Auto.box changing

[Merlin]

My 3.9 seems to "hang-on" to3rd.too long.  It changes into top at 52. Is this the norm?, i think it would be better going into top at 46/7, save a goodly amount of juice that way.
Can you adjust them your-self to change at speeds you want?--Cogs

[Thrasher]

52 is the correct lock up point for that engine with your t/fer box and diffs ;-)

[muddyweb]

It's the Torque converter locking up.  The 3.5 boxes lock up at a lower speed, closer to 40mph.

There are ways to change them, but it's not a simple adjustment.

[Merlin]

Thanks, best to leave well alone I recon, just hoped to get a bit more mpg, still, much better than a S111 for comfort & lack of drafts.--Cogs

[SPIKEY]

My 3.5 ( F Reg ) Goes into 4th at exactly 30m.p.h.

My 3.9 ( G Reg ) stays in 1st for 5 miles because the governor is sticking :!:

Cheers,

SPIKEY.

[muddyweb]

Right then... after much digging around in the gearbox manual, and a few discussions with Dave @ Ashcroft.....

Changing the kickdown speed involves swapping a few little bits and pieces in the valve body of the box.  (A couple of springs, maybe a cam)

The good news is that the cost of parts is only around 15 quid... the bad news is that it's an absolute b***er of a job to do as it involves removing and stripping the valve body..  (This is not for the faint hearted)

The other alternative you have is to swap the whole valve body for one from a different box, or an exchange one from Ashcroft.  Dave does the exchange control unit for 150 quid.

Hope that helps.

[gnasha]

never noticed on mine as i hardly tell it changes smothest auto i have had

[Merlin]

How does the "valve body" come out?, is it a" box out" job or an accessable from" in situe" part?

[muddyweb]

You need to take the box sump off (with all the cafuffle that entails) then it's just a case of undoing about 8 Torx bolts.

Then the fun begins......