Sliding Block Rear Suspention Castings-New Repro

**kengta** · #1 (**permalink**) 07-25-2009, 10:45 AM

Hi All,

I am doing some other work with my foundryman and will investigate the possibility of casting some sets of the 3 sliding block castings in aluminum alloy A356, straightening them and having them heat treated to spec T6;

If there is interest that turns into committed interest prior to casting.

I cannot offer machining.

I have done this process previously and those castings were successfully machined, combined with the other manufactured parts, mounted and raced on a GTV. I have original dimensions and specs for the other material requirements and for suitable rod ends and shoulder bolts, etc.

The patterns are original Autodelta parts doctored to allow for machining and shrinkage of the new castings but as such will vary from the originals, for the most part, at the extremities. The pictures show the patterns. The red areas denote surfaces to be machined and are built up for that reason. In a previous casting run the AUTODELTA script reproduced nicely. The web on the right side of the U-section is for stiffness during casting and heat treatment and is completely machined away in the finished product per the original.

Some of you may want to consider the cross piece alone for your panhard rod or watts link set up.

Given any interest I will work up a price.

Ciao

Ken

**Blue Flame** · #2 (**permalink**) 07-26-2009, 05:41 AM

Hi Ken
I'm interested in a cross piece (mine has been welded) certainly and the other two pieces to boot. PM with details if you will.

**kengta** · #3 (**permalink**) 07-26-2009, 08:23 AM

Quote:

Originally Posted by Blue Flame

Hi Ken
I'm interested in a cross piece (mine has been welded) certainly and the other two pieces to boot. PM with details if you will.

South Africa · #4 (**permalink**) 07-26-2009, 09:56 AM

Hello interested parties,

Why reproduce these items? Have you taken into consideration all the macining required to complete these items?

I do have some spare items. Find attached photographs of the items available. I do not have spare 'chassis cross members' and that is all you would have to reproduce.

**kengta** · #5 (**permalink**) 07-26-2009, 11:55 AM

Quote:

Originally Posted by South Africa

Hello interested parties,

Why reproduce these items? Have you taken into consideration all the macining required to complete these items?

I do have some spare items. Find attached photographs of the items available. I do not have spare 'chassis cross members' and that is all you would have to reproduce.

alfazagato · #6 (**permalink**) 07-28-2009, 10:01 AM

South Africa,
Could you please send me a PM with the costs etc. Thanks

**kengta** · #7 (**permalink**) 07-29-2009, 11:02 AM

I've had question about the possibility of reproducing the sliding block differential casting.

While this could be done using an adjusted original as a pattern, in this case at least 2 core block patterns would also have to be accurately made and the following machining required extensive and very precise. I would say much more so than the other 3 castings as the final gear and axel alignment is critical.

The actual casting would likely prove to be a small part of the equation. Having the core blocks made by a pattern maker would be a significant one off cost. The machining of the bearing carriers, a steel insert to carry the inner pinion bearing, axel housing mounting flanges and the bottom cover surface would be time consuming unless there was a large enough order to justify the set up and any special tooling.

I doubt there is sufficient demand to justify pursuing this further.

I have had a look at both types of diff castings and there are other differences mostly in the webbing reinforcements and of course in the location of the oil in hole and the addition of the pin plate mount. See the side by side comparion in the attached photos. The SB diff house on the left came with GTA 752507 with Dunlop axel tubes and coarse splines and the standard housing on right is NOS.

FWIW

Ken

charlino.1 · #8 (**permalink**) 08-14-2009, 04:07 PM

Dear South Africa,
I might be interested in installing this rear suspension on my Giulia Gt 1300 Junior.
how much would cost the spare parts?
are they new or are they a recreation?
thanks
charlino.1

**davbert** · #9 (**permalink**) 08-15-2009, 04:34 AM

ken

thats some fantastic reference material your posting up.

what about casting the deep fin diff sump that are found on montreal? where some of the later gta/gtam cars equipped with them

cheers

db

**andyb6** · #10 (**permalink**) 08-15-2009, 05:58 AM

Ken,

Sorry for the Hi-Jack....I have a 105 rear end that has been modified to run in the sliding block braces. It has a 5.12 R&P and the O.S.Giken lsd that is sitting on a shelf gathering dust. Somebody could buy your castings and my rear end and be up and running.

**kengta** · #11 (**permalink**) 08-17-2009, 07:45 AM

Quote:

Originally Posted by andyb6

Ken,

Sorry for the Hi-Jack....I have a 105 rear end that has been modified to run in the sliding block braces. It has a 5.12 R&P and the O.S.Giken lsd that is sitting on a shelf gathering dust. Somebody could buy your castings and my rear end and be up and running.

**kengta** · #12 (**permalink**) 08-17-2009, 08:36 AM

Quote:

Originally Posted by davbert

ken

thats some fantastic reference material your posting up.

what about casting the deep fin diff sump that are found on montreal? where some of the later gta/gtam cars equipped with them

cheers

db

**kengta** · #13 (**permalink**) 08-28-2009, 09:36 AM

I have spoken with one unenthusiastic heat treater about treating the repro SB parts from Alloy A356 to T6 as I believe were the original AD parts based on assays I did. He was driving me away with the cost. A356 must be first solution annealed and quenched and then heat treated, 2 steps

My foundry man is suggesting a room temperature self aging alloy known as Tenzaloy 713.

It is said to be a good substitute for the heat treatable alloys for large castings that are not easily treated.

Attached are data sheets for both alloys and they have quite comparable properties.

Any Technical opinions welcomed and those interested in such parts your thoughts.

Ciao

Ken

**andyb6** · #14 (**permalink**) 08-28-2009, 12:02 PM

Quote:

Originally Posted by kengta

Hi Andy, is that the axel that you got with #39 69 GTV racer? What are you using in her now and what of the Repro Sliding Block Suspension parts that I think you also got. Did it fail in any way?

Ciao

Ken

Dave Anderson · #15 (**permalink**) 09-13-2009, 10:07 AM

Perhaps a more economical solution and alternative to casting a whole new differential housing would be a cast aluminum piece that would be welded to the back and wrap around the side of a stock housing. We could mill off the rear strengthening webs at the appropriate angle (88 degrees) and a portion of the side webs where the new cast aluminum piece would be welded in. This would be much neater than welding pieces of aluminum between the webs like I have seen done.

For the differential lube filler hole, we would either drill and tap one into the aluminum or make a smaller hole for a pipe plug in the left axle tube.

Dave Anderson