S3 Rear Tub Cracks

[Snapperpaul]

While replacing the diff with a Quiafe ATB and just after I had got all the bolts in, I noticed some cracks.

The top tunnel plate extends through the rear bulkhead under the boot floor, it's a wide but short flat U, there are cut outs for the Sierra A member and for access to diff bolts.

The side parts either side have bowed out and cracked vertically.

To fix this I have cut lengths of 25 x 50 box and run 2 down the outer face under the floor, these will bolt through the floor and the outer face of the U. Another piece goes across inside the U at the rear and a fourth goes inside the boot tying in the 2 main members and the front bolts of the diff mount.

This should hold it all together for another season, if problems persist after this its a substantial rebuild.

I have still plans in place to fit a Haynes Roadster rear with double wishbones and at this time will tie in the whole car to the rear cage/subframe.

I am now 2 days behind schedule for my first Essex kit car club run out to Chatham Dockyard festival, don't you just love owning a Robin Hood

Edited March 8, 2015 by Snapperpaul

[cb750]

Sorry to hear that Paul, they crack in enough places already ! My floor had taken on a slight bulge just above the diff when I bought it. I fitted a reinforcing plate from 3 mil steel across the area with load spreader plates underneath the floor all bolted together to try to stop the channel from flexing.

 

Mine's still sound at the moment but I am going to keep an eye on it when the car is back on the road

 

Rob

[Snapperpaul]

 

 

13 ½ hours of my life and I'm back to where I started Saturday morning, still no diff in

Edited March 8, 2015 by Snapperpaul

[Guest Ian & Carole]

With a car weighing in at the same as a Granada .

 

Need that new engine in there now Paul.

[Guest mower man]

I have a drawing that adresses this and coilover fitting free copy if you send your Postal address mick

[Snapperpaul]

Thanks Mick I think I've got it already

As you can see I've done the job, possibly the problem will move elswhere, I'll keep checking and push plans forward for the double wishbone rear end