1966 coronet 2dr sedan general overhauling

[Ugk]

Nice car. Not to many of those around.

 

[Cranky]

This is the way my 66 Belvedere sat.....the rear was already low due to tired springs and I lowered the front down to give it a bit of rake. Looks like they are both close to the same color. Nice job you're doing on yours!! Wish I had a better pic of mine.

 

[Basoline]

I've been privileged to ride shotgun in this very nice car. Tell 'm about the dyno Antoon. Tell 'm!

 

[Thedeputy]

Indeed that was a lot of fun. check out the youtube links and one of my other topics below.
http://www.forbbodiesonly.com/moparforum/threads/440-power-reality-check.119755/



Enjoy,

Antoon

 

[Thedeputy]

This week I went ahead with the leaf springs. I had installed the new 'hemi' leafsprings to check how much they sagged and how much lift they would need to come up to the ride height I'm looking for. I measured it and made a small drawing of what I had. the next step was get the off the car and see how they act when there's no load on them.

 

[Thedeputy]

I calculated that the front eyelets should be raised about 4,5 cm and the rear about 8 cm. So I disassembled the springs and traced around each individual leaf. That way I was able to determine how much each leaf should be raised in perspective to the total amount of lift.

Next up will be the task of setting the arch of the springs.

 

[Thedeputy]

I haven't had the time to re-arch my springs, but in the mean time I did pick up two 8 3/4 axles from a dodge truck and a dodge Van. I need to use the 489 casing to change the current 741 3.91 sure grip to a 489 3.23 sure grip.
I was hoping for a saleable 3.55 sure grip or something but sadly it's an open 2.76 :-(

The axles:

 

[Thedeputy]

The disassembly of the 489 pumpkin went smooth.

 

[Thedeputy]

I also test fitted the 'new' 11 x 2,5 backing plates and found out one of them took a hit sometime in history. To determine where it needed to be tweaked I temporary installed it on the axle and measured the run out with a cheap tool. A few blows with a BFH cured the crooked backing plate.
They can now get cleaned, blasted and painted.

 

[Thedeputy]

Yesterday I had some spare time to give the springs the lift I calculated. I used a big press and pressed down every 2 inches. The result is in the pics. The next step is to temporarily assemble and install them on the car to see if my calculations were correct.

 

[Thedeputy]

Today I went to work to install the springs temporarily. I first assembled them and checked the arch on the cardboard. They have more lift than I anticipated. When installed however things are looking good. The body now has 7 mm more lift than calculated. That means I just need to jump on the individual leaves a bit to lower them a little. Then they can be painted and they are ready to install.

 

[Thedeputy]

Now that the springs are sorted out and just need te be cleaned up, painted and assembled I'm going to start the next upgrade. The rear end gears.
Since I need to order parts, which may take a month to get here, I first need to know what to order. If I disassemble it now and finish up the springs while the parts are underway everything keeps going.

Anyhow, lets have the pics do the talking.
I removed the rear axle and took out off the brakes and half shafts. The 10" brakes seem to have been serviced recently. I'm going with 11-2,5" brakes so these are for spare. One small issue I found was a previous owners cheap way of reparing a worn thrust button.

 

[Thedeputy]

The rear end now is a 741 3.91 with a power lok sure grip. Apart from the issue with the thrust button it looks pretty good.

One question, How can I determine if I need to replace the clutch pack? There is some scoring on the clutch disc surfaces but it doesn't seem to be very deep.

 

[Cranky]

Spread the clutches and plates out and post pics of them but since it's apart this far, why not just install new ones? On the thrust pin, might not be a bad idea to just install the Green bearings and do away with the pin. Then you can grind off that weld but I'm wondering if the axles might be on the short side and the weld was done to add the needed length? Do the splines look like they been engaged all the way into the splines of the clutches?

 

[Thedeputy]

Here they are. The scratches are deep enough to scratch with a fingernail. They are primarily on the dished discs. I don't plan on driving the car a lot and when I do it will see only street duty on narrow roads with lots of curves. I read online that a new clutch kit could result in a strong locking action causing excessive tire wear? My point is, if it's still reuseable I would like to do that to keep the cost low.

About the welded-on thrust button; It appears the splines were fully into the spider gears. The adjustable passenger side mounting bracket was turned almost fully in and the thrust button seemed to have worn down on both sides. I think they welded it on to still be able to adjust axle shaft end play and give it a bit more life the easy way. I'm confident that changing the thrust button will allow good adjustment.
Or is it perhaps possible that later style axle shafts for a solid thrust button don't match with the earlier style thryst button?

I'm not a fan of the non-adjustable green bearings. I prefer the strong original tapered design, especially because I only use it as a street car. Luckily I have a complete set of axle shaft bearings so that's not a problem as well.

 

[Cranky]

Unless you have a way to check how much grab it has, I would replace em....and if your axles are the right ones for the rear end and it's the right one for the car (66-67), then things should be right. Give Dr. Diff a call and talk to him about your concerns on the replacement parts making it too tight and he'll work you through it....and yes, there's a tight set up and one that's not so tight. This is how I check em....cone type or clutch....I stand on the bottom T bar and grunt on the top one. They are made from and old set of axles.

 

[Superfreak]

Very nice work you are doing.

 

[Thedeputy]

Thanks.
I mailed Cass from DoctorDiff today and he advised me to change the clutches. I'm going to order it along with a rebuild kit for the 489 and add an additional inner pinion bearing to make the pinion depth adjustment a little easier.

 

[Cranky]

Thanks.
I mailed Cass from DoctorDiff today and he advised me to change the clutches. I'm going to order it along with a rebuild kit for the 489 and add an additional inner pinion bearing to make the pinion depth adjustment a little easier.

I took a used but good rear bearing and honed it to be a slip fit for setting up. The wear difference between a used and a new one is very small and so far they've set up quiet. I'll check the depth with the new bearing and I never get more than .002" difference.

 

[Thedeputy]

That was my plan as well. I set up another 741 casing like this years ago and it ran great.