I need some dimensions or pic moustache bar area

[madkaw]

I made my own RT mount for my diff and I'm thinking I didn't make it quite right and it is causing my clunk in the rear. I'm looking to compare my spacing between the moustache bar and rear control arm down braces to your set up. I think my diff mount pushed my diff and moustache bar back too far and it is hitting my braces for the control arm.

Pics or a measurement would be great showing the spacing between the two.

I am running a r180 diff and moustache bar

[madkaw]

Anyone- please!

[Mikes Z car]

I have an early 240Z (MFR 1/70) and I remember reading the moustache bar is flipped over for my car compared to yours meaning I think there would be much less room between the moustache bar and the suspension hangar for you than what is seen on my picture. Maybe you need a picture aimed straight up between the two?

I might be the only one having difficulty figuring out exactly what you need to see. As I have rambled here you have helped me figure out what they meant by flipping the moustache bar over in converting my rear end setup to the setup you have for the later Z.

Mike

Edited July 18, 2012 by Mikes Z car

[madkaw]

Mike,

The first pic was what I was looking for. It looks like you have about an inch between your moustache bar and the vertical brackets for the control arms. As far as what they did with the moustache bar on the later 240's, I'm not sure, so enlighten me. I thought I remember reading that they changed things ,but I can't remeber why or how.

I was also hoping someone will chime in that has installed the RT mount with their r180 diff.Hopefully a model later than 71

[Zed Head]

Clunking would be caused by looseness. Do you have any loose fits on the diff's points of contact with the body, the two mustache bar ends and the mount itself? And the two nuts and studs that bolt the cover to the bar? And did you use a snubber and keep the original mount, or a GM mount and removed the original mount?

I have a self-made RT-style mount and poly bushings on the mustache bare ends and don't have any clunking beyond the lash in the diff gears. I'm using the poly GM trans. mount though so the nose of the diff can't move any farther than the urethane flexes.

If you had a misalignment in your RT mount you would probably a get drive line vibration, but not necessarily a clunk.

If you show a picture of your setup you might get some constructive comments.

[madkaw]

Well I thought I had some pictures, but I must have deleted them and I am out of town.

I used the GM poly mount and have removed the lower mount. I have checked everything, but I will check again for tightness.

Mike posted a pic of what I was looking for, but his year is so early that his moustache bar is straight, which is different then mine. I was looking for the spacing or gap between the moustache bar and the down-brackets. With a curved-type moustache bar it will be closer than Mike's car. I think mine is too close and with any flexing of the moustache bar it is coming in contact with the down bracket and creating a clunk. Now that I am running a R-180 STI limited slip, I believe the flexing might be more prevelant-coupled with the fact that the r-180 moustache bar is not as strong as the r-200.

Also, I had done some reinforcement-gussets that actually connect the control arm brackets which makes the clearance even less.

I will post this pic of my set-up with the r-200, so you see what I mean

[Zed Head]

I get it, I missed the point. Wouldn't there be signs of rubbing on the bar and brackets if they were touching when clunking?

[madkaw]

Those rubbing points would be difficult to see because they would be close to the top of the bar, which is very hard to see. I will be taking a closer look this week when I get time. Meanwhile I was wanting to look others and see how their spacing was.

[Zed Head]

An experiment that might tell something would be to lodge a piece of rubber or urethane or maybe even wood in between the bracket and bar to see if the clunk goes away.

Just a thought. I'll let the R180 guys in now.

[Mikes Z car]

Steve,

From memory of another thread, on the moustache bar being flipped, the early 240Z had the diffy a few inches forward towards the front of the car compared to later 240Zs. This meant the half shafts came back from the diffy towards the wheel at an angle instead of straight out like on the later Zs. The change was supposed to reduce noise. This new setup apparently required the moustache bar to be flipped over 180 degrees around its length so it provided support further back than the original setup. Others I feel sure understand this better than me.

Mike

[madkaw]

Dragging up an old thread and still a problem. Hopefully these pics will help folks see what's going on. The only thing different from this initial post is that I bought a Techno version of the RT mount thinking I had made mine wrong.

The only time I hear a thud(not really metal clunking sound) is sometimes letting out on clutch taking off or stabbing the throttle slightly in a higher gear at a low speed. If I was to picture what's going on I would think the moustache bar is slamming into the downlinks during this heavy torque moments.

I have a very quiet running gear other then that.

I do support the front of my diff with a trans mount and no bottom diff mount. I can get the diff to line up with the stock diff mount very easily, but I don't run it because it raises the front of the diff enough to cause diff whine and noise.

I tried flipping the moustache bar around(loops are to the back now) and this gave me clearance but pushed the diff beyond the Rt mount hole by an inch. It did give me lots of clearance in the back, but I would have to do something different up front to the mount.

I added gussetting to the downlinks that adds material to the inside edges of the downlinks. I wish I could get a better picture of this but it's hard to get the camera in there.

I didn't see much evidence of contact when I swapped the moustache bar around, but honestly I should have taken a better look.

Edited June 3, 2014 by madkaw

[Zed Head]

Is there play in the mustache bar bushings? Can't tell if you're using urethane or stock rubber. When you hit the gas the front of the diff lifts up and the back, with the mustache bar, gets pressed down. Pivoting around the axles. Maybe you're hearing the mustache bar bottom out on the washer and bolt at the end of the mounting shaft. You could probably tell by grabbing the bar and checking play, from underneath..