Doomed transfer case?
 

This, from the jag-lovers board, doesn't sound too good! FJT, is this your experience?
Some comments on the 'Air Scoop' used to aid cooling of the TC.

"These scoops are what the engineering world calls an '11th hour
patch' added at the last minute to help mitigate a high failure
rated part that became too late to fix the right way in the
development process.

The TC in the X-Type is woefully undersized and weak for a car of
this weight and engine size (and why engine modifications on this
car meant to produce more HP and torque will cause chronic failures
elsewhere in the drivetrain). Jaguar engineering was already in
field test, likely at the beta level when they discovered the TC
would be a problem, so they tacked on this air scoop to help rather
than reengineer correctly, but frankly, it is about the equivalent
of using a wine cork to stop a leak in the dike.

Engineering simply evaluated the cost of reengineering compared to
a clugy fix, and compared that to the estimated number of field
failures expected and concluded it was less expensive just to
replace TCs under warranty for a certain number of units. Of
course, now the car is old enough that many are off factory
warranty, and MANY TCs are succumbing on the owner's dime.

Because of the poor and late in the process design, these scoops
sit too low on the under chassis and are contiually ripped off in
deep snow and in encounters with other road obstructions. It is
much less a matter of lazy mechanics forgetting to relpace it after
oil changes. So, if you are going to replace yours, consider
purchasing a 'few' of them as inevitably you'll lose it more than
once if you drive regularly in deep snow or, god forbid, off road.

I agree, I'd rather have the scoop in place than missing, however,
failures of the TC are related to driving habits combined with
climatic operating conditions and condition of the oil inside the
case.

In other words, if you drive this car very sensibly in a colder
climate, with a fully filled TC and occasionally have to lock up
the VC, you might never experience a TC failure with or without the
scoop. However, if you're a leadfoot with a 3.0L and constant hard
accelerations driving in the very hot climate of Phoenix with a
half filled TC, even with the scoop, it's only a matter of short
time and you will be replacing the TC. "

________

1999 XJR

RE: Doomed transfer case?
 

i dont get it. what is TC? sorry newbie question...

RE: Doomed transfer case?
 

Transfer Case
________

1999 XJR

RE: Doomed transfer case?
 

mostly fair comments.. but I doubt the TC cant take the power of the engine.
Engineering the shafts, bearing, gears etc... for a certain torque, and power is not new technology.
From what I have heard the failures are mostly from bearing failures. This is probably due to all that you are talking about. - High heat, and oil issues.

The real culprit is the "lifetime fill" If you changed the fluid annually, I believe the problem would be reduced to significantly lower levels.

Car makers are not going to change.. not anytime soon. So your only defence is to be wise....

change your TC oil once in a while.

This is a little contrary to my rants about doing engine oil changes too often. Trust me there is always middle ground available for the truth to lie...

RE: Doomed transfer case?
 

I've heard about this "scoop" before, would anybody happen to have a pic so I can see what I'd be looking for to see if mine's still there?

RE: Doomed transfer case?
 

I am picking up one today.. ill post a pic next week..

RE: Doomed transfer case?
 

Ya know Bo,..Now that I changed my TC lube out to Royal Purple and you did the Red Line product (both top shelf lubes)...I believe, unless I was planning on keeping the car for another90K to 100K miles, I will not be changing it out again...We put in better than factory lubes and probably filled it to the proper level as well..

RE: Doomed transfer case?
 

really helps to cool it. some times they brake off or people just throw them out.. im selling one to bo tonight you will see his soon

RE: Doomed transfer case?
 

I don't have a picture but - crouch down and look uder the front end of the car. Toward the back of the engine oil pan you'll see ahard plastic air scoop sticking down if its there. I've managed to knock off 2 of them.

Regards:
Oldengineer