Lazy Overdrive

[Radiation Man]

Hi

Just bought a Spit 1500 with OD gearbox that was fine on the test drive but I noticed on a long drive home that perhaps all isnt well.

The last couple of years the car has done no real miles.

Overdrive engages fine, no hesitation.  On the motorway however after time its very slow to disengage from either 3rd or 4th.  Seems OK for short duration on a dual carriageway switching in and out fine.

Also feels like in 3rd gear without overdrive switched on then I am getting clutch slip with hard acceleration.  Clutch isnt slipping in 1st and 2nd so i dont think its the main car clutch.  Also it isnt doing it all the time so not sure what it is.  I am hoping its related to the 

Hoping its something simple related to lack of use over the recent history of the car.  

Any ideas?  

Other than that I am over the moon with the car and if I can get this sorted then that is a result.

Thanks in anticipation of your thoughts.

Ian

[ahebron]

Welcome Ian
Oil change with the proper oil would be the first thing I would do.

Spend some time on this site researching the correct oil

Adrian

[johny]

yes the oil could be contaminated with an additive or be fully synthetic which might cause slipping so worth changing by draining from both the gearbox and OD drain plugs. However its also possible theres a problem in the hydraulic system such as blockage of the operating valve or a dirty filter both of which can be serviced while the oils drained....

[Clive]

24 minutes ago, johny said:

yes the oil could be contaminated with an additive or be fully synthetic which might cause slipping so worth changing by draining from both the gearbox and OD drain plugs. However its also possible theres a problem in the hydraulic system such as blockage of the operating valve or a dirty filter both of which can be serviced while the oils drained....

Fuly synthetic won't cause an issue. The grade might, of if an unsuitable additive has been used. (John Kipping was recommending synthetic oil many years ago)

I would be checking the filters, but more likely is the soleniod. Possibly new o rings will fix the issue.

https://www.canleyclassics.com/?archive=the-j-type-overdrive

[Pete Lewis]

any J type with a mind of its own needs the solenoid INTERNAL   spool valve piston 0 rings checking

see the other posts recently about J type solenoids ,

need to unscrew the solenoid, needs a thin 1" af spanner ,dont use grips on the body 

once off remove the small 10mm circlip, and shake the piston out it should be a free and rattle when you give the thing a shake .

if its stiff or the rings leak it will do many uncotrolled engages disengages slips and slow in no particular order

Pete

 

[Colin Lindsay]

If it comes on easily it's not electrical; if it's slow to go off then as Pete says the piston is not retracting quickly so is probably gummed up; I'd check the oil as the other posters have already said but the solenoid might just require a good clean. To remove it you'll need a very thin, long spanner - I had to grind one right down to make it fit.

Make sure you don't break the small circlip on the end of the solenoid piston as I've still not obtained a replacement for my old unit.

[Radiation Man]

Thank you all.  

Will drop the oil next weekend, look at the filter and valves.

I just been playing and sitting and you can hear the solenoid click to engage, could not hear it click on disengagement.  Just had a little drive and not clicking to engage or engage so I could suppose the solenoid has just died or is gunned up and stuck.

[Colin Lindsay]

Happened to me very recently, which is how I know! I'm assuming it clicks to engage but when disengaged, the current stops so it just drops back under oil pressure, hence no click. However when it doesn't click at all then like mine it's probably now stuck and needs cleaning or replaced (£140 for a replacement solenoid...)

[Radiation Man]

Just now, Colin Lindsay said:

Happened to me very recently, which is how I know! I'm assuming it clicks to engage but when disengaged, the current stops so it just drops back under oil pressure, hence no click. However when it doesn't click at all then like mine it's probably now stuck and needs cleaning or replaced (£140 for a replacement solenoid...)

ouch... will go for cleaning before replacing

[Pete Lewis]

if you need a thin spanner J paddocks sell one 

https://www.jamespaddock.co.uk/gearbox-od?pagenumber=4

Pete

[Radiation Man]

2 hours ago, Pete Lewis said:

if you need a thin spanner J paddocks sell one 

https://www.jamespaddock.co.uk/gearbox-od?pagenumber=4

Pete

Thanks.

[daverclasper]

On 31/08/2020 at 18:20, Colin Lindsay said:

(£140 for a replacement solenoid...)

Just looked, Wins International have solonoid at £120 new, or £79 reconditioned (exchange)

[Colin Lindsay]

47 minutes ago, daverclasper said:

Just looked, Wins International have solonoid at £120 new, or £79 reconditioned (exchange)

Believe me, being tighter than a cow's whatever in the fly season, I checked a lot of prices!!

£120 then add VAT and carriage... it all adds up. £140 was all in, so I went for that. I didn't really fancy a reconditioned version and besides hadn't removed the old one at time of purchase, just in case...

[Pete Lewis]

so this is why guys spend ages converting to a J type  when the good olde Dtype solenoid is sub£30

what price is reliability  ??????

pete

[Colin Lindsay]

2 hours ago, Pete Lewis said:

what price is reliability  ??????

pete

However much it takes to either source a D-type GT6 gearbox or adapt a non-overdrive box to fit one, which is probably a lot... you must admit, mine did work for 20 years, after all.

[NonMember]

14 hours ago, Pete Lewis said:

what price is reliability  ??????

I've had two broken D-types in my time - one of which was worn beyond repair. Both cars (Spitfire and GT6) now have J-types. The GT6 has been like that for 26 years and has never had the slightest glitch from it. The Spitfire hasn't been used enough to really judge, but the Vitesse has had a J-type for thirty years, ten of which saw it being used for daily commute, and the only trouble I've ever had with the overdrive was chafed or broken wires.

[68vitesse]

Did have the yellow metal thrust washer under the one way clutch breakup in the J type in my Vitesse, but how long it lasted prior to that is anybody's guess, "second hand" when I bought it.

Is a refurbished j type solenoid just a coat of paint and perhaps change the o rings if you're lucky?.

Regards

Paul

 

 

[Radiation Man]

Fresh oil and a new solenoid appears to have fixed things.  Found a wire on the gear knob switch with damaged insulation so fixed that with a bit of heat shrink.

 

Managed to run out of petrol this evening while giving it a run out to test the overdrive.  My mistake😂

Thanks for all the advice.

[Badwolf]

The overdrive wire is a popular problem, will not really popular! Best replaced with slightly thinner wire. I have used thinner speaker cable with extra heat shrink insulation at the top and also where it emerges out of the gearstick further down. I also put a bit of heat shrink around each of the little connectors onto the switch.

[Pete Lewis]

best to use silicon sleeved wires its far more flexible and copes far better with the heat of the gearstick.

pete

[Badwolf]

Thanks Pete, I didn't know that. Will get a couple of metres for when I pull out my gear lever in the winter for repair.

[Radiation Man]

Thanks for that info, probably will pull things apart again in the future so will look to change the wires in the future to something more robust.

[Pete Lewis]

got my last from maplins  but they have long gone 

Pete

[Badwolf]

Fleabay will have some oriental firewire somewhere.

[Peter Truman]

What about modern car wiring thin with a harder and thinner insulation