r200 front mount shims/height

[thedarkie]

Hey guys, this might be a rudimentary question.. or maybe not. I've got a V8 with a T5 swap, custom driveshaft and an R200 diff. This was all done by the previous owner. He mounted the front of the diff on a rubber isolator about 1/4" thick sandwiched between two washers.. the rubbers are cracked and ripped, and I believe Im getting a clunk from this area because of this setup.

 

My question is: if I get rid of the rubbers do I have to make up the lost height? How important is the 1/8" to 1/4" difference if I just ditch the rubbers and bolt the diff back down onto the washers (or even ditch the washers entirely)? I've never dealt with driveline stuff and I dont know how this change in angle/height will affect it. Is this variable something thats measured and accounted for when building and installing the driveshaft?

 

Thanks for your feedback

[thedarkie]

The front mount is from AZCar, similar in design to this one:

 

 

Edited April 28, 2013 by thedarkie

[NewZed]

Is this variable something thats measured and accounted for when building and installing the driveshaft?

 

 

 

The angle between the transmission shaft's axes and the pinion shaft axis should be parallel to avoid u-joint motion induced vibration. RTz's dff mount design drops the nose of the diff because he designed it for a V8 application.  An RTz-style mount might be better all around for you, with the right angle and a urethane piece to damp diff whine.

 

Pretty sure I've seen accounts of the solid mount causing fatigue cracking of the cross-member.  If you have a stock mustache bar the looseness of the end mounting points will put a lot of stress on that solid mount.  They'll move but the solid mount won't

[thedarkie]

Thanks for your reply. I too saw the discussions of front mount failures due to the rear flexing. With that in mind, it seems that I should either look to buy an aftermarket billet mustache bar, or an RT style front mount.

 

With the RT style mount being a 'one for all' design, and V8 swaps being inherently different from one to the next, does the angle of the diff have to be measured and adjusted during installation? How can it be a bolt-in affair, unless the tolerance -/+ 1/4"-1/2" just isn't all that important? That's my original question anyway: how much does 1/4" up or down on the nose of the diff really matter?

Edited April 29, 2013 by thedarkie

[z240]

First read this to get a sense of what's important in drive shaft alignment.

 

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

 

R/T mounts when used simply as a replacement for the strap, ie the tiny bump stop/snubber above that just touches the diff nose, and complete use of the stock cross member and stock diff mount, do nothing to change the stock diff nose location. At best it means you put it back to the right spot when you replace your worn diff mount/insulator with a new one.

[thedarkie]

Yeah I realized that after looking at the technoversions site, though they offer the mount in a configuration that replaces the stock bottom mount entirely. Alas, as per original post, I already have an Arizona Z car mount and my question remains if lowering the nose of the diff by about 1/4" will make a big difference or if things will still be okay. 

 

Seeing as I already have the rigid front mount, I may be better advised to also just get a billet mustache bar and call it a day. Adding the RT mount to my Arizona Z Car mount doesn't sound like it would be beneficial at all, except as an additional stop.

 

(thanks for the pdf link, reading it now)

Edited April 29, 2013 by thedarkie