Which oil for LT77 gearbox

[tonym]

Originally Posted by DELAGE

D J Ellis when supplying me with a new R380 told me to use Vavoline fully synthetic 72W/90 I think or similar and nothing else.

I, personally, wouldn't trust Dave Ellis with a lawn mower engine so i'll stick with ATF which has been in my second hand, high mileage LT77 for the last 4 years

[Sidecarbod]

Originally Posted by DELAGE

Hi Pete yes exactly that, If my memory serves me correctly the older boxes LT77 fitted to TR7, SD1 and the like used to use EP80/90 gear oil, but Leyland in there wisdom due to complaints by women who could not get it in gear on a cold start recommended using auto/TQF type fluid the alleviate the problem. Perfectly okay for normal day to day work but not for heavy loading. I have recked three gearboxes (LT77) doing track days with this oil. I then woke up and D J Ellis when supplying me with a new R380 told me to use Vavoline fully synthetic 72W/90 I think or similar and nothing else.

Not had a problem since that time, but I have to say the R380 box in my opinion is a far better box which helps

LEO, Redline MTL is not an ATF oil it is a fully synthetic 70/80 gearbox oil, so I'm not sure why you think that is is no good for an LT77.

Pete

[DELAGE]

Originally Posted by tonym

I, personally, wouldn't trust Dave Ellis with a lawn mower engine so i'll stick with ATF which has been in my second hand, high mileage LT77 for the last 4 years

Tony I just don't know why I bother posting advice but must say not a fan of Ellis myself but I stuck with what he recommended in view of my previous experiences and the fact the unit carried a 1 year warranty. But hang on a moment was not Peter Jones singing his praises some time back in Snake Torque? I think you will find Russell Ram and Cheng Lim also advise the type oil I mentioned Perhaps your Sumo just ain't that quick to encounter problems with ATF/TQF in the gear box

[DELAGE]

Originally Posted by Sidecarbod

LEO, Redline MTL is not an ATF oil it is a fully synthetic 70/80 gearbox oil, so I'm not sure why you think that is is no good for an LT77.

Pete

Well thats fine then I thought you were referring to ATF/TQF auto transmission/power steering type (red) fluid. Just passing on my own experiences thats all Pete.

[Sidecarbod]

Originally Posted by DELAGE

Well thats fine then I thought you were referring to ATF/TQF auto transmission/power steering type (red) fluid. Just passing on my own experiences thats all Pete.

Hey Leo I'm with you on this one, I would not trust putting ATF in a manual gearbox, its not what the oil is intended for. I also know that the likes of Russell RAM is of the same opinion. (There have been many posts on this subject!)

If your bored you should have a read of the PDF doc on the Redline website, its quite interesting if you like oil and all things oily!

Pete

[craggle]

Interesting that the oil of choice for the Tremec box is a good quality ATF.

Craig.

[Sidecarbod]

Originally Posted by craggle

Interesting that the oil of choice for the Tremec box is a good quality ATF.

Craig.

Tremec....what do they know! just because they have built tyhe odd gearbox here and there they think that that gives them the right to go specifying oil willy-nilly

Seriously though, if they designed their box right from the start so that it would work correctly with ATF then that could be why they specify it. The syncro timing and levels of friction of the syncro rings may have all been designed around ATF.

I don't think that the LT77 box was designed round ATF, that oil was specified later when people moaned about the slow gear change when cold.

Having said all that I know that oils that are not designed for the extreme loads between gear teeth get their polymer chains shredded by being put through gears, I still don't think that ATF was ment to be used in this way. AJMHO. (My get out clause).

Pete

[wilf]

The thing that I find funny is the (unspoken) assumption that auto gearboxes somehow don't have gears in them, and so don't need an EP oil.

Of course they do, and they work just fine with some massive torque ratings, and only ever ATF in them.

However, I always did wonder about the use of ATF in an "old" box like the Rover unit, surely they were designed to use an EP oil to begin with?

[DELAGE]

Originally Posted by craggle

Interesting that the oil of choice for the Tremec box is a good quality ATF.

Craig.

Craig its funny but some time back I entered into dialog with a couple of people in the oil industry senior management/sales people who stated that semi or fully synthetic of various type was perfectly okay in the RV8 and superior as opposed to mineral oil, I tried both options with disastrous results. Noisy hydraulic tappets and for a short while with solid lifters and a drop in oil pressure by 10lb was the result, so my point is those who should know don't always know and to re cap all that glistens is not always gold.

My car runs very well using mid range Comma 20W/50 mineral oil which I change every 500-1,000 miles with filter, resulting in 75psi when cold and 50psi when hot & 25lb @ idle, so my point is that some folk who suggest using a cheaper oil ruins an engine are talking pants

[DELAGE]

Originally Posted by wilf

The thing that I find funny is the (unspoken) assumption that auto gearboxes somehow don't have gears in them, and so don't need an EP oil.

Of course they do, and they work just fine with some massive torque ratings, and only ever ATF in them.

However, I always did wonder about the use of ATF in an "old" box like the Rover unit, surely they were designed to use an EP oil to begin with?

Yes correct Wilf, TR7 5 speed up-to vin number 211002 Hypoid gear oil viscosity SAE 75EP (Duckhams hypoid 90S), and from Vin number 211002 they changed to ATF type G to M2C 33G (Duckhams Q-Matic) and much the same story for the SD1, as complaints from ladies were that they could not get it in when cold