Trans build

[NoHaveMSG]

Originally Posted by Fa20Toybaru

Thanks for sharing the information regarding the gearing. I had information regarding the MPH. I am just concerned about the vibrations, it is crazy...I am unable to even look out the rear mirror. The car will be on the track eventually, I am however testing it on the street. I am thinking about doing the home balancing of the driveshaft and seeing if that helps.
I am just stuck on where to start, I think it is just test and move, test and move...until it is right. Thanks for all the information and help

What ring and pinion gears are you running? If it is the cusco 4.56 it will vibrate even lower speeds then I was getting. When the driveshaft hits around 6200rpm is when it exceeds its CS. So if you are running 4.56's it is going to happen around 95mph. There is nothing that can be done balance wise to fix it, or trying to shim the diff/engine to get it in better alignment and it is at risk of failing. The issue is for the length of the shaft, it is not big enough in diameter to be made out of aluminum.

[Fa20Toybaru]

Thanks for reaching out, yes it is the CUSCO ring and pinion at 4.556. So if I understood you correctly, we cant balance the shaft to fix the vibrations at acceleration? Also the shim part, will that cause it to fail, or I need to shim it further to prevent early failure for the diff? I appreciate your time, I cant find anyone in TX that has any knowledge on this.

[NoHaveMSG]

Originally Posted by Fa20Toybaru

Thanks for reaching out, yes it is the CUSCO ring and pinion at 4.556. So if I understood you correctly, we cant balance the shaft to fix the vibrations at acceleration? Also the shim part, will that cause it to fail, or I need to shim it further to prevent early failure for the diff? I appreciate your time, I cant find anyone in TX that has any knowledge on this.

The only way the issue can be fixed is to have DSS make you a new AL shaft out of 3.5, or go to a carbon shaft, or go back to stock. I would recommend calling DSS about it. You can also email Kevin at Kevin@driveshaftshop.com.

They won't flatout replace it for you, but will work with you on a replacement.

Edit: The 3.5" shaft won't clear the stock shifter extension. Need to measure under the car to see if it will fit.

[Capt Spaulding]

Originally Posted by NoHaveMSG

The only way the issue can be fixed is to have DSS make you a new AL shaft out of 3.5, or go to a carbon shaft, or go back to stock. I would recommend calling DSS about it. You can also email Kevin at Kevin@driveshaftshop.com.

They won't flatout replace it for you, but will work with you on a replacement.

Edit: The 3.5" shaft won't clear the stock shifter extension. Need to measure under the car to see if it will fit.

Sorry to threadjack, but I have never been really clear on the reasons for replacing the driveshaft. Can someone help me here? Reading numerous posts over the years has persuaded me that doing so is just borrowing trouble.

[DarkPira7e]

Originally Posted by Capt Spaulding

Sorry to threadjack, but I have never been really clear on the reasons for replacing the driveshaft. Can someone help me here? Reading numerous posts over the years has persuaded me that doing so is just borrowing trouble.

For me, the car drives smoother with sudden inputs and after harsh shifts with boost as a part of the recipe. The Verus carbon fiber driveshaft was a nice upgrade and I think it'll help reduce shock through the diff and transmission.

[NoHaveMSG]

Originally Posted by Capt Spaulding

Sorry to threadjack, but I have never been really clear on the reasons for replacing the driveshaft. Can someone help me here? Reading numerous posts over the years has persuaded me that doing so is just borrowing trouble.

The aluminum DSS shaft is cheaper then stock and 1/3 the weight. Price alone convinced me to buy this 5ft long paperweight.

[Capt Spaulding]

Thanks. I guess I’m in the IIABDFI (if it ain’t broke don’t fix it) camp on this part. That’s unusual for me. I’m usually in the “if it ain’t broke let’s fix it til it is” crowd.

[NoHaveMSG]

Originally Posted by Capt Spaulding

Thanks. I guess I’m in the IIABDFI (if it ain’t broke don’t fix it) camp on this part. That’s unusual for me. I’m usually in the “if it ain’t broke let’s fix it til it is” crowd.

I had a rear u joint that was feeling bad in my car so I swapped it. I think the stock driveshaft is a couple hundred more. Now I have a new stock driveshaft and a used spare.

[blsfrs]

Even the 3.5" have a critical speed. With the 4.55 gearing you might reach it sooner than you think. Like 8100 rpm.

[jeepmor]

Originally Posted by Fa20Toybaru

I am able to go through every gear, no grinding, it is loud, but it does make the car move a little quicker and reduce speed as well.

Did you have a trans with mileage updated, or a new one modified. Curious about the noise and if it'll degrade over time or you learn to live with it.

My CJ7's T-18 took a year for the shifting detents to wear in and get smooth. My arm hurt after driving it quite a few times shifting all day in it on the trails.