Overdrive issue

[StagNL]

Hi Folks,

Again the overdrive (J) is doing strange things. Stag is just back on the road after an extensive rebuild and the overdrive operates a little slowly sometimes, but worst of all it has a tendency to engage in 2nd just after being disengaged in 3rd or 4th.

I have yet to check the filters and pistons but if this sounds familiar then any tips are welcome.

Julian

[Mad Mart]

I would check the filters and make sure you have enough oil in the gearbox. It could be the oil pump in the o/d unit. The o/d operating in 2nd could be due to a sticking inhibitor switch on the gearbox.

[stagdad]

I would think an electrical fault as it should't be able to engage in 2nd due to the inhibitor switch, I would suspect the inhibitor switch is sticking.

Or on other words what mad mart suggested :-)

Cheers Steve

[StagNL]

Update:

I was ruling out electrical due to the OD never engaging in 1st or 2nd when activated by the gear lever switch.  It only was ever in OD in those gears when it failed to disengage due to the delay in disengagement.  

The filters and such behind the sump cover have been cleaned.  Fluid has been topped up.

This morning the OD was quick to engage and disengage - as it should do.  This afternoon the engagement was swift, disengagement too until nearly home after 12km when it disengaged quickly but as soon as I applied throttle the OD engaged again (in 2nd gear) and then took a good 10 seconds to slowly disengage again on its own - all this time the gear lever switch was 'off'.


Could be the solenoid is getting slow when hot...or gunk in that area...

Julian

[Doug Paterson]

I had similar many years ago on a J-Type.

It could be a sticky solenoid - it can happen.  Worth trying to replace the o-rings on the valve, at the same time as draining the oil from both the drain plug on the gearbox and the OD sump.

Something I tried on a whim and seemed to solve the problem was initially filling with thinner EP oil (eg EP70) and running it like that for 100 miles or so before refilling with EP90.  Had no problems afterwards so my theory that a bit of crud was interfering (E.g. with the pressure relief valve or similar) stood up - i.e. the clean new thinner oil may have flushed stuff out

Not a definite but maybe worth a try

[Pete Lewis]

have had this odd operating mind of its own with the J tpye on my recently acquired T2000 with the J type, if the solenoid piston is sticking partly open you get some very odd operations when you dont expect them.

you need a thin 1" af spanner to unscrew the solenoid assy,  jack up the rear to avoid oil loss, although not a lot will spill out

remove the solenoid, ( do not be tempted to use grips on the body)

in the end of the solenoid is a small circlip. remove this and tap the body on a block to shake the internal piston out

give it a good clean up and refit, you can test it with any simple leads to a 12v source it doesnt take much current , you will here and see the piston click and snap quickly on the move ( if you test before you strip it will be slow sluggish or not move at all)

screw back into the geabox, do not overtighten, top up the oil at the gearbox level filler  

and all will be smooth and seamless changes .

Pete

[StagNL]

Thank you  for the tips.  I shall look at the solenoid soon and see how it works out.

Been fine recently but I have not used it for more than 5 minutes.  Anything more and it may give trouble.


Julian