Rear gear noise

[BBodyfastgirl]

Help need advice...I bought this car last Oct. Paid alot of money. I want it to be a cruiser 340. Not looking to drag race. Love the power but want to take on a road trip next year. The car has 45000 original miles. It had a 3.55 gear in when I bought have now paid someone to switch to 3.23 gear and it whines bad. Didn't change the whole center piece cuz didn't know better. Since have learned that's how it should have been done. Should I keep 3.23 or put 2.93 this time for road crusin? It's going to have to changed so want to make right decision. Factory was 3.23.

 

[Jerry Hall]

3.23 Is a good all around gear, with stock size tires. Increasing the rear tire diameter will numerically decrease the overall ratio. Today's aftermarket gears are tuff to setup and be totally quiet. With a 340 you can still cruise at a higher speed with a 2.90 something gear. For local cruising I would stay with the 3.23. If cruising for long periods at interstate speeds definitely go to the higher gear. Just my opinion.

 

[BBodyfastgirl]

I do plan to drive with it on a road trip to MN to mopars in the park. I bought it to cruise mostly with it. Most people trailer their cars. I want to enjoy the ride. And Right now have 14s but want to eventually change to 15s when ai go to disc brakes. So sounds like you may be suggesting 2.93 if crusin and is that ok for when I change to 15s?

 

[Ron H]

I had made a swap in my ride (’63) from something around its stock set up, 2.76 or near, to sure grip 842 rear, 3:23 dropping the old tapered axles (’65 setup) NOT something related to your car to 3:23. MO, should have left that just BE. Nope, went to 3:55 and with a SB, not something I needed for a ‘cruiser’. Burned out the first Yukon 3:55 gear set in 5-miles putting my faith in a guy who was a mechanic buddy, but only familiar with Ford and GM rears. Setting up a sure-grip…isn’t the same knowledge set. So with another smart bud, we installed a new set closely following the FSM.

MO, if it whines ‘bad’ the gear set might be trashed needing a new set. Once toasted no going back. If you still might have the 3:23’s, locate a guy who KNOWS how to set up a mopar rear, and maybe put those back in. If those are gone, go with a new 3:23 set and forget the 3:55’s. Yeah, JMO – the difference btw the 3:23 and 55 didn’t mean squat in my case, other than unwanted higher rpm’s at cruising speeds.

 

[69Bee]

Welcome from AZ...

 

[ckessel]

Welcome from the left coast. My BIL lives in P-Cola. Good idea on changing to 15's in the future. Waayy more tire size choices which will help My 67 Coronet wagon has 14's. Too short even with 3.23's. In the future when I can swing it, it will get 15's. Putting disc's on is very wise. Having more whoa power is very important.

 

[hunt2elk]

If the gear set is noisy, they are toast. Might as well pick the ratio you want and have it redone.

 

[AR67GTX]

A 2.93 will take some of the snap out of that 340. I would want at least a 3.55 but if a lot of highway driving is in your plans then a 3.23 is a good compromise for performance and cruising.

 

[Charlie Brown]

I have 3.23, 28 inch dia, tires, cruises at 2800 rpm at 70 mph with auto trans.

 

[Bird 426]

2.76's

 

[jimbosride]

You can find a disc brake set up that will let you keep the 14 inch wheels. Check end play on you axles?

I had a guy set up my 323 sure grip.... it needs a new crush washer and yellow paint the gears to get the right mesh pattern when tightening
the yoke ....

But I just watched ..... I'm not an experienced
gear guy

 

[Geoff 2]

When I bought my GTO, it some whine while coasting. This was gear whine. Since the oil was old, I replaced it. A little better. I then tried Redline 85/140 & it completely fixed the whine.