Transmission oil Temp

I have recently fitted oil temp guage to my auto transmission so I can monitor temps etc. I would be grateful if someone could advise me what the oil temp operating range should be between for say daily driving and hard driving.

I also have a mocal 16 row transmission cooler fitted and was wandering how much this should drop the temps by. My auto box is currently seeing between 70 and 90 degrees celsius depending on how hard i drive.

Is this to high, taking into account I am running a single so my auto box is probably under a bit more stress

cheers

Anyone have an answer!

Low temp. Up to 120 C is OK with the correct fluid is fine.. 100 C will ensure any water is driven off.

sorry yo hijake

but when fitting a temp gauge which oil line do you fit it on?

cheers baldy

Where did u get the oil cooler? Im after one myself and was looking at thinkauto.com for the bits but im unsure what to order, Can u point me in the right direction of what parts to order ?

Thanks.

Kenny.

Cheers Chris for the info, please confirm that upto 120 degrees C is okay for the auto box as long as I am using ATF Type IV fluid or equivalent. I thought it was under 100degrees C for the auto box but I dont doubt you, you are the expert.

Baldy, Leon at JPS fitted it, all I can tell you was the sensor went striaght into the sump and then was rerouted back to the cabin and wired into the guage.

Mad K, my apologies but I cant remember which supplier Leon uses but the kit was a Mocal 16 Row Oil Cooler kit with all the lines etc complete. Give him a bell mate on 01908 367100

cheers

Think automotive are Mocal distributers, got my 16 row coolers from them.

I don't think any ATF is capable to 120degC without shearing very quickly.

A proper gear oil is as it's more shear stable but normal expected temps for an ATF are up to 100degC.

The problem is that ATF's are very thin, approx 0w-20 in engine oil terms whereas a 75w-90 gear oil is equivalent to a 10w-40.

There are fully synthetic ATF's about (expensive stuff) which is more capable but you need to check what you're buying.

Cheers

Simon

after doing a bit of reseach into this myself i found the optimum temp for an auto box is more in the 60-80 degrees C region, if you think about it the stock auto cooler runs in the bottom of the rad, when the top of the rad is stinkin hot the bottom is still relatively cool, this came up a while ago and dude poped up with 4 (!) transmission coolers and was told by thinkauto not to run any thermostat and just run the box as cool as possible, i think if you ran the box in the 120 C region you would cook it completely, BTW i got a nice cooler from MVP and at a good price

I don't think any ATF is capable to 120degC without shearing very quickly.

 

A proper gear oil is as it's more shear stable but normal expected temps for an ATF are up to 100degC.

 

The problem is that ATF's are very thin, approx 0w-20 in engine oil terms whereas a 75w-90 gear oil is equivalent to a 10w-40.

 

There are fully synthetic ATF's about (expensive stuff) which is more capable but you need to check what you're buying.

 

Cheers

Simon

I only buy from you - so if it shears Im bringing the stuff back

I have had a quick look for the aricle I once read about auto box oils. It was a race magazine article discussing auto transmissions in competition, and I was pretty sure they said up to 120 degrees was the limit for ATF. I may well have remembered incorrectly, but it's a figure that seemed to be pretty firmly in mind.

Not 100% relevant, but Opel had the cut-off point of 160C for the transfer box (before taking measures to protect the box from overheating)

No ATF in there, but synthetic 75w90.

ATF will froth and boil way before 160C (as people keep finding the hard way!)