What I am hoping to find with this thread is basically stock operating driveline angles for the S -30. Some folks just refer to them as pinion angles, but I would like to know all the angles from trans to diff. Since my car is not stock having the newer Nissan T-5, I had to alter the trans bracket to mount the trans, so offering up my pinion angles would not be stock.

I am trying to come up with is how Nissan set the angles up for such a short driveshaft. I have been having vibration issues at higher speeds and I am almost positive it is the DS. I have set the angles to what SHOULD work by reading about it, but the Nissan engineers might have had something different in mind with these chassis.

I guess I am asking of those who have done this before and know how to take these readings. When I did mine I took my measurements off of the U- joint caps

This is my favorite reference:

http://www.roadranger.com/ecm/idcplg?IdcService=GET_FILE&dID=287236

The other trick I like is putting a laser pointer into the end of the transmisson so that you know EXACTLY where it points on the plane of the diff flange. Or visa versa. Of course the trick is building a "thing" that slips on the trans splines and supports the laser point in its center... Let google be your friend.

There's many methods to setting up the driveline. I'm after someone to measure their driveline angles and report in.

I might eventually find someone to come over to my place to measure , but meanwhile I am hoping to compare to one of you guys.

I guess I will be on my own for this one. This would benefit those of you that did the RT mount and are using the GM mount ,or have done like me and switched to the T-5 trans.

Steve,

I have a 73 with the RT mount and the GM mount. I had this installed a few years ago as part of a major (suspension, bushings, bearings, brakes, etc) refurb and really didn't drive the car at highway speeds until last year. I found that at speeds over 65 the car felt "uncomfortable" with a subtle vibration. I had the front end rebuilt/reviewed last winter (including tire balance and alignment) by Eiji at Datsun Spirit and then I had him install an 82 5 speed with corresponding 3.90 R180.

Guess what? Even though the engine was now turning fewer revs at 65 the same "uneasiness" was still there!

The next step was new tires, but when I had them installed last week the shop told me that all six u-joints had play. What? I had all replaced less than 1,000 miles ago by a very reputable shop.

Could this be related to change in pinion angle caused by the RT/GM mount? Then I read this thread about the Ron Tyler Mount, which I'm sure you've seen too.

Right now I'm waiting for a new driveshaft and heavy duty half-shaft u-joints from MSA. I going to replace the GM mount with the Energy Suspension 9.9101G bump stop ($11 from Amazon) to see if this makes a difference.

TechnoVersions, which now sells a similar diff mount has some interesting comments about driveshaft angle, which has sent me in this direction.

Of course, this is all guess work on my part.

Peter

I'm assuming your 5 speed is the Nissan? Then the only angles that changed for you was the Techno mount- which is what I am running.

The GM mount changes the angle by at least 3 degrees.

Keep us updated.

I just put a 1983 ZX 5 speed in my 73. I had restored the tranny cross member on the tranny I removed and it had a brand new tranny mount and a 1/2 inch spacer (between the tranny mount and the tranny), so I used that crossmember, tranny mount and spacer. When I test drove it, everything was fine except when I stopped and made a hard right turn. At that point it made an irritating vibration noise on acceleration that lasted a few moments......kinda made you want to throw up! I kept driving it and it kept sending me weird vibrating signals that something wasn't right. I took it back to the house, raised it on the lift and proceeded to take off the crossmember, mount,and removed the spacer. Went back without the spacer......on the 2nd test drive, everything was perfect. A half inch spacer bunged up the works.....amazing how critical pinion angles to smooth function of the drive train are.Peter.....get rid of the GM mount....it's your problem. Steve keep using spacers to raise or lower the rear of the tranny until you get it right. When you finally get the correct angle, you'll love your cars again.

Edited October 2, 201311 yr by Diseazd

Thanks for sharing. It's true that 1/2" can make a difference. A half inch can be as much as 3 degrees nose up or down and throw everything off. That's why I was hoping to document some actual degree numbers for future reference. My vibration is much more subtle than yours and occurs at high speeds, so it makes it harder to diagnose.

This might help.....Guy

Nice tool to check angles....

Here is another great angle measuring tool.

Its small enough that it may fit above a Z drive shaft, and even better, because of its small size and square box shape, you can put it on the bottom of the shaft. There seem to be many varieties of this gauge available now.

Because the car is likely not parked on a level surface,or when up on jack stands or a hoist. The angles you read may not be actual drive shaft/Trans or Dshaft/Diff angles.

Measure the engine/trans angle by measuring the angle at the valve cover. Then measure the driveshaft angle and subtract the two. keep up/downhill straight.

The diff is more problematic. No flat top or bottom to use as a reference. Have to take the drive shaft off and and measure the flange face angle, then subtract 90.

Use the same dshaft angle minus diff angle thing to get that angle.

The trick is to get them both (trans/shaft and shaft/diff) the same, and both between 1 and 3 degrees. You need some angle to make the u-joint move all the bearings and stay lubed, but not more than 3 deg to minimize vibration.

Also the trans centerline and diff center lines must be parallel. This is pretty hard wired if you're using the stock mounts, but worn engine and or trans mounts will contribute their own error.

DIY laser tool.

Differential Laser Alignment Tool - Powertrain - HybridZ