Differential part number?

[jcote75]

Hi,

Drop the differential last night and notice the part number on top which is: 38311 N3100

Been searching around to found out from which model it is and can't find nothing.

Help would be appreciated since I wan't to change a few seal and gasket.

Thanks as usual,

Joce

[Zealous]

I believe that is the part number for the housing of an R200 but as to the model I am not sure as I think the same housing was used for the majority of R200s. Not sure if that helps maybe some of the more knowledge people here can help.

Cheers

JC

[jcote75]

Thanks.

The housing is offset on the driver side. I guess this confirm it's a R200.

Next is the found out what the gear in it. I'll try counting turn tonight.

Is there a way to know if it's a LSD without opening the differentiel? It doesn't have a vent cover. Is this how you identify them?

[sblake01]

The 38311 part of the number seems to indicate that it's an S130 differential according to my research materials but I can't find the N3100 coupled to it anywhere. Also the last five digits of the R180 limited slip differential part numbers end in 15, 16, or 20 so yours is not a limited slip. If it's offset to the drivers side, it's not an R200 but rather an R180.

Edited November 5, 2008 by sblake01

[jcote75]

oh oh....... I'm getting mix up!

Check the following link

http://www.geocities.com/bry593/diffswap/diffswap.htm

Here is a copy of what that wesite is stating:

"At first glance, the assemblies look very similar. However, the R-200 on the right has a wider center, offset toward the driver’s side. To accommodate the offset, Datsun engineers designed the driver’s side halfshaft 3/8” to 7/16" shorter than the passenger side. For this reason, be careful not to mix these up and don’t use R-180 shafts on an R-200."

[sblake01]

My scans are from the Nissan Competition Parts catalog. As you can see, the R200 is larger (as it would be). One must be careful when reading info on a site that's based on someone else's observation. To say that it's 'offset to the driver's side' would actually be true in both cases though more visable on the R180 at a glance. Which one does yours look like?

[jcote75]

true

I'll post a picture tonight but it definetly look like the R200 in your picture.

[sblake01]

I just go by the size and shape of the cover. Octagon-R200, smaller and semi rectangular-R180.

[Zealous]

Perhaps posting a picture of the differential would help?

Edited November 6, 2008 by Zealous
Ok just saw the new posts, Moderator please delete this post

[John Coffey]

To accommodate the offset, Datsun engineers designed the driver’s side halfshaft 3/8” to 7/16" shorter than the passenger side.

And, after measuring dozens of halfshafts from 280Zs, 260Zs, and 240Zs I have yet to find any variance in length. I've also had a couple Z racers measure the halfshafts in their piles and a couple parts hoarders measure halfshafts in their stashes. So far, no luck in finding a S30 halfshaft that is any shorter fully compressed then any other S30 halfshaft.

[sblake01]

I was going to comment on that point also as I've read that somewhere before but I've never seen an S30 halfshaft that vaired in length from any other S30 halfshaft.

[Gurmal]

I have the same rear-end for my 240z.  I bought 1982 280zx 2+2 unmolested and that was the original rear end out of it.