Topic: 1968 Shelby Rear Diff/Leaf/Shock detail

[dwdshelby]

Hi all,

I have a June 3, 1968 Shelby GT500KR (Metuchen Build) Convertible.

I have finished the unibody with much expert advice from members on this site. Thanks for that!

I am moving (after a summer break) to the rear suspension and differential detailing.

I tried searching the site for some info but didn't find so I hope I am not repeating already well answered questions.

The differential case itself with the brake plates should be chassis black. The pumpkin should be red oxide. The driveshaft guard should be argent. I think the driveshaft interface on the pinion is left a natural metal colour.

I am hoping to get confirmation of these facts but also some of the finer points - paint no paint on the pinion bolts and the pumpkin bolts - anything else I am missing?

On the leaf springs - I think they are black but I have seen pictures online with a grey or metal colour as well.

What were the shocks utilized on this car - colour and make?

I believe the rear drums are left a natural metal colour.

Thanks for all your help in the past.

Best
dwdshelby

[J_Speegle]

This will get you started

I have a June 3, 1968 Shelby GT500KR (Metuchen Build) Convertible.
I am moving (after a summer break) to the rear suspension and differential detailing.

The differential case itself with the brake plates should be chassis black. The pumpkin should be red oxide. The driveshaft guard should be argent. I think the driveshaft interface on the pinion is left a natural metal colour.

Backing plates can be a bit more glossy due to the way the black was applied - and it was done at a different location, time and different batch of paint

Main housing (rearend) face (where the pumpkin attaches) was left bare but few builders add this detail

Pumpkin has a number of machined surfaces that are left bare metal as well as the pinion support face

Yokes are natural cast iron with brighter machined surfaces

I am hoping to get confirmation of these facts but also some of the finer points - paint no paint on the pinion bolts and the pumpkin bolts - anything else I am missing?

No paint on any bolts. Don't forget the brass/copper washers


On the leaf springs - I think they are black but I have seen pictures online with a grey or metal colour as well.

What were the shocks utilized on this car - colour and make?

Regular semi-gloss black painted non-adjustable shocks with AUTOLITE, date and engineering number stamped into the outer surface

I believe the rear drums are left a natural metal colour.

A darker steel case color with machined surfaces depending on year and vendor

Since your car likely  had hubcaps no black out other other painted surfaces

[TLea]

Pinion support, pinion seal oil guard, u bolts, shock plates, brake line loop and vent  tube nipple are natural bare steel.
Leaf springs are darkened heat treated steel

I might a picture or two

[Bob Gaines]

If KR 4 speed shocks are as Jeff discribed if auto they would be autolite adjustable and painted blue.

[dwdshelby]

Thanks!

Indeed it is an automatic - so I did note the blue vs black shocks.

TLea if you have a couple pictures of the correct differential/suspension for this car that would be a great help.

I am struggling a bit on what colour or paint might replicated the proper "darkened heat treated steel" colour referred to for the leaf springs. They have been painted black sometime in their 45 year history.

The pinion support that is bare metal is where the pinion yoke is secured to the larger ring gear/axle pumpkin or where the driveshaft guard is fastened to? Just want to ensure I understand so I can communicate properly to the builder.

In that vein, is the driveshaft guard bare metal as well?

Thanks again.
Dwdshelby

[Bob Gaines]

Thanks!

Indeed it is an automatic - so I did note the blue vs black shocks.

TLea if you have a couple pictures of the correct differential/suspension for this car that would be a great help.

I am struggling a bit on what colour or paint might replicated the proper "darkened heat treated steel" colour referred to for the leaf springs. They have been painted black sometime in their 45 year history.

The pinion support that is bare metal is where the pinion yoke is secured to the larger ring gear/axle pumpkin or where the driveshaft guard is fastened to? Just want to ensure I understand so I can communicate properly to the builder.

In that vein, is the driveshaft guard bare metal as well?

Thanks again.
Dwdshelby

A easy out of the spray can alternative is eastwoods zinc phosphate spray it has a dark metallic look similar to harden spring steel . It is used by a lot of people. Better closer looks require custom mix to match. I think the best look as well as maintenance friendly is to strip and replate with gun bluing or the like and then coat with one of the great rust preventive products on the market like boe shield or the one by ECS etc. The paint will chip and start to rust at the point where the springs contact each other . Not to say you will not have maintenance issues with the assemblyline look but you can doctor it much better then doctoring a painted part on the car. there are other threads here describing the process. In any event do not short cut the process.  Disassemble ALL leafs -restore and then reassemble with new correct straps available from numerous vendors.  If I am understanding you correctly the area you are talking about is a combination of machined metal and painted metal . A picture of the area in question would be helpful. Snubber shield/drive shaft shield is bare steel.

[dwdshelby]

Hi Bob, here is a picture of the diff.

I take it that where the sticky is on the pinion face that is all bare steel as is the oil guard/yoke, etc as per TLea's post.

Thanks
Dwdshelby

[TLea]

Yes that area is machined. Dont forget the little half moon cutouts on the bottom that are bare steel plus the shim (if used) between housing and support. Here are several photos for reference. Caution to not copy paint marks as they may not apply to your car. Also your KR auto will not have separate vent hose as these do