Driveshaft Design Problem

pokeyl · 07-11-2016, 07:36 AM

Now that I "made you look", Nissan has boned me (us) again. The 370 has IRS and as such no movement in the relation from the trans to the differential. The result is you only use a very small number of the bearings in the "U" joints.

If you remove your drive shaft and inspect it; you will find a flat spot as you move the bearing around; it should be smooth as you move it; it will not be. I have no play in my shaft at this time but it is the start of failure.

Also the drive shaft is "Not Re-buildable" you have to pay Nissan $1500 for a new one. I am working with a master tool and die maker (friend) to see if the factory shaft can me made re-buildable. The cost, TBD, but after I will be able to change the "U" joints like any other car. I will out of town for the next 4 months, so the project will start in Nov-Dec.

We may be able to lower the aft trans mount and induce some movement in the drive shaft and allow the bearing to function normal, same at the differential mounts. It only takes 1 to 2 degrees and the flat spot issue should go away. The trade off is a very small power loss?

This is why some cars need drive shafts after only 12-15K miles and the harder you hammer the drive line the sooner the failure.

Please let me know if you have had to replace your drive shaft or have a noise/vibration the dealer has not been able to pin down.

You can check the rear "U" joint by removing the 4 bolts at the differential and slide the shaft forward into the trans as far as you can. Now you should have room to move the rear bearing and feel for the flat spot.

I found all this during my triple disk clutch install, along with some calls to drive shaft shops. I have been looking at after market custom shafts as well. I am at 65K miles now, 40K are SC 480-500 RWHP.

Thanks for reading.

Slartibartfas · 07-11-2016, 01:00 PM

Quote:

Originally Posted by pokeyl

The 370 has IRS and as such no movement in the relation from the trans to the differential.

Not quite true. Engine/transmission and diff use rubber mounts so there is movement as the assemblies wobble about. Not a lot but enough to require some sort of accommodation.

Spooler · 07-11-2016, 02:24 PM

This is normal and nothing new, run it. It has been this way for many Z models. When it starts clicking rolling out in first or reverse, replace it.

Rusty · 07-12-2016, 10:51 PM

If I need a driveshaft. I'm going to Tom Woods. He made the driveshafts for my Power Wagon.

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

pokeyl · 07-13-2016, 08:03 AM

Quote:

Originally Posted by Rusty

If I need a driveshaft. I'm going to Tom Woods. He made the driveshafts for my Power Wagon.

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

Can you change the "U" joints in his shaft?

I just want to have something I can fix. I never trade cars so this is a problem for me as I will need one every 3 -5 years? sooner with the triple disk clutch.

If my friend can rework my factory shaft for less than $700 I will go that route.

Rusty · 07-13-2016, 10:52 AM

Quote:

Originally Posted by pokeyl

Can you change the "U" joints in his shaft?
Yeah, you can even grease them too.

I just want to have something I can fix. I never trade cars so this is a problem for me as I will need one every 3 -5 years? sooner with the triple disk clutch.

If my friend can rework my factory shaft for less than $700 I will go that route.

Tom can make anything you want.

07-11-2016, 07:36 AM	#1 (permalink)
pokeyl Track Member Join Date: Nov 2010 Location: DFS Posts: 896 Drives: ??? Rep Power: 55	Driveshaft Design Problem Now that I "made you look", Nissan has boned me (us) again. The 370 has IRS and as such no movement in the relation from the trans to the differential. The result is you only use a very small number of the bearings in the "U" joints. If you remove your drive shaft and inspect it; you will find a flat spot as you move the bearing around; it should be smooth as you move it; it will not be. I have no play in my shaft at this time but it is the start of failure. Also the drive shaft is "Not Re-buildable" you have to pay Nissan $1500 for a new one. I am working with a master tool and die maker (friend) to see if the factory shaft can me made re-buildable. The cost, TBD, but after I will be able to change the "U" joints like any other car. I will out of town for the next 4 months, so the project will start in Nov-Dec. We may be able to lower the aft trans mount and induce some movement in the drive shaft and allow the bearing to function normal, same at the differential mounts. It only takes 1 to 2 degrees and the flat spot issue should go away. The trade off is a very small power loss? This is why some cars need drive shafts after only 12-15K miles and the harder you hammer the drive line the sooner the failure. Please let me know if you have had to replace your drive shaft or have a noise/vibration the dealer has not been able to pin down. You can check the rear "U" joint by removing the 4 bolts at the differential and slide the shaft forward into the trans as far as you can. Now you should have room to move the rear bearing and feel for the flat spot. I found all this during my triple disk clutch install, along with some calls to drive shaft shops. I have been looking at after market custom shafts as well. I am at 65K miles now, 40K are SC 480-500 RWHP. Thanks for reading. __________________ It's not my fault I'm old, I was born a very long time ago!

07-12-2016, 10:51 PM	#4 (permalink)
Rusty Ronin Samurai - Assassin Join Date: Dec 2011 Location: Fayettenam,Pennsyltucky Age: 68 Posts: 35,184 Drives: 2011 Nismo GM 6M Rep Power: 2684437	If I need a driveshaft. I'm going to Tom Woods. He made the driveshafts for my Power Wagon. Tom Wood's Custom Drive Shafts - Tom Woods Custom Drive Shafts Custom Driveshafts Specialist __________________ 浪人 - 殺し屋 "The Difficult Anytime, The Impossible By Appointment Only" http://www.the370z.com/members-370z-...o-journal.html

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07-11-2016, 02:24 PM	#3 (permalink)
Spooler A True Z Fanatic Join Date: Jun 2014 Location: Ga Posts: 13,800 Drives: 2013 Nismo 370z Rep Power: 2684392	This is normal and nothing new, run it. It has been this way for many Z models. When it starts clicking rolling out in first or reverse, replace it.