OD not engaging

[Henk]

After gearbox swap my OD won't work. Firstly I thought that the new, stronger, release springs were too strong so I replaced them with the original ones. Then the only thing I changed was the solenoid: a new one.

Solenoid gets 12V and draws 2A when switched on. With engine off but ignition switch on I can hear it switching (a click, never heard it at previous solenoids). When the solenoid is out of the od, I can see the valve stem move about 1,5 mm.

Fitted a pressure gauge and measured a 1,7 bar which corresponds to 25 psi. This should be correct, but pressure doesn't build up when od is switched in.

In my opinion electrical circuit is correct, and there's residual pressure so pump assembly is functioning correctly. Following the troubleshooting list on buckeyetriumphs.org the operating valve should get the blame. Since the thing is purchased new, and visually functioning correct I don't now which further step to make.

Any thoughts?

[80Sprint]

Henk

What is new , the valve ?

We're filters cleaned out and oil feeds clear ?

[Henk]

Yes, solenoid is new. Not disassembled before fitting though, assumed it would be ok inside. Maybe not...
By oil feed you mean the channels between the holes? I checked them visually (the ones I could) and used an air line to be sure.

[80Sprint]

Henk

No engagement points to electrical but as you have the solenoid working on the car but out of its location all seems well.

Did you follow the second section of the guide that shows the sump, filter and relief valve. If you have had the box out it may have disturbed some crud/dirt and caused a problem. It also shows where you can blow through with an air line.

If it worked before you may have to go back and eliminate any changes made. If the only ones were spring and new solenoid i would be more inclined to think dirt etc as the solonoid is new ( assuming its not also faulty But you test would imply all is ok ) and you have put the standard springs back.

Why did you change the solenoid. Did you have O/D issues before ?

[Henk]

Thanks Mike.
Yes solenoid was changed because of a faulty one: when driving for about 30 minutes the od didn't disengage anymore. After cooling down it functioned as it should. This seemed to be a signal of a solenoid giving up.

Yes I followed the whole text: sump, filter, pressure relieve valve and pump assembly were all checked and cleaned. In fact the od was stripped (not the rear casting) so I'm thinking to have something reassemled wrong.

[80Sprint]

Henk

I would inclined to eliminate the solenoid first then before stripping it all down again. Would you be able to borrow another as I know you have a few Sprint fans in NL.

[wiggybum]

There's not much to stop an O/D working other than lack of oil pressure behind the pistons. If there's:

1. Enough oil (assume you got this right)
2. Solenoid is operational (you hear it clicking)
3. Filter gauze is clean
4. You have the correct O seals

Did the new solenoid come with O rings and are they the correct ones?

Did you replace the O seals on the two pistons?

Did you reassemble the pump non return valve correctly? ie sprung loaded disc

Is the pressure relief valve ball and spring correctly assembled?

Has anyone put Slick 50 or any friction eliminating stuff in the oil ?? The clutch will slip then.

[Henk]

Thanks, first three points are checked.
O rings are next to do, will remove sump cover and replace rings at solenoid, oil pump assembly and pressure relieve valve. If that won't help the od has to come off and I'll replace the piston ones. Didn't do it before because it wasn't giving trouble...

[wiggybum]

You will need to make pin spanners to remove the pressure relief and pump non return assemblies.

I used a piece of flat steel with two M5 screws in it.

Still puzzling though...

[Carledo]

Just a thought, did you remember to swap over the pump drive eccentric when swapping the gearbox? Its easily missed!

Steve

[Henk]

Thanks, yes eccentric cam is placed and pump is therefore going up and down. I just removed sump cover and all three plugs with items behind it.
Then I used an air line at the filter housing and got an air flow (I guess via the two piston) to the pressure relieve valve housing. So no particles are blocking the oil channels.
Now I am about to replace the rubber O rings, after purchasing my 407 pieces rubber ring kit... to discover that really thin O rings have to be used. Will get after them on monday.
To be clear, I am talking about rings at NKC0026, NKC0091, NKC0092, NKC0100, NKC0102 as shown in picture below:


Will check the effects of this first and when this won't solve it I have to remove the od and replace the O rings on the pistons.

[Edin Dundee]

Henk, buy the o-rings from Overdrive Repair Services in Sheffield, v cheap and the correct items.

[wiggybum]

Don't forget the solonoid o seals. If they are missing,the solonoid will have a limited effect when engaged.

Hope you get some success soon as this must be depressing and frustrating..

[Henk]

Replaced all O rings except the piston ones, because therefore I have to take the OD off. Now that wasn't an option because of a weekend Ardennes. Unfortunately this didn't gave a solution, so I had to visit the Ardennes without OD. Weekend was good fun though, some really nice quiet roads over there. It's just travelling to and back on the highway wasn't that comfortable: 100 km/h and 4000-4500 rpm.
Additional problem was the throttle cable, the pedal movement got heavier during the weekend and eventually I stripped the outer cable (bulkhead side). This meant that pedal movement didn't have any influence on throttle so I had to temporarily fix that (with two cords out of my aunties pants... ).

Keep you informed as OD will come off soon!

[trackerjack]

In this case it is not the fault, but after time the solenoid wears the pin holes oval and the barrel can be turned and redrilled.