Hi All,

I am new to both Jaguar and automatic car ownership and had a couple of questions. My 1976 series 2 has the Borg Warner 65 or 66 automatic, it shifts fairly smoothly and at the speeds the manual says it should so I assume it is mostly good. A few things worry me though as I do not fully understand autos:

I have noticed the car can read different revvs at the one speed ie: at 80kph on level ground it is around 1900rpm, but if I pull uphill at 80kph still in top gear the revvs will slowly rise to around 2500rpm. Is this sort of slip a normal part of torque convertor design or it is a sign of wear?

My other issue I have mentioned before - once the car is up to running temperature if I accelerate at all hard from takeoff there is a noisy slip/bind - it is definitely a friction noise and momentum is minimal until I back off and the noise goes away. Only seems to happen at rolling speeds, so I assume first gear. I have been told it could be worn gearbox mounts which I will take a look at tomorrow, I also intend to change the transmission fluid as while it is nice and clean it appears it has been a few years since it was last done. Reading the workshop manual makes me think it could also be a worn cone clutch?

Any advice would be greatly appreciated, I have only ever owned manual cars so this is all very new to me.

 

my opinion is: if the transmission is working fine, and the transmission fluid is nice and clean, leave it alone! Just keep it topped up; Check the transmission fluid level when the engine has reached normal working temperature, i.e.: after driving it for some 45 minutes or more.

 

Levels are fine when warm. Unfortunately the second issue makes me think the transmission is not working fine and I don't know enough to know if the first bit is a sign as well?

 

Check your fluid level and filter... unit may be starving for fluid. That will gave a cavitation noise but based on your description it sounds like clutches are slipping. Also make sure the throttle cable is properly adjusted. If the cable is too loose there wont be enough main pressure to hold the clutches.

 

The S2 has a BW65, unless someone has upgraded it to a BW66 (S3) over the years, I did all ours.

The squeal at HARD take off is more than likely failing torque convertor thrust bearing, VERY common sadly. Lack of decent trans fluid maintenance is the prime cause here. The BW66 was a tad stronger in this area. I had this on 2 of ours, and a change to synthetic fluid, and 1/2ltr "overfull" HOT, saw many more years out of them, and silent. Once they died, BW66 replaced them.

HOWEVER I never "stood on the gas" in them with that known issue, no need, they get up and go quite quick enough in a graceful fashion as is. It is a Jaguar after all, mmm.

There is NO easy fix, the torque convertor needs "splitting" and rebuilding for that to be sorted.

The rise in revs you mention is "about right" from memory.

 

Thanks Grant,

I flushed the fluid today and fitted a new filter (I assume it was a 66 filter, the kit was for a 65/66, the old filter was just flat gauze, the new one had a pressed channel to pick up oil slightly lower and more central in the sump). Filled the gearbox to spec and no more noise Gearbox mounts are a bit spongy so will be replaced at some point, but very happy that the noise and slip hasn't reoccured yet. I did overfill a bit so this may be part of it based on other descriptions

 

SWEET.

Now mark on your diary to simply undo the dipstick flange nut and drain the fluid again in 2 months time, and then refill with fresh again.

The new fluid will be getting contaminated by the old left in the system, and several drain and refills "may" be required to increase the "new" concentration somewhat.

The filter for 65/66 is the same unit, and gauze is correct, usually brass, but some are stainless steel.

If my understanding is wrong in that you used a flushing machine and about 20ltrs of fluid, then forget what I just typed.

 

haha, no your understanding is very much correct, I was very surprised how little fluid drained out given the capacity. I actually misjudged and put way too much back in the first time so used that as an excuse to redrain in the hope of getting more of the old out and then refill with the correct amount of new oil.

 

There is a maintenance process for brake band adjustment, I remember doing it on a BW 66 when I had the engine and gearbox out of the car in around 1993. However like most things wear takes its toll, so you may have to get a rebuilt torque converter because these are not maintainable. I have seen a recent magazine article showing one being opened up, repaired, then welded back shut.