[A knight]

Does anyone know if someone makes 4.30 ring and pinion gears that can be put into the 6 speed 226mm getrag unit? Doing some math, it would seem that 4.30 gears would have 4th end at 126 mph at 6400 rpms, which would be perfect for the 1/4 mile. For NA guys I feel like this would be a really good mod.



EDIT: ended up getting 4.30s put in my car, review is on page 11. All I can say is that I have zero regrets!!

 

[Cuda340]

Is your Challenger a daily driver, or a weekend car? A set of 4.30s will have your car revving very high in normal driving, especially on the interstates. Also, your gas mileage will really suffer.

 

[Slidd]

Found something saying BFNY Performance used to, don't know if they still do.

Should work fine. RPMs not much more than the stock 3.92, at 70 mph still only about 1800 revs.


Sent from my SM-G550T using Tapatalk

 

[A knight]

Is your Challenger a daily driver, or a weekend car? A set of 4.30s will have your car revving very high in normal driving, especially on the interstates. Also, your gas mileage will really suffer.

Like slidd said, 6th gear in these cars are so low it wouldn't really impact it that much. Still would only be turning 1800 rpms on the highway.

 

[Curtisville Challenger's]

strange

 

[babyivan]

Like slidd said, 6th gear in these cars are so low it wouldn't really impact it that much. Still would only be turning 1800 rpms on the highway.

yeah, 6th gear is ridiculously low.

 

[A Guy]

I remembered something about 4.29...is this it?

https://www.summitracing.com/parts/ugr-03487429lclx/overview/

Chrysler 8.7" IRS Getrag H226 4.29 Ring and Pinion US Gear Set - Ron's Machining Service

A Guy

 

[McCloud]

I"m actually installing these next week US Gear 4.29 (03-487429LC/LX). If you want to see what your actual RPMs are going to be go to Tremec's and go to aftermarket then Support Center then Gear Ratio Calculator. it's actually spot on. I verified with my current configuration. The gear ratios for the Manual are below. I assume you have the six speed. The 4.29 gears are way too short for the 5 speed auto. You will need Richmond half install kit ( 83-1086-C ) and if you don't take the car to the dealership to have it done or a shop that has never performed this on these cars you will need special tools to help them with the install. You can find these by searching for Miller Tools then the tool number. I have them listed below. They are required to set the pinion depth and the backlash. I recommend finding Kit 10145 then grab the Pinion Block and Scooter block. You will also need the service manual to get the specs and know how to set the Pinion depth and backlash. If you have a good Chrysler/Doge dealership It may be easier to simply use them. I went this route as the dealerships near me either wouldn't install the after market parts or charge $110 an hour estimating a 6 hour job. Also please note you will notice the kit 83-1086-C doesn't have a crush sleeve.. The pinion depth is set using spacers hence the special tools.


Tools:
10148 - Installer, Pinion Head Bearing Cup

Originally Shipped In Kit Number(s) 10145.
10149-2 - Arbor

Originally Shipped In Kit Number(s) 10145.
10149-5 - Washer

Originally Shipped In Kit Number(s) 10145.
6739 - Block, Height

10149-1 - Block, Pinion

D-115-2A - Block, Scooter

Tremec TR-6060 Gear Ratios:
1st 2.97
2nd 2.10
3rd 1.46
4th 1.00
5th 0.74
6th 0.50
Reverse 2.90

 

[Curtisville Challenger's]

I run 4.30s with an a5

 

[bWiLKINS]

So that US gear set plus the Richmond half install kit plus taking it to the dealer to have them installed will cover everything needed to put in a 2016 SRT 392 correct? It is a tremec 6speed not an auto to clarify.

Thanks.

 

[McCloud]

Duplicate post deleting

 

[A knight]

I"m actually installing these next week US Gear 4.29 (03-487429LC/LX). If you want to see what your actual RPMs are going to be go to Tremec's and go to aftermarket then Support Center then Gear Ratio Calculator. it's actually spot on. I verified with my current configuration. The gear ratios for the Manual are below. I assume you have the six speed. The 4.29 gears are way too short for the 5 speed auto. You will need Richmond half install kit ( 83-1086-C ) and if you don't take the car to the dealership to have it done or a shop that has never performed this on these cars you will need special tools to help them with the install. You can find these by searching for Miller Tools then the tool number. I have them listed below. They are required to set the pinion depth and the backlash. I recommend finding Kit 10145 then grab the Pinion Block and Scooter block. You will also need the service manual to get the specs and know how to set the Pinion depth and backlash. If you have a good Chrysler/Doge dealership It may be easier to simply use them. I went this route as the dealerships near me either wouldn't install the after market parts or charge $110 an hour estimating a 6 hour job. Also please note you will notice the kit 83-1086-C doesn't have a crush sleeve.. The pinion depth is set using spacers hence the special tools.


Tools:
10148 - Installer, Pinion Head Bearing Cup

Originally Shipped In Kit Number(s) 10145.
10149-2 - Arbor

Originally Shipped In Kit Number(s) 10145.
10149-5 - Washer

Originally Shipped In Kit Number(s) 10145.
6739 - Block, Height

10149-1 - Block, Pinion

D-115-2A - Block, Scooter

Tremec TR-6060 Gear Ratios:
1st 2.97
2nd 2.10
3rd 1.46
4th 1.00
5th 0.74
6th 0.50
Reverse 2.90

Would love to hear on any updates with this!

 

[McCloud]

That must have a really put you in the seat launch. Did you have that installed at a dealership?

 

[McCloud]

If you find a dealership that will perform the install they would have the shims and the seal too. It may cost you more but it could be worth it for the convenience. I have done a lot of mods lately so I'm working to save as much as possible.

 

[bWiLKINS]

Ok great, thanks. I'll talk to my local dealer today and get the R&P set ordered this weekend.

 

[Slidd]

So that US gear set plus the Richmond half install kit plus taking it to the dealer to have them installed will cover everything needed to put in a 2016 SRT 392 correct? It is a tremec 6speed not an auto to clarify.

Thanks.

No, there is no gear set available for any 2015+ Challenger and the new ZF rears are not serviceable. I'm afraid you are stuck with the 3.90 ratio you have now.

Sent from my SM-N920T using Tapatalk

 

[cdahl383]

For an M6 car I could see stepping it up a bit, but for an A8 car the first gear is so steep I think it'd be a waste of time. The 3.09 rear end and steep first gear in the A8 (4.70:1) work great together.

Swapping from 3.92 to 4.30 gears in an M6 would not be a huge difference though. Do they make 4.56's like they do for the GM cars?

6th gear already revs super low with 3.92 gears so the RPM's would not be too high with 4.30's or even 4.56's at all.

With steeper gears you would also want to think about getting some stickier tires on the back to put the power to the ground, otherwise all it will be is a burnout mod, make it easier to do massive burnouts.

 

[Curtisville Challenger's]

were did you get the gears

 

[McCloud]

I"m actually installing these next week US Gear 4.29 (03-487429LC/LX). If you want to see what your actual RPMs are going to be go to Tremec's and go to aftermarket then Support Center then Gear Ratio Calculator. it's actually spot on. I verified with my current configuration. The gear ratios for the Manual are below. I assume you have the six speed. The 4.29 gears are way too short for the 5 speed auto. You will need Richmond half install kit ( 83-1086-C ) and if you don't take the car to the dealership to have it done or a shop that has never performed this on these cars you will need special tools to help them with the install. You can find these by searching for Miller Tools then the tool number. I have them listed below. They are required to set the pinion depth and the backlash. I recommend finding Kit 10145 then grab the Pinion Block and Scooter block. You will also need the service manual to get the specs and know how to set the Pinion depth and backlash. If you have a good Chrysler/Doge dealership It may be easier to simply use them. I went this route as the dealerships near me either wouldn't install the after market parts or charge $110 an hour estimating a 6 hour job. Also please note you will notice the kit 83-1086-C doesn't have a crush sleeve.. The pinion depth is set using spacers hence the special tools.


Tools:
10148 - Installer, Pinion Head Bearing Cup

Originally Shipped In Kit Number(s) 10145.
10149-2 - Arbor

Originally Shipped In Kit Number(s) 10145.
10149-5 - Washer

Originally Shipped In Kit Number(s) 10145.
6739 - Block, Height

10149-1 - Block, Pinion

D-115-2A - Block, Scooter

Tremec TR-6060 Gear Ratios:
1st 2.97
2nd 2.10
3rd 1.46
4th 1.00
5th 0.74
6th 0.50
Reverse 2.90

Performed the install as planned last week. I pulled the diff myself and dropped it off at the shop. The ring and pinion was able to be installed in one day. There was an issue with the pinion bearing. The OEM bearing was too small for the new pinion gear. However the guy I took it too was able to find a bearing that fit by taking measurements. He knew exactly which bearing to grab and had one in stock. I have a feeling if it was a less experienced mechanic it probably wouldn’t have happened. This is his specialty so I recommend you taking it to a shop that specializes in ring and pinion. The odd thing is there was a spacer in the shim for the pinion to make it fit the OEM pinion gear, and the shim fit the new pinion perfectly…. So the pinion in mine may not be the norm so there could be a chance not everyone will have the bearing size issue. Not sure if it was something they did to keep production up. Really seems odd to use a space inside of a shim to fit the pinion gear.

Now that I have performed the break-in procedure and put a few miles on it for good measure I was able to really test it out. The acceleration has improved quite a bit over the 3.73 gears. The “seat of your pants feel” is very noticeable. It’s also nicer under light acceleration too, doesn’t take much of the pedal to get it moving. I assume I may get better gas mileage when driving in city/around town situations. The Highway RPMs aren’t bad either 2100 at 80 MPH. Overall It really compliments the Phaser 274 cam I’m running. ( For those that don’t know It has a power band of 2400-7400 rpms ). I’m not sure this is the best mod for a stock R/T maybe go with 4.10 instead. The stock cam has such good low end torque.. To each his own though, just a suggestion.

Any questions please feel free.

 

[McCloud]

Ron' Machine Service