Kirkham rear differential query

[Dimis]

Originally Posted by Morris

FYI ...... we run 3 different Kirkham Diff with Quaiffe Differential in all three ..... and they were notorious for puking oil out of them ...... some folks had issues just driving on the street.....

Many folks had a problem with the oil going up to the catch can .... and filling the catch can up from the rear end....... Also you should notice the line drawn on the steel cover ....that shows the kirkham cover fill hole is to high and over filling is what a lot of folks did..... The aluminum Jag cover shows the correct height the oil level should be.....

We built this mod on the steel covers and tested at Road America/St Louis International/Road Atlanta...... and did not puke any oil out and were able to control our rear end oil temp down to 280*degrees from 320*degrees...... and yes we run a oil cooler and fan on our rear end cooler.......

Morris

Thanks Morris,
Most informative, but this raises my curiosity, so if I may, a couple of questions.

1) How does your mod on the steel cover actually work? ie: the reasoning behind it?
Doesn't the oil still heat up & thus pressure formed & thus hot oil getting puked up the catch can? or does it act as a physical barrier preventing the hot viscous oil from splashing up?

2) I'm going to need to add an oil modifier into my diff (as advised by Kirkham), so what ratio of oil modifier to oil should one be using to prevent going above the "yellow line" and puking oil everywhere if a) on the street, b) club tracking this car (not on slicks... so temps not as high as yours)?

3) Did you have any problems with increased temps & pressures blowing out seals? or was the catch can sufficient in reliving the pressures? Reason for asking is because it will determine how I go about capping the 2nd breather.

[fordracing65]

Im so confused.

[Morris]

Dimis

Without this mod ..... the oil can be slung off of the ring gear and directly into the vent hole ..... which will continously pump oil out of the rear end.

So we have installed 3 each barriers..... one to separate the ring gear side from the differential side of the spinning carrier..... one to stop oil that is coming off of the differential carrier .... one over the actual vent hole that only allows air to pass on 2 sides......

The major fence is the large one that is dividing the ring gear and differential.... that keeps the majority of oil on the gear side.

The oil that should be used is Mobil 1 75w140. this is the best oil we have tested and reduced our temp by 40-60*degrees. way better then all of the other products.

I've enclosed a photo to show that the one vent line is on top and the other line is oil cooler back in to flow oil where the ring and pinion meet.

The catch can runs clean now and no pressure from heat or motion.

Morris