Two Piece Front Driveshaft

[aglinks]

Hey all,

I have a TF727/D300 in my CJ7 and have a 4" BDS lift. I still had clearance issues with the driveshaft so I built a pillow block support and ordered a two piece front driveshaft. This thing shakes like a homedepot paint mixer. I know people have done this before but I havent found detailed enough info on how to execute without creating a vibration. I dont want to blow apart my U-Joints after one of two times on the trail. Any tips?

 

[mitchelllogic]

Hey all,



I have a TF727/D300 in my CJ7 and have a 4" BDS lift. I still had clearance issues with the driveshaft so I built a pillow block support and ordered a two piece front driveshaft. This thing shakes like a homedepot paint mixer. I know people have done this before but I havent found detailed enough info on how to execute without creating a vibration. I dont want to blow apart my U-Joints after one of two times on the trail. Any tips?

Pictures of your driveline angles, u-joints, connections, and clearance issues would help.

Not sure what your budget or skill level are so:

If you want vibration free then work through the exercise of preparing a custom driveshaft worksheet.

You will figure out pretty quick you likely are exceeding recommended driveline angles. (Ok but you will need to deal with the issues that arise as a result).

Solved my issues at the back by rotating the diff to point at the tcase. Then with a custom double cardan driveshaft from Tom Woods.

Here are a few (very useful) links:

Tom Woods knows driveshafts (understatement of the year).

http://www.4xshaft.com/driveline101.asp

http://www.4xshaft.com/tech_slopesVSangles.html

http://www.4xshaft.com/MeasuringGuide.pdf

http://www.4xshaft.com/JR7_TW_Driveshaft.pdf

http://www.4xshaft.com/

Worth every minute of reading and every dollar spent.


Sent from my Pixel 2 using Tapatalk

 

[RiverandSand]

Solved my issues at the back by rotating the diff to point at the tcase. Then with a custom double cardan driveshaft from Tom Woods.

Here are a few (very useful) links:

Tom Woods knows driveshafts (understatement of the year).

Tom Wood's Custom Drive Shafts - Driveline 101

Tom Wood's Custom Drive Shafts - Slopes VS Angles

http://www.4xshaft.com/MeasuringGuide.pdf

http://www.4xshaft.com/JR7_TW_Driveshaft.pdf

Tom Wood's Custom Drive Shafts - Tom Woods Custom Drive Shafts Custom Driveshafts Specialist

Worth every minute of reading and every dollar spent.


Sent from my Pixel 2 using Tapatalk

X2-I did the same thing, great service, very knowledgeable. I also have the smaller diameter front shaft which TW sells for the automatics, however I am not sure of the maker, it was already on the jeep.

 

[aglinks]

Pictures of your driveline angles, u-joints, connections, and clearance issues would help.

Not sure what your budget or skill level are so:

If you want vibration free then work through the exercise of preparing a custom driveshaft worksheet.

You will figure out pretty quick you likely are exceeding recommended driveline angles. (Ok but you will need to deal with the issues that arise as a result).

Solved my issues at the back by rotating the diff to point at the tcase. Then with a custom double cardan driveshaft from Tom Woods.

Here are a few (very useful) links:

Tom Woods knows driveshafts (understatement of the year).

Tom Wood's Custom Drive Shafts - Driveline 101

Tom Wood's Custom Drive Shafts - Slopes VS Angles

http://www.4xshaft.com/MeasuringGuide.pdf

http://www.4xshaft.com/JR7_TW_Driveshaft.pdf

Tom Wood's Custom Drive Shafts - Tom Woods Custom Drive Shafts Custom Driveshafts Specialist

Worth every minute of reading and every dollar spent.


Sent from my Pixel 2 using Tapatalk

I modified my design last night and I THINK I solved it. I get a minor vibration at 20-22 MPH but anything above or below that is perfect. I will need to take it offroad and make sure my clearance issues are still solved. I will post updates! And yes my shafts are from Tom Woods. They got them built and shipped in literally less than a day. I was amazed.

My next question:
The shafts were built with greasable joints; however, I am wondering if I should put a solid u-joint at the pillow block. I think that will see the most stress. Thoughts?

 

[mitchelllogic]

I modified my design last night and I THINK I solved it. I get a minor vibration at 20-22 MPH but anything above or below that is perfect. I will need to take it offroad and make sure my clearance issues are still solved. I will post updates! And yes my shafts are from Tom Woods. They got them built and shipped in literally less than a day. I was amazed.



My next question:

The shafts were built with greasable joints; however, I am wondering if I should put a solid u-joint at the pillow block. I think that will see the most stress. Thoughts?

Picture of the "pillow block" please.....
I don't understand.

Sent from my Pixel 2 using Tapatalk

 

[aglinks]

Picture of the "pillow block" please.....
I don't understand.

Sent from my Pixel 2 using Tapatalk

Once I confirm that this works well offroad, I will pull it apart and have the parts powder coated. Keep in mind I am not a great fabricator but it seems solid! Also, I will be getting shorter bolts lol.

 

[Lumpy Grits]

Be sure your engine a tranny mount aren't damaged.
Gary

 

[mitchelllogic]

Once I confirm that this works well offroad, I will pull it apart and have the parts powder coated. Keep in mind I am not a great fabricator but it seems solid! Also, I will be getting shorter bolts lol.

Images aren't showing.....

Sent from my Pixel 2 using Tapatalk

 

[JeeperChris]

Never mind.

 

[aglinks]

I got everything powdercoated and put back together!...and broke another flexplate. So as much time and effort as I put into this...I am going to switch to a manual. If anyone wants a 2 piece front driveshaft setup, let me know.

 

[Patrick]

Wait, wait. Honestly I don’t see why you are having driveline fitment issues. LS 4.8/TF999 in a CJ 7 should fit just right. Giving up the automatic transmission is a tough choice. Elaborate more, someone has the answer for you here.

 

[aglinks]

Wait, wait. Honestly I don’t see why you are having driveline fitment issues. LS 4.8/TF999 in a CJ 7 should fit just right. Giving up the automatic transmission is a tough choice. Elaborate more, someone has the answer for you here.

I blew up the TF999 after about a year of use (also broke a flexplate in that time). I found a fresh rebuilt TF727 out of a wagoneer so I opted to go that route. I was having driveshaft clearance issues like everyone else that does that swap, so I built a sweet two piece driveline setup. In the time that the TF727 has been in, I broken 4 more flexplates. Each time working with Novak to try to solve the problem. Ultimately, Novak decided to pull the kit since we couldnt fix the issue. I am super tired of pulling the trans every 4-6 months to put in another flexplate so I am going manual.

 

[Patrick]

Ok, so Novak has been involved all along. The TF 999/727 trannies pose an inherent front driveline challenge. The engine to slushbox marriage kit was pulled or recalled by Novak due to flexplates breaking. I can’t suggest anything but reconsider your transmission choice to a classic space saving GM HM 350 since you already have an SBC. I miss my automatic transmission myself. Thank you for clarifying the issues.

 

[aglinks]

Ok, so Novak has been involved all along. The TF 999/727 trannies pose an inherent front driveline challenge. The engine to slushbox marriage kit was pulled or recalled by Novak due to flexplates breaking. I can’t suggest anything but reconsider your transmission choice to a classic space saving GM HM 350 since you already have an SBC. I miss my automatic transmission myself. Thank you for clarifying the issues.

I’m planning to switch to an AX15 this spring. Hopefully someone with an AMC motor can get some use out of my auto.

 

[mriplaybass]

Just saw the post. I'm a bit confused, but never having done the kind of swap that you have done, maybe I'm not looking at things correctly. It looks like you put the pillow block in so that it could clear the plate under it. Or was that put in to support the pillow block? From the pictures, it looks like the slope on the front segment of the driveshaft increases unnecessarily. Why doesn't a one piece shaft work? I can't see what it interferes with. Or is it lateral interference, such as that the shaft hits the oil pan, and the pillow block allows the shaft to be slightly pushed away from the pan?

 

[aglinks]

Just saw the post. I'm a bit confused, but never having done the kind of swap that you have done, maybe I'm not looking at things correctly. It looks like you put the pillow block in so that it could clear the plate under it. Or was that put in to support the pillow block? From the pictures, it looks like the slope on the front segment of the driveshaft increases unnecessarily. Why doesn't a one piece shaft work? I can't see what it interferes with. Or is it lateral interference, such as that the shaft hits the oil pan, and the pillow block allows the shaft to be slightly pushed away from the pan?

The one piece shaft has a lateral interference with the 727 pan. By putting the pillow block where I did, this no longer happens.

 

[Patrick]

How about clocking the t-case full horizontal...

And did Novak figure out the reason for flexplates breaking?

 

[aglinks]

How about clocking the t-case full horizontal...

And did Novak figure out the reason for flexplates breaking?

Clocking the T-case does not solve the problem. I even dropped it into CAD and checked different possibilities. The two piece shaft works well.

The big problem is the flexplate issue. Novak did not solve the problem and as a result no longer stocks the kit.

 

[Patrick]

Got it. Good luck with the manual conversion.

 

[mriplaybass]

The one piece shaft has a lateral interference with the 727 pan. By putting the pillow block where I did, this no longer happens.

Ah! I see that now after looking more closely at your pictures. Good luck with your conversion to a manual transmission.