bw65 kickdown cable

how can i check the adjustment on the bw65 kick down cable, while i think the car drives fine there is mention of it being incorrect? the car by the way has got this box instead of the original type 35.

thanks craig

Probably the most important things are the throttle linkage bushes and the fluid level are correct before you start.
The setting for the cable should be done with the throttle at rest, and at that point there should be no slack in the cable whatsoever, but it shouldn't be so tight as to move the cam inside the box off its stop. To be certain of that you would need to drop the sump on the box and make sure the heel of the cam is all the way back against the valve, (There's an illustration in the book that shows this), but I'd suggest roadtesting instead and comparing the shift speeds with those given in the WM.
If the pressures are too low then it will upshift too early, and if they're really low you'll lose kickdown, if they're too high you'll have to lift off the throttle to prompt the upshifts, and you'll get a "clonk" on the 2-1 downshift when coming to rest on a closed throttle.

I don't expect you've bought the book just yet awhile! Make sure you buy the factory Workshop Manual rather than a Haynes or similar. There are plenty for sale on Ebay. If you are a member of the Rover P6 Club we sell both this manual and the factory spares manual (really useful for assembly diagrams of how everything goes together) digitised onto a CD ROM so that you can print the page you're interested in.

So the book specifies:

Full throttle (including any resistance felt for the kickdown)

Gear 1 to gear 2 44 mph
Gear 2 to gear 3 77 mph


Light throttle:

Gear 1 to gear 2 4 mph
Gear 2 to gear 3 8 mph

For down changes

Zero throttle drive in D, box changes from 3 to 1 just before stop, ? 2 ? mph. To check it has changed, engage reverse, if reverse slips then fault with 1 to 2 shift valve.

Max kick down speed:

Travelling at 60 mph in third, operate kickdown. Kickdown should occour. Releasing the throttle should give immediate reversion to 3rd speed.. Attempting kickdown at higher speed should have no result.

Other tests are given as well, but these should be sufficient to set kickdown.

Also note. To avoid thumps when engaging gears at rest, the idle speed should be set between 600 and 650 rpm. If you can get it to idle at 500, so much the better!


Hope that helps!

Chris

"If the pressures are too [...] high you'll have to lift off the throttle to prompt the upshifts, and you'll get a "clonk" on the 2-1 downshift when coming to rest on a closed throttle."

I have exactly this effect with the 'new' gearbox, courtesy of fylde69 (many, many thanks again!).
So does the cable need to be slackened, or tightened, to lower the pressure, and by what amount to start with?

Junkman said:

"If the pressures are too [...] high you'll have to lift off the throttle to prompt the upshifts, and you'll get a "clonk" on the 2-1 downshift when coming to rest on a closed throttle."

I have exactly this effect with the 'new' gearbox, courtesy of fylde69 (many, many thanks again!).
So does the cable need to be slackened, or tightened, to lower the pressure, and by what amount to start with?

Click to expand...

You need to lower the pressures, and to do that you move the adjuster on the outer cable upwards. You can move it a set amount each time (eg one complete turn) and roadtest inbetween, but make a note of your starting point. The perfect setting is when there is no slack on the inner cable, but tightening it any further would hold the valve open, (which is what is happening in your case), so you need to adjust it to the point where the valve is no longer being held open, but there is no slack in the cable.

My inner cable has a collar about half an inch down, so if I move the outer casing up, it will pull the inner cable further out of the gearbox.
I did adjust it down, to the extend, that I could feel the inner cable being pulled against a mechanical stop, concluding this means the valve is fully closed.
I then adjusted the outer cable as far up, so that there is no gap between its upper end and the collar around the inner cable.

Anyway, the behaviour didn't change at all.

Junkman said:

My inner cable has a collar about half an inch down, so if I move the outer casing up, it will pull the inner cable further out of the gearbox.

I did adjust it down, to the extend, that I could feel the inner cable being pulled against a mechanical stop, concluding this means the valve is fully closed.
I then adjusted the outer cable as far up, so that there is no gap between its upper end and the collar around the inner cable.

Anyway, the behaviour didn't change at all.

Click to expand...

If you still have to lift off to prompt the upshifts, and are still getting the clonk on the 2-1 downshift when the top of the outer cable is touching the bottom of the crimp, then the crimp has been fitted in the wrong place. The solution is to cut the crimp off the cable (or squeeze it so it goes round rather than flat, so it's loose on the cable). The further you screw the adjuster downwards (away from the crimp) the more the pressures will increase, and the worse the problem will get. As you say, with the crimp in place (the wrong place) then winding the adjuster upwards against it just increases the pressures.

Yes, this makes sense. If I would (not done yet) move the crimp further up on the inner cable, the latter would go further down into the outer casing and hence into the gearbox, until the valve is completely shut. Then I also would have the effect you describe, adjusting the outer casing upwards would decrease the pressure, adjusting it down would increase it.
I will try it tomorrow and report back.

Now all downshifts, even 2-1, are so smoth, they aren't even noticeable.
1-2 upshift is fine, 2-3 needs slight lifting off to happen where I"d expect it under moderate acceleration.
All upshifts get slightly clonky when the gearbox gets hot, i.e. in city driving, but never the downshifts.
Kickdown is prompt and never fails.