Topic: Please educate me on the Solstice differential

[Acadian]

I am looking of a used positraction rear end, as i have a 2006 , the differential i am looking for should not have the torque arm mounting bracket.


does every gxp had the torque arm ?
does the manual transmission equipped solstice ( gxp or na )have this feature ?
does all automatic equipped solstice regardless  (gxp or na) came without the arm ?

I want the most recent locking diff that i can get that is bolt on for my 2006.

a little unsure if i should get the same gears as i currently have (3.91) since i am running a ddmworks stage2 on my 2.4l .
Anyone tried 3.73 with this set up and his willing to give his opinion

thanks

[Sol Asylum]

Not sure I can answer all your questions but I can answer some so here goes.

The torque arm was developed for the GXP so to the best of my knowledge all the GXPs had it.  At least the manuals have it I am not sure about the autos the shop manual isn't very clear as to which cars will have it, they call the arm the "driveline support."

The dif mounts into the car the same regardless of if it has the torque arm.  The arm is just a bracket that mounts to the dif and the trans.  I am not sure if the mounting holes on the trans were something that was also added to the GXP or if they were already there.  You should be able to mount a GXP dif to an NA you just won't need the arm however if the mounting holes are already on the trans I would get the arm too.  The big difference between the GXP and the NA will be the gear ratio.  If you go with a GXP gear set in a NA you will cruse at a lower RPM but you may trade your acceleration time for it if your engine doesn't have the torque to overcome the added strain that the change in ratios will cause.  However since you have the SC 2.4 you probably will have enough HP/torque to make this negligible.

[JRinKY]

I do not have the information here, so I am working from memory. I think that the torque arm replaces the front drive axle mount. If the unit you find had a torque arm you will need to find the front mount to bolt on.

I wouldn't hesitate to change to the 3.73 with the stage 2 SC. You might also look at CTS drive axles.

[Critterman]

Talk to Dave and Randy about this.  you should be able to handle the ratio without a problem, and believe the 1st half of the 07's didn't have the torque arm

[Dirkdaddy]

I have a used posi rear diff for the Kappa, as have a project car where I am building one from two front end wrecks.  Its NA, but I'm thinking of swapping to the NA for my RL conversion and would then be able to sell the RL version.  You can PM me regarding this - Cheers,
Scott

[Hal 9000]

After going through two 06 diffs, I can tell you that the differential used on the 08/09 automatic GXP's and N/A's is the same, and it will mount on an 06.  That's what my third differential is and it has no clunk or whine issues.  It has a stouter arm connecting to the front mounting point.

Manual diffs after the addition of the torque arm in early 07's will not mount on an 06, at least not easily.

I just saw one of these auto diffs at performance autowerks.

Here's the link.
http://www.performanceautowerks.com/catalog/product_info.php?cPath=158_168&products_id=1659

[JRinKY]

Hal9000: After going through two 06 diffs, I can tell you that the differential used on the 08/09 automatic GXP's and N/A's is the same, and it will mount on an 06.  That's what my third differential is and it has no clunk or whine issues.  It has a stouter arm connecting to the front mounting point.

Manual diffs after the addition of the torque arm in early 07's will not mount on an 06, at least not easily.

Now I'm confused. I have always thought that the autos and manuals used the same drive axles, and the difference was between NA and turbo. This sounds like you are saying that automatic NAs and turbos use the same drive axle. If so, which ratio ?

Literature I saw from Getrag made it look like the drive axle housing was changed when the torque arms were added to give the arm a mounting point. For applications without the arm, a mount is attached that duplicates the mounting of the pre-arm units. Is this not correct ?

[Hal 9000]

Believe me, it's a confusing subject. 

I have no knowledge of the ratios or internals of the various differential units.  All I can tell you is that the casing on newer model auto's was revised to incorporate a stronger arm connecting to the forward mounting bushing.  This casing works on all Solstices without the torque arm.

Here's a pic.



The one on the bottom is the newer unit.

I believe the part number is 25858219

[Critterman]

That's what I got in my 06, the bottom one

[JimmyBaja]

I have an 09 NA auto & it has the bottom one.

[JRinKY]

Hal 9000: Believe me, it's a confusing subject. 

I have no knowledge of the ratios or internals of the various differential units.  All I can tell you is that the casing on newer model auto's was revised to incorporate a stronger arm connecting to the forward mounting bushing.  This casing works on all Solstices without the torque arm.

Actually I didn't think it was confusing at all until I read your earlier post. Now I understand that it was your post that was confused, and not me.
 

[Critterman]

I guess I should have mentioned that mine was replaced.  there are two ratios.  3.73 and 3.91 I think

There are two transmission, the early model (06) has a very long 3rd gear, 07 and above have a tighter ratio

[JRinKY]

For the Kappa you are correct. 3.73 is turbo, 3.91 is NA.
The same drive axle is used in other applications with 2.73, 3.23, and 3.42 ratios.
Early Kappa housings in both ratios had an integral cast front mount.
Later housings had tapped holes for either a front mount or a reaction bar.

[Hal 9000]

Actually I didn't think it was confusing at all until I read your earlier post. Now I understand that it was your post that was confused, and not me.
 

Guess you took offense to my post.  Wasn't meant to be anything but friendly.