Overdrive failed!

[dingle]

I am sure you are familiar with the Buckeye tech articles, but here is the link anyway- http://www.buckeyetriumphs.org/technical/AOD/AOD5/AOD5.htm

The troubleshooting guide should prove helpful as well as the rebuild sections.

Hopefully,the problem will be minor. The pressure gauge is also useful.

Berry

[TriumphV8]

Hi Paul it is helpfull to aproach the problem step by step.

 

Besides that I would test the gearbox before fitting by engaging the 4th

and opening the switch valve on top, removing ball and spring and

turning the input shaft with an strong electric driller

that has a low speed of about 800rpm.

 

Now you can do that with the tunnel removed and rear jacked up.

Take great care not to pop off from the jack!

 

If there does not pop out oil at the valve plug even when turning slowly

there is a problem with the pump.

 

If oil comes out the switch lever can be tested. Pulling the lever by hand should

let the shaft look out of the middle of the hole. Would try to press that down with

a screwdriver and feel that at the lever arm you pull with the other hand.

Notice how easy the lever can be pulled. Than refit spring, ball and plug and pull the lever again,

should have a bit resistance against the spring.

 

Next the driller is engaged, best by a second person. If you now pull the lever and after

a short way there is a resistance and if pulled over that resistance it is gone and the lever

can be pulled fully. The faster you drill the input shaft the more you notice the resistance.

It is caused by the pressure built up in the accumulator.

 

If there is no resistance the oil pops out somewhere internally.

 

If all seems to work that way I would build a pressure measuring unit that fits instead of

the pressure switch plug. 27bars are the normal pressure but with the driller that is not

achived. With the car jacked you can go faster and should see those figures.

 

There can be a lot of smaller probs like air in the pump but is necessary to look

first where to search for the problem.

[AlanT]

You have dropped the operating valve.

[Lord Flashart]

Cheers guys,

 

I'll start looking at it again next week.

 

Alan, I wish I had just dropped the valve out, that would be easy to fix, but alas, that is not the case!

 

Paul

[AlanT]

No, you misunderstand. Without the shaft and cam the valve falls down into the OD.

 

When you put the shaft and cam back you have to fish the valve back up so it rests on the cam.

 

This means taking out the ball and other little bits and putting a thin rod down until it

finds the hole in the end of the valve where the ball sits.

 

You draw the valve back up and fit the shaft and cam, then you drop the valve on it.

 

I can clearly remember having to do this.

[Don Elliott]

Paul - Is it possible that the ball valve that gets lifted on the right end of that cross-rod is sticky, dirty or scored. Maybe all you have to do is clean that area and change the ball.

 

Also remember that when you are putting it back together you will be tightening it all back together again with those two longer threaded rods. MAKE SURE THAT YOU HAVE PULLED DOWN THE O/D OIL PUMP ROD AND ROLLER WHEEL ABOVE WITH A SHORT LENGTH OF FINE WIRE THE VIA THE DRAIN HOLE FROM BELOW BEFORE YOU REASSEMBLE IT ALL . IF YOU DON'T,

YOU WILL DAMAGE THE PUMP AND CRACK THE ADAPTER PLATE!

[Lord Flashart]

Thanks again guys.

I'm going to have a look at it sometime next week.

I think I'm one of the few who is not that impressed by the overdrive and I'm happy to drive the car without it.

 

Alan, I understand completely and it's the rod valve that was bent and I replaced it along with new spring and ball. When I reassembled the thing I made sure it was sitting on the cam and now when I move the operating lever I can feel the pressure of the spring operations against the cam.

I'm starting to think that it could be pump related as although I can feel the spring against the cam, it doesn't feel like there is any hydraulic pressure even after driving the car for a bit. So that's where I'm going to look first, although I did have the side cover off as the old one was cracking around the solonoid mounting and I could see that the pump was engaged and moving up and down when the shaft was rotated by hand.

Hopefully I can fix it without removing the 'box again though as I really don't want to have to do that again!

 

Paul

Edited August 9, 2015 by Lord Flashart

[TriumphV8]

Hopefully I can fix it without removing the 'box again though as I really don't want to have to do that again!

 

 

That is the great advantage of the J-Type: You get access to a lot of hydraulic parts from outside

and can be checked and changed easily, even the pump housing and pump valve pop out easy.

 

Good luck that the fault is in an area you can get access to!

[Lord Flashart]

Bit of a report back.

 

I removed the gearbox cover and had a good look at the overdrive again.

There is now fluid at the hole when I remove the activation valve cover and run the engine with it in gear.

The overdrive still refuses to engage however.

 

I don't have the time to strip everything again so I'm Just going to drive it how it is and this winter I'll refit the non overdrive 'box and sell the overdrive to some other poor bugger!

 

Thanks for the help

 

Paul

[TR 2100]

Flash,

 

That really is a b***er. You have had way more than your fair share of problems and

deserve much better luck in keeping your TR running properly in such an outpost.

 

Overdrive is a brilliant extra when it's working properly, so I hope you will be able to find

a solution and get it sorted.

 

AlanR

[TorontoTim]

Paul, maybe we should talk....... ;-)

[Lord Flashart]

Well chaps,

Refitted everything and took the car for a good and proper thrashing around some of the back roads.

No overdrive, but it restored my love of driving my TR. After three weeks of fighting it in the garage, I was considering selling the damn thing.

I'm not convinced the overdrive adds much at all to the car, just even more unreliability. I'm going to keep driving it for what's left of the summer and then decide what to do.

Tim, are you looking for an overdrive?

 

Paul

[TriumphV8]

Never ever would I give up and be fooled by such a simple mechanic.

From my opinion the problem is too much input from too many people

and you did not find the problem because you did not approach step by

step as I recommended.

 

So now I would recommend to pick up each hint you like and follow only this hint.

If that did nor solve the problem forget that completely take another hint and do the same.

If you do that as a step by step work and do not hesitate to do the additional work

as making the tool for measuring the oil pressure you will succeed at last over the

nasty overdrive!

 

Tell us what the hydaulic system does, comes oil, and is what is the pressure at what speed?

That is still the main point from where to decide how to proceed.

 

And I can tell you from my own experience if there is success where others failed

or if you have success after struggeling for a longer time and went to bed without

a solution you wil be very, very proud and happy with the result when it works!

I can tell you that I had trouble with a German guy, claiming being the pope of EFI

and my planned system would never work. What I great feeling when I finished and could drive

back to back one of his cars to see what a really worse system this guy had built!!!

 

I can tell you that I got rubber o-rings from several suppliers like Rimmer and

changed all the rings in my J-Type with the result it did work only when cold.

That was a long search especially because I replaced bad parts with other bad parts.

At last I converted the pressure valve system to another viton o-ring type by doing

severe modifications what at last solved the problem perfectly.

 

A simple rubber ring, even when new, can make the whole system faulty

and it is first necessary to know where such an faulty item is located.

Edited August 14, 2015 by TriumphV8

[RogerH]

Hi Paul,

don't give up. You deserve a medal!!

 

Roger

[Dave Larnder]

Paul

 

I had the same problem with my TR3A everything was to the book but no joy. I was very fortunate that Pete Cox has a holiday home only 30kms from my house in Spain and he came round and fixed it. As he says it can only be a mm out and it won´t work. He did it as well with the tunnel in position, but I had previously made an opening to get at the solenoid (for replacement if needed) as told me by Don Elliott using a floor jack cover grommet to cover the hole.

Must say that it never worked so positively before with a very large audible click when it engages and disengages.

 

Dave

[AlanT]

Setting the lever with the 3/16in rod is not good when there is some wear.

 

I measure the valve lift with a dial-indicator.

You can learn a lot by watching one of these.

 

A depth mic woks well also but is a bit slower.

[Lord Flashart]

Cheers guys,

 

Don't worry, I'm not giving up, I'm just out of time. The car drives well without the overdrive so I'm just going to keep driving until the winter.

 

It takes between 10 day to 3 weeks to get parts sometimes so if I strip the 'box again and find I need something it probably stop me driving the car this season.

I'm starting a new career in a month and I'm trying to get as much car time as I can before I rejoin the workforce and don't have the time!!

 

Regards

 

Paul

[RogerH]

HI Paul,

enjoy what is left of the Summer/Autumn - get that car out there

 

Roger

[TorontoTim]

Hey Paul, I don't have overdrive and don't especially miss it (I've had it on previous cars and it's fun but, other than high-speed cruising [which I think is a long way from where a TR is at its best anyway], not particularly necessary.

 

Having said that, I'm open to fitting it. So if you really are thinking of getting rid of your OD box, let me know and we can maybe hatch a deal :-)

 

In the meantime, I agree with others (and you) - get out and drive it OD-free. TR's truly are fun to drive in pretty much any specification and driving is WAY more fun than rebuilding an overdrive .

[stuart]

FWIW they are quicker without overdrive as there is a certain amount of power loss with having to drive the extra components and the added weight. Its only long distance driving where it is a real must have.

Stuart.