R200 Long Nose Lubrication

[260DET]

In particular the front pinion bearing, I've heard that in certain circumstances that bearing will fail due to a lack of lubrication.  Obviously power is relevant overall, I'm guessing that compared with the short nose the longer LN pinion shaft  would be more prone to flexing but the claim is that long periods of acceleration or hill climbing tending to drain oil away from the front is the more likely cause of failure.

 

So what I'm thinking of is making up a small scoop to fit up high inside the diff and connected by an external hose to a fitting allowing the oil caught to run into the front of the diff. Of course a pump would guarantee such oil flow but too much oil may cause pinion seal problems besides KISS is good.

 

Anyone with actual experience with this sort of stuff?

[nizm0zed]

Couldn't you just drive downhill?

Its faster too

(jokes, obviously)

 

Edit, As a serious answer, after looking at an assembly diagram I wonder how much room there is around the pinion shaft to place something similar to a sump baffle, to help keep the oil around the seal and bearing.
Youd want to make sure its not going to come loose though, it'd make a big mess if it made its way back into the gearset.
I wonder if you could machine a spiral groove around the body of the shaft to help pull the oil towards the nose of the diff, however I would be concerned that it may create a weakness along the shaft itself that could become problematic on a high torque vehicle under heavy loads?

(im not an engineer, so im just guessing)
They used to use a similar method on old distributor drive shafts (in gemini's anyway) to pull oil up to the top bearing.

 

Something like this?

Edited May 2, 2017 by nizm0zed

[260DET]

Wonder if that long spacer could be modified to bring oil forward like you suggest nismo, I wouldn't like to get the pinion shaft modified.

[44014]

Is it a problem? you rarely hear of anyone breaking a R200 that isn't a 1000hp drag car?

[nizm0zed]

Is it a problem? you rarely hear of anyone breaking a R200 that isn't a 1000hp drag car?

true, but machining a spiral groove around the shaft in the same direction as the torque twist loading down the shaft could weaken it substantially.

Or maybe it'll have no bearing on it at all. I don't know, im not an engineer and i don't have any experience with that sort of situation, just whatever logically makes sense to me.

That spacer would be a lot better to modify, but is it a sleeve around the shaft? Or an extension of the shaft? Like a short nose pinion shaft with an extra shaft keyed onto the end of it.

No doubt someone knowledgeable will chime in, maybe chuck it up on Hybridz too, they seem to have a few real smart guys on there

[Groundhog]

Or raise the oil level?

[260DET]

Is it a problem? you rarely hear of anyone breaking a R200 that isn't a 1000hp drag car?

 

The bloke with the race V8 280ZX, the proper one broke one (or two?) at Bathurst sprints 2016, heard of another one too.  

[dat2kman]

The internals of the main casing has a cast in upper channel, that permits the slung oil to mve up to the front.

 

This so called "race" zx, exactly what broke in that diff,,,,,,

[260DET]

There are at least two externally different R200 cases so I'm wondering if the internal channels are different, it may also be that those channels have insufficient slope to ensure that oil runs to the front in all situations. Just throwing possibilities around at the moment because the instances I'm aware of were possibly lubrication related. Anyway, there is nothing wrong with making an improvement even if it may not be absolutely essential.

[600Z]

If there is room you could get a spiral like a worm wheel turned up and press it onto that section of shaft

 

Obviously make sure it's the right hand so it's not dragging oil from there lol

Edited May 2, 2017 by 600Z

[dat2kman]

Still doesn't explain whay you did to your diff!

What broke, and how?

What oil were you using?

What centre did it have?

You broke one, or you broke two?

[260DET]

Not me you duffer Jason, tir33d post # 109 http://www.viczcar.com/forum/topic/14646-challenge-bathurst-2016/page-6

[260DET]

Had a good look at the case which is going to be used for  the Z31 project's diff and decided that a mod which will feed some oil to the front will do no harm and should do some good. The standard case has a drain channel at the bottom with a oil feed channel at the top which catches oil thrown up by the crown wheel, see the pic below which shows the drain channel on the right of the pinion hole and the feed channel on the left. However the feed channel ends in between the two main pinion bearings, it does not extend to the front where the support (third) bearing and pinion seal are.

 

So what I've done is drill and tap a hole from the outside into the feed channel and similarly at the front right behind the support bearing. Fittings in both are connected by a hose so the collected oil can run down hill to the front, pic shows this dummied up. The feed channel hole can be seen in the case pic, this setup should ensure that some oil is fed to the front support bearing and seal when the car is going up hill, particularly relevant to a powerful race car. 

 

 

[dat2kman]

You weren't able to get bigger tapped holes and fittings into it, like around 3/4" ones?

You'll work out that you just overfill it, by half a finger width on the fill hole, and run an extended vent tube, straight up through the floor, into a small can, then vent line up around and back down and out.

Solves foaming, bubbling up, expansion etc.

[260DET]

The crown wheel must throw a lot of oil up so the idea is that even a small fitting will catch a steady dribble of oil at least which will be a big improvement, besides bigger holes would tend to weaken the case.

 

Like the vent idea, source of a suitable small vent can may be a problem though, I usually use one of those small plastic universal fuel filters.

[Riceburner]

Not me you duffer Jason, tir33d post # 109 http://www.viczcar.com/forum/topic/14646-challenge-bathurst-2016/page-6

It says he sheared half the pinion gear off, there's nothing I could find about bearing failure from lack of oil?

 

I'd be worried about putting any foreign parts inside the diff. What about over filling like others have said, run a catch can in the boot with a line to drain oil back into the diff.

[260DET]

Yes, no reason given for that particular pinion failure but I have been advised about marginal front bearing lubrication, there is nothing put inside the diff with my mod. Overfilling the diff does not appeal, if you think about it there must be a lot of oil flying around inside the diff so the thought was to use that to improve oil distribution.