New LT85 oil issues

[coops71]

I know there is a lot of info regarding oil selection for the LT85 online but I have a couple of questions anyway. I installed an Ashcrofts LT85 in my 110 around May this year. I filled it with TOTAL BV 75-80 MTF and have had no real issues except for annoying baulky gear changes especially into third. This happens even with sedate shifting. Just wondering if the crunchy changes are a result of too higher viscosity? The old box never had a problem with motor oil. Motor oil may solve my problem but Im not sure how it will go with heavy work on the gears regards to sheer etc.

[coops71]

oh and I was going to ask if Penrite 70 mtf would be any better?

[Blknight.aus]

Run ATF or Engine oil

[dmdigital]

As said use ATF - Dexron III or IV.

[abaddonxi]

I had a problem with baulky shifting until everything warmed up, and jumping out of second. Gearbox had been recently rebuilt - so I was told, and no reason not to believe po. Everyone reckoned the jumping out of second was a bent first/second shift fork.

So, I put Syntrans into it, and bought myself a replacement gearbox.

I reckon the shift fork got bent due to manful shifting when cold.

Been running the Syntrans for a few thousand Kms, no problems with cold shift - and I've since moved to a cold place -and only jumps out of second on the odd ocassion on overrun.

[Bigbjorn]

I now use Castrol Syntrans 75W85. Expensive but the difference is worth it. Easier shifting and quieter. I use Castrol VMX80 in the transfer.

[87County]

ours is very smooth, with no synchro baulks even when cold since changing to Castrol Syntrans 75 85.... with the added benefit of extended period/ks for transmission oil changes

[coops71]

I drained the gearbox today and noticed the oil had a grey appearance to it with very very fine metallic flecks in it that would not settle. Perhaps this is partly due to some sort of assembly grease? I bought some Penrite 70-75 synth and managed to get it in my eyes and on my shoulder. That drain plug and filler plug on the 110 is a real pain(directly above the crossmember). Once it was going the whole thing was a lot quieter and shifting is noticeably better. Shifting into third from fourth is now perfect but 2nd into third is 50% of the time nasty. Why would all the other shifts be sweet except this one?

[maggsie]

The book says BP Visco 2000, that's all I have ever used and no problems.

Regards
Maggsie
04 V8 Disco
85 V8 County

[Freestyler]

I'm running Castrol VMX 80 in my LT 85 gbox and LT230 transfer which is a Light weight, extreme pressure GBox oil, which is light enough to make the gear changes very smooth, but still is a gbox oil which engine oil isn't. The viscosity of engine oils cannot be compared directly to gbox oils as the measurements are different. This oil was recomended to my by a mechanical engineer, which did 30years in the lube business in the hunter valley coal mines. This is the oil he ran in his 101 in the gbox and transfer. The oils is more expencive that the oil you probably use but the gear changes are smooth and light, you don't get that horrible clattering noise when idling and it is a gearbox oil and also meets the specs in the county manual. My box has only ever jumped out of gear twice. I have pulled the box apart since and found a broken circlip as in my posting on that. ATF has reduced lubrication properties to allow the clutch packs to grip in an auto box. If you put VMX 80 in an auto box the clutch packs wont grip. Would you put ATF in a manual gbox? ATF is great if you like rebuilding them. It is for automatic boxed only! Gearboxes always make metal, thats why the manual tells you to change it, so it doesn't turn grey and put metal through you bearing it also reduces wear on the main shaft in the transfer which is another catch in these boxes as well as 1st, 2nd selector fork wearing out. Tim

[incisor]

vmx80 is okay and works well in the LT85 but syntrans is a quantum leap better...

[Bigbjorn]

vmx80 is okay and works well in the LT85 but syntrans is a quantum leap better...

Wholeheartedly agree.

[isuzurover]

Wholeheartedly agree.

x3

And, for those who go "by the book" - lubricant technology has improved in leaps and bounds since the book was written. A dedicated gear oil should provide much better lubrication than engine oil or ATF in a gearbox.

[maggsie]

And, for those who go "by the book" - lubricant technology has improved in leaps and bounds since the book was written. A dedicated gear oil should provide much better lubrication than engine oil or ATF in a gearbox.[/QUOTE]

Regardless of the improvements in oil technology the box hasn't changed and therefore is still matched to the 'oil of the day'. There is no guarantee or tangible proof that the newer oils are going to provide a quantum leap in a gearbox that was designed nearly 25 years ago.

Maggsie
04 V8 Disco
85 V8 County

[Blknight.aus]

I now use Castrol Syntrans 75W85. Expensive but the difference is worth it. Easier shifting and quieter. I use Castrol VMX80 in the transfer.

yes but you cheated, you also had a reco'd box re-bearinged before you ran this lot of VMX. (hows it holding up BTW?)


And, for those who go "by the book" - lubricant technology has improved in leaps and bounds since the book was written. A dedicated gear oil should provide much better lubrication than engine oil or ATF in a gearbox.

Regardless of the improvements in oil technology the box hasn't changed and therefore is still matched to the 'oil of the day'. There is no guarantee or tangible proof that the newer oils are going to provide a quantum leap in a gearbox that was designed nearly 25 years ago.

Maggsie
04 V8 Disco
85 V8 County[/QUOTE]

Sorry going to disagree.

In this day and age of "racey shift" drivers that are used to driving itsy boxes with short throws and ratios the benifits of the oil are there you can shift the boxes faster and at cooler temps and the syncros will last longer.

I still advise running the normal ATF or the Engine oil because thats what the book says but then the book also explains the correct driving techniques to use with the vehicle.

[incisor]

tangible proof that the newer oils are going to provide a quantum leap in a gearbox that was designed nearly 25 years ago.

there is when you fill the box and drive it for a month.... ;)

[isuzurover]

there is when you fill the box and drive it for a month.... ;)

Exactly. Change to Syntrans and let it settle in for a month and tell us then if you think it doesn't make a significant difference.

When the R380 was first released didn't Land Rover spec ATF, then changed their spec shortly after to MTF94 when it became available??? Obviously Land Rover thought it worth switching to the new oils.... ;)

[Jesse.s]

I was running 15w40 semi synthetic engine oil. I checked the levels and noticed it was foaming.
this could be due to the previous unknown to me oil reacting to the detergents in the engine oil? I put vmx 75-85 in today I haven't heard lots of people say this yet but I found the 15w40 to be way smoother shifting, given you let it warm up for a few minuets.
The vmx just feels horribly crunchy and light the whole time especially if your changing 1st to 2nd to 3rd with higher revs no mater how slow I shift it feels crunchy. It dose feel better changing down gears then the engine oil but I feel like I have way more control over how it shifts with the 15w40.
Any one else feel that way or is it possible Im just used the way the gearbox behaves with the 15w40

[gromit]

ATF has reduced lubrication properties to allow the clutch packs to grip in an auto box. If you put VMX 80 in an auto box the clutch packs wont grip. Would you put ATF in a manual gbox? ATF is great if you like rebuilding them. It is for automatic boxed only!

ATF doesn't have the EP additives which are I understand are mainly needed for hypoid gears, an auto box still has gears but doesn't have synchro's.
The ATF also has to act as a hydraulic fluid in an auto box but is still recommended for some manual boxes.
My Defender at about 130,000 is running ATF with no problems.






I still advise running the normal ATF or the Engine oil because thats what the book says but then the book also explains the correct driving techniques to use with the vehicle.

I was looking at changing to Syntrans or similar but the recommendation was to stay with ATF if everything is OK.
I'm guessing that any ATF is suitable ? I was using Castrol 'ATF' which doesn't exist any more now it's 'ATF Dex III' or some other spec.

Automatic Transmission Fluid & Manual Transmission Fluid: What’s the Difference? (https://amsoil.com.au/blog/automatic-transmission-fluid-manual-transmission-fluid-whats-the-difference/)


Colin