Questions on OSG diff install.

[shadow85]

Got my brand new OSG LSD for Auto 370Z. It will be replacing the Quaife in my Z.

Got a quote for a professional install by a high performance Differential and gearbox specialist. Quote to install is $2K.

They said they will do the following:
1. 370Z differential rebuild: Strip and inspect Chemical clean components Install Customer Supplied OS Giken LSD Set bearing preload Set pinion height Set crown wheel backlash Check mesh pattern Reassemble to factory specs.

2. Genuine Nissan Bearing & Seal Kit - inc Crown Wheel Bolts & Pinion Nut

3. Custom Solid Pinion Collar - for added Strength and Reliability with High Horsepower

4. Shims

5. **OPTION - FOR HIGH HORSEPOWER APPLICATION** Peen and Polish crown wheel and pinion: Crack test Demagnetise Shot peen to SAE J2441 guidelines Isotropic Super-Finish approximately 30% fatigue resistance improvement

I am just wondering, is all this necessary or will I be paying too much?

I asked if the strip and inspect is necessary on a brand new diff, and this is their reply:


"This quote is based around a complete rebuild/upgrade + installing your supplied LSD. As you are running higher horsepower than most, while upgrading the LSD, is it the ideal time to do what we can to strength/future proof the diff as much as possible. So to complete a rebuild and replace the bearings the diff will be entirely stripped down.

Even if we do not complete a full rebuild, we still list the strip and inspect as a process. This process means that we open the diff and strip it as far as required to do the work.

For example for even a basic LSD install we would perform a crown wheel pattern and back lash check as a part of the strip down. Also, as the OS Giken LSD can have customised settings internally, we would do what is required, in consultation with you, to ensure that it is adjusted internally to operate in the best fashion to suit your usage."

It doesn't seem like anyone else here has gone to these measures when installing their diffs, I tried searching some diff builds here. What do you guys rekon?

[BGTV8]

This is exactly what has been done to all my diff's (Nissan and non-Nissan race car). Checking the lash is mandatory, putting in new bearings and replacing the bolts the same - esp in a turbo'd car. Shot-peening is also something I do on my race car (~530hp running 290/625x16 slicks) for longevity following a CWP failure over 20 years ago. The 4.08:1 diff to go into my Z34 has been set up in this manner as well

Modifications "cost".

[shadow85]

Ok thanks. So i guess its worth having all this done.

Just curious, because I don't recall the original shop doing this on the Quaife install when I had that done.

[Hotrodz]

This is exactly what I had done for my OSG install.

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[Hotrodz]

Originally Posted by shadow85

Ok thanks. So i guess its worth having all this done.

Just curious, because I don't recall the original shop doing this on the Quaife install when I had that done.

Some of what is listed should be done for yours as helical diff. It is the not a clutch diff which requires more tuning in a since than helical diff.

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[Rusty]

When I did my install. I checked the back lash and toe pattern before I tore it apart. Measured the shims. Installed new bearings on the carrier. Put everything back together. Checked back lash and toe pattern to make sure it good. It's been good.