What are people's thoughts on installing an additional transmission cooler?
I was driving my wife's Volvo 960 up in San Francisco on Friday and the transmission overheated! Managed to limp home with ATF smoking on the exhaust. Not sure if a line went or if it blew out of the breather. I will be taking a look at it this afternoon.
I want to drive the Jag up there without problems and it might lessen the chance of future A drum failure.
Thanks,
Dan

 

Ax you have seen, it's not a problem with design but lack of servicing
and a mechanical failure that created the problem with your Volvo.
The Jaguar is not renowned for trans overheat situations unless severely abused and the normal setup is perfectly adequate and if it can handle our 105 deg it shouldn't worry you but if you want to try an external cooler
then you would need to disconnect both inlet and outlet pipes that connect to the left of the radiator and redirect these into an aftermarket cooler or
a simple trick is to use a second hand power steering cooler from a scrap XJ
as they will have the same fitting sizes of the gland nuts.
But frankly, I think you are creating a solution looking for a problem ;o)

 

Don't think the A-drum faliure is from heat... overpressure from the valve body and a weak design.

 

Either way, a rebuilt transmission is in its future. I'm starting to recommend having one spare for XJ8 owners with the faulty parts replaced, it's odds on it'll go bang at some point.

 

+1

Agreed. It's not a question, especially if it's an early box, of "If" it goes BANG! but "When" it does.

Went through this last November; got an updated overhaul box out of Ericcson Industries with the upgraded valve body and A drum and complete refreshed bearings, clutches, etc. Been smooth driving since then, and the price, while it did pinch a bit ($2800 USD all up) especially that close to Christmas, was a great investment in the ongoing enjoyment of the car.

(I won't talk about the spares I have for the Lotus...all of them NLA, and NOS to boot).

 

The option of auxiliary transmission coolers is often fraught with as many opinions as 'oil threads'

But one thing is certain, one is introducing another possible failure point where transmission fluid can leak. This is especially true of aftermarket generic coolers that aren't OEM designed.

OEM aux transmission coolers are almost always (I've never seen an exception) hard line connected in-line with the main radiator housed transmission cooler circuit. Most aftermarket coolers use rubber hoses, hose barb ends, and sometimes require cutting the hard line flares to install. All of those characteristics considerably increase the chance of a leak.

.... and of course being pumped under pressure, even a small leak will drain your transmission of its fluid in short order.

As noted in the replies above, most automobiles driven on the street and not towing have few transmission overheating problems. Even mountain driving should be fine. If it were me, I'd avoid the aux transmission cooler since the benefit is debatable, but the increased complexity of the system and new possible point of failure is not.


Did Jaguar even offer an auxiliary transmission cooler as an option? If not, I think that says something.

To be fair, my 1995 Buick Roadmaster has the same transmission as my X300 XJR, and the Buick DOES have an OEM aux transmission cooler. But that was part of a "tow" package. That little radiator does get darned hot to the touch even on a short drive, but then again what we think is hot is the optimal operating temp for the transmission.


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