Help – Gearbox Oil Advice Needed

I recently had my 25th Anniversary serviced. Everything was normal for about 250 miles then the gearbox started to get noisy in 3rd, 4th and 5th.

 

Last night I took it to a friend who’s a gearbox design engineer for a listen. He immediately said “oil”. So we checked the oil. Doing this in the street outside his house it wasn’t possible to get the car level so we had to check it with the car pointing down onto its nose. This would have made the oil level appear higher than it actually was.

 

It took 0.5L (about 0.13 US Gallons) of 85W/90 he had in his garage. If it had been level we could have put some more in so it must have been quite low. We took it for a drive and the noise was significantly better.

 

There is no sign of any leak out of the gearbox. So assuming it was filled properly at the service, where could the oil be going?

If it wasn’t filled properly at the service, why would the noise only start after a couple of hundred miles?

 

I’m planning to drain it completely and refill it with the car level so I know for sure it’s full.

 

What oil do you guys recommend?

 

The manual says Agip SAE 85W90 and I think that’s what was put in it at the service. However I’ve discovered that there are actually 2 types of Agip SAE 85W90 (Rotra MP and Rotra MP-S, see below for full info) so which one would you use?

 

My gearbox expert friend recommends trying Castrol Semi-synthetic 75W/90, I trust his judgement but as he has no previous experience of Lambos I wanted to get a few other opinions.

 

Any oil advice would be gratefully received.

 

TSS

 

The two types of Agip SAE 85W90:

 

AGIP Rotra MP *SAE 80w-90, 85w-140, mineral /AGIP Rotra MP is an EP (Extreme Pressure) gear oil recommended for hypoid gears operating under severe conditions and for very highly loaded gears in general, especially those subject to dynamic loads. It can also be used in conventional gear-boxes and steering-boxes on cars and trucks, and in gear-boxes, final drives and power take-offs on farm and earth-moving machinery. It can thus be used for lubricating all gears, whatever they are made of, for which the manufacturer recommend an EP lubricant.

/API: GL-5, MAN: 342; ZF: TE-ML 1/5/7; GM: MS 9985 290; MIL: L-2105D;

VW: TL 727/726; VOLVO: 97313/97314; CHRYSLER: MS-5644; OPEL: B 0401010;

FORD: ESW-M2C-105A/ESP-M2C-154A/SQM-2C-9002A/9008A/9101A./

 

AGIP Rotra MP-S *SAE 85w-90, mineral /AGIP Rotra MP/S is a special gear oil with modified EP (Extreme Pressure) characteristics. It is particularly recommended for lubrication of limited-slip differentials and associated hypoid gears, subject to high dynamic loads at high sliding speeds between gear teeth and at high temperature. In general, AGIP Rotra MP/S is suitable for those transmissions where manufacturers suggest lubricants having antistick-slip properties.

/API: GL-5, MAN: 342; ZF: TE-ML 1/5/7; GM: MS 9985 290; MIL: L-2105D;

VW: TL 727/726; VOLVO: 97313/97314; CHRYSLER: MS-5644; OPEL: B 0401010;

FORD: ESW-M2C-105A/ESP-M2C-154A/SQM-2C-9002A/9008A/9101A./

In my about 50 years of racing, building, designing parts, and driving cars, I have found that the best oil for a standard trans, especially one that cost around $30,000.00, is a combination of GL oil and Auto trans fluid.

In all the Lambo transmission I build, I run a mixture of around 75 % syn auto trans fluid and 25% 75 w GL oil.

The weak point of the Lambo trans is the 2nd gear sync. On a cold start up everybody likes to shift from 1st to 2nd, this is very hard on the sync assy. The use of the auto/gl oil lessens this.

The best thing when first starting a Lambo is to shift from 1st to 3rd until the gearbox has had a chance to warm up.

Also if you will check, you will find that most of todays cars with std.trans in them, use auto trans fluid.

Chadbourn Bolles

803 798 ****

 

 

What oil do you guys recommend?

 

The manual says Agip SAE 85W90 and I think that’s what was put in it at the service. However I’ve discovered that there are actually 2 types of Agip SAE 85W90 (Rotra MP and Rotra MP-S, see below for full info) so which one would you use?

 

My gearbox expert friend recommends trying Castrol Semi-synthetic 75W/90, I trust his judgement but as he has no previous experience of Lambos I wanted to get a few other opinions.

 

Any oil advice would be gratefully received.

 

TSS

 

[

i used REDLINE in the 308's, the Jalpa, the Uracco and Swepco 201 in 1 308 and my 911.

 

seems a Redline gear oil in the proper weight mixed with a bit of auto trans fluid would work?

 

Chad, was it type F (Ford) auto fluid or Dextron / Mercron ( GM ) ?

 

type F has a higher amount of both detergents and friction enhancers, and that may be a good thing, if it indeed can be safely mixed in a $30k

 

transaxle.

 

it would be neat to know.

I am using AMSOL syn type ATF in my trans.

Chadbourn Bolles

803 798 ****

 

Chad, was it type F (Ford) auto fluid or Dextron / Mercron ( GM ) ?

 

type F has a higher amount of both detergents and friction enhancers, and that may be a good thing, if it indeed can be safely mixed in a $30k

 

transaxle.

 

it would be neat to know.

I am in the process of replacing the gar oil (yes it has been a 3 month process because it take that long to get simple oil plug that can only be ordered from the factory at this time...)

 

After some research and many discussions I had, I ordered Redline 75w90 NS. It seems that is what my car needs. Dennis led me onto this one.

Thanks for the replies.

 

After much deliberation we decided to go with Castrol Semi-synthetic 75W/90. We drained the gearbox last week and it seems there was about 2.2 litres of oil in it (before we initially topped it up) when there should have been 3.2 litres. The good news is there was very little swarf in the oil we drained out.

 

We filled it right up and I’ve done about 300 miles this weekend. The gearbox sounds much, much better. Now I just have to keep an eye on the oil level and make sure it’s not going anywhere.

 

PS Chad, thanks for the tip on shifting from 1st to 3rd until its warmed up, I’ve started doing that now.

I am in the process of replacing the gar oil (yes it has been a 3 month process because it take that long to get simple oil plug that can only be ordered from the factory at this time...)

 

After some research and many discussions I had, I ordered Redline 75w90 NS. It seems that is what my car needs. Dennis led me onto this one.

 

 

? wow, i would think if you have the old one and can verify the threads, that you can match one up!!!

? wow, i would think if you have the old one and can verify the threads, that you can match one up!!!

Yep you'd think and we did. No luck. Got it from Chad who ordered it from the factory...The plugs are magnetized. Waiting for this was just dismaying. Next time i need to change oil, i'll wait for a major service....