Dumb question.

Anyplace that sells NEW ring and pinions for a R180? Or am I stuck using the old set and replacing only the bearings and seals?

Thanks!

Polecat

Don't think you'll find a ring and pinion for an older R180. In 1976 I think it was they changed the ID of the ring gear and so you have one set of gears for the older cars and another for the newer cars. They're still using the R180 today, so if you want to find a different ratio or if yours is making noise, finding a used unit is an easy way to get what you want. If your diff isn't making noise, change the seals and call it a day.

What JM said, I think you would be hard pressed to find anything on a car that can take more abuse than the diff gears. If they aren't whining, clunking or grinding, there good.

I would however recommend taking it to a shop to have it set up properly. I can't speak to the R180 per say, but I have done a couple of Ford 9" and Dana rears, and its a PITA to time the gears without the proper gauges. I used plastigauge, and it takes a lot of patients and time to get it right.

What you need to set up a ring and pinion is a dial indicator and magnetic base and gear marking compound. Plastigage shouldn't be used for setting up a ring and pinion. It is meant for bearing clearances and that sort of thing where you bolt on the bearing cap and torque it down, then take it back off and measure how much squish you've got. There isn't a way to measure backlash with plastigage because you would have to TURN the gears in order to get it into the ring and pinion where they mesh. This would be roughly akin to putting plastigage on a main bearing and then spinning the crankshaft.

Gear setup manual: http://www.ringpinion.com/Content/HowTo/TechnicalInstructions/Yukon_Installation_Kit_Instructions.pdf

Actually, Nissan Motorsports USA has one new 4.88 110mm ID ring and pinion available. $660 last time I checked.

What you need to set up a ring and pinion is a dial indicator and magnetic base and gear marking compound. Plastigage shouldn't be used for setting up a ring and pinion. It is meant for bearing clearances and that sort of thing where you bolt on the bearing cap and torque it down, then take it back off and measure how much squish you've got. There isn't a way to measure backlash with plastigage because you would have to TURN the gears in order to get it into the ring and pinion where they mesh. This would be roughly akin to putting plastigage on a main bearing and then spinning the crankshaft.

Gear setup manual: http://www.ringpinion.com/Content/HowTo/TechnicalInstructions/Yukon_Installation_Kit_Instructions.pdf

Which is why I recommended taking it to a shop, an old timer showed me how to with the plastigauge under a shim made out of feeler gauge material spun through the gears to measure lash. Hense the PITA.