77 280z T56 and z31 LSD drive shaft questions.

[Chris Laswell]

I'm swapping an ls1/Lm7/Gen III v8 into my 77 280z. I'll be using a t56 trans and a clsd from a z31 turbo....

Question is:

 

What do I do about making a drive shaft for it? I don't have a drive shaft now to source parts from... so what components do I need to purchase or who should I contact?

 

Thanks!

[Zfan1]

A drive line shop can build you one from scratch

[RebekahsZ]

Your town may have a driveshaft shop that can build you something. But mine does not. So, I bought my first driveshaft thru Johns cars Inc. it was great. Call John and he will tell you just what you need. I would not, however get a driveshaft from JCI if you plan to race-that driveshaft is for a street car only. If racing, call The Driveshaft Shop (google them). If you want to do this and do it once, get a steel shaft with either a forged or billet yoke. 1350 front u-joint. I think the largest rear ujoint that will fit the Datsun flange is a 1310. The auto guys can use a weaker driveshaft than us manual guys. A 240z really only has room in the tunnel for a 3" driveshaft, but a 280z has room for 3-1/2" driveshaft.

Edited December 10, 2014 by RebekahsZ

[weedburner]

I have built thousands of driveshafts for V8 swapped RX-7's over the last 20 years...1310 u-joints and 2-1/2" diameter, same materials that i use in my personal car (manual trans, 275 drag radials, good for 5.73 w/ 1.30 60').

 

1350 u-joints and 3-1/2" tubing are brutally strong, but the bigger/heavier parts only slow you down if 1310 and 2-1/2" can do the job. These cars are short, so no need for larger dia tubing w/ regards to critical speed. Smaller diameter driveshaft also allows for larger dia exhaust in the small rear portion of the tunnel.

 

Use quality 1310's (I recommend Spicer) and orient them so that the grease fitting passage is compressed under power. The cold forged Spicer Life 1310 joints are the strongest (and no grease fitting), there are people getting 1000hp thru those. 

[RebekahsZ]

Good to know. I went big after cracking a driveshaft where the tube welds to the flanges and twisting off 2 yokes, so I may be guilty of going over-board. Can you draw out what you mean about orienting the u-joints in compression?

[weedburner]

Placing the weaker grease passage area in compression (rather than tension) as power is applied will make it less likely to fracture.

 

For u-joints that have a grease fitting in the cross, the drilled hole from the fitting to the center of the cross is a weak area. If viewed from the front of the car, power from the transmission is transferred in a clockwise direction into the u-joint.

...Placing the grease fitting ahead of the slip yoke ear (as it rotates) will compress the grease passage area as power is applied.

...Placing the grease fitting behind the slip yoke ear will place the weak area in tension, making it easier for a crack to form.

For the rear u-joint, the grease fitting should be placed ahead of the driveshaft ear as it rotates.

[Phantom]

Weedburner - good info. Never knew that.  Where in WA are you?

[weedburner]

Western WA, near the North Cross Hwy.

[JMortensen]

Just use non-serviceable u-joints. The 4x4 guys figured that one out a long time ago. The newer forged cross 1310 should be strong enough for most people here.

 

I bought the driveshaft end from JCI and then had a local driveshaft shop make a 3" shaft for me. They told me that they could have sold me the adapter cheaper than JCI. Just FYI...