Singing rear end

[Hissses]

Just had 3:55 gears installed and was driving on the freeway. Light throttle seems to sing; is this normal break in, as I have never had 2 cut gears before. Does this go away as the gears seat? Sure like the feel of 3:55's though. Any imput appreciated.

 

[CitySnake]

Had to see EXACTLY what that topic would lead to

Oh well...sharper minds will follow.

 

[GTS Dean]

Gear whine is not uncommon with performance ring & pinion sets. There's an art to setting them up correctly, but some sets will still whine. OEM gearsets for passenger cars are subjected to stringent tests for noise. Some folks have used GM Corvette R&Ps (3:31) to boost performance with less noise.

Nice to know now that you've already spent the bux, eh?

(Remember Marv's slogan: "A Search Key is a terrible thing to waste.")

 

[VIPR GTS]

this is often caused by improper gear lash being set when setting up the rear end with new gears

 

[Kevin Stitely]

Michael,
Last year I had that "horrible" singing noise coming from the stock gears. Took a trip to Maryland's best viper tuner, Jason Heffner and had the gears replaced with 3:55's. From that day forward, no more singing, even during the break-in period. You may want to re-visit the shop who did the work.

 

[jimandela]

i wanted 3.55 gears
but no one local wanted to install them
now i am glad that I still have stock...
not worth the headache
sorry to hear about your problem hope it
is a easy
fix.

JIM

 

[Hissses]

Thanks guys,
I pulled the diff. out myself and had a local shop that specializes in this do the work. I came back as he was checking the pattern and mesuring the back lash. dial indicator showed approx 2-4. Was told that the 2 cut gears needed to wear in and that it is hard to get an exact reading due to the surface. Was this a line? He said that this wear in was why you needed to change the fluid at 500 miles. When I called and asked about the singing on light load he said it would go away in a couple of hundred miles.I have never used Unitrax 2 cut gears so my only comparision has been all the fords that I have changed gears in with no noise. Should I find some one else to set this rear end up... maybe just send it to Unitrax?

 

[George Bryce]

Hi guys, on singing subject...I bought a complete rear from John B. at Partsrack....new in the box from Mopar. It is a 3.55. I put 300 miles on it today. It is the quietest rear I have ever not heard. It is way fun to drive too!!!!

GB3

 

[Jack B]

A ring and pinion set up with a tolerance over the max clearance will sing and cause premature failure. All of the Dana super 44's will have a little hum/sing in them in that neutral spot on the throttle under cruise. Little to some is loud to others.

 

[Tom and Vipers]

Setting up a rear end is a real pain in the a$$.

First of all, "clearance" is meaningless.

You set the pinion depth as per the dimension etched on the pinion face.

Then you shim the carrier for the best tooth contact pattern.

If you are lucky you will get a good one. If not, you have to perturb the pinion and start over.

It is customary to get no whine in drive and coast. (I have done this.)

==============================

It is claimed that racing gear sets should be set up by pinion depth and backlash clearance specifically.

While this results in a less than optimum contact pattern that whines, the claim is that when under load, the desired contact pattern will be achieved.

I seriously doubt this because I don't think these aftermarket gear companies have the engineering ability to do the required finite element analysis which is quite daunting since it is a contact problem.

 

[weed43]

Just went through with what you are talking about GEAR Whine. I had mine done by a guy who does off road vehicles Dodge trucks.I drove it home which was 50 miles real bad whine on the load side, he sent his roll back wrecker an took it back to his shop and re done the job. This time they were much better but still had a whine that was no acceptable, but this time I picked up a vibration so I took it home and pulled it my self and sent it to Unitrax, Devin told me that the gears were junk and I only drove it 70 miles, Thanks to JonB He gave me a break on the second set of gears and Unitrax worked with me on the labor. The people here in Cincy don't even know what a 2 cut gear is and 2-4 thousands is correct on the lash. Don't let any one tell you that whine is something to be expected on any Spicier set of gears. I would go through the expense and the aggravation again for the 355 ratio for it is totally a different car to drive. The car is stronger and all the gears are useable now.

 

[PBJ]

**** 53 is correct...if the ring and pinion were set up incorrectly it will set a wear pattern in a matter of a few miles. The pinion depth is the most crucial point of setting up gears...MP and factory dana gears (spicer) have a number marked on the pinion. You take your new gear and check the number and add or subtract pinion shim thickness accordingly. If you use the old bearings, make sure that you do not overtighten the pinion bearings...20-25 inch pounds of rolling torque VS. 40-45 on a new set. Then you can set up your backlash...I like mine a little snug....003-.005. I always chalk the set up to make sure what the wear pattern looks like in load and coast...if it is set up correctly there should be no noise at all. I have had issues with US gears, Richmond, and Motive gears for having some accel whine...minimal but more than I like. I have never had an issue with Mopar Performance gears of any of the factory Dana gears.
Hope that helps,
Joe

 

[Tom and Vipers]

I don't think you have a choice in the backlash, you have to use the contact pattern to establish the correct backlash.

 

[Hissses]

Ok, pulling the diff. out today and going to send it to Unitrax to have them do it right! Should have done that in the first place as pointed out these are not your standard rear diff. Let ya know what they say. Thanks again for all your input

 

[joe117]

I have the Unitrax 3.55 gears. I had them set up by a local shop. No noise at all. I've just reached the 500 mile mark and I plan to take it back to them for a gear oil change. Perhaps I'll get a chance to see the wear pattern.

 

[VIPR GTS]

weed53, what was the total cost of shipping and set up with Unitrax, mine are set up wrong and I have noise in the 60 to 70 mph range. don't know if I want to trust the same shop to try the set up again or not.

 

[jimandela]

hissses,
if i ever did it .. that is the way to go Unitrax.
and Jon B.

I was actually all set to make it happen that way.

When my lovely local dealership told me i could not leave my
car in its shop for 1 week total.
While i have the rear end removed pretty much overnited to california to get it done and sent back asap.

Just no luck.

Oh well maybe if voi 8 is in California i can stay a extra day and get it done.

good luck
JIM

 

[weed43]

VIPR GTS you have e mail

 

[weed43]

Joe 117, don't think you will get to see the ring gear Joe' they pump it out and replace oil the same way, If you ever pull it out again have them drill and tap for a drain plug.

 

[Hissses]

Got a phone call from Unitrax today. They had picked up my diff. and checked it out. What great sevice, The problem was no backlash, probably due to improper assembly. So after only 50 miles the gears are shot! Should have sent the diff to Unitrax.
After being mad at myself I called Jon at Parts Rack to see if he had any suggestions. His respose was call me back in 15 minutes...I'll call Unitrax. 10 minutes later he calls me back and tells me how he and Unitrax can help me out. Wow, I could not believe the service and the way he helped me even though it was all my problem! What incredible customer service. So now in a couple of days I will have my diff back and done right thanks to the Great guys at Unitrax (Jerry & Devan) and Jon at Parts Rack...Thanks Guys

 

[Paul Hawker]

Devin and Jerry at Unitrax are fantastic guys, and great ViperClub supporters.
Best deal is to make an appointment and drive your car to their shop in Anaheim. They will perform their magic on the spot while you wait.
They have done so many Viper pumpkins that they should declare Halloween their official holiday.