How to properly plumb and fill Quaife Transaxle when using external cooler pump and cooler?

Skip Markley

Supporter
I have a Quaife QBE62G 5 Speed Transaxle. I am adding the external oil pump to pump oil to the cooler located on top of the battery box. Because the cooler is above the transaxle I am worried that it will drain back to the gearbox and overflow into the clutch area when parked. Anybody have advise as to how to plumb this and avoid the problem?
 
Hi Skip,
personally I wouldn't be concerned about this issue, the oil seals on the output & input shafts will retain the oil. Generally the oil fill on these type of transmissions is to the centre-line of the diff, so adding an oil cooler won't be an issue

Regards,
Andy
 

Skip Markley

Supporter
Thank you for your responses. I did slightly overfill my transaxle initially by removing the upper level plug, filling the unit until oil came out and then installing the plug before the overflow stopped. This was enough to cause leakage from the input shaft seal into the bell housing and clutch and leave a puddle on the floor underneath. Problem fixed by removing the plug and allowing the excess to come out (about 1/2 Qt). So this is the reason for my question: if I must maintain that level and no more, how can I do this with the cooler in the correct position above the battery and hence above the transaxle?

A check valve would work on the pressure side between the pump and cooler (to prevent backflow) but what will prevent the oil from draining from the cooler to the transaxle sump?
 

Skip Markley

Supporter
Maybe the real answer is that the cooler, lines and pump hold an insignificant amount of fluid - fill the transaxle to the high level plug and then let the system stabilize? Maintain oil level when cold and oil has drained back from cooler? Would welcome your thoughts - Thank you everyone!
 

Howard Jones

Supporter
I have a cooler fitted to a R21 Renault in my GTD. 350HP SBF. The first thing is it's not needed. I also have a temp sensor in the GEBX so I can monitor lube temp. On the street, the oil in the transaxle never gets above 160-170F and that's after hours on the highway @ 70-75 MPH. On track (very hot day) for 30 min stints, I have never seen it anywhere near 200F. That data is with the pump off. That's just not hot enough to need to cool the oil.

How do I accommodate the additional oil? I just add the amount that it takes to fill the cooler and lines. The pump inlet is low, below the oil level of the GRBX so it primes fine. The oil returns to the top of the ring and pinion and 5th gear area and I have a filter in the "to pump" line and the cooler is about 3X7 inches. I think I add about another 1/2 quart. No check valves necessary.

An extra 1/2 quart isn't enough to concern yourself. On a Gal that's about 10%. Better 10% too much than 10% too little.

Skip, drain the GRBX, and put back the required spec amount. You don't need a cooler in a streetcar.
 
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