Rear End

[James]

So - I was re-doing the rear brakes on my 72 510 today - had the car in the air, and when I was rotating wheels, I noticed a noise/vibration in the rear end. I disconnected the half shafts to eliminate the wheel bearings as a possibility - but yes it is the rear end. I want to keep it on the road. Its been sitting for a bit, and sitting is not doing it any favors.

Car is essentially stock (slightly upgraded engine - L18 bottom end, closed chambered a-87 with a cam and su's). It has a Z 5 speed.

So - I guess I could hunt down a clsd but it will likely have a 3.70 gear (probably not the best with a small engine and the 5 speed). Not sure I would ever put the lsd to use in reality, but maybe it would make sense?

I'm in so cal and I know most of you on this site are PNW/Canada. Anyone have a decent used open 3.90 or ? that they want to sell.

Thanks, James

[icehouse]

If you are just cruising around I would just keep 3.7 the 3.9 won't even be noticeable for acceleration just more noise at high speeds.

[datzenmike]

Agree, and you have the warmed over L18 anyway: that will pull 5.1% more gear, yet not powerful enough to need two driven rear wheels.

[James]

I must have made it confusing. My car has a an open (stock) 3.90 in it. Was just seeing if someone had pulled one to put in an lsd that they wanted to unload. Thanks for the input!

[iceman510]

James, I have one 3.90 welded R160 if you have interest in trying that. I also should be able to come up with a stock 3.70 R160 if you want. I also have a 610 rear diff here, but not sure what ratio it has. I have never checked, but can.

[510rob]

James, your original post was crystal clear to me:
1) you are sniffing around for a replacement rear diff that isn't clunky and tired (like all of us!)
2) you need at least a stock open 3.90 R160
3) you are asking about positives/negatives of using a 3.7 CLSD R160

" Anyone have a decent used open 3.90 or ? that they want to sell."

[James]

Iceman - welded would not be for me - but I may follow up with you on one of the other options. Give me a week or so, and I'll let you know one way or the other.
Thanks!
James

[yenpit]

FYI an R180 out of a DATSUN (not a Subbie snap ring stub axle cuz they require the $450 custom stub axles) will bolt RIGHT IN, no mods, use the R180 stub axles & your stock 510 axle shafts. However, you are limited to the 240Z 3.36 or the 280Z 3.54. There are 3.7 3.9 4.11, but they are all harder to find, as they were Maxima rear diff & 720 4WD front diff. Some of these later DATSUN R180's were also snap ring stub axles.

Also, if you have somebody ship one, you better be sure they know HOW to pack it well! We have had two shipped in to us over the last few years, the sellers basically threw them in a box with some paper packing............both boxes were completely destroyed, cuz the big heavy diff bounced around. We were lucky BOTH times to have gotten them, cuz it was NOT the carriers problem, it was the seller/shippers problem with packing!! A seller MUST stuff the box tightly with packing AND use heavy duty white strap tape all around the outside of the box.............clear packaging tape does not hold up to that kind of weight. Good luck in your quest!