Hello all. I have a shiny rebuilt BW-65 and a TQ ready to bolt onto my XK6. Even though these are going into a D Type replica, I figured I’d post here since the block and transmission are from a 1975 XJ6 Series 2.
Before I start asking lots of questions, can anyone point me to a web site, YouTube video, or previous forum thread that has some reasonably detailed steps for setting up this transmission? I have the proper type of fluid and I know how much it needs. I’ve installed a few GM transmissions in the past, so I’m reasonably familiar with the process, but since it’s Jaguar, I’m assuming it’ll have a weird quirk or two.
First three questions are…
Should the TQ be filled with fluid before installation?
What position is ‘Park’.? The lever, pointed up, all the way forward?
Also… since my Speedometer is run by GPS, can I just block off the governor without it causing problems?
Hi Doug, the TQ will fill up when first started, then correct the level (more towards the low mark) while it’s running and after selecting all gear positions, then P. Same again when the fluid is hot.
The throttle cable must be correctly adjusted and connected to the throttle in some way.
P is where the output shaft locks, should be obvious. Think forwards.
You certainly cannot disconnect the governor but you can plug the bullet or leave the angle drive disconnected.
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It is absolutely essential that the downshift cable to the gearbox is properly connected to the throttle pedal, Doug - as David says. Hopefully you got the throttle linkages from the donor.
There are not any real Jaguar quirks in box installation - apart from general vehicle differences (D-type in this case), it should be straight forward…
When installed the the downshift cable must be adjusted using fluid pressure - it’s a standard procedure, and specifics for the BW65 should be readily available.
The lever fully forward is indeed ‘P’, then N-R-D-2-1 - assuming you haven’t something exotic with the shift lever linkages…
Thank you very much. I do have the original linkage, but since this engine and transmission are going into a D Type replica, the throttle linkage with the triple Webers is different. I did install an adjustable arm onto the main rod for the downshift cable. I’ll have to fine tune the adjustment before the engine is started and the car is moving, but hopefully this will do the trick.
If in doubt make it shift harder, soft ships and flare-ups eat the bands (and it’s supposed to be sporty, so higher shift points and quicker downshifts of course)
[quote=“DougM, post:9, topic:425317, full:true”]
Ok. So, since softer shifts eat the bands more, start harder and adjust from there?
With bands correctly adjusted, Doug, there is very little band wear - whether soft or hard shift settings. The main difference is that hard shifting induces unnecessary mechanical strain on components and drive train - and is ‘uncomfortable’ and indeed pointless…
As bands (and clutches) are applied; fluid is squeezed out, but allows ‘lubricated’ slip until the parts lock together - hard or soft.
The real danger is of course slipping bands, which will very quickly wear off the very thin linings.
The properties of the fluid used are twofold; to lubricate the mechanical parts and at the same time minimizes band wear - while ensuring smooth transition between gears when shifting. Box manufacturers may specify different fluids for their boxes - which should be adhered to, of course…
While you aren’t wrong the manuals are very clear that a wrong cable setting will drastically shorten life expectancy.
The strain on the drivetrain is well within its capabilities, far more so with a lighter car, which will always feel jerkier due to its lower mass.
My otherwise, probably-OK gearbox only lasted a couple hundred miles, when I thought that that cable was only a kickdown cable. When it was taken apart, all the lining on the bands was gone.
Set to spec, as indeed the manufacturers intend, the shift is to be smooth - anything else is mentioned as ‘faults’ in the manuals. So ‘wrong cable setting’, which does give anomalous shifting, will certainly ‘shorten life expectancy’. And while the drivetrain may be robust, the internals of the box may be less tolerant - which is then the cause of the… warning…?
To wit; the main function of the base cable setting is to ‘tune’ the box pressures to the engine driven pump’s pressure. Ie to relate engine rpms to the valve body. The rpms is one input to the box, the others being the road speed and pedal position. So the base setting relates ‘no pedal’ shift points…sort of.
The valves in the valve body is moved by hydraulic pressures against calibrated springs. So the specified base pressure gives the shift points specified - which varies with pedal and road speed. Adjusting the downshift cable changes the base pressure - it is not an independent adjustment only related to pedal position; it may confuse the box as to engine rpms…
Thank you all. Still some things to finish before I start it all up.
Since I’m using a GPS speedometer, I made a block-off plate and gasket where the Speedo cable would normally connect. It’s very high tech and I’ve applied for a patent so I can make lots of money from the design.
Seriously though, any reason why removing and blocking off the geared unit isn’t a good idea?
Yeah, the transducer took up some much needed space in the narrow transmission tunnel. If the inner gear works don’t rely on a transducer being part of the system for proper long term operation, then I’ll check it off the list and keep going forward. =)
It took a bit of time, but I located a new breather connector thingy for the BW65. I have never removed or installed the transmission in an actual XJ6, so I don’t know if the hose goes into a filter or just vents somewhere.
Based on a parts diagram, it looks like the hose goes up and then down, but doesn’t go below the transmission. Does anyone know if this is crucial? Or can I just run a short length of hose and be done with it?
