Two Technical Questions

[jakeslouw]

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

Syn Trax is for transaxles (differentials and transfer cases with center diffs). Don't use it in gearboxes, the additives will eat the synchromesh rings.

[Paul#25]

Manny, if you refer back to my previous post, I asked what type of oil the manufacturer specified?
Do they specify either your first or second attempt at being more clever than the design engineers.
As mentioned by others as well, the incorrect oil will destroy the gearbox.

[jakeslouw]

As far as I can see, Isuzu recommend Castrol BOT402 75W85 or similar.
If you can't find that:
This is basically the same spec as Castrol Syntrans 75W90 Multi Vehicle.

[Paul#25]

Here is a write up on the specified oil.
https://www.startmycar.co.za/products/b ... 1449778636

[Mad Manny]

Paul, I've replaced the ATF with 75W85, I just didn't use Castrol or Fuchs.
The manufacturer makes no mention of the correct oil to use when you get to 250000km and have a failing Synchromesh...
So their recommendation means fokol....

[Mad Manny]

BOT402 75W85 or similar...

That's what I have now used....

[Paul#25]

Paul, I've replaced the ATF with 75W85, I just didn't use Castrol or Fuchs.
The manufacturer makes no mention of the correct oil to use when you get to 250000km and have a failing Synchromesh...
So their recommendation means fokol....

You can't fix a mechanical problem with different oils. The synco rings are made out of brass and do wear. Like all mechanical products they have a design life that you are obviously getting to the end of. If the driver hammered the gearbox the life will be reduced.
Any decent gearbox repair shop should be able to replace the synco's quite easily. If they aren't changed then you start damaging the gears and the selectors. It's cheaper to fix only the synco's now instead of replacing most of the innards of the gearbox.
My recommendation is to have the gearbox repaired properly. Use it, don't use it, it's your choice.

[jakeslouw]

He's a cheap porra, he'll drive it till it breaks.

[Disco Nic]

Paul, I've replaced the ATF with 75W85, I just didn't use Castrol or Fuchs.
The manufacturer makes no mention of the correct oil to use when you get to 250000km and have a failing Synchromesh...
So their recommendation means fokol....

You can't fix a mechanical problem with different oils. The synco rings are made out of brass and do wear. Like all mechanical products they have a design life that you are obviously getting to the end of. If the driver hammered the gearbox the life will be reduced.
Any decent gearbox repair shop should be able to replace the synco's quite easily. If they aren't changed then you start damaging the gears and the selectors. It's cheaper to fix only the synco's now instead of replacing most of the innards of the gearbox.
My recommendation is to have the gearbox repaired properly. Use it, don't use it, it's your choice.

if its not broken, don't fix it... Its the Porra way.

[jakeslouw]

I had a really rough gearbox on my 110 V8. That was the LT85 5-speed and when it comes to Leyland Transmissions, they aren't known for excellent shifting and robust synchros. So I had a really bad synchro between 2nd and 3rd. Switching away from the "factory recommended" 15W40 to Syntrans 75W90 obviously couldn't/didn't solve the problem, but heck, it made it so much better that I could live with it.

It also dropped the transmission temperatures a LOT.
Before the Syntrans, you couldn't touch the gearbox tunnel without getting burned. Afterwards it was still a little hot but not above around 50 degC on the tunnel.

[Mad Manny]

It's cheaper to fix only the synco's now instead of replacing most of the innards of the gearbox.
My recommendation is to have the gearbox repaired properly. Use it, don't use it, it's your choice.

The oil was R540 for 5L.
I've requested a quote for the gearbox repair.
I'll get back to you on how prices compare.

I appreciate that fixing it is the wiser option.
But economic reality rules.
A mate of mine had his Disco II Turbo shatter like the peace in a US School when someone opens up with an AR15.
He fitted a recon unit rather than going OEM.

Times are as tough as trying to drink 8 glasses of water a day in Hammanskraal....

Capish...

r

[Johannes]

You are a dickhead Manny. You get recon gearboxes as well. Just like recon turbos. Now you want to compare fixing a gearbox with oil to buying a recon unit ??? What a twat !!

[Mad Manny]

Says a guy building a house on the cheap...

[Johannes]

Not to worry . Its getting there. Slow . But getting there

[Mad Manny]

Why not get a professional Construction company in to build it?
Take your own advice...