[B]DISCUSSION ON OIL COOLERS: Manual Trans & Diffs[/B]

**Rhyno** · 08-06-2011, 02:19 PM

Hey all,

Been doing a fair bit of research for my current project, and have been looking at Manual Transmission and Diff Coolers. Plenty of info on Engine oil, power steering and auto trans coolers, but haven't found much good info so thought I would start a thread covering the points:

1. When they are required: (E.g. Power levels/use of vehicle)
2. How to go about it (When to get pick-up/return/cooler/pump)
3. Legality

Now I realise Auto's from there design run much hotter, and require a cooler. Also from design a Manual or Diff does not require one in most situations.

But what about when you want build a car for a Burnout Competition, Rallying or Mud racing; or anything that will put a large sustained load on your driveline. Surely there must be some requirement for them when you start putting say in excess of 500+ hp through your GB and Diff?

Looking forward to your thoughts and views.

Kind regards,

Ryan

**TERRA Operative** · 09-06-2011, 06:06 PM

I know the FWD boxes have a little loop of pipe on the front underside that the oil flows through. It's called an 'oil cooler' in the parts catalogue, but it wouldn't do much. It wouldn't take much to fit some -an fittings and run a cooler. A pump isn't needed as there is one in the gearbox already.

I'm thinking of doing just that, with a filter (to catch worn synchro junk) and a cooler bypass thermostat on my build, just because I can.

As for RWD applications, I wouldn't have a clue....

**love ke70** · 13-06-2011, 07:36 PM

in for this, been thinking about for a long while in my patrol when touring at 3.5 tonne on 35's doing 10 hrs a day in 35 - 40 degree heat the tunnel gets so hot you cant touch it, just have no idea how to do it, so any info would be interesting

**mullett** · 13-06-2011, 11:01 PM

The trouble is that manual boxes (unlike autos) don't have an internal pump, therefore no transfer pressure, so the only way to do it is run an external pump, making it much more expensive and difficult. They also don't (shouldn't?) generate anywhere near as much temperature...

-RM

**briney** · 14-06-2011, 01:52 PM

i wouldn't be too sure of the manuals not getting as hot. i work on an HZB50 coaster, (admittedly an extreme example.) which i fitted some temp monitoring strips to the transmission and they went over 130 degrees c ! the days in the middle of summer here are around 45 admittedly, but there is definitely room for coolers on hard working manual trans.

the pain in the arse i can see is how to pump the oil ? i've seen transfer cases on 'cruiser wagons with a little pump inside them. electric gear pumps which will handle the heat seem expensive.

**Rhyno** · 15-06-2011, 12:52 PM

Thanks guys that is really interesting to know! I have read of GT4 Rally edition Celica's having them fitted - so cn't be too hard to get something similar working. I have been putting a fair bit of thought into this and I can only think of one way.

Looking at a RWD Gearbox you already have 2 access points:

Your Drain and Filler Bung. If you could get some fittings to adapt that thread, the next step would be to have a thermostat of some description that would allow the GB to warm up quickly, then switch a pump on to pump the oil up to your cooler. This approach would be best, as I can see pump selection is going to be the most expensive part, and that way you don't have to find a pump that can pump hot or cold 80/90 oil. Add a couple of check valves in line and allow for a drain point (unless you just wanna undo a line) and I think that should be all thats needed...?

Only problem with that is the diff... mine only has a filling or level checking bung. To do the same to the diff I think I am going to have to weld a fitting to the bottom of the plate to act as a pick up... or change the diff.

What do you guys reckon?

I'm off to search for an appropiate pump...

**oldcorollas** · 15-06-2011, 01:23 PM

drill holes...

oh and you might want to measure the temps before going to the effort and expense

edit: and also need to think abotu where the oil goes back in.
see, the reason for needing oil cooling, is not because the oil gets hot....
the reason is because the gear teeth are gettng hot and heatign the oil... in which case yo would want to think about putting in spray bars etc to direct the oil onto gear teeth to increase the coolign effect of the oil on the teeth.

look up what they do with nascar and V8 supercars etc etc.. and maybe also what is done with better gearboxed liek Hewlands etc

**Rhyno** · 15-06-2011, 01:24 PM

I have to get back to work but thought you guys might be interested in this: http://www.rbracing-rsr.com/oilsystems.htm

Its for bikes - but the second bit seems relative.

Ryan

**Rhyno** · 27-06-2011, 03:40 PM

Hey all,

So after a fair bit of searching and annoying local suppliers it seems as though there is only one good option the Tilton pump... some info http://www.tiltonracing.com/content....st2&id=222&m=d & http://www.tiltonracing.com/pdfs/43.pdf

These things are about $400... now to buy one and see what happens!

Kind regards,

Ryan

**thechuckster** · 27-06-2011, 06:41 PM

Originally Posted by TERRA Operative

I know the FWD boxes have a little loop of pipe on the front underside that the oil flows through. It's called an 'oil cooler' in the parts catalogue, but it wouldn't do much. It wouldn't take much to fit some -an fittings and run a cooler. A pump isn't needed as there is one in the gearbox already.

If your FWD box has that loop, just get the gearbox oil cooler & lines from a GT4 and connect it up.

**Rhyno** · 28-06-2011, 01:24 PM

Re Old Corrola

Just seen your edit, fair point on checking temps to see if it is warranted, but as mentioned in the case of the Coaster Bus and the Nissan Patrol, some form of cooling is required, perhaps the methods you mentioned.

I did some googling last night and couldn't find much on Nascar/V8SC's Diff's, care to elaborate?

Ryan