XJ Transmission Oil Coolers

[Rodgebone]

dunno about the tranny but the only way i know (besides the obvious) to blow up a 4.0L is to overheat them or ingest water. i consider them fairly bulletproof. they do get hot offroad and i agree completely with that statement. obviously Jeep didnt care or give any thought as to how they performed here in Oz but i also think there are ways to help alleviate that. so ill always plug away at trying to improve it even if its in vain. i think this thread is in the spirit of that effort and a worthwhile discussion and ill be quite happy if all this info helps keep my tranny within its designed operating window.

[carvesdodo]

Originally Posted by Rodgebone

im of the opinion the radiator s/b bypassed unless its USA style like Nakkas and even then im wondering if its really necessary.

what we really need is some temp recordings before and after mods.

Im all for bypassing it .... If I go to jindabyne to laugh at people spending a fortune to get cold and wet .... I'll just let it idle awhile, while I light a smoke, change the music and put the seatbelt on ..... same as Ive always done ......

Stock tranny sump temps on mine were definitely higher before bypassing the heat exchanger .... but I didnt get enough temp readings to do a decent comparison table ...... before I had to replace a busted radiator, as I mentioned in a previous post along with what few temps I did get.

Without the heat exchanger in the circuit ... The factory aux cooler alone, allowed the (my) tranny to operate at about the FSM temp specs instead of higher.

Problem was ... underload on hills/towing etc it couldnt cool enough to maintain the factory specs ...... same as the factory radiator struggles to maintain a constant engine temp with a load. Even two factory aux tranny coolers barely manage on their own - on my vehicle anyway.

Therefore ... as an assumption ... the whole system is not designed to work hard .... as verified by the info in the FSM about reasons for overheating ...

As you said ....... the location, use, and driver will determine how well the system manages .... Its why some have no problems, or only minor problems ... or lots of problems.

Originally Posted by dazza96

ok i am just going to throw this out there in the old days of the torannas and the 202 motor same basic construstion no alloy in the motor at all i use to just rip the thermo state out and never had a problom with damage to the motor at all if any thing the non ally motor prefer to run cool instead of hot and just watch the temp guage go up and down but didnt damage the motor at all i still got 500 thousand ks of the engine before i needed a new one the temp would go up when it was put under load but went back down after it started to cruise along again

i think it is a given xj just over heat off road all we are chasing is a window of useable temps before we cook them corect me if i am wrong

aaaaaghhhhh .... engine cooling in the tranny thread ......

Here we can get away without a thermostat if the conditions are right but you end up with those fluctuating temps you mentioned .... and its not something I would recommend for normal driving .... especially when our mild climate and lack of altitude variations, makes stable temps in vehicles relatively easy to achieve.

[Oli-dogg]

Originally Posted by carvesdodo

Having them flared properly would make a nice job of it ....

I only have a crappy flare tool and figured the "sharp" upturned edge was more likely to damage the hose inner surface .... than any danger of the hose coming off.

Just slide it on a good 50mm - 75mm and double clamp it ..... Its all most do - and I have had no leaks that way yet. The oil pressure is not really that high to cause an issue anyway.

I made the mistake of flaring mine and the 'sharp' upturned edge did damage the hose causing a split within a few weeks. The fluid got between the layers of the hose.

I've redone it now without the flare and used extra hose clamps instead.

[carvesdodo]

Finally got my act together and made a start ...... so as to replace the junk setup Ive been limping around on for a while ....

First up ... A little pic tutorial of how to use those disconnect tools in case its handy for someone ....

The pics show the aircon lines ... but its the same process for the tranny & fuel lines.

Select the right tool and slip it over the thinnest part of the line.
Then slide it into the fitting.



Make sure its fully home.
Then wriggle the join apart ... keep a thumb on the tool while gripping the line and pulling - as the tool needs to apply pressure to the spring/clip




Eazy peazy ...... OK ... on to the long delayed oil cooler job ....
..... and its happening slow as the weather is too hot and the beers too cool ....

Took a punt that a PWR cooler with a core size of 280mm wide & 250 high would be adequate .... RD No PDG 365/2001.
Why a PWR cooler ??? ... coz it, me and my chequebook happened to all be in the same place at the same time ....

Soooo ....

Old cooler mounts ....
And of course ... its going to be one of those days .... sighhhhh ...



OK then ... new cooler mounts ....
Bolted at the top and held at the bottom by the vac cannister .... another inch left of where IT was ...



Cooler position as it looks untill I get it all off again, give it a lick of black paint to keep deezleweazle - and myself happy, fit the nylocs and rubber pads ... trim the nosecone around the cooler hose fittings (4mm ) and plumb it all up.



Will put some pics of plumbing in later ... and will update this post with temp recordings as I get around to them.

.

[Rodgebone]

Carves, is it just me? it looks like you disconnected the AC lines in those pics...or were they tranny cooler lines? they look like AC lines.

[carvesdodo]

Yeah its the AC lines in the photo ... got no tranny joins that need the tool anymore ....

Will reword it a bit better.

[Rodgebone]

so what happened to the AC?