chatsworth, CA to Las Vegas.

Having said all that, it doesn't mean you shouldn't take it easy for the first few miles if you want to. Won't hurt.

Sway_NV

iTrader: (3)

Brought the car home today... I'll break it up first for you speed readers.
Stock 3.69 --> 4.08 gears + whiteline bushings
Told to take it easy for the first 250 miles.
Advised to change diff fluid after 500 miles. (Shop offered to do it for free)
135 mile trip home.
Cruised at 75mph and just a smidge above 3k rpms.
Averaged 25.4 mpg.
No gear whine, feels and sounds like OEM quality.

I did think I heard some gear whine once while on the decel and in gear... But I think it might've been in my head because I never heard it again and it sounded like it came from the front of the car. Idk

So obviously I haven't opened her up yet, but I'm anxious to. I'm going to listen to their 250/500 mile recommendation, can't hurt. As far as acceleration she feels the same as she did before the gear swap... With the exception I was only using 10-15% throttle instead of 30-40%

I'm very curious how she feels at wot and launch now... But I'm still thinking about those heavy *** wheels lol.

I'll do an update in my build thread after the break in period to add more on my thoughts.


https://www.myg37.com/forums/build-t...c-heavy-3.html

Edit: my old gears look perfect, like new. Idk if anyone buys used gears, but if they do, how much is reasonable? They look fine so id list them for one of the at guys to grab