Datsun Roadster Forum-311s.org

Given all of the discussion on prior threads that I’ve read regarding grease catchers and whether or not they should be gasketed, I thought I’d post a set of said gaskets to prove they really do exist. I wasn’t convinced for the longest time that they did, and still didn’t believe it until I held this set in my hands. Now, whether to use them or not is a whole other discussion

I am sure that some intrepid entrepreneur can laser cut those and make them available

Part is NLA. I just redid my axles without gaskets in September. No leaks (yet).

Back in stock:

https://www.ebay.com/itm/235329300080?h ... SwgNZdr0A8

Jon

I used two per side to replace the rusty beat up shims. I have some and going to order a few. Plan to change out to a 3.7 diff in the stroker.

We can make them if you guys want them. That being said. there is really no reason for them.

The gaskets were probably intended for use with the older style "non-rubber coated" grease catchers (made of plain steel).

All the later black rubber coated catchers seal perfectly against the brake plates, so there is zero need for a gasket.

Nissan used thin steel shims between the axle housing and the backing plate to locate the axle, not a paper gasket. If there were steel shims on your axle, you should use them.

Shrug, good luck finding shims. I didn't even bother to look and I was not going to make them. Measured the shims, measured the gaskets and it came out the same. I'll live with it.

We'll make them..both gaskets and shims. No problem. The reason for shims vs. gaskets is the shims don't crush. Gaskets will compress if used between the backing plate and the housing. The shims prevent side improper side load on the diff bearings.

JT, didn't you have something posted here earlier about side play? I take it that means axle end play? There's a couple old threads about the shims and end play. Guess I'll get myself a dial indicator one of these days.

I just ordered a dozen from Japan to have around if needed. Called Nissan dealer and he said it looks like someone bought up all the stock in the USA. Maybe later they'll be some more.

Hi Curtis, Personally, I don't think the spec is super-uber critical for street cars. Tons of axles have been installed without the little shims and I don't know of any failures directly traceable to that.

That being said, Nissan did install the shims because some one there considered them necessary- basically the axle should not be side loading the diff bearing and the diff bearing should not be side loading the wheel bearing and the (somewhat wimpy) wheel bearing/collar assembly. equal&opposite forces you know.

The bearing retaining collars are known to fail occasionally, so that is a critical part.

Ideally, the axle just "floats" in the diff splines and the bearings don't get side loaded. So any small amount of axle end play is probably a good thing and allows for thermal expansion of everything. (There is probably an end-play spec hiding somewhere in the old Nissan shop manuals). Obviously, the wheel bearing takes all the side loads during cornering.

It is interesting that in the overall context of automotive axle designs, roadster rear axle bearings don't fair too well. Most need replacement well before 100k miles. There are lots of wheel bearing assemblies on other makes that go past 300k with no issue from the factory.

Like I said above, if there are shims there, it is best to save them and keep them in place. I'll keep my eye out for a spec, but didn't see one in the FSM. Probably about .005-.010" as a rough guess. Almost certainly not a whole lot more than that.

The shims, as I was told at Datsun
Are to space the Axle away from coming in contact with the pinion pin ,as at the factory they had a slightly longer Axle tool if it hit or was close to the pinion pin they shimed it out ,it could get a different longer barely Axle at some point in its life and may hit or the diff had a bit of wiggle room too , I'd bet the axles were a vendor item