Custom cooling a transfer

[joshg123]

As most tx3 owners would know, the gearbox's in our cars are notoriously weak. In particular the transfer. After much reading, there are two modifications i can do to my transfer to make it much stronger. One, is to modify the bearing position. And the other is two have good cooling of the fluid, as it is a seperate case from the gearbox. It gets pretty hot, and this is said to be the cause of many high power failures (clutch dumps are another story).

So i had an idea to get two new sump plugs (filler and drain), and machine a hole into the centre of them, then braze or weld speedflow fittings into the centre of them. Then using braided hose, a scavanger pump, and a small front mounted oil cooler to circulate cooler transfer oil through the unit. Thus keeping the operating temperature down, and hopefully, lengthening the time that the box can handle 300whp through it (or round abouts that figure)\

Can anyone think of any pro's and con's of doing a setup like this?..... I was told the oil might cavitate with the pump pushing. So if i had the pump on the hot side of the cooler then maybe it will suck, rather than push.

Any comments much appreciated

Josh

[SilentKilla]

Are you sure overheating is the issue rather then gears being made out of glass?

[Lump]

pump should suck out of the sump, (if it sucks air it will cavitate), then feed the cooler & return to sump
maybe try a oil temp gauge first to see what it gets too, at least then if you do it you should see an improvement.

[LarryDavid]

not really sure what sort of pump you mean by a "scavenger pump" but when you talk about "sucking" the only relevant pump would be a self priming pump.

generally pumps (e.g centrifugal) do not “suck” fluid. they rely on there being sufficient pressure on the inlet side, and then add energy to the fluid. when the inlet pressure is not high enough, the pump will cavitate and fail to pump the fluid, and this can still happen even if the pump is not running dry. so for example a centrifugal pump located above the fluid level will generally not pump the fluid.

a self priming pump however is capable of producing enough vacuum on the inlet side to draw the fluid to the impeller, even if it may be below the pump. In this case the pump cannot “suck” rather than “push”. how is a pump going to suck the fluid without pushing it, or vice versa.. just something to think about

anyway you would want your pump to discharge through the cooler, with the inlet close to the oil source. You want to be very careful in selecting the pump and line sizes, as it could be very easy to guess something which looks good but may not work at all.

Also be aware that you will still get a lot of heat tranfer from your engine/gearbox to the transfer case. So I don’t know how much point there is in just cooling one of them.

Hope I wasn’t too confusing!

[Lump]

"not really sure what sort of pump you mean by a "scavenger pump" "

i think he means like the oil pumps in a 911 dry sump, extra one used for the oil cooler.

[Z24O]

what about modifying and running an "in sump" oil pump externally of a pulley/belt....not sure off what engine....just thinking outside the square(ok it is a very big square)

[Z24O]

.....can't stop mulling this one over,what about a power steering pump?

[joshg123]

hmmmm, u can actually buy scavenger pumps for this purpose, my problem was that how do u get the oil there and back without cavitating it.

Never to worry, shitty mazda box, celica box here we come.

[Lump]

you stop cavitation by not letting the pump suck air, having too much intake restriction or too many pump revs