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TR2/3/3A how to question for overdrive

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Dr_Mike

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Drained the oil (after 25 years laid up) and would like to take out the strainer and magnets (if any). I have to do this at arms length with only jack stand clearance. Is the pump going to fall out when i undo the bolt holding the strainer? Or can I just get the strainer and replace it after cleaning?

All advice welcome! I am in unknown territory
 
Nope! Very simple. When you remove the large plug it will expose the small bolt holding the screen. Unscrew the bolt and the screen falls out with it. You then also have to drain the tranny by it’s separate plug. There is no magnet on the OEM set-up.

Ps...check should reach you today or tomorrow...let me know if it doesn’t!!
 
My od unit was purchased rebuilt and does have the stacked magnets in the plug recess under the screen and small bolt and they do collect some gunk.
Tom
 
Thank you all ( especially John!) I am off this afternoon to undo that little bolt and see what follows it out. Will keep you informed.

Oh Joy
 
Surprise... not surprising really.

Oil was very clean: looked like PO had done it recently . Strainer was clean too.

Strainer had come out with the plug and is (was) not held in by a bolt. See photo that shows a protrusion on the plug..

I cannot see without a mirror but it seems that the bolt is held with a cotter pin or some such device and that the setup was original, but original to what? Moss catalogue and parts catalogue unhelpful.
 

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Your going to need to find a bolt that will hold th strainer place, otherwise the strainer is not doing anything other than just sitting there. I think its a 1/4/20 bolt just a little longer than strainer.
 
thanx... I will also have to find or make the spacer to go inside the strainer. Ah , the joy of rebuilding, and the prayer that theDPO did not leave more faults for me to find.
 
The bolt is not a standard bolt, but rather has a long shank on it. The shank allows you to tighten the bolt without crushing the screen:

KElu4ke.jpg


c2r4iDr.jpg


Also, the flat paper gasket around the big plug tends to leak. I went to Ace hardware and found an o-ring to go around the plug threads and used that. Not leaking at all now. If you do go the o-ring route, you do not need to over-tighten the plug. The rubber will seal and prevent the plug from backing off when just snug.

I'm still curious about the magents Geo and Tom are talking about. My early OD does not have them, but I would not mind adding them!?!
 
The magnets ,I think there are three,are stacked rings.They seem like magnetic screen embedded in a rubber like washer.Sorry no pics.The bottom of the screen sits on top and slightly inside in the hole of the rings,and the magnets od fits the plug recess.
When you remove magnets you can see the impression of the bowl screen in the rubber.
So they are held in place with no glue.I wipe them off to clean the gunk as the first time I shot them with some carb cleaner and it seemed like it was dissolving the rubber.
Tom
 
"Big Three" do not list bolt or spacer, so I am calling UK (Revington) to see if they can help. If not I shall have to find a way to make them (i.e. find someone who can do it for me). Do any of you have dimensions for those pieces?
Might as well add magnets while I am there!
 
I checked the S-T parts catalogs for the Tr6 (with A type OD), Tr250 and the Tr4A.
It looks like the OD filter attachment bolt/spacer/washer was deleted for those models.

The S-T parts catalog for the Tr4 does show those parts, but as it happens my '63Tr4 does not have the bolt, etc. But its OD does have the large drain plug with the spanner wrench slots.

It looks like the requirement for the filter attachment hardware went away with the change in the OD to the large drain plug with the spanner wrench slots. These ODs do use a pump body plug (p/n 513902) that seals the hole used by the older versions of the OD units to attach the OD filter element.

This type of large drain plug has a recess to accommodate three large rubberized magnetic washers and a center protruding boss into which the center hole in the OD filter element fits, this boss centers and locates the filter element for installation in the OD.

Looks like OD units with this type of large drain plug depend on the presence of the magnetic washer stack to ensure that the filter element seals at the OD end.

I don’t have an OD drain plug like CJD has illustrated in his post for comparison to the latter version of the OD drain plug.

CJD, does your OD drain plug have an internal protruding boss?


M.
 
Last edited:
Merlin63Tr4 said:
CJD, does your OD drain plug have an internal protruding boss?[/FONT]


M.
Click to expand...

No it doesn’t.

One note...I ordered a new filter from Rimmers. It came as a beautiful stainless screen filter, but it did not fit my bolt. The filter was about 3/8” shorter. As a result I would recommend ordering the filter and bolt from the same vendor, if you can.
 
thank you all again for identifying the problem. I used all my ancient medical training and a gloved finger followed by a camera perched underneath the car to determine that there is indeed no hole for a bolt, and the OD must come from a later incarnation than shown in the catalogues or part lists. It does show up on TR250 an TR6 at Moss.

The magnets seem to be the same for them all so I shall order a set of three and be satisfied that I have done all I can
 

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Mike
the hole for the screen is in the bolt in the oil pump,in your picture there is no hole,the previous owner could have just changed the bolt and you still may have an early overdrive,whats the number on the overdrive
also overdrive spares has a great price on those magnets
Philstr6
 
Mike, i see a hex bolt in the center of the pump which is in the normal bolt hole for the screen bolt. So the bolt hole is still there, just plugged with a short bolt.
 
I looked through the TR250/6 parts list on Moss website and it shows a short "plug" ( a short hex head bolt ) in the base of the punp, which would correspond with what can be seem on my lousy photo I think it must be a vestigial remnant in the evolution of the unit, rather like my appendix.
Is there a number hidden on the unit that would give a clue to its origin? I will look. Without it we have a lot of guesswork.
At the moment, with the boss on the plug, I am inclined to think it is just a later version of the OD that may have more in common with the TR250 than the TR3/4.
I will check with Overdrive Spares.
 
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