The Stovebolt Site Forums The Shop Area Driveline 58 stepside with STRANGE rear end

I purchased a 58 step side VIN-3A58B1044954 and have begun restoration. Discovered that the rear end
is not the normal. It has 2 sets of leaf springs and shocks with coil springs. The brake lines (mostly rotted or gone,
but is not kosher. Only the front brakes were connected, but the line to the rear was on the Driver's side!
The flexible assembly is on that side with bracket welded to rear axle. There is no hardware for brake line on
passenger side. There is no evidence that there was ever a brake line on the right side rear?

Extra springs

Drivers Side

Passenger side

Has anyone seen something like this?

Those extra leaves are overload springs that engage the frame when the normal springs compress enough. The PO probably put the coilover shocks in an attempt to increase the load rating. You might check the axle housing to be sure it's not bent from being overloaded.

On the brakes, there's typically only one hose between frame and axle and a hard line between the backing plates on the axles.

Coil over shocks are a bad idea IMHO, I had them on the front of my 3100 and the upper shock mounts were broke on both sides. The shock mounts are not designed to hold the vehicle weight or payload IMHO.

I agree. Shocks are easy to replace. Overload springs are a bit more difficult. Leaving them in place won't hurt except they add weight.

You probably should bring the rear springs back to original configuration.

Yes rear of truck is "modified". Who knows why. Diff does seem to be a drop out style, so may be original. PO decided to run tube down left side during some kind of swap.

Brake lines 55-59: A tee at rear of master cylinder, one tube to front left wheel, one tube toward rear to next cross member. Across front of that member to another tee. One tube to front right wheel, one tube down right frame to rear frame mounted transition bracket. Transition to rubber hose. Rubber hose to a tee mounted on axle tube bracket. One tube to right rear wheel, one tube up and over diff cover to left rear wheel. That will be Kosher and correct.

The differential has a stamped code on the right side looking from the front - AF412. There are NO IDs on the axle shaft.
As for the brake line mystery, there is a bracket on the left side attached to the frame with a big rivet. There is NO evidence of
any such bracket on the right side. I have done some searching online without luck on a differential code AF412. any ideas?
Joel

First of all, a truck has a left side and a right side. It also has a front and a rear. It also has a top and bottom. So lets not get into "right side looking from the front" jazz. The right side is the passenger side and the left side is the driver's side

There is a code of AF for a 62-64 diff. It designates a 3.70 ratio. The rest could be a date with 2 as 62. This is all a guess. There are plenty of other numbers on that diff. They are covered up by paint, grime and some are stamped and some are cast. The stamped can be hard to see.

The question now is: What are we trying to figure out about this diff? What do you want to know and what are you going to do when you find out? You already know it's brake plumbing needs redone. You can figure the ratio. The era can be determined by visual comparison to other diffs and their covers. The shock mounts look correct from what I see. The helper springs were offered as a RPO. As said, it looks like a drop out, which is period correct (55-62). So what do you need? If you strip it down to find all the cast and stamped numbers you will then be able to research it down to detail. If you don't, you won't.

The 62 would have trailing arm rear suspension. Started in 1960. I don't see any signs of trailing arm brackets so probably a pre 1960 diff. Maybe even a 1958!!!!

The axle shaft is inside the axle tube. The markings are on the axle tube and possibly some in the webs of the dropout center section.

I agree that the riveted-on brake bracket looks original. But it was on the other side for 1958. So the only answer is it's some other chassis or a right hand drive frame or not a 1/2T or the guy had a giant rivet tool......or there is always the excuse: The Canadians did it.

I'm sure this is not a Ford 9"? What is the lug pattern? Does it have a rear cover on the diff?

That looks just like the rear end on my 59 1/2 ton. Mine doesn't have the helper springs ( the second set on top). The brake line is on the left side(driver side ) of the frame, goes to a bracket on the frame. Changes to a rubber line from the frame to the rear end itself, then into a t fitting and then to each side of the rear end. The coil over springs are just some kind of helper spring, get some regular shocks. You can remove the upper set of springs also they are just for extra capacity.

Well then I'm baffled. 55-59 Assembly manual shows line crossing over to right side. TF's had line crossed over went back on right side. I don't have an explanation. The AD's go to diif on right side. The 60-66 go to diff on right side. 67-72......go to diff on right side.

My experience is that in many 58 and 59 3100's, the brake line feeding the rear brakes is run down the left (drivers) side which was apparently a change from 55.2 thru 57 in which that line was run down the right (passengers) side. Again, from my experience & I have worked with several.
Delky Dave in WYO

Dave, You are indeed correct. Thank you for posting that. Thanks to Tommy also.

It would be interesting to read the 1958 Chevy Truck Shop Manual Supplement. I have a 59 Supplement and it says the only major design change to 1/2T brakes was rear shoes changed from 11 X 1 3/4 to 11 X 2.


1959 Chevy Panel truck Pics below.

Sorry for my absence - surgery and recovery. I should have mentioned that the factory assembly manual clearly shows right (passenger) side rear bracket and brake lines front to rear on that side. I got the brake lines from Jim Carter and found that they are designed for the rear bracket and lines are on the left side with a separate line from the left front to right front via tee. Also,
before I found that manual seems to be wrong, I purchased a brake tee that I could modify to attach to the Right side frame.
I got it from Pacific Boat trailers (www.pacifictrailers.com) bracket # 7812. It works great on the left side. I stripped down the diff and there are no other markings except for a coded date on the side of the brake bracket. Brake line problem solved. My diff is in very good condition, one seal needs replacing and I was curious because It did not match what I found on this site.
My diff has 10 bolts.
Thanks for verifying that left side is correct!
Joel

Joel, note that the FAM is actually from 55, so not "wrong", but not entirely applicable to 58, as Dave sez

Bill