Testing overdrive

[griffipaul]

Just checking that normal forward direction of rotation of engine is clockwise viewed from front.

Driving input shaft with drill , want to make sure not going in reverse direction.

Not able to check on engine at moment.

Cheers

 

 

[rogerguzzi]

Yes

Roger

ps this how I tested mine and to check pressures

[griffipaul]

Thanks Roger,

It was given a clean bill of health by Overdrive guys in Nuneaton , 2 yrs ago , so just checking this and gb conversion from non o/d before it all goes back in.

Fingers crossed.

As an aside I camped behind you at CLM 2016 , knew your brother in law Derek and actually bumped into him at Castle Combe Autumn classic in October. It was nice to see him again after a while.

You going this year , ?

 

[rogerguzzi]

Hello Paul

                    No we are not doing Classic Le Mans this year (we have been 4 times!)

I went to Spa 6hours in September (been to the Classic 4times)and has spoilt me as the racing is so much better and there is no silly parades between races(waste of time!)

Plus the tickets were only £30(group discount £40 without) for the weekend and free classic parking and you can go anywhere around the circuit any stand and the pits.

I have been looking at going to Zandvoort or the old timers Germany

We are off to Spain in June for 2 weeks

Roger

ps Derek has gone over to the Dark side and bought a Volvo Amazon!  TR6 has gone!!!!!!!!!!!!!!!!!

[Pete Lewis]

just to add drive the mainshaft not the input shaft 

this operates the pump cam and mainshaft  also drives all synchromesh operation  

what do you expect to find ???   

Pete

 

[griffipaul]

Pete

Just wanted to check o/d is engaging and disengaging and working properly before get in all back in and find something silly and its all got to come out again.

Set up is similar to Rogers except using a drill not a motor. 

Its hard work for the drill , surprised how much torque to drive.

 

G/b and o/d assembled together no option but to drive input shaft , why is this an issue.

Cheers

 

Paul

[Pete Lewis]

driving the coupling only rotates the mainshaft  inside the gear sets  in  neutral not all the gears as driving via the input shaft

so less torque required   and its the pump cam is all that needs to turn to pump the pressure to get the cone to shift 

i will look the test pressures up in the morning but dont feel a drill will be that constructive in real world 

Pete

 

[griffipaul]

Just seemed the easiest thing to do , and the engine drives the gearbox in real life . Got no means to drive output flange or measure pressure so was just looking to do a functional check that when engaged in 4th to maximise rotation speed ,output flange speeds up when solenoid engages.

[rogerguzzi]

Hello Paul

                  My Motor is 1/2hp and will turn the gearbox at 1400

Here you go for pressures I could lend you a gauge and adapter if you like?

A new "J" Type Overdrive Unit is currently being incorporated on the Triumph range of vehicles; consequently, the "A" and "D" Types will be discontinued. Incorporation of the "J" Type Unit was effective commencing with the following vehicle identification numbers:

 

Model	Vehicle Ident. #	Color	Number	Part #	Working Pressure
Stag	LE 20857	Yellow	115837	312377	510-540
TR-6	CF 1	Blue	115838	313242	430-460
Spitfire	*	Lilac	115840	313305	320-350
GT-6	*	Lt. Green	115850	313304	350-380

* - Estimated incorporation -- Late February, 1973

 

Hydraulic Pressure Test

 

When running in direct drive, a residual pressure of 20 lbs. per square inch maintains the overdrive unit in a primed condition and provides lubrication. When overdrive is selected, the hydraulic pressure is increased to within the figures quoted above,

 

To check the operating pressures:

 

1. Check that the gearbox oil level is correct.

 

2. Remove the hexagon headed plug adjacent to the solenoid and fit hydraulic pressure gauge L188A together with the adaptor L188A-2.

 

3. Jack up the rear wheels and run the transmission at approximately 25 m.p.h.

 

Note 1. When in direct drive the residual pressure reading should be approximately 20 lb./in.

 

Note 2. When the overdrive is engaged, the pressure should be as specified.

 

Interchageability Of Parts

 

"J" Type Overdrive parts are not interchangeable with those for "A" or "D" Type Units.

Roger

ps I set my pressure at 350/380 psi

[griffipaul]

Thanks Roger for you very kind offer but I don't think that's necessary.

I bought the o/d a couple of years back at a very good price complete with adaptors and right angle drive so I could afford a check up with Overdrive spares at rugby , who said It worked fine just a bit stuck from lack of use .

So all I needed to check was that I had done nothing silly in convering  the mainshaft ,  and reassembling it all . nothing worse than getting it all back in the car and its got to come out again for something daft , especially as this is the first time I 've done it .  Pete's advice has been invaluable along the way.

Gearbox works fine selects gears ok after rebuild , pump cam fitted and all reassembled back together .

so just checking for the obvious really. seems to work ok , output shaft speeds up when solenoid engages .

[Pete Lewis]

nothing wrong with trying , its just all work done by the gearbox comes from the prop end not the engine end

when testing a geabox you drive the coupling all the synchro is driven from here it has to spin the clutch disc up to or down to speed 

not the other way round as most think 

same reason the OD is pumped from the mainshaft not the input shaft the pump is in constant use when car is moving , the opposite is if you dipped the clutch on OD engagaes you would loose pressure if pumped from the engine end of the box as the clutch would be off drive and could even be stationary until the change happens .

 Most automatics have the same as most are pumped from the prop drive end not the engine end if that helps the idea here 

Pete

 

[NonMember]

9 hours ago, griffipaul said:

 seems to work ok , output shaft speeds up when solenoid engages .

If you have no reason to suspect it's other than properly set up, this is about as convincing a confirmation test as you could ever want!

[Pete Lewis]

time to refit and get the smile 

good job .............. hope my baulkrings work  OK  

pete

[griffipaul]

Understand what your saying now Pete . Thanks for the explanation. 

I hope the rings work as well. I'll let you know.

Pete.

[Pete Lewis]

if they dont its got bedford warranty   ...once out of bedfordshire it expires    ha "!

Im sure you can fill guys in with brake testing from the good old days we had with trucks 

Pete

[griffipaul]

We are go for launch, No 1 son coming round tomorrow to give me a lift with it.

Bearing carrier re pinned in new position and fork pins refurbed so less losses in clutch system.

[SpitFire6]

Hi,

 Never seen one with a switch mounted on a bracket before. I love the rubber deals.

Cheers,

Iain.

[griffipaul]

Sorry not sure I understand your point re ' rubber deals '

[Pete Lewis]

early boxes had two brackets on for OD one opposite for reverse lamp switch, both bolt to the front of the top cover

Like the garage we had one lasted years till the top parted company with the base and found they used 3 " nails to assemble it 

the lift band stretched and in the end it was past recovery .  but lasted 20years 

Pete

[griffipaul]

the bracket had to be bent  " to suit " and the cam redrilled for it all to work … another example of simple parts not correct.

 

 

if you look carefully you can see that I have also put a screw  in the gearbocx breather hole . any views...…….. yes , no , necessary or  advised 

[Colin Lindsay]

6 minutes ago, griffipaul said:

if you look carefully you can see that I have also put a screw  in the gearbocx breather hole . any views...…….. yes , no , necessary or  advised 

To block it off, or keep it clear? Diff uses a split pin to keep the breather hole open, that's what I'd use, but I'd be wary of closing it completely as it was once thought necessary. Having said that, one out of three gearboxes I refurbished recently (bearings and seals) had no breather in the top cover, so it was either unnecessary in earlier cars and added later, or else it was in the early cars, and then deleted from later ones - sadly the top covers were detached from the boxes long ago so no way of telling which.

[Pete Lewis]

the OD has a big open breather should do all the work ever needed ,  they can leak as its not splash protected ,

i had to put a tube on mine  

pete

[griffipaul]

I added it because a blanking rivet ( no longer available ) was listed in the spares manual o/d conversion kit , but logic of why to blank it when you add o/d defeats me. 

 

[Pete Lewis]

 A  whim of  heavy breathing ..................doesnt apply to triumphs   ...........   Erm !!!

like humans we have a number of vents some are less popular than others  

bit like the small holes inside the top cover to free oil trapped in the bore for the selector rod  . as they fill with oil and hydraulic to stop you selecting 

the hole is  also good for punching out the welch plugs 

just some waffle 

Pete

 

 

 

[Gully]

On 12 February 2020 at 12:27, griffipaul said:

I added it because a blanking rivet ( no longer available ) was listed in the spares manual o/d conversion kit , but logic of why to blank it when you add o/d defeats me. 

 

I read on another forum that leaving the top cover breather open when the OD has sufficient breathing for the gearbox and OD leads to excessive oil leakage. No idea if it's true! Mine has both and leaks a little from the top cover.

Gully