GL4 Recommendations What tranny oil to use to protect bronze

[TDLightweight]

Hi,

I have just finished rebuilding my transmission and transfer case and now that the whole assembly will hopefully be leak free, I am wondering what oil to use.

Despite much research on the net I have been unable to find a Hypoid gear oil that is easily available which states in in its specifications that it is safe to use in a transmission with bronze parts.

GL-4 seems to virtually impossible to find save for semi or fully synthetic blends. GL-5 is not recommended as it uses Molybdenum as an additive which apparently attacks the bronze (i.e syncros).

I am curious to what other penny pinching series owners use.

Despite my best efforts I am pretty sure the drive train will find a way to leak in the accepted British way.

Any recommendations greatly appreciated. The truck is going to be sitting until Founder's Day but I do need to move it out of the garage to make room for other projects so if you have an answer please let me know know soon.

Thanks Brodie

[red90]

As I understand it, it is not the Moly, but certain sulfur compounds. I know people will flame me.... but quality modern EP lubricants use additives that don't attack white metals. So in reality any high quality lubricant should be safe despite the GL-5 designation. BUT, a cheap gear oil will probably still use the "bad" additives.

http://www.noria.com/learning_center/ca ... icleid=496
http://www.lubrizol.com/products/automo ... il/GL5.asp

Having a GL-5 designation versus GL-4 has no actual bearing (excuse the pun) on white metal corrosion. The confusion is due to the additives that were/are used (mostly in the past) to allow the lubricant to meet GL-5. Having an MT-1 designation is a bit more helpful as it assures that the lubricant meets the ASTM copper strip corrosion test in addition to the GL-5 requirements.

Now.... If you are not confused enough... A normal EP gear lubricant is not a great candidate in a synchronized transmission. This is mainly due to improper friction characteristics to enable smooth synchronization. Due to much of this, almost all modern transmissions use low viscosity transmission lubricants with special friction modifiers.

I know little about Series boxes and their desired viscosity, but probably Redline MT-90 would make a good choice.

http://www.redlineoil.com/products_gear ... tegoryID=7

http://www.redlineoil.com/pdf/6.pdf

[rick.m]

i cant go into too much detail here, but i will tell you in the over 7 years i have had the 65 IIA, 109, i have used CASTROL 75-90 FULL SYNTHETIC gear oil, the tranny and transfer cases get the same, and have since the rebuild a few years before i got the truck. i am in the habit of changing it every spring, and always dump the old, hardly used,[lol] into a clean white pail, each one seperately, and leave is sit for a few days. and pour off into the old containers, almost all the old oil, and look at the nice clean bottom to see if there has been any sign of carnage, there hasnt been, in my 20,000 miles, thankfully, I usually use lordco and or walmart as it comes in around $12.00 I see canadian tire is now selling a full synthetic 75-90 gear oil, at a reasonable cost, I have convinced my self, that the $100. oo buck is cheap insurance for each season. all the best rick.m

[DaveB]

There are now quite a few gear lubes sporting the GL-5 AND the MT-1 designation, so as Red90 says, I would look for one that has the MT-1 designation on its label.

I don't know what the evolution of this stuff is, but I do know from personal experience, if you put a straight GL-5 in that doesn't have the MT-1 designation, you will have an oil that is shiny with bronze within about 3000 miles.

Until the MT-1 designation was added (about 2 years ago) it was beginning to be a challenge to find a gear oil that was lower than GL-5.

In my experience, my gearbox always leaked too much with full synthetic so it went against my grain to take something as expensive as that and essentially pour it out on the ground. Glad to hear you got lucky and don't have a leaker, Rick.

cheers — with no flames!!!

Dave

[red90]

I assume Brodie's gearbox is synchronized? If so, the shifting is helped by having a "manual transmission fluid" over "gear oil". There is much less chance of the synchros touching each other.

The MT-90 does not cost any more than any other synthetic lube. Around $10 a liter. Being newly rebuild, he should not have leakage issues.

[Rob]

The Series 2 Club has some excellent information regarding oils and lubricants in rovers. Their site is at http://www.series2club.co.uk/frame.htm (look for the technical tab on the left side of the page).

Regards, Rob.

[Greg S]

I've done a little research myself. Look on my Website for the answer. The right stuff is available from Chevron and recorded at the following link for your viewing pleasure.

http://www.vanislelandrovernetwork.com/ ... l#article3

[TDLightweight]

Hi Guys.

Thanks for the tips and links.

I went with the Castrol Syntec 75/90 we will see how that works out. For the record the transmission spec is as follows:

- "D" series IIA transmission with better layshaft and syncro on 3rd and 4th only.
- "B" Series low ratio transfer case

- Rocky Mountain Overdrive