XJ Transmission Oil Coolers

[carvesdodo]

Originally Posted by rainman

....take cover hear come CARVS....

Baaahaaahaaa .... Its all good rainman ....

All the adhoc methods work to varying degrees ... There is just so many that dont provide any data in regard to before and after results. If they all did ... they wouldnt be adhoc methods.

Im still only running two crappy XJ factory coolers with the heat exchanger bypassed ... blasted xmas and moving house ... Recorded temps are still averaging 70'C as long as I keep it out of overdrive .... Thats low range / highway / and towing results.

I dont doubt the actual oil temps are slightly higher as Im only measuring the sump housing temp ... not the oil.

As a comparison ... the sump housing is now up to 30 degrees cooler than what it used to be in the standard factory configuration.

So big bling, imported coolers arent an absolute nescessity .... just a better quality / properly made one - than the pathetic thing provided. ... With the exchange rate at the moment ... importing is perhaps a consideration.

I Will be fitting a std 6cyl auto falcon cooler for a comparison when the damn rain stops out here and will provide the temps that that cooler provides .... Then I will be fitting a 678 davies craig unit as I believe that will be more than satisfactory ... and locally available for easy replacement if damaged. The others I have here are big enough and work well under testing ... but I dont know what they came off so are of no value in regards to info for others.

The idea being that finally .... someone will have provided some before and after results with a variety of setups in different operating conditions ... so individuals will be able to make a decision using the results ... and their needs ... rather than relying on the guesses posted on a private web site as being the ultimate answer

In fact Im really really surprised that the difference between US and Oz heat exchanger placement in the XJ wasnt picked up on and posted on the net ... long before I started taking an interest in what I was driving .... I'm pretty sure if it had ... it would have led to a completely different approach to the issue.

Originally Posted by TERRA Operative

If you do that, you'll be heating your cooled oil back to the temp your engine cooling system is running at.....

You can buy inline thermostats, they bypass the oil cooler when cold, and allow full flow when hot. That way you get the best of both worlds, quick warm up, and no heat loading across cooling systems.

Originally Posted by tazwegion

Not entirely, returning via the radiator's heat exchanger will the increase transmission oil temperature but not to precisely the same as the engine coolant there will be a variance, adoption of configuration depends entirely on local environmental conditions

Hence the reason that those who support the ... aftermarket oil cooler first - then the XJ heat exchanger set up ... without fitting a temp gauge NEED the biggest cooler they can lay their hands on ... in the hope it cools the oil enough so the engine coolant temp doesnt affect the benefits of the new oil cooler tooooo much

Not having a go at you Taz .... Doing it that way is a fairly safe way of getting some cooling without using a gauge to confirm results. I would rather have the gauge first ... see whats happening temp wise ... and then know how well I had fixed the issue going by the new operating temps.

Lots of aftermarket coolers have built in bypasses for initial startup / cold climate operation. The thermostat versions sound good ... but again ... a temp gauge would be needed to ensure the the thermostat was always functioning correctly .... just like the engine coolant thermostat with its stuck open / stuck closed issues.

Its also worth considering repeated comments over the years about how hot the AW4 box gets compared to other autos .... Having read plenty of them over the last 18mnths on the web ..... I really dont think the AW4 is like an old GMH 3spd slushmatic that had to be left idling in the driveway for 10min during winter in Tumut or Omeo ... Personally I think the cold climate operation comments / concerns really ought to be left on the north american forums where they belong ....... Our cold weather is a joke by comparison to theirs.

[junglejuice]

Originally Posted by carvesdodo

Baaahaaahaaa .... Its all good rainman ....

All the adhoc methods work to varying degrees ... There is just so many that dont provide any data in regard to before and after results. If they all did ... they wouldnt be adhoc methods.

Im still only running two crappy XJ factory coolers with the heat exchanger bypassed ... blasted xmas and moving house ... Recorded temps are still averaging 70'C as long as I keep it out of overdrive .... Thats low range / highway / and towing results.

I dont doubt the actual oil temps are slightly higher as Im only measuring the sump housing temp ... not the oil.

As a comparison ... the sump housing is now up to 30 degrees cooler than what it used to be in the standard factory configuration.

So big bling, imported coolers arent an absolute nescessity .... just a better quality / properly made one - than the pathetic thing provided. ... With the exchange rate at the moment ... importing is perhaps a consideration.

I Will be fitting a std 6cyl auto falcon cooler for a comparison when the damn rain stops out here and will provide the temps that that cooler provides .... Then I will be fitting a 678 davies craig unit as I believe that will be more than satisfactory ... and locally available for easy replacement if damaged. The others I have here are big enough and work well under testing ... but I dont know what they came off so are of no value in regards to info for others.

The idea being that finally .... someone will have provided some before and after results with a variety of setups in different operating conditions ... so individuals will be able to make a decision using the results ... and their needs ... rather than relying on the guesses posted on a private web site as being the ultimate answer

In fact Im really really surprised that the difference between US and Oz heat exchanger placement in the XJ wasnt picked up on and posted on the net ... long before I started taking an interest in what I was driving .... I'm pretty sure if it had ... it would have led to a completely different approach to the issue.





Hence the reason that those who support the ... aftermarket oil cooler first - then the XJ heat exchanger set up ... without fitting a temp gauge NEED the biggest cooler they can lay their hands on ... in the hope it cools the oil enough so the engine coolant temp doesnt affect the benefits of the new oil cooler tooooo much

Not having a go at you Taz .... Doing it that way is a fairly safe way of getting some cooling without using a gauge to confirm results. I would rather have the gauge first ... see whats happening temp wise ... and then know how well I had fixed the issue going by the new operating temps.

Lots of aftermarket coolers have built in bypasses for initial startup / cold climate operation. The thermostat versions sound good ... but again ... a temp gauge would be needed to ensure the the thermostat was always functioning correctly .... just like the engine coolant thermostat with its stuck open / stuck closed issues.

Its also worth considering repeated comments over the years about how hot the AW4 box gets compared to other autos .... Having read plenty of them over the last 18mnths on the web ..... I really dont think the AW4 is like an old GMH 3spd slushmatic that had to be left idling in the driveway for 10min during winter in Tumut or Omeo ... Personally I think the cold climate operation comments / concerns really ought to be left on the north american forums where they belong ....... Our cold weather is a joke by comparison to theirs.

I knew it was only a matter of time before you jumped in on this one Carves...

Now why would we want actual data, isn't anecdotal evidence good enough????

I agree with the cold weather issue I think that you are spot seeing that these are used in the icy winters of North America and Europe though as you mentioned the cooler is plumbed differently.

I myself have an alloy Landrover cooler plumbed in between the radiator and the factory cooler, not to fix a problem but as an enhancement for towing duties...

[junglejuice]

Originally Posted by TERRA Operative

My preference is to get rid of the radiator oil cooler all together to reduce the total heat load on the engine cooling system.
When off load, the oil passing through the radiator can also reduce the avaliable thermal capacity of the oil cooler for the transmission, as you are effectively using it as a heat exchanger for the engine cooling system. (Which should be up to scratch to not need the oil cooler to help it cool down).

The number one killer of transmissions is heat, my philosohy is to keep them as cool as possible, especially on slow moving vehicles. They need all the help they can get with their inherant lack of free airflow.

In the cars I have built, we have found that it is beneficial to have the transmission cooling system seperate to the engine cooling system for this reason. The Trans-Am Firebird we built benefited greatly with two big trans coolers in place of the radiator oil cooler, we not only saw much cooler trans temps (the box was built to handle up to 700Hp) but also saw cooler temps from the worked 351 Chev we squeezed into the engine bay.

In Australia, most of the time the climate will allow the box to heat up quickly enough anyway. On my supercharged Levin import (and the N/A race car), the manual gearbox doesn't have a thermostat on the oil cooler and it has no dramas with spinning the synchros up quick enough when cold.

Just my opinion anyway...

Hey Terra, where did you get a 351 chev from?????

[ChrisXJ]

Hey Carves, Apreciate what you have stated. I have just purchased an oil temp gauge and will fit it to the Trans Sump ASAP. My XJ still has the Standard Jeep Cooler Setup. I want to see what the temps are at present before I get the New Cooler Setup. I will keep you posted with the results.

[junglejuice]

Originally Posted by ChrisXJ

Hey Carves, Apreciate what you have stated. I have just purchased an oil temp gauge and will fit it to the Trans Sump ASAP. My XJ still has the Standard Jeep Cooler Setup. I want to see what the temps are at present before I get the New Cooler Setup. I will keep you posted with the results.

Let us know how you go with the temp testing both before and after and if possible can you include ambient temperature as well or at least try to test both on similar temp days and similar times of the day if possible to try and get a reasonble comparison....

[ChrisXJ]

No Worries. I will need some time as I have to fly back to work and won't be back for another month.

[tazwegion]

Originally Posted by carvesdodo

Not having a go at you Taz .... Doing it that way is a fairly safe way of getting some cooling without using a gauge to confirm results. I would rather have the gauge first ... see whats happening temp wise ... and then know how well I had fixed the issue going by the new operating temps.

That's okay, I could already see the "tranny cooler" was struggling and opted not to hang off until I already had a sensor gauge fitted, I wondered if anyone made brass t pieces that a sensor could fit into with the transmission oil running past it?

* off to a plumbing supply *