My New Diff Mount and Strap Project

[Zed Head]

On 8/13/2016 at 4:49 AM, grannyknot said:

ZH, your metal strap design does everything the R/T mount does but is simpler, easier to install and lighter, thinking of going into production?

Thanks GK.  I don't think that one product would be enough for a business though.  Plus I didn't keep the jigs, which were a patio expansion crack and a saw kerf in a log.  And a spare parts car in the garage for trial fittings.  I did it mainly for the challenge and because the new rubber stock mount was $70.

I think that somebody with a big metal brake could pop out one piece steel mounts that would use the four mounting holes in the body.  No welding, just two  bends and five or six drilled holes, depending on GM mount or snubber..

[Tomcat]

On 8/12/2016 at 8:44 PM, Zed Head said:

The leather one?  Won't you need to apply conditioner on a regular basis?  Or the timing belt?  Probably only good for 80,000 miles.

https://zcardepot.com/driveline/rear-axle/differential-arrestor-band-goto-240z-260z-280z.html?search=differential

https://zcardepot.com/driveline/rear-axle/differential-diff-arrestor-band-belt-rear.html?search=differential

I like the nylon strap.  Same material as towing strap, it could be rated for 30,000 lbs.  https://www.amazon.com/Smittybilt-CC330-30-Recovery-Strap/dp/B001CF4UXU

I converted mine to metal.

 

I'd like to have one of those!

[Tomcat]

Socket head cap screws ... excellent idea ... wish I'd known that LAST weekend. To tighten the bolts on mine I took off both rear wheels, got a long flex-head ratchet on the top bolts with the handle pointed toward the gas tank, and reached through the fender wells to grab the handle. I was only able to turn the nut a single ratchet click or two at a time. To an outsider I'm sure it looked like I was artificially inseminating the car.

I'm an EE too, but this Z sometimes makes me wish I was a mechanic/welder/bodyman/psychic instead.

[Captain Obvious]

Haha! Sorry. I had the work done before the prior weekend, but was too rushed leading up to Zcon to get something posted. File it away and if you're ever psychic enough to find yourself messing with that thing again, do the hardware switch then!

And as for your posture working on yours... Pics or it didn't happen. 

 

[Namerow]

On 8/12/2016 at 9:30 PM, Namerow said:

After measuring for proper length, I sewed the loop on the second end and it looks like this. Like I said, I'm no seamstress. I was focused more on strength than looks:

Question for CO:  How did you do the stitching?  By hand?  Household sewing machine?  Jobbed out to your local shoe repair shop? 

[Captain Obvious]

I stitched that blue one myself on an old household strength Singer machine that came to us from my Mother-In-Law. Here's the whole story about the sewing process...

I made that blue one as proof of concept. Easy peasy. As soon as proof of concept was a success, I pulled the trigger on the higher quality material from McMaster. The black webbing arrived and I started making a better strap to replace the blue one. First thing I did was doubled up the black webbing for additional strength. That worked fine, so I figured "If two layers was OK, then three would be even better."

Well not so... I blowed up the sewing machine. Ripped the teeth off one of the plastic gears inside. I knew I was overtaxing the poor old girl, but I pushed ahead anyway and she made it clear that she just couldn't handle the strain.

So since then I have learned more about sewing machine repair than I ever wanted to know, and I have purchased and installed a replacement gear as well as clean, adjust, and lube the whole thing. So at this point the machine is back to better than before I started, but I haven't gotten back to working on the final strap yet. I do know, however, that my household grade machine can deal with two layers of that black stuff, but not three.

I really didn't need to triple it up anywhere, but it was the over-engineer in me. When I get back to it, I'll either farm out the final sewing, or I'll limit my layers to two.

[sweatybetty]

i have some old seatbelts. i bet they would work. maybe fold in half length wise and sew them up

[Captain Obvious]

I do too, and I looked at using them for this project. They're very flexible and I think that kind of webbing would work fine, but the reason I didn't use them was because of the age. Most plastics deteriorate with time and I didn't want to use 40 year old plastic webbing. I wanted new. I wouldn't use the old stuff. Webbing is cheap.

[sweatybetty]

newer car at a wrecking yard, pick your color.

[Zed Head]

On 8/16/2016 at 5:01 PM, Tomcat said:

I'd like to have one of those!

Thanks Tomcat.  Maybe Ryan from zcardepot can work up his own variant.  I'm surprised he doesn't have something like the RT style mount, considering how fast his development work is going on other areas.  His new Ford diff mount shows some imagination.

[Captain Obvious]

One of my off season projects for this year was to replace my temporary light duty nylon web diff strap with a more substantial version made using a stronger webbing which I purchased from McMaster. I also figured out a simple way to adjust the webbing tension to account for stretch that may occur over time.

Here's what I started with. The blue webbing is whatever the local hardware store had on shelf. Worked great for the six months it was on the car, but I had already planned on replacing it after proof of concept. The black webbing is McMaster P/N 3510T83 - Shock-Absorbing Nylon Webbing, 1-1/2" Web Width, 5100 lb Breaking Strength:

To adjust the strap tension, I designed a new adjustable anchor bracket for the driver's side mount. I had originally planned to put these new brackets on both sides, but the diff doesn't sit in the middle of the tunnel, and it was an uncomfortably tight fit on the passenger side. With the help of our resident sheet metal magician @disepyon doing the bending for me, here's what I came up with:

Here's the adjustable anchor assembled. The strap loop goes around the center shaft and the bolt slides in the slots to adjust:

Here's my new strap in place. Original anchor on the left in the pic my new anchor on the right in the pic (driver's side):

And here's my adjustable anchor bracket in use. Loosen the bolt, pull down until desired tension is achieved, and then tighten the lock bolt through the middle:

Works great!! Thanks again disepyon for the help!!

[disepyon]

Anytime! Looks great.