How much resistance should there be?

[CoronetDarter]

I'm sorting through some drive line and braking issues on the Coronet. How much resistance should there be turning the rear axle with the car in neutral? It's a 727 with a Dynamics 3000 stall converter; 8 3/4 rear with an Auburn LSD housing 3.55 gears. Rear axle's have been converted to green style bearings.
With the rear wheels and drums removed (to eliminate brake resistance) and the trans in neutral, it is rather difficult to rotate the axle at the studs. I know I'm losing leverage without the tire on, but I'm a big guy so I wouldn't think it would be that difficult. Feels like a lot of horsepower just to turn the axle.

 

[Kern Dog]

It sure spins a LOT easier with an OPEN diff!
I do not have a direct answer to you except to suggest that you bring the car to my place. We can put it up on the lift. We could even check my car first to compare the resistance. I know that my car was easier to push when I had a 2.76 open diff in it for a few weeks.
PM me if you want my phone number. I am working FAR out of town Mon-Fri but I can make time for you on the weekends.

 

[69L48Z27]

It’s going to take some effort, like Kern Dog said it’s hard to say. Drop the drive shaft and see what it does then. You neutral driveshaft resistance shouldn’t be that bad.

 

[OSDart]

My 68' was a bear to roll around the shop. Just back, forwards was ok. Rolled very easy both directions when I disconnected the driveshaft. I asked the guy that built the 727 if there might be issues. He said all 727's rolled easy in one direction. Guess he was not quite right. After 1200-1300 miles, I burnt that sucker up.
New one rolls easy forwards and backwards.
Like he said, drop the driveshaft.

 

[khryslerkid]

The Green bearings do have a little more resistance compared to the factory tapered roller, being the seals in the bearings drag some.

Like stated, drop the driveshaft and see if there's a difference. Should be easier to turn the yoke than the axel flanges too.

 

[Fran Blacker]

Think you should be able to turn d shaft by hand no tires and no drums.

 

[dvw]

Without the trans connected it should turn pretty easy. With the driveshaft installed it'll be tough. Especially in reverse as many internal parts are rolling in the trans.
Doug

 

[HawkRod]

Barry and I will stop by next year (Aug 2020) and check it out!

With my old (now my son's) 73 Road Runner, it wasn't easy but wasn't hard either. Hard to describe in words though. His car is a 340, 727, 3.55 sure grip with tapered bearings. I would usually grab the tires though without taking the wheels off.

I agree with unbolting the drive shaft and see what happens. At least then you will have a good idea of where the resistance is coming from.

Good Luck!

Hawk

 

[CoronetDarter]

Thanks everyone for the responses. Dropping the driveshaft is a good idea, I'll do it tomorrow.

 

[CoronetDarter]

It sure spins a LOT easier with an OPEN diff!
I do not have a direct answer to you except to suggest that you bring the car to my place. We can put it up on the lift. We could even check my car first to compare the resistance. I know that my car was easier to push when I had a 2.76 open diff in it for a few weeks.
PM me if you want my phone number. I am working FAR out of town Mon-Fri but I can make time for you on the weekends.

Hey Greg, I appreciate the offer and will take you up on it when our schedules work out.

 

[CoronetDarter]

Think you should be able to turn d shaft by hand no tires and no drums.

I can do it but takes some effort. And there's no free-spin after gaining some momentum.

 

[CoronetDarter]

Barry and I will stop by next year (Aug 2020) and check it out!

With my old (now my son's) 73 Road Runner, it wasn't easy but wasn't hard either. Hard to describe in words though. His car is a 340, 727, 3.55 sure grip with tapered bearings. I would usually grab the tires though without taking the wheels off.

I agree with unbolting the drive shaft and see what happens. At least then you will have a good idea of where the resistance is coming from.

Good Luck!

Hawk

Thanks Hawk. The way things are going, I'll have a laundry list of things that still need addressing a year from now.

 

[CoronetDarter]

I dropped the driveshaft. The rear hub spun almost effortlessly so I'm relieved. Still have to tackle the rear brake issue, but that's the next thread...
Thanks to FBBO members for their advice.

 

[Cranky]

I can do it but takes some effort. And there's no free-spin after gaining some momentum.

There won't be any free spin. And there's a good bit of hp loss between the engine and the tires on the ground because of all the drag in the trans and rear end.

 

[CoronetDarter]

There won't be any free spin. And there's a good bit of hp loss between the engine and the tires on the ground because of all the drag in the trans and rear end.

I've read 15 - 20% for an automatic. On the Coronet the drag is more from the 727 than the rear end.

 

[CoronetDarter]

A quick update - the drag is hydraulic lockup from the booster push rod interfering with the m/c piston.

 

[Kern Dog]

I've dealt with that. I have a 1975 Dart power booster in the Charger and it has an adjustable pushrod that presses into the back of the master cylinder. I was messing with it to reduce the pedal free play. I'd adjust, then drive....adjust some more. I took it too far ad smoked the brakes on the ride home and had to back it off a bit!

 

[CoronetDarter]

I'm getting a new m/c from Ram Man. The one on the car now is some jenky POS. I'll have to post a pic.
My rear wheels got so hot the last time I drove, I couldn't touch the lug nuts by hand.

 

[Cranky]

You removed the drums from your first post, right? Did you have to back off on the adjusters before they would move? I would think so if they were dragging and that would have been a good clue. You could have put the wheels back on without the drums to feel a difference by hand....

 

[CoronetDarter]

You removed the drums from your first post, right? Did you have to back off on the adjusters before they would move? I would think so if they were dragging and that would have been a good clue. You could have put the wheels back on without the drums to feel a difference by hand....

I had to adjust the shoes all the way in to get the drums off. At the time I didn't even consider hydraulic lock otherwise i would've loosened a wheel cylinder bleeder screw to try to release some pressure.