987S MY06 vs. 986S MY03: same manual transmission?

[Kamox]

Hello,
tins is my first post on the forum and I'll start with a technical one.
I've asked the same thing on renntech.org, but received no answers, hope to get some help here :-)

I'd like to order a limited slip differential from Quaife, they list a Cayman S and a Boxster S (986) version.
I own a MY06 Boxster S (3.2 liters, 280hp).
I've downloaded from the official Porsche site the PET parts catalogues.
For the 986, *from* MY03 onwards, the replacement trasmission code is "986 300 010 22".
For the 987, *up to* MY06 (so that's the one in my car) the replacement trasmission code is "987 300 010 22" and the PET also lists a "G87.20" model code next to the replacement part code.

I assume it's the same gearbox (and so, I should order the Quaife 986 Boxster S LSD).
Am I right? Thanks in advance for your replies.

[mayes911]

i believe the gearbox is different in the cayman s 3.4 to the 3.2 boxster(1st and 2nd gears taller in the cayman so as not to whoop the 911 on acceleration)

[Kamox]

Yes mayes. And I own a 3.2 Boxster, as you can read

[911perv]

OK,, bit confused...............

You have a 987 Boxster?

You dont want anything to do with a 986 then, do you?

If yours is a 2006 Boxster S manual you have a G87.20 box

If you have a 2007 Boxster S manual you have a G87.21 box, which is also on a Cayman S


Simples............

[Kamox]

Well 911perv, my question comes from the fact that the part replacement codes are very similar... they only differ for having "986" and "987" at the beginning.
Now I know this could simply mean that those are different products, but I noticed that many Porsche part codes on fvd.de and other porsche-specific sites show that often (for example, concerning brake pads) the same part is coded differently, but it's the same thing; that's the reason for my question.
Also, if you look at the technical drawing in the PET catalogue, the two gearboxes look the same.
I just want to be sure about that before ordering the LSD from Quaife.

Edited by Kamox on Wednesday 9th December 14:58

[911perv]

Arrhhh I see where youre coming from

You are quite right on the brake pads etc, and that is easy to check and compare

The internals of a gearbox though!! Well difficult to say the least

I have no idea.........................wheres me coat?

[mayes911]

might be wrong but i thought porsche put a different gearbox on the 987 3.2 to the 3.2 986 although ratios remained the same(can check have both brochures somewhere) whereas the 3.4 shares same box as 3.2 987 but first 2 ratios different

[Escy]

I know it's an old thread but i'm going to bump it as i'm having the same issue. I have bought a used transaxle, a G87.20 from a 2005 Boxster S 3.2.

I need an LSD for it, on Quaife's website it lists the 986 and 987 3.2's as the same diff. I wanted a plated diff so I bought a KAAZ LSD from EMC Motorsport, they sold me one that they fit on the 986 S. My axle flanges are too small for the diff. They are 25mm diameter and the diff takes 30mm. That makes me think either Quaife are incorrect on their website or I don't have the transaxle I thought I did. It looks like the 987 3.2 trans but the 3.4 one looks similar, perhaps that's what i've got. Does anyone happen to know the stub axle diameter for a 987 3.4?

If it does turn out to be 3.2 trans and the diff is different to the 986 3.2 and the 987 3.4, are there any options for an LSD?

It's currently at EMC, when I collect it i'll try and get some part numbers off it and contact Porsche.

[WallyCarrera]

Hi.I'm confused by what appears to be a V6 engine?

[v8ksn]

WallyCarrera said:

Hi.I'm confused by what appears to be a V6 engine?

Me too!

[Escy]

You should have a look at my build thread in the readers rides section

[WallyCarrera]

Ah, I see. Interesting project, good stuff.

[Escy]

From speaking to someone that knows, the G86.20 from the 986 Boxster S runs the G50 differential, the G87.20 uses a G87 type differential which is different. What are Quaife doing advertising the these diffs as the same thing?