rear axle; 3.0cs and CSi differneces?

[eriknetherlands]

Hi all,

I am planning to rebuild the rear end of my '73 CS (originally sold in May '73 in switserland, with carbs and all wheel discs) as the body near the subframe mounts are rusted. It's an original carbed with 4 wheel dicsbrake car.

I now have the option to purchase a rebuilt rear subframe with revised brake calipers and new discs from an '74 Csi.

Are there differences in the rear axle / wheel bearings /brake setup between the '74 Csi and my '73 3.0 CS?

And, of lesser importance, any advice on how best to remove and install the rear axle with suspension parts without having a garage style car lift?
I'm opting to unscrew the rear axle, jack the body up 2 feet (i have to weld anyway on the underside) and support it by a welded frame.
The front wheel i'll probably put on 2 of these drive-on-type ramps, so it'll be more or less horizontal.

I'm just trying to prevent a squashed e9coupe member here....:-?

regards,
Erik.

 

[Tierfreund]

Only difference might be in the rear diff gearing (I believe some market CSIs had longer gearing). Anything else on the rear of the 3.0CS and CSi is the same. Only the 2800CS had a different setup (drum brakes etc.)

 

[Sven]

Erik,

There are not any really good places to support the coupe at the rear while removing the main cross member. I used the area immediately in front of the main cross member bolts (at the location where the two bolts secure the ~30 cm support plates - running from the cross member bolt to the underside) and as close to the pinch weld as possible. As this was one of the first things I installed, after body/paint work, the rear of the car was still very light. Another option is to leave the rubber bushings in place and unbolt the cross member bolts (4 on each side). That way you place jack stands under the bushings.

With the drive up ramps is there a way to keep the car from rolling off as you raise and lower the rear end?

good luck,

 

[siscobmw]

I saw csi with 3,45 and 3,25:1 diff ratio, cs only with 3,45:1....the only difference I know about CS/CSi rear axle.....
Francesco

 

[eriknetherlands]

Thanks to all & some answer to your questions.

Hi there,

Thanks for the feedback.
Based on your replies i'll go ahead and check out the offered rear suspension.

Would it matter if i installed a different diff? I'm not sure which one i have and which one is offered, and how many different versions actualy exist.
My car is 3.0 CS build may '73. I think it then has a 3,45:1 ratio. The donor car is a '71 CSi. If the '71 Csi's ratio is different, what would change? Would i have higher or lower revs on the highway? (i'm using it as a daily driver; Comfort (lower revs) are favoured over acceleration / sportyness.

To answer the questions from you;
- regarding the support of the rear; As i have to fight the rust monster at the location of the rubber bushes (under the rear seat) i'll have to keep this space free as well. So i have been thinking to use 2 wooden 4*4 beams on the left sill parallel to the flange and the same on the other sill. When long enough, they should spread the forces and prevent dents ; i hope. I'll supoprt the wood with steel, and let it hinge (bush&bolt)on the top of the axle stands that i'll be using. I'll probably brace the two axle stands to prevent them tipping over. By the way, there are no covers on the sills, they appearently went Missing in Action during the restauration by the previous owner.
- the drive up ramps have a flat surface with a "saddle" to hold the wheels + an end stopper to prevent driving of the other end. Maybe i'll even connect them to the axle stands i'm using to support the rear.

Regards, Erik.