Found an r180 3.90 4x4 differential but....

[SledZ]

Well I found a R180 3.90 out of a 83 Nissan Truck front end. Went through all the work to swap it out and it sounds like a truck! It has a growling kind of noise and I don't think I can drive around that way. It looks almost brand new as you can see in the picture compared to my original, any ideas of what could be wrong? Hard to believe the bearing are bad...?

[g72s20]

Could it be that it is actually turning backwards? If it was from a front diff wouldn't the crownwheel and pinion be for the reverse direction? Had to chase up a different set of gears for a Toyota Landcruiser front diff once, and the front diff gears were specific for the front, I.E. the tooth pitch was opposite to the rear diff. Just an idea....

Jim.

[kenz240z]

You may consider taking it to a driveline shop and having someone insure the bearings & seals are good. Hopefully it can be inspected & set up to work well without costing too much. It sure looks clean inside, you'd think it would be great shape.

[nwcubsman]

Could it be that it is actually turning backwards? If it was from a front diff wouldn't the crownwheel and pinion be for the reverse direction? Had to chase up a different set of gears for a Toyota Landcruiser front diff once, and the front diff gears were specific for the front, I.E. the tooth pitch was opposite to the rear diff. Just an idea....

Jim.

I spoke to a Datsun mechanic about this very topic this week. I had heard that very thing, about them whining since they are turning backwards. He says that is BS. He says the problem is that they get set up slightly differently from the way they wore in and they make noise. I happened to ride in a friends car that Beandip was driving today. It has a 4.11 R180 from a 4x4 and no noise. I don't think Beandip noticed anything either. How bout it Beandip??

I know this is all hearsay, but this guy has a solid reputation. Escanlon uses this guy also. But then, who says Scanlon knows anything. Just Kidding, E!

[jmortensen]

There are reverse rotation ring and pinions and they are put into the front of 4wds. The reason is that driving the ring and pinion on the "drive" side of the gear is stronger. Dana 44 is available in a high pinion reverse rotation, as are some Toyota front diffs and many others. In the Datsun truck the ring and pinion the gears are not reverse cut, and when it is in the front of a truck it drives on the "coast" side of the gear. So the gears are turning the correct direction when you install it in the rear. I have heard that the backlash setting was set a little different due to them being driven backward, but I haven't run one so I never checked.

[nwcubsman]

Nice explanation Jon!

[=Enigma=]

This might also explain why going in reverse is so loud.

[beandip]

I agree with nucubsman , about the lack of noise from the diff. However the streets were wet from a light rain at the time and that could have muffled a slight whine . I did however hear a slight whine in my own diff on the way home , go figure . Gary Yah what does es know any away ??

[SledZ]

Hmm so I'm not sure what to think the problem is. That reverse comment is right on, it sounds exactly like being reverse all the time! If I didn't have it back up on my casters I'd drive it in reverse to see if it was quieter...

If I took both of them in to a transmission shop do you think they could figure it out or make one good one out of both of them? I guess I should plan on it and see if the mystery can be put to rest.

I never should have went to the Upullit that day that truck was there... oh what a lot of work it was...!!:knockedou

[nwcubsman]

Hey Steve,

Don't get down on yourself. The only way to know for sure what you are going to get is to either, pull it out of a car that is running and swap it in directly or buy a new gear set (ouch, about $900 is my understanding). I have been on the lookout for 4.11 R180 but haven't found one yet. I'd be in the same boat as you. I'd talk to a tranny guy, especially if you know and trust someone. Get a price and an idea if it will help. Keep us informed!!!

[John Coffey]

Just take it to a driveline shop and have them set the backlash correctly. I've run a number of R180s out of 4x4s (4.56, 4.38, 4.11) and one needed the backlash reset.

[jmortensen]

I agree with John. In fact I'd just pull the cover and check the b/l. On the R200 its supposed to between .005 adn .007. If yours was outside that spec, then it could be adjusted if necessary.

Here's more info on diagnosing diff noises in general, what bearings sound like, noises under load, noises while coasting, etc. (1st 2 links on this page):

http://www.ringpinion.com/content/technicalhelp/default.asp?pid=45