rear end woes

-
SpeedracerX

SpeedracerX

Still on this side of the dirt member
Joined
Nov 19, 2008
Messages
3,404
Reaction score
179
Location
Irwin, Pa
Howdy gang.. Been a long time since I've checked in... Spent some time with the Dart today, and frankly im a bit frustrated....

So... The Dart has only seen partial action the last few seasons because of rear end troubles. I had a 741 case 3:91 chunk in it... the pinion bearing went bad and I wound up with all kinds of noise and issues.. I still drove the car, as I didnt have the money to deal with it. Plus the 741 is the weakest of the three different chunks, and I was holding out for a different one... Last season I got a 742 center with aftermarket Richmond 3:73's and what appears to be a spool style posi (its not the typical Mopar clutch style so call it posi instead of sure grip)... I got the chunk from a guy who has a pretty monstered up 72 Dart that he races. He had this center section redone and it had very little time on it, and they he went in a different direction, so he no longer had a use for it.... seemed like a good thing for me..

Here is the problem.. it whines like crazy.. most notably on the decel side.. now some of my friends are telling me that Richmonds are notorious for whining... Ive looked on the web and my research shows me that there are def two camps... the Richmonds are noisy and whine camp, and the 'your gears werent set up properly / the shop screwed them up / or they werent broken in properly... I suspect i will get much the same divide or response here as well..

If it is a case of improper set up.. theres no telling really how much time were on the gears when i got them.. they looked pretty darn new to me tho... and if the break in procedures (of which i wasnt previously aware there were any) werent followed, its most likely the damage is already done.. much like a tire that wears uneven due to poor alignment, the alignment can be fixed but the tire will still be messed up.. So i guess rather than just let the Dart sit another season, I am just going to drive it and get back to enjoying the car.. I really have missed it..

My question is... has anyone else experienced noisy Richmond gears? or any other brand for that matter....
 
I have 3.55 Richmond gears, they are quiet. Prolly have 3000 or so miles on them now.
 
The gears are probably fine there just not set up correctly.
 
Good move with the 742 case, as it doesn’t have a crush sleeve to have to contend with. This makes setting one up relatively easy. If you get a shim kit before you start and some gear marking compound, you should be able to correct it yourself. One thing that does need to be checked first and foremost though is the run out on the ring gear and on the carrier itself. Usually, whining from an improperly set up ring and pinion is from the pinion depth being off by a few thousandths. You’re better off to go ahead and correct the situation before it starts to wear the pinion bearings from the extra loading. Once they wear enough for the pinion to start rocking a little with the depth off, it starts chewing the teeth pretty hard and things tend to go downhill quickly from there.
 
Garrett Ellison said:
Good move with the 742 case, as it doesn’t have a crush sleeve to have to contend with. This makes setting one up relatively easy. If you get a shim kit before you start and some gear marking compound, you should be able to correct it yourself. One thing that does need to be checked first and foremost though is the run out on the ring gear and on the carrier itself. Usually, whining from an improperly set up ring and pinion is from the pinion depth being off by a few thousandths. You’re better off to go ahead and correct the situation before it starts to wear the pinion bearings from the extra loading. Once they wear enough for the pinion to start rocking a little with the depth off, it starts chewing the teeth pretty hard and things tend to go downhill quickly from there.
Click to expand...


Thanks for the info. Guess I will be tearing the rear end again
 
My Richmond 4.30s were quiet.

My experience with gears is that once they have been run noisy, it doesn't seem to make a difference where you set things, it still whines.
In your case tho, being mostly noisy on decel; you stand a chance of being able to make it better. All the best to you.
 
Gears do not whine because of brand. They whine because they were set up incorrectly. The pinion gear depth is incorrect. If it has not been run long, you can probably fix it.
 
I agree- too much wine too much slop.
Just go by the book- tear it down and reassembly starting from scratch. No easy way about it if you want to save those gears.

Once apart you will know using the wear patterns if they are good or worn beyond use.

And without pictures - on here... you won’t get any info because most of us do not have a crystal ball to see inside your axle.
Keep us posted and good luck- you can do this.
 
I did intend to mention for checking the pinion depth measurement numbers there is a tool set but the least expensive method is to get a piece of precision ground 9 X 1 X .100 stock and a depth mic. Lay the stock across the parting line where the caps go (diagonally, if need be), hold everything together firmly, and measure down to the machined point in the gear and subtract the .1 from the reading. The standard depth setting for a set of gears marked zero is 4.35 inches in a 742 case. Positive numbers etched or stamped into the end of the pinion gear indicate the amount to be added to the depth and negative numbers are subtracted from the depth. Whining on decel usually will pattern toward the outer edge of the gear indicating the pinion isn't setting high enough to the ring gear.
 
Garrett Ellison said:
I did intend to mention for checking the pinion depth measurement numbers there is a tool set but the least expensive method is to get a piece of precision ground 9 X 1 X .100 stock and a depth mic. Lay the stock across the parting line where the caps go (diagonally, if need be), hold everything together firmly, and measure down to the machined point in the gear and subtract the .1 from the reading. The standard depth setting for a set of gears marked zero is 4.35 inches in a 742 case. Positive numbers etched or stamped into the end of the pinion gear indicate the amount to be added to the depth and negative numbers are subtracted from the depth. Whining on decel usually will pattern toward the outer edge of the gear indicating the pinion isn't setting high enough to the ring gear.
Click to expand...

What a great idea. You can also use a pushrod and calibrate the thickness of it as zero in order to get a accurate reading from the top of the push rod to the pinion face.
 
Jadaharabi said:
What a great idea. You can also use a pushrod and calibrate the thickness of it as zero in order to get a accurate reading from the top of the push rod to the pinion face.
Click to expand...
I have to give a shout out to Paul Cangialosi at GearBoxVideos on the pinion depth measurement technique. I have heard it described by some heavy truck mechanics I know but he shows doing it with a Dana44 Jaguar center section. So much simpler and quicker than most of the fixture tools used to set pinion depth.
 
Garrett Ellison said:
I have to give a shout out to Paul Cangialosi at GearBoxVideos on the pinion depth measurement technique. I have heard it described by some heavy truck mechanics I know but he shows doing it with a Dana44 Jaguar center section. So much simpler and quicker than most of the fixture tools used to set pinion depth.
Click to expand...

Post #18

8 3/4 gear setup
 
Kudos to you, sir! I love when people are able to figure out a simpler and inexpensive way to do something that the aftermarket sells a nearly $1000 tool set. Personally, I wouldn’t hesitate to use the depth checker on a quality dial indicator to confirm the pinion depth. The final contact pattern is what really is going to matter.
 
RustyRatRod said:
Gears do not whine because of brand. They whine because they were set up incorrectly. The pinion gear depth is incorrect. If it has not been run long, you can probably fix it.
Click to expand...

Agree, here are photos of improperly set gears, and a properly set gear set with the white grease.

Incorrect-patterns.jpg

WhiteGreaseProper.jpg

Nicely centered pattern, runs quiet . . .
 
Jadaharabi said:
I think in the bottom picture the pattern shows the pinion is not deep enough and is to close to the outside of the tooth. Just seeing it on my phone that's what I see.
Click to expand...

Really? Maybe your phone ain't showin the right picture. The big picture with the white compound shows a perfectly centered pattern.
 
Okay, maybe the pinion depth is off, but maybe the ring is too far from the pinion. Both would cause a whine on decell. That's why old rearends whine on decell; the side bearings are worn and allow the carrier to move away from the pinion. I threw a set of gears in my Aerostar four years ago cuz the 7.5 was blown and it's been whining on accel ever since; ring gear too close to the pinion. I'm gonna fix it one of these days tho.
 
You must log in or register to reply here.
-

Back
Top