Rear End Makeover: Day 1

    Well I am finally getting back in the garage.

    The car would bottom out with weight in the trunk or a person in the back seat so I was leaning towards replacing the springs. The shocks look new so it has to be the springs, right?

    Anyway I ran across a guy on facebook who offered up a kit for a 49-54 Chevy so I sent him the cash. The kit arrived so time to tear down the rear.

   I got the car up on stands and printed out the directions from Chassis Engineering. The guy states the kit is from them. Well right off I notice none of the parts look like the ones in the directions or the web photos of their kit. The bracket holes do line up so I proceeded.

    Here is a link to the kit Chassis Engineering lists for 49-54 Chevy. LINK

    Here are the directions they sent me...

Here is what they show on their site...

    I received everything in the above photo except the shock mounting bar and the shocks. The shocks were not part of the agreement and he says the kit did not come with the shock bar since the shocks for 50 Chevy mount to the bottom of the trunk floor (that's how they are on my car). I can live with that as long as the kit works. Here are the components I have...

Rear hanger with shackle

Bottom plate and bottom shock mounting

Front hanger

So lets get started.....

Here a view of how it was set up when I got it. Original springs and hangers but a different rear and pads.

    I was going to try and do this without removing the rear. I unbolted the shock and spring hangers and removed the spring.

The cardboard was to deflect sparks away from the gas tank.

 Then I used a flap disc on my grinder and ground down the factory rivets. Once I had them flush with the hanger I drilled a relief hole in the center of each rivet and tapped them out. Over all an easy job.

    So right away I have my first problem. The directions specifically tell you how to mount the hangers based on the shape of the ones in their kit, which is different than the ones I have. After playing with the passenger side front hanger I found they could only be mounted one way and match the holes. If you tried to mount the one for the drivers side it would be a totally wrong angle. So no problem. First one one. Like the directions say, only three holes match up and you have to drill the third. This told me the kit must at least be for my car.

   I attached the spring by looking at the picture in the directions. One eye curls down and one up. You can see the one closest to the front of the car has the eye turned up. Also the two spring retainers/clamps(?) compared to only one towards the back.

No problem, yet.

    But there is one that I am going to have to deal with. The center spring bolt is not going to line up with the center of the axle. The spring that was on it did not either but that one fell just in front of the pad and did not cause an issue. I have never done this kind of job before so I am not sure how to handle it yet. If I move the axle forward a little the drive shaft will then be too long and the tire would not sit center in the wheel well like it does currently. Also if I do line it up with the spring bolt , I will have to take the bolt out and flip it because currently the nut is on top and is too big for the hole in the pad??

 The other side has a round cylinder for a head and it fits in the hole.

    I decided not to worry too much about it until I get the rear hanger on. Another problem I thin I am going to run into is the new spring does not seem to line up in the existing spring pad on the axle. The original spring seemed to hit center of it but this one seems to hit off center. It is possible the rear could have shifted but I doubt it. I will have to do some measurements tomorrow and see whats going on. I may have to cut off the pads and use the ones that came with the kit. Not fun!

    By the way, the rear I have appears to be a GM 8.5-inch 10-bolt or GM Commercial. I have no idea what it came off of. The guy I got it from said it was a 3.73:1 geared posi but I have not confirmed that yet. You can find a 10-bolt 8.5-inch differential in any of these cars or trucks:

1971-'76 Chevrolet full-size cars
1994-'96 Impala
1971-'81 Buick full-size cars
1973-'77 Buick Gran Sport
1972-'77 Pontiac GTO and Le Mans
1970-'81 Chevy Camaro and Z28
1970-'81 Pontiac Firebird
1971-'77 Olds Cutlass and F-85 and Pontiac Grand Prix
1971-'79 Chevy II, Nova, Buick Skylark and Olds Omega
1973-'77 Chevelle, Malibu and El Camino
1971-'77 Pontiac Ventura and Phoenix
1971-'81 Pontiac Bonneville
1973-'77 Monte Carlo
1973-'77 Buick Apollo, Regal and Century
1980-'94 Chevy ½-ton and ¾-ton pickups
1977-'94 GMC Jimmy and Chevy Blazer

A 10-bolt front axle was used on GM 4WD vehicles as well. It was available in three ring gear choices. Axle codes were GU6 (3.43:1) GT4 (3.73:1) and GT5 (4.10:1). You can find a front 10-bolt in these trucks: 

1977-'87 K and V-series half- and three-quarter-ton Chevy pickups
1977-'91 Jimmy and Blazer 4WD
1988-'97 K1500 and K-2500 pickups 

    OK, back to the job... I moved on to the rear hanger. I ground those rivets and removed the hanger. I had a little more trouble getting to these with my grinder. Between the exhaust pipe and spare tire well, there was not much room to maneuver! Once off, again I had trouble with the directions. I can not use their description because mine look different. How they are mounted will determine the location of the shackles. One way sets it back further than the other. I will have to play around with it and see what happens. Also only two holes line up with my hanger and the directions kind of match that. They are not real clear on that.

I ran out of time so I cleaned up the garage and put everything away.