Two Technical Questions

[Mad Manny]

Please help with two technical questions:

1. I have an Isuzu KB300 D-Teq.
It's like a Ranger, but for people who don't covert their mothers booty.
We recently replaced the clutch & replaced the Gearbox Oil.
We used ATF (my Mechanic INSISTED), in fact, I hat to take the MTF back & exchange it.

Changing gear in to 2nd grates the gears, whether from 1st up to 2nd or from 3rd down to 2nd.
It's like the Syncromesh is gone.
It did this long before we did the clutch.
However, I noticed it does not do this until the vehicle has properly warmed up.
With the recent cold snap, I've noticed that it takes longer to start grating my gears.

ATF is Automatic Transmission Fluid for the uninitiated.

Question: Would replacing the ATF with a thicker gear oil help?

Question two;
2. I have a Generator, 5.5kVA Honda (to make this 'On Topic' let's assume I take it with when camping like Mike Nel does).
It has no AVR.
My Inverter hates it & I'm sure it's not good for my fridge, laptop or TV.

Question: Is there a way of fitting a 'Freestanding AVR' either at the Gennie or in the line from Gennie to DB?
Do you get such a thing.

For those not in the know AVR is Automatic Voltage Regulator - Most Gennies now come with it fitted.

Thanks in advance....

[Paul#25]

Answer to Question 1......
What oil does the manufacturer of the gearbox specify for that specific gearbox. If it was me, I'd only use the oil specified and not a substitute that a mechanic thinks is better. The bearing materials in most gearboxes require very specific oil types to prevent damage. The manufacturer always knows best.
If the syncrow rings are worn there is no much you can do other than replacing them. A thicker oil will possibly help slow a fast spinning shaft down for a while but may not give adequate lubrication in other areas of the gearbox.
Answer to Question 2.........
The dangerous situation that you want to prevent is under-voltage or a grey-out. As the voltage drops, the amps increase and open the doors in the electronic components for the smoke to escape. Once the smoke escapes, your money normal follows.
There are plug in voltage protection units available from most reputable electrical suppliers. You must check that it protects against both over and under voltage. They were always sold as lightning protection plugs.
I'll have a look what AC-DC has and the prices later today.

[Donkerpoort4x4]

Use fuchs MTF 75W90 synthetic oil and after 1500km the box will be smooth again, unless your geabox was damaged...

[Mad Manny]

Thanks Paul and Ernie....

[grips]

Freestanding AVR.

https://deal-hub.co.za/products/avr-40a ... p8QAvD_BwE

[Bugjuic]

Hi Manny

If you look at the two oils

1.ATF

Source:https://wiki.anton-paar.com/za-en/autom ... fluid-atf/

2. Gear Oil 75W140

Source: https://wiki.anton-paar.com/za-en/autom ... fluid-atf/

You will see at about 80Deg Celsius the ATF viscosity sits at 9.57mm^2/s and the MTF sits at 33.544mm^2/s (Dynamic)

So seeing at this viscosity is MUCH lower, it will slip much faster. Thus your synchro gears that depend on friction to match the speeds is not that effective anymore and causes your scratching.

Also just check some ATF fluids are synthetic whereas MTF oils are mineral. Make sure you flush out the old oil properly!

The hotter the gearbox becomes the lower the atf drops, the worse the synchro mesh will be.

Or atleast that is my opinion...

[Mad Manny]

OK, I bought oil recommended by Ernie.
Will do it this weekend and report back...

[Mad Manny]

Next is to buy the AVR recommended by Christo....

[Mad Manny]

Thanks everyone!!!

[jakeslouw]

Too late for the advice, but I've had excellent result with Castrol Syntrans. ATF is a stupid idea in African climates.

[Donkerpoort4x4]

I have also used castrol syntrax with very good results. I think it is also synthetic

[Donkerpoort4x4]

Manny any feedback with scratchy box

[Ricof4e]

Stop getting excited about moving a long stick about - mens ruk en pluk nie aan die rathefboom nie.

[HenriSteyn]

Stop getting excited about moving a long stick about - mens ruk en pluk nie aan die rathefboom nie.

[Mad Manny]

Manny any feedback with scratchy box

Oil was changed on the weekend.
I couldn't get Fuchs, I used the equivalent CST oil.

The vehicle FEELS smoother (the box is less scratcht going in & out of 2nd).
But, I did very little mileage yesterday & today & it's been very cool.
The problem got worse when the box got hot.
So I'll report back on a day with more driving & a hot box.