Borg Warner 65 automatic transmission: shifting problem

(André) #1


Last week I bought a 1976 Jag XJ6 - S2 4,2 in british racing green!

Now I have a problem with the Borg Warner 65 automatic transmission. When I start driving, the transmission does not shift from the first gear to the second / third gear for approximately one mile. After warming up, it will shift bumpy into second and third gear. The delayed shifting behavior improves after a longer journey.

I have changed the fluid (Liqui Moly Top Tec ATF 1300: specification Ford ESW-M2C 33G) and filter two times now. I also checked the fluid level when the trans was hot.

Before the first fluid change, the gearbox made a ticking noise after I had driven 300 miles home from the dealer. The ticking noise has gone after the first fluid change.

What would be the fix?

Thanks in advance!

(Frank Andersen) #2

Apart from the fluid type, Andre - did you check level using the proper procedure?

Box hot, engine idling; first pass the lever through all positions - then check, engine idling…

The initial shift problem is reminiscent of ‘morning sickness’ - however the bumpy shift quality implies kickdown cable adjustment required.

Shift points are also an indicator; 1/2 upshift under light throttle should occur at 8 - 12 mph, and 2/3 at 13 - 19. Ie, with light throttle the upshifts should be early, smooth and seamless at all box temps…

The upshift speed varies with pedal position - the more pedal, the later the upshifts. The cable adjustment should in principle be done using fuel pressure gauge - any transmission shop can do it. Or DIY with the right equipment…

But first; check at the cable adjuster on the throttle pedal pedestal. When adjusted a ferrule is crimped on to the cable with a clearance of 0,010". If the ferrule is present; check and adjust cable…

And welcome on board…

xj6 85 Sov Europe (UK/NZ)

(David Jauch) #3

Welcome from me as well.
There will be ample reading on morning sickness. Just use #xj in the search function, and include the BW66 in your reading as these boxes are very similar. Frank is a great help as well.
The transmission is determining shift point and quality via the throttle position. the further the cable is pulled out, the higher the rpm and the harder the shift process itself. It is important to get the pressure right, otherwise the transmission won’t last long. I wouldn’t mess with the cable by trial and error, but it can be done theoretically. I did it with a long hose and a pressure gauge, not as hard as I thought. That for now.

If you did check with the engine running, in park, after going through all positions, the fluid should be okay (Type F is recommended and Dexron III gives softer shifts at the cost of shortening the life of the friction elements, so it is okay, just not the best choice) you shouldn’t worry about fluid levels and look for what happens when the seals go bad or the pump pressure / governor pressure drops off for any reason. You implied that it gets better when it warms up, so it must be more of a temperature thing than adjustment related.

I don’t recommend that you do this but if you removed the throttle cable (don’t push it in, lest if slips off inside the transmission, tie it up somewhere in a just slack position), it should shift very early and very soft. Not good for the transmission, but as a test. This would indicate that the system operates well and the cable is maladjusted. Better if you read up first and find better reasons for your behaviour.

One thing, what did the old fluid look like?

(tony) #4

Frank, I was recently speaking to a veteran trans pro about BW8 trans, and he mentioned to me that BW65 never changed well from 1-2, and he used to fix it by shortening a spring in the valve body, he stated the BW66 rectified this issue.

not sure whether the OP is affected by this issue

presumably it would be a “common” issue, if he is right, just out of interest FYI

(motorcarman) #5

First thing to do (one of the easiest) is to remove and clean the Governor.
I never rebuilt the BW65/66 gearboxes but I did strip them for parts and cleaned the governor and valve bodies ‘back-in-the-day’.


(André) #6


do I have to drain the fluid to check and clean the governor?


(motorcarman) #7

I don’t think much fluid will leak if the propshaft is displaced and the gearbox is not tilted too much.

I have not cleaned a BW65/66 governor in about 30 years so I’m going on memory.


(Frank Andersen) #8

No, Andre - but you have to remove the rear extension housing for access…

xj6 85 Sov Europe (UK/NZ)

(André) #9


yesterday I checked the kick down cable. I have checked the cable once completely unhooked for mobility. You can pull it out about 3 inches. When pulling it out it hacks a little bit on half way. Then I reinstalled the kick down cable and varied the length. The behavior is unchanged:-(

Next will be the governor, right?


(André) #10

recommendations for a supplier of reconditioned BW-65 in Germany/UK?

(Frank Andersen) #11

That was a very crude and insufficient test, Andre - likely worthless. It certainly does not eliminate an adjustment fault - or pinpoint the governor as the problem…

The adjustment of cable length is very sensitive. If rough adjustments, trial and error, is used - steps of 1/4 turn, either way, is relevant between test drives…

The advantage of doing this properly, using pressure gauge, is that it will give the correct result - and/or reveal if cable adjustment is not the cause of malfunctions.

Certainly; governor input must be correct - it gives road speed inputs to the valve body. To be compared with pressure related to engine rpms, and pressure varying with pedal position - for the box to shift as intended…

As an aside; the cable adjustment, using pressures, ‘tunes’ the various elements to engine rpms…

xj6 85 Sov Europe (UK/NZ)

(tony) #12

If your vehicle in general changes gears up & down at the right speed for throttle settings,
in most gears, but you have jerky change from 1-2, that will not be a govenor fault

(Geoff Allam) #13

I had a series 2 xj6l with the 65 as a daily driver for a number if years and spent a considerable amount of time trying to get it to shift smoothly. I had the pressures checked and also did a lot of minute adjustments of cable lengths. No matter what despite shifting correctly at the correct speed the 1-2 downshift was always harsh. Upshift not as bad but could hardly be described as “grace”. Even a rebuild as a result of an unrelated problem did not solve the issue. I would suggest that you have the pressures adjusted to ensure that they are in spec and then if it shifts up and down at the correct speed that is as good as you will get. I also had a series 3 with a bw66 that was still driveable when I bought it. The shifts were much less clunky on that car so if you contemplate a swap go for the 66.

(David Jauch) #14

It is supposed to hack. This showed you that it is hooked up inside the transmission and not binding, nothing related to your fault. Only if it still won’t upshift with the cable unhooked it would rule out the cable once and for all. Likely worthless.
I don’t know about reconditioning in Germany, but if you happen to find somebody I can sell my (condition unknown) BW65 to please tell.
Not for use, more for parts if anything as I got it full of cobwebs.
It is easy, perhaps easier, to do things like band adjustment or removing the valve body in the garage. Tony is right about the shift speeds/governor, but you said morning sickness is your issue so find the solution in this field.
The 65 became worthless the instant the uprated 66 came along. It is roughly the same, with a few upgrades - deeper oil pan, stronger parts. Aim for a 66 if you want R&R.

(Frank Andersen) #15

To some extent the shift quality is also affected by the fluid type, Geoff…

There were some previous discussions on fluid type, mainly related to the BW66 - some preferred the firmer shifting on the Ford type fluid…

As the bands/clutches engage, there is always a brief ‘slip’ as fluid is squeezed out and the bands ‘locks on’. The ‘slip’ only dampens the shift - which, if done dry, would indeed be jerky.

As said, there are some differences between fluids - which are formulated to lubricate and cool the different boxes, without causing unwanted slip in bands and clutches…

xj6 85 Sov Europe (UK/NZ)

(Geoff Allam) #16

Moot point for me now Frank as the tin worm took control eventually. It still remains my favourite daily driver of all time. Seats, brakes handling and just the general feel were perfect. Had a couple of modern s types after that and they were just not the same. Plus the self destructing engines were a turn off. I still have the series 2 in dry storage. Yup I am going to restore that car some day…

(André) #17

I’m just checking the alternative of exchanging the old transmission with a reconditioned one.

I have found the following companies offering reconditioned BW 65 gearboxes:

  1. :



Has anyone already had experience with these companies? Private messages welcome! :wink: