Jump to content

GEARBOX-0/D SERVICE


Recommended Posts

Hi all, after your good advice have sorted out oil and filter to use for the engine

I am sure this subject has been done to death but I will change the oil in the box/OD

Which oil to use 20/50 or EP90 ?

I noticed a post about the assembly of the brass filter is there a definitive picture

showing correct way, do I need a special tool to get this off?

Any tips gratefully received

kind regards Lee

 

Link to post
Share on other sites

I am sure you'll get many responses concerning lubrication & foaming and other technicalities...but i have a simple human factor for you...use anything but EP90 because EP90 stinks and your gearbox will leak (they all leak) and EP90 on the hot gearbox casing or, worse still, on the exhaust will give your car a special aroma that will avoid issues with insects & animals but also frighten children and cause WAGs to develop headaches and alternative plans... 

Link to post
Share on other sites

Hi Lee,

in the 50's early 60's the OD manufacturer warned against using EP oils. However in the mid 60's onwards TRiumph recommended EP90 etc. !!!

Gearbox oils work well - I use Penrite GB40.

The easiest thing to remember is what not to use.

Do not use an engine oil - as these may contain detergents that may froth and cause the OD pump to have issues.

Do not use GL5 oils as these contain some nasties.

 

Roger

Link to post
Share on other sites

Hello All

               I use Morris Golden Film SAE40 low detergent 

I talked to this man at Stoneleigh and he said it is just as good and if you look at the specs on his site you can see that!

But it is cheaper!

https://www.classic-oils.net/

Roger

ps it has been in my rebuilt(by me) gearbox/od all this year and works fine

pps when I rebuilt the gearbox I tested it on the bench to set the oil pressures and it did not foam just a bit aerated !

ppps this is how I tested mine

DSC08517.JPG

Edited by rogerguzzi
Link to post
Share on other sites

You should certainly clean the filter from time to time Lee, if nothing else it's condition will give a guide as to the internal state of the overdrive. The filter sits on top of three magnetic washers, which should also be cleaned of ferromagnetic particles before reassembly. The best tool to remove the plug is a 'C' spanner of suitable size. In the absence of this you could unscrew the plug by gently tapping on one of the ears with a brass drift.

Tim

Link to post
Share on other sites
17 hours ago, rogerguzzi said:

Hello All

               I use Morris Golden Film SAE40 low detergent 

I talked to this man at Stoneleigh and he said it is just as good and if you look at the specs on his site you can see that!

But it is cheaper!

https://www.classic-oils.net/

Roger

ps it has been in my rebuilt(by me) gearbox/od all this year and works fine

pps when I rebuilt the gearbox I tested it on the bench to set the oil pressures and it did not foam just a bit aerated !

ppps this is how I tested mine

DSC08517.JPG

Used Morris  straight 40 for a decade now, plus their 20;50 engine oil without issue, Great value product.

Thanks for the link Roger, and a great test rig.

Can you detail the coupling between the motor and box.

Cheers,

John.

Link to post
Share on other sites

The best tool to remove the overdrive's large eared plug is that available from Overdrive Repair Services - not cheap, but doesn't damage the ears.

Ian Cornish

Link to post
Share on other sites
1 minute ago, ianc said:

The best tool to remove the overdrive's large eared plug is that available from Overdrive Repair Services - not cheap, but doesn't damage the ears.

Ian Cornish

Illustrated here half way down the page. https://www.overdrive-repairs.co.uk/buy-spares.php?cat=A Type Spare Parts List

Stuart.

Link to post
Share on other sites
5 hours ago, John Morrison said:

Used Morris  straight 40 for a decade now, plus their 20;50 engine oil without issue, Great value product.

Thanks for the link Roger, and a great test rig.

Can you detail the coupling between the motor and box.

Cheers,

John.

Hello John

This what I wrote on Sideways forum

The other gearbox drive is just a tube to fit over the input shaft with 2 screws for the drive(numpty threw an old course spline plate away before thinking!)

The motor coupling is 4 dogs on each one and a rubber disc in the middle so does not need to be perfectly in line(old stock from a previous life?)

            Roger  

I built the test rig with the centre from and old clutch plate a bit of tube and bit of old rocker shaft 

 motor is only 1/2hp so struggles a bit but O/Drive works in all gears (solenoid direct power)

My 2nd gear interlock works and it also drops out between 3rd and 4th now so I have achieved what I set out to do

Results as listed 

1st motor 1450   non o/d 415  with o/d 533          oil pressures    320 psi

2nd            1432                 662                  853                                     330psi                                      

3rd             1385                 995                 1276                                    340psi

4th             1400                1400                1800                                    350psi    

I have decided to use Morris Golden Film SAE 40 Classic    API SD/CC   

The reason is  Penrite only do their GB40 in 1lt bottles at about £8 and Morris is £20 for 5lt and it states it is anti foam so what is needed for an O/Drive?

I looked at the specs on classic oils web site and they are as near as dam it the same and I asked the man at Stoneleigh and he said it would be fine.

I am not sure whether to increase the pump pressure as I noticed in the works manual it say 375 to 400psi not as that chart I posted?

I wonder if this was so they did not have to stock 2 different O/Ds for Spitfire and GT6s ?

Hello All

               I have had another play at it today and drained the oil out after running it for some minutes and it was not frothy just a bit aerated  

I have added a 0.006" shim under the relief spring and now I am getting

1st  @ 1450rpm     415 rpm   @ 340 psi     = 7.5mph (but a lot of pulsing on the gauge 320/360)as you would expect?

2nd @ 1445 rpm    667 rpm   &  350 psi     = 12mph

3rd @  1417rpm     1005rpm &   360 psi     =18.5 mph

4th @ 1355 rpm      1355rpm &  375 psi     = 24.5mph

I get very slightly higher pressures than these when it has been stood and presumably the oil has de aerated ?

I get the same as Buckeye describes a pause in pressure rise at 180 to 200 psi(pistons moving!)

So overall I am pleased now and I think I will have overdrive on 2nd  so at say 2000rpm(925rpm) = 16.6 mph = 21.25mph or 2400 rpm = 24mph = 30.772mph

Roger

ps I will run it a bit more on the bench and the fill with fresh oil as a few bits came out with 1st lot but I filtered it through a 400 micron strainer and reused it for testing

     A small update

I took Spitty for a spin up our bridle track today and I am pleased to say the Overdrive works in 2nd , 3rd and 4th and drops out between all gears

It will engage at about 10/15mph in 2nd(may be a bit slowish) but if I rev to 2000rpm in 2nd and engage it  seems the same as normal and drops revs by 500rpm

So I am pleased with my efforts (just some trim to refit and track the rear wheels)

DSC08444.JPG

DSC08448.JPG

DSC08442.JPG

DSC00990-001.JPG

Edited by rogerguzzi
Link to post
Share on other sites
1 hour ago, John Morrison said:

Many thanks Roger, 

hope you are well chuffed with yourself- you should be.

 

John

Hello John

                   Yes it works well and I have a home made overdrive logic box so I wanted the o/d to drop out between 4th and 3rd 

I do not use the 2nd o/d much but it is useful when we are touring in the mountains as Spitty,s  2nd gear is a bit low and 3rd a bit high when fully loaded and going around hairpin bends!

A small update on my Mad Idea of O/D on second gear (as posted on Sideways forum last year)

Well as some of you know we are touring Spain & Portugal.

I have hardly used 2nd O/D until today and we were going up steep hills and hairpin bends with all the load in the boot and I can say it works a treat it gives a useable 20 to 30 mph range.(about 3000 rpm @ 30mph) and you can flick in and out on the hairpins as needed

So instead of revving the nuts off in 2nd or slogging in 3rd  2nd O/D is just right(or driving like a maniac not possible with the Memsahib on board!)

Roger

Link to post
Share on other sites

The concern with using 20 50 engine oil in a gearbox is that some of the viscosity modulators will break down when subject to the shearing forces in the gear mechanism. This isn’t a problem if you are prepared to change the oil annually.

Otherwise I would stick with decent 40 gearbox oil or EP 90 providing it is marked as safe for use with yellow metals an overdrive.

Link to post
Share on other sites

Hi All

Picked up on the O/D testing picture and thought I would show you mine

Basically the gearbox is mounted onto the engine stand and an electric motor (borrowed from a friend) has pulley diameter 6" is added to fit a fan belt 'v'

a similar size pulley is mackled to the output flange and  fan belt attached to the two

Switch on and slowly tighten the belt to take the drive to the flange

Several things are important, first the flange is driven anticlockwise as you see it from the gearbox end, second gearbox oil in my cold garage is very viscous so the fan heater needs to warm up the box before start up.

Results using a gauge from ORS (no connection apart from their good advice on the phone when asked) show 450lbs pressure dropping to about 350 on switch on but quickly recovering pressure to 450

The who;e problem started when my O/D decided to stop working so after the simple things you can do with the box still in the car I swopped the box giving me time to sort this out.

got a rebuild set and the gauge from ORS and took it to bits

Details on how to do it : try  Pete Cox's article in technicalities and or look at "Buckeye Triumphs" article on the web

PS I have rebuilt O/Ds before - often with help from ORS

Hope this helps/inspires others

Oh BTW I just use EP90 on road diffs and gearboxes

Michael

IMG_5756.JPG

Link to post
Share on other sites

Hello Michael

                     I did mine that way the first time but then I thought I would do it as it in service? no idea if it makes any difference!

But it has worked ok for a few thousand miles!

Roger

Link to post
Share on other sites
On 1/24/2020 at 1:27 PM, Andy Moltu said:

The concern with using 20 50 engine oil in a gearbox is that some of the viscosity modulators will break down when subject to the shearing forces in the gear mechanism. This isn’t a problem if you are prepared to change the oil annually.

Otherwise I would stick with decent 40 gearbox oil or EP 90 providing it is marked as safe for use with yellow metals an overdrive.

Ah,

just in case I inadvertantly caused confusion, I meant in addition to straight 40 in my

O/D Box, I use Morris 20/50 in my Engine.

Andy is correct about using 20/50 in a O/D Gearbox.

John.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.