Very small gear oil pump for LT230 / overdrive

[FridgeFreezer]

Per the title really, following on from a thread on overdrives and the issues with oiling the rear bearing I've been pondering rigging a small oil pump to lift a little oil from the LT230 and squirt it into the rear of the OD case via a small fitting.

It doesn't need any great volume of oil, just a dribble really.

Ideally I'd like it to be purely mechanical but I'm not seeing a straightforward way to rig that up - if I was going to Project Binky levels I'd build a small gear pump to sit inside the extended sump on the LT230 and mesh with the input or intermediate gears, but that seems a tad above my abilities never mind the amount of time & money I really want to spend on this.

Other thoughts are just using a very small cheapy electric pump from eBay and bolting it in a box somewhere convenient, but that means wiring and I'm fairly suspicious of cheap eBay pumps and the like especially if they're going to be coming into contact with warm gear oil.

I did find that a lot of 2-stroke scooters have small electric or mechanical pumps for dosing 2-stroke oil which seems like a pretty good bet.

Any other suggestions, sources of small pumps, projects that have picked up drive from inside an LT230, etc.?

[Nonimouse]

I'd go for a two stroke pump. Pretty heat resistant. If it works you can always go bling

[Carloz]

Maybe you can instal a sort of rain gutter somewhere high in the LT230 housing and leading the catched oil to the OD via a small hose: the pumps are the existing gears inside the LT230.

Super low tech and reliable but needs opening the LT230 of course.

[L19MUD]

59 minutes ago, Carloz said:

Maybe you can instal a sort of rain gutter somewhere high in the LT230 housing and leading the catched oil to the OD via a small hose: the pumps are the existing gears inside the LT230.

Super low tech and reliable but needs opening the LT230 of course.

I like this idea as the oil is sure to be everywhere in the box when moving and once proven will be as reliable as you can get. Could run the pipe externally to a temporary pot and see how effective it is? Not sure how the oil returns on the overdrive but will too much oil be a problem?

[FridgeFreezer]

3 hours ago, Carloz said:

Maybe you can instal a sort of rain gutter somewhere high in the LT230 housing and leading the catched oil to the OD via a small hose: the pumps are the existing gears inside the LT230.

Super low tech and reliable but needs opening the LT230 of course.

I was pondering something like this and I must say it's my favourite, as you say super low-tech & reliable - the "output" is on the back of the OD roughly in the centre of the input shaft, so as long as you can pick a little oil up from higher than that, you can get it to dribble down to where it's needed. It's basically the rear input shaft bearing that needs lube.

[toenden]

The lt77 uses a small plastic oilpickup/catcher directing oil to the 5'th gear section (if memorial serve right). Maybe you can adapt this/use it as a starting point. (IT does seem a bit underengineered though. I remember thinking, "what?" 🙂) 

/mads

 

[elbekko]

I would think a small peristaltic pump would work as well. They're usually made to be on 24/7, although I have some doubts about the longevity of the flexible hose.

[smallfry]

What about one of those Webasto parking heater pumps ? A cheap one at first to experiment with.

[RedLineMike]

not sure if you had seen this thread from the good old days of pirate

https://www.pirate4x4.com/threads/i-blew-up-my-lt-230-at-koh-and-it-took-me-out.1626818/

[Daan]

Can you sandwich a plate between the transfer case and the O/D with a hole as small as the shaft? This to achieve a higher oil level.

I normally fill my PTO to the required height, however, after the first steep hill, the PTO fills up completely with oil to the top. I usually have to refill the transfer box after this.

[miketomcat]

Having seem the other thread on this topic what about using one of these.

https://www.fuelpumpsonline.co.uk/facet-cube-pumps-12v-1820-c.asp

They are pressure based rather than flow (you could make a restrictor to increase pressure and reduce flow).

Mike

[dangerous doug]

story time

when drilling the breather for my new diff cover on the front Salisbury I decided to do as they did and drill it in a similar location to the oem. On the oem cover there is a plate over the fitting on the inside which I thought odd so decided to not copy(read I was too lazy) as a consequence, the crown wheel spun and splashed oil at the breather opening, sent oil all the way up the breather pipe and down the side of my truck and over me…..Good times

 so could a hole not be drilled by a gear and use the same principle only not by mistake like me😂

[ped]

on my hydraulic pump take off there is an oil catcher you have to make sure is fitted correctly to feed oil to the bearings
it's just a tube with the top cut off part way so oil spashed in the t/case runs back into the pto unit
i may be stripping the pto off tomorrow to clean it all up prior to fitting new output o rings so i'll take pics if i do

[ped]

Pic of it

[hurbie]

part seems to be FRC6933 "catcher manual transmission oil "

 

[Northwards]

16 hours ago, ped said:

Pic of it

Aah! That’s a really useful photo. I’ve just re-fitted my overdrive and before doing so had a wee ‘feel’ about inside the casing to see if there was anything there to direct oil out beyond the PTO opening. There was nothing in the casting, but that shows how things are supposed to work, and why the hole in the LT230 casing is as big as 16mm.

That would certainly guarantee plenty of oil in the overdrive - but in relation to identifying a small pump to feed the rear bearing (of the Roamerdrive) I think that’s still a useful quest. Even if the main body of the o’drive was ‘stuffed’ with oil then I still wonder about oil feed from there to the rear bearing.

But thanks for posting that pic!

 

[FridgeFreezer]

I wonder if a "catcher" like that plus a drilling in the side of the LT230 would direct some oil to the back of the OD.

All a bit academical as I'm not really inclined to split mine while it's all working happily but if it's ever apart I will definitely do *something*.

[Snagger]

I was just thinking the same - a drilling with a similar open half-tube catcher with a cunifer line to gravity feed the overdrive rear bearing would do it.  With the vehicle in motion, there would be more than enough splash to fill the catcher, even high up.  Ideally, you’d have it on the side of the overdrive output gear that is after the 12o’clock position in forward motion, ie vehicle left, opposite from the hand brake and intermediate cluster.  Not sure how much room is in there, and it might need a new drilling if the PTO feed is not high enough above the centreline of the main shaft for gravity to feed all the way to the overdrive back end.  Obvi, this will be helped if you mount the overdrive bearing feed tapping as low as is practicable on the rear cover.

I wonder if there is space to do the same on a Series transfer case. 🤔

[reb78]

Could you adapt/use one of the bolts or bolt locations that holds the OD onto the txb for this?

If you used a long threaded bar that extended into the txb, drilled the centre so it was hollow, adapted the end in the txb so that it had an oil catcher and adapted the other end so it would take a pipe to the location on the OD? If you made the centre drilling gradually wider in diameter, that might give you some sort of venuri type effect to pull oil through? On the outside, just run a nut up the bar so it still does the holding job?

No idea if that makes sense but it does in my head. Could potentially try it without removing anything either...

[JohnnoK]

What of the pump in the R380 running off the PTO flange?

It'd need a fair bit of planning and work to fit, but it's small enough and volumetrically up to task.

[Northwards]

^ That’s like a ‘chicken and egg’ thing. The point of sourcing the pump is to try and improve oil feed to an overdrive bearing - and the overdrive is mounted into the PTO slot.

Unless I’ve completely missed something obvious in what you’ve said, which is always possible!

[Northwards]

On 5/14/2023 at 10:23 AM, reb78 said:

Could you adapt/use one of the bolts or bolt locations that holds the OD onto the txb for this?

If you used a long threaded bar that extended into the txb, drilled the centre so it was hollow, adapted the end in the txb so that it had an oil catcher and adapted the other end so it would take a pipe to the location on the OD? If you made the centre drilling gradually wider in diameter, that might give you some sort of venuri type effect to pull oil through? On the outside, just run a nut up the bar so it still does the holding job?

No idea if that makes sense but it does in my head. Could potentially try it without removing anything either...

This does make perfect sense. I can follow precisely what you’re suggesting. I think if you were designing an overdrive from scratch that would certainly be worth considering, or at very least taking more advantage of the oil capture pipe that’s in Ped’s pic. But I think this would mean significant re-engineering of the existing Roamerdrive casing, and also the TBox one. I know that at least some of the 6 bolts holding on the Roamerdrive (and the PTO cover where there’s nothing fitted) go into blind holes with no oil feed so you’d also need to open them up.

I’ve been too busy to even think about this recently, but I had started to think that the easiest way around this might actually be as someone suggested, to get a low-flow pump suitable for underneath the car, and then rig it up to some sort of thermostatically controlled timer such that it would only activate when the transfer box was up to temperature, and then on a timed basis - just delivering a wee ‘slug’ of oil every 5 minutes or so.

Edit - …and as a ‘PS’ - part number FRC6933 ( the oil catcher in the pics above) is on a ‘clearance’ price at Craddock’s. £40 as opposed to £200+.

I’ve gone for it, as even if I don’t fit any kind of pump, this cannot be a bad thing to fit the next time I have the Roamerdrive off. The better the flow of oil into the unit, from wherever it comes, would surely help that vulnerable rear bearing.

 

[reb78]

16 hours ago, Northwards said:

This does make perfect sense. I can follow precisely what you’re suggesting. I think if you were designing an overdrive from scratch that would certainly be worth considering, or at very least taking more advantage of the oil capture pipe that’s in Ped’s pic. But I think this would mean significant re-engineering of the existing Roamerdrive casing, and also the TBox one. I know that at least some of the 6 bolts holding on the Roamerdrive (and the PTO cover where there’s nothing fitted) go into blind holes with no oil feed so you’d also need to open them up.

I’ve been too busy to even think about this recently, but I had started to think that the easiest way around this might actually be as someone suggested, to get a low-flow pump suitable for underneath the car, and then rig it up to some sort of thermostatically controlled timer such that it would only activate when the transfer box was up to temperature, and then on a timed basis - just delivering a wee ‘slug’ of oil every 5 minutes or so.

Edit - …and as a ‘PS’ - part number FRC6933 ( the oil catcher in the pics above) is on a ‘clearance’ price at Craddock’s. £40 as opposed to £200+.

I’ve gone for it, as even if I don’t fit any kind of pump, this cannot be a bad thing to fit the next time I have the Roamerdrive off. The better the flow of oil into the unit, from wherever it comes, would surely help that vulnerable rear bearing.

 

Ah, you are right I think. I had it in my head that some of those PTO cover bolts went straight into the open casing. If they did then the top one would be prime candidate for this I think. One downside would be that it wouldnt be as effective if bouncing around at all angles off road but then i guess the OD would be unlikely to be under load at that point.

 

Although - doesnt the part shown by PED go through a standard hole at the back of the txb?

Edited May 17, 2023 by reb78

[FridgeFreezer]

23 minutes ago, reb78 said:

I had it in my head that some of those PTO cover bolts went straight into the open casing.

If that were the case it would not help the problem at hand which is lubricating the rear bearing - the rest of the OD gets plenty of oil from the LT230 through the PTO hole, it just doesn't make its way to the rear bearing as much as it might.

The job at hand is trickling a small amount of oil into the back of the housing, which a "catcher" pickup and small external pipe would do.

Only reason I'm not doing that right now is I don't have the time for it and my OD and LT230 are working happily, if I ever have to have them apart or even just have the LT230 cover off I will be looking at adding this mod.

[reb78]

12 hours ago, FridgeFreezer said:

If that were the case it would not help the problem at hand which is lubricating the rear bearing - the rest of the OD gets plenty of oil from the LT230 through the PTO hole, it just doesn't make its way to the rear bearing as much as it might.

The job at hand is trickling a small amount of oil into the back of the housing, which a "catcher" pickup and small external pipe would do.

Only reason I'm not doing that right now is I don't have the time for it and my OD and LT230 are working happily, if I ever have to have them apart or even just have the LT230 cover off I will be looking at adding this mod.

I get what you are trying to do - my suggestion was to use those holes to create an oil pick up from which you could direct oil to the back of the OD with a pipe from the pickup.

Edited May 17, 2023 by reb78