IRS upgrade pics

[HRPufNStuf]

I have an 89 780 with IRS..3.73 open diff and no provision for rear bar. (I do have a custom set of brackets to mount one currently)
After the M90 swap it has great acceleration, but a little loud on the open road.
Solution.(hopefully)

IRS from a 92 964.

http://s140.photobucket.com/albums/r33/purchasepwr/?action=view&current=rearirs.jpg

Started breaking it down this past week to replace a few bushings and generally clean it up.

http://www.we-todd-did-racing.com/view/1007986_ykspx

Found diff serial number and it definitely says 3.31 and cross checking it against VADIS showed it was a autolocker. cracked off the rear cover to check number of tone ring slots and it has 48. 88-90 was some crazy tone ring time and I'm hoping the one in my 89 currently is a 48 and not a 96 tone. I just received the Volvo green book for axles that covers 82-98 and it is a little vague on change over for the indivual types.

This pic shows the IRS mounting holes and slight extension to the frame for the IRS bar.
http://www.we-todd-did-racing.com/view/1007980_61ysg

This pic shows it definitely is an auto locker.

http://www.we-todd-did-racing.com/view/1007981_c8iky

Other swap that will be required is the removal of the crazy CV joint input flange and replace with the flat flange currently on the car compatible with the 780 M90 driveshaft. 960 has a nice aluminum cover and a filter assembly built into the cover which the green book states was designed to never have to change fluid.

[impulse922]

are the gears swappable between the two?

example: i want 3.73 to replace the 3.31 out of the 960( i want a locking diff)

good luck on the swap, and props for being the first

[HRPufNStuf]

I don't think they will swap. Most diffs I've seen usually need a different sized carrier around the 3.31 change over size.
The green book does say that the 1045 came in 3.31(not until 92) 3.54, 3.73 and 3.91 in the US, so I would look for one of those complete before trying to swap gear sets.

When looking for a replacement 960 axle, look for part #1216421 or 1216423 on the axle tag as they should indicate 3.73 auto locker from VADIS.



are the gears swappable between the two?

example: i want 3.73 to replace the 3.31 out of the 960( i want a locking diff)

good luck on the swap, and props for being the first

[impulse922]

is it possible to check if those were just on the 95+ models?(because they DID get 3.73s but i think the arrangement of the rear end changed

[HRPufNStuf]

My green book was published in 1990 and specificies includes all modifications up to and including August 1990. so everything I quoted above from the green book was available in the US market before Aug 1990.

Also the late models were specified as 1055 IRS diffs(95+) rather than the 87-90 1035(open diff) and the 91-94(?) were specified as 1045. According to VADIS diff changed in 95 ...V90/S90 in the US market were equipped with pumpkins denoted as 1055 and were available in 3.54, 3.73, 3.91, 4.10.

95+ diffs were also available in 1065 flavour in 3.73, 3.91 and 4.10. and they look an awful like the rear diff in my old 98 V70R and my dads 97 AWD 850 wagon...Both 1055 and 1065 appear to have been available in both sedan and wagon.




is it possible to check if those were just on the 95+ models?(because they DID get 3.73s but i think the arrangement of the rear end changed