GS450h without external oil pump

[nino500]

Hi, I'm looking seriously at the GS450h for a next project
(currently working on something which uses all drive components from same source for simplicity).

The GS450h looks ideal for a RWD car BUT could some added complexities be taken out?
If the PSD is locked, then the internal pump would run as long as the vehicle is in motion. Then there only remains the issue of pressure to engage one of the 2 spd auto gears. So, if the output ratio is mechanically locked in high, the high pressure is no longer required to engage the clutches and the oil is only required to circulate for lubrication/cooling.

Further to that, could several components of the hydraulic servos/clutches be removed and discarded to save weight?

Newbie here so please excuse any protocol breaches

[Jacobsmess]

Sounds like you might be best served using the IS300H/GS300H transmission

[celeron55]

I don't think you necessarily have to lock the output gears. As long as the PSD is locked, just make sure to ramp the torque slowly from standstill to let the oil pump engage the clutches without too much heat from slippage. Some kind of special software limit would be a good idea.

Or, of course, you could just lock the output gears.

I do agree the GS450H transmission does have better gearing for common diff ratios due to its high gear, and the oil pump seems like an uncomfortable weakest link. Personally, I simply got and installed said pump, though. The aging inverter is probably the second weakest link.

[nino500]

Sounds like you might be best served using the IS300H/GS300H transmission

I had been considering this but there's still much discussion on the overall gearing issues and would rather use something proven.

[Jacobsmess]

I had been considering this but there's still much discussion on the overall gearing issues and would rather use something proven.

I don't think there is any gearing issues, you just need to know what your desires top speed it and what your diff ratio and tyre size is. If this doesn't work for you then yes the GS450H is the unfortunate option but IMO, the GS300H is a much better choice if you can make it work.

[Ev8]

I think if you plan to remove the external pump then you’ll have to find a way to mechanically lock the output into gear, there’s no way those clutches are going to like being slipped, I’ve not had the ga450 transmission apart but it could be as simple as drilling and tapping the housing to wind a bolt in behind whatever hydraulic cylinder engages the clutch for hi gear… or it could involve welding of the planet gears to the carrier much like locking the psd will… I see it being totally possible though

[jrbe]

What about something like an accusump to store oil pressure while driving? They make them with a solenoid to store the combustion engines oil pressure while the vehicle is off. Key on typically turns on the solenoid to send pressurized oil into the engine. You could potentially use something like this to store oil pressure while not moving but a few points:

1 you'd have to build up oil pressure with the wheels up then turn off the accusump solenoid.

2 if you managed to run out of pressure while out you're screwed.

3 still looking like an auxiliary pump is required for slow moving traffic. I'm not sure what speed the transmissions internal pump takes over. An external pump that turns on < 0 throttle but < wheel speed. Then could watch pressure in the accumulator and kick on when necessary or run variably to maintain some acceptable pressure.

You could use an adapter like this,
https://www.ebay.com/itm/175936880476

Along with one of the many universal oil pumps available that could work as a backup pump plumbed into an adapter.

I'd be willing to draw an adapter up in Solidworks if someone got me good dimensions of everything.

[Ev8]

I was wondering about an accumulator, but without knowing the flow rate of the valve body it would be hard to appropriately size, and yes you’d have 1 shot at pulling away and need to continue moving to refill it, stop start traffic would be impossible. I think the only solution is keep the pump or mechanical lock into gear

[jrbe]

...you’d have 1 shot at pulling away and need to continue moving to refill it, stop start traffic would be impossible.

I don't know how long 1.5 quarts of pressurized oil would last. 3 seconds, 3 minutes?

Do you know at what speed the internal pump can take over? If it's very minimal and if the accumulated pressurized oil lasted a while, an accumulator could be workable.

But I'd still want a backup electric pump. I was cleaning up my mess of a post when you replied.

[barracuda816]

This is a really interesting topic. I was thinking of going the other way to solve the problem and want to in the next 6 months or so buy the l210 and the L110 to see if it is feasible to either;

a) take the 1.9:1 gearing out of the 110 and fit into a 210 or
b) design and get made some replacement 210 gears that change the ratio from the 2.6:1 to around 2:1 (I would have to look at what the most appropriate gearing would be with a rear end or around 3.6:1) I have a feeling the cost for this would be quite high but would really help for conversions where you can't easily find a high ratio diff.

[nino500]

What about something like an accusump to store oil pressure while driving? They make them with a solenoid to store the combustion engines oil pressure while the vehicle is off. Key on typically turns on the solenoid to send pressurized oil into the engine. You could potentially use something like this to store oil pressure while not moving but a few points:

1 you'd have to build up oil pressure with the wheels up then turn off the accusump solenoid.

2 if you managed to run out of pressure while out you're screwed.

3 still looking like an auxiliary pump is required for slow moving traffic. I'm not sure what speed the transmissions internal pump takes over. An external pump that turns on < 0 throttle but < wheel speed. Then could watch pressure in the accumulator and kick on when necessary or run variably to maintain some acceptable pressure.

You could use an adapter like this,

Errr...yes... I was thinking of simplifying things though. I think that approach is a whole lot more complex than just using the original outboard pump.
Mechanically locking the output gears in 'high' shouldn't be much of a challenge and I believe someone has already successfully locked the PSD.

[jrbe]

The GS450h transmission has been run without the oil pump but with some other tricks.

viewtopic.php?t=644&start=225

viewtopic.php?p=39923#p39923

[nino500]

The GS450h transmission has been run without the oil pump but with some other tricks.

viewtopic.php?t=644&start=225

viewtopic.php?p=39923#p39923

Thanks. The locked high ratio clutch with locked PSD is exactly what I had in mind.