2000 Honda Insight - Heating the manual trans with engine coolant

[rmay635703]

Originally Posted by jrnsr

I don't mean to rain on your parade, but...

In the good old days, 90 weight oil went into the rear end and transmission. A Honda was the first car I had that used 10W30 in the manual trans, so they already have built the transmissions around thinner oil. Not sure what the newest cars are using. Heating it thinner may jeopardize the trans

If you want thinner oil, toss in a cup of diesel and then cross your fingers.

10w30 oil is the same viscosity as 85wt gear lube

Thinner, yes but not by much.

https://bobistheoilguy.com/viscosity-charts/

My old diffs all took 90w140

[jrnsr]

85wt may in the ballpark with straight 30 weight, but nowhere near the viscosity of a 10W motor oil.

A newly-wed couple didn’t know the difference between putty and Vaseline.
A week after the marriage all their windows fell out, which was the least of their worries.

[rmay635703]

Originally Posted by jrnsr

85wt may in the ballpark with straight 30 weight, but nowhere near the viscosity of a 10W motor oil.

A newly-wed couple didn’t know the difference between putty and Vaseline.
A week after the marriage all their windows fell out, which was the least of their worries.

Read the chart again

10w30 in gear lube terms is like 75w85

It's in the chart I linked to

Also makes me wonder
Mobil 1 used to sell monograde 0 weight synthetic motor oil

What happened to that stuff?

[dancam]

Originally Posted by diesel_john

What are the pros and cons between hot thick oil and cool thin oil like john deere hy-gard?

No difference other than the additives of the oil and energy is required to heat oil.
What the goal is here is to thin the oil so there is less resistance inside the transmission.
Most if not all 90's mazda manual transmissions speced ATF from the factory. Thats what was put in them and on the cheaper cars like mine it often was never changed. There are manual transmissions in festivas that have gone 300k miles just fine on ATF.
So, amsoil has an equivilant of honda mtf. They post the viscosity specs. Same with their synthetic ATF.
MTF is thicker than 0w20 but thinner than 0w30 engine oil. ATF is thinner than both.
I put the numbers into a viscosity calculator. Lets say you managed to get your mtf up to 195f on a long drive. ATF would be the same viscosity 37 degrees lower at 158f.

With my small car towing a big trailer in 86f when my coolant overheated the transmission case was 155f. The oil was probably not as hot because the trans shell would have been hotter from the rad fan blowing 220f air directly onto it.
Normal driving is 120f iirc.
Lets say where you live is hotter and your transmission gets to 130f naturally on a long drive when its hot out. Atf would be at the same viscosity 25f lower at 104f.
We usually commute when its cooler and i dont know how cold your area gets in the winter, but mtf at 77f is the same as atf at 61f.
Atf is just as thin at 21f as mtf at 32f (11f colder)
Atf is just as thin at 6f as mtf at 14f.

So i hope you can record the demterature difference this jacket makes on your oil. If it doesnt heat it up quickly perhaps consider using a thinner oil to begin with.

*edit* my point with all this which i forgot to mention is that on a 7 mile drive starting with thinner oil like this will likely make more of a difference than trying to heat it through the transmission case.

[NHB]

Originally Posted by diesel_john

What are the pros and cons between hot thick oil and cool thin oil like john deere hy-gard?

Thinner grade oil has the advantage in efficiency, because it has lower viscosity after cold start. This is the most critical moment if we want to improve the efficiency. It takes a lot of time before oil in a gearbox will heat up. Oil aging process is slower with colder oil so the oil doesn't need to be changed as often as hot oil. Also rubber seals will age faster when the temperature is higher.

Hotter oil has one advantage. Moisture in oil will evaporate faster at higher temperatures.

[gumby79]

Galvanic action

Adding brass/copper to your systom could cause a corrosion problem. Theas 2 meterals were removed from the cooling system with the introduction of Al rad. It took the manufacturers a few years to figure it out . How ling wi it take to decime a problem? Dono... 3 years on my '79K-20 with a 4core Al rad. and copper/brass heater core no coolent related trouble.
---
An idea to make your sealed chamber.
Braze up your shape (3sides 4th is the trans case). Use some gas tank sealer epoxy.
This will remove the air/water tight requirements, making your welds structural only reducing the likelihood of a contamination leek. Oil has soked into the metal and will surface when heated.
---
add a trans temp Gage.
Add codes for cooling function, to allow lower oil weight without the threat of over heat failure in summer.
---
Not enough rum time to justify this mod???
Add a pump .
Im shure thar you have already exploited the low hanging fruit (block heater). With a relatively short commute lack of heat bulid up is what your trying to fight. Set the circ pump to come on after the motor is warmed(on the plug)
----
Alternative to a jacketed heater.
Use a tube/fin or stacked plate type cooler were you want the jacket then insolate . Option to improve heat transfer fill the fins with Al chips/shavings/ powder improving the contact patch with the cooler and trans case as air space only transfer IR heat (slower)

Well enough ideas for now.

Dream Big Chisel Down To Reality

[t vago]

Been toying with this idea to heat up manual transmission oil. My Magnum has a radiator having a currently unused transmission cooler, from when it used to have an automatic tranny. I was thinking to get a replacement set of cooler lines and route them to the threaded fill and drain plugs on the 6-speed transmission currently in it. Was thinking also to use a small electric oil pump to do the circulation, controlled by an Arduino reading a thermistor.

[Daox]

Yesterday I continued this mod on the Insight. I started with a good ol cereal box as any reasonable ecomodder would do, and started marking it and trimming it as needed to make a template to cut the aluminum sheet.


I had to be careful for things like bolt clearance.



I decided to go with a single sheet. There will be some forming / bending involved in it, but it shouldn't be too bad. I kept it as simple as possible. It wraps as much of the transmission case as possible. It also wraps the transmission pretty tight, so it won't hold a huge volume of coolant which was also a design goal. Once the valve opens, I don't want a huge volume of coolant rushing in and cooling the engine off. The circles are the inlet and outlet.




I also marked where the sheet will attach to the transmission case, and I started sanding down to raw / clean metal so that the brazing will bond well with the case.

[Daox]

I cut up the template in aluminum and started forming it last night. I think I have it pretty close to where I want it and want to start brazing it up. However, I need an inlet and outlet before I do so.

Roughed up the brazing area.






Then cut the aluminum.





And formed it.

[AlaricD]

I view this as sacrificing engine warmup to try to warm the transmission. It seems any mechanical efficiency you might gain with the transmission would be lost if the engine itself isn't running at its peak efficiency.

It might be better to just install an electric pad heater to the transmission (granted, it's only useful if you can plug it in).