| Author |
Message |
john beaucher (Spider348)
Junior Member
Username: Spider348
Post Number: 62
Registered: 11-2002
| | Posted on Thursday, May 22, 2003 - 2:49 pm: | |
Hans,
Thank you, you are correct. The line I read on the Redline site referenced typical GL-5 gear oils, not the Redline product.
I should have known better. I have used Redline in various Ferraris and Porsches, never encountered a problem. Good products.
Swepco 201 was mentioned. Never used in a Ferrari but replaced Mobil 1 gear oil in my prior 930S with the Swepco product. Deffinitely better in the older Porsche transmissions. Told by Porsche experts the older Porsche transmission design does not perform well using Mobil 1 gear oil, too "slippery" to allow proper synchro function. |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1346
Registered: 4-2002
| | Posted on Thursday, May 22, 2003 - 11:53 am: | |
John: Better re-read the Redline info. They say that syncro life is 1/2 for MOST GL-5 oils. The various additives that they use are brass-safe up to 300 deg.
A quote from Redline literature:
"The extreme pressure chemistry used in many gear oils can be corrosive to brass and bronze used in synchronizers and bushings. Most gear oils are corrosive at temperatures of 200 F. Red Line Gear Oils are non-corrosive up to 300 F and the MTL in excss of 375 F. A corrosive gear oil can shorten synchronizer life by half and can also contribute to rust problems."
Ali (a few posts down) verified with Mobil that their GL-5 *will* be corrosive.
So, Redline is safe. I'd imagine that some other GL-5 oils are too, but which ones??? |
john beaucher (Spider348)
Junior Member
Username: Spider348
Post Number: 61
Registered: 11-2002
| | Posted on Thursday, May 22, 2003 - 9:59 am: | |
Have followed this post with considerable interest. Last year I researched gearbox lube for my 348 spider. The factory recommended oil is Agip Rotra LSX 75W90. This is synthetic GL5 gear oil formulated for limited slip. The product that matched this Agip gear oil is Redline 75W90 Gear oil. I have used this product for the past 10 months. Shifting appears marginally better than the gear oil replaced(do not know what the prior owner used). The �chatter� problem I had with the limited slip was eliminated. Good news thus far.
My concern stems from issues pointed out in this post, and on the Redline site, regarding synchro life using the GL5 speced gear lube. Redline states the synchro life is reduced by half using GL5 gear oil, in their experience.
As in most mechanical assemblies compromises are made. The GL5 products are designed to protect the high sheer forces generated in hypoid gear assemblies. The GL4 products are designed to reduce synchro wear and improve shift quality.
My question, and others posting this topic, is based on a street driven Ferrari, what is the best choice between 2 evils?
GL5 for the differential protection and lubricity or GL4 for longer synchro ring life and better shift quality?
|
Robert W. Garven Jr. (Robertgarven)
Junior Member
Username: Robertgarven
Post Number: 142
Registered: 2-2002
| | Posted on Wednesday, May 21, 2003 - 5:49 pm: | |
Tazio,
Read my post the AGIP is the right stuff and Paul it should be very easy to get, it is over here, you just have to buy a 5 gallon tub, I change the oil every year and usually loan some to a friend and keep the great yellow 5 gallon pail with the agip logo! |
J R K (Kenyon)
Member
Username: Kenyon
Post Number: 297
Registered: 10-2002
| | Posted on Wednesday, May 21, 2003 - 12:44 am: | |
I use Castrol Synthrax 75-95 (Partial synthetic)and never had any problems with my 348 spider. No problems shifting when cold. |
Tazio Nuvolari (Nuvolari)
Junior Member
Username: Nuvolari
Post Number: 224
Registered: 9-2002
| | Posted on Tuesday, May 20, 2003 - 8:06 pm: | |
I have followed this thread with great interest however I am a little confused as to which oil should I put in my 308's gearbox.
So the question is, which oil / combination of oils should I put in the gearbox of a 308 that is used on the road (not on the track)? |
Matt Morgan (Kermit)
Junior Member
Username: Kermit
Post Number: 134
Registered: 8-2001
| | Posted on Tuesday, May 20, 2003 - 1:01 pm: | |
One small detail I might add to this excellent thread. In some forms of racing, particularly 1/4 mile stuff, they often use a much lighter weight than one would think in high output motor/trans combinations. The rational is that the effort necessary to squish the oil from between the teeth on the gears increases dramitacally with higher RPM, and can cause a transmission that may have been marginal in handleing the higher output to further press the gears apart. |
Paul Jeffery (Peajay)
New member
Username: Peajay
Post Number: 47
Registered: 4-2002
| | Posted on Tuesday, May 20, 2003 - 10:31 am: | |
The chassis plate gives the details of the AGIP GL5 oil to be used, but I would expect it to be very difficult find being an Italian oil company, even for me here in Europe. Mobil is certainly more easily obtained here, but I will look out for the correct AGIP. |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1315
Registered: 4-2002
| | Posted on Monday, May 19, 2003 - 2:18 pm: | |
PS - kind of bummed that you confirmed the Mobil 1 corrosion thing. I was thinking of giving it another try. |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1314
Registered: 4-2002
| | Posted on Monday, May 19, 2003 - 2:16 pm: | |
Rereading what I just wrote - I may not have chosen my words correctly. Dave at Redline didn't say you couldn't mix the oils, as they are compatible, but he didn't see an advantage to doing so. He thought the friction modifiers in the LightWeight wouldn't work as well with the Porsche syncro rings in the old 308 gearbox. I had told him that I mixed the oils in my gearbox and have a very slight "kerchunk" when cold. He recommended using straight 75W90NS, which is the only oil they have w/o friction modifiers. He said he hadn't heard of problems with the positrac when using this oil in these cars. |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1313
Registered: 4-2002
| | Posted on Monday, May 19, 2003 - 2:01 pm: | |
Interesting, Ali. Dave is who I talked to and he recommended *not* mixing the oils.
Note that we may be talking apples and oranges, as the old 308 gearboxes use Porsche-designed syncros, and do not have a hypoid ring & pinion, whereas a 550 does have a ring & pinion, and ???? designed syncros. He mentioned that the Porsche designed syncros specifically are intolerant of friction modifers. This might not apply to newer designs.
Hmmm..... Gets more confusing all the time. |
Ali Haas (Aehaas)
New member
Username: Aehaas
Post Number: 9
Registered: 5-2003
| | Posted on Monday, May 19, 2003 - 2:01 pm: | |
Hans,
Once again I reviewed your old posts here. I first thought of and suggested the mixing of 75W-90 NS with 1.5 oz of anti friction additive but Dave convinced me that mixing the LW gear oil would do this to the correct amount and give me a thinner oil by a little. Therefore easier shifting and a thinner oil at my otherwise too low operating temperatures.
You stated that Mobil 1 gear oil gave better shifting. That is because it is thinner. Somebody also said they thought many used Mobil 1 with good success and liking. I did too in my old 550 Maranello but I was told not to use it by Mobil because it is corrosive as rumored, to those yellow metals. I will not use it in my 575 M.
Paul,
You can always use what the manual actually recommends. The only drawback is that it is too thick for around the town use in my mind and causes harder shifting.
You guys have to remember that the transmission will not get hot unless there is a lot of horsepower and torque going through it for sustained periods. This condition only occurs on the track at high speeds.
Oils have to be at the correct viscosity. If thicker was better than all gear oils would be 140W. Operating temperature when stressed, like on the track, can loosely be defined as 212F. Most 75W-90 gear lubes have a viscosity of 115 at 104 F and 15 at 212 F. The correct operating viscosity for the transaxle is 15 for all temperatures if this was possible, but it is not.
My 140 F degree transaxle probably has an oil viscosity of 50. This is just too thick.
Higher and lower viscosities are bad and cause more wear. You need to adjust the viscosity for the temperature of the engine and transmission for the conditions that you drive.
The object of multi viscosity lubricants is to thin out the otherwise way too thick oils at cooler temperatures while maintaining the final thickness at hot operating temperature. It is the cold end of the spectrum that we are trying to optimize by making the oil less like molasses when the oil is cold.
Remember that a cold engine is defined as 104 F. |
Paul Jeffery (Peajay)
New member
Username: Peajay
Post Number: 45
Registered: 4-2002
| | Posted on Monday, May 19, 2003 - 1:01 pm: | |
I started this thread off and now I think I am more confused than when I started :-) |
Ali Haas (Aehaas)
New member
Username: Aehaas
Post Number: 8
Registered: 5-2003
| | Posted on Monday, May 19, 2003 - 12:12 pm: | |
Hans,
That thicker gear oil is fine for racing with a constant 500 HP going through the transaxle. It never gets that hot and is otherwise too thick for just around town driving at 25 HP.
I just talked to Dave at Redline. He recommended 1qt Lightweight LW Gear oil and 3 qts 75W-90 NS mixed. These are both GL-5. Only the LW has the friction reducer and it is at 5 percent. He thought a final of 1.25 percent wound best serve the purpose. This is a good mix for around the town driving as it is thinner at low temperatures. Neither corrode yellow metals.
Remember that oil is not that versatile. It is OK to use one oil for racing and another for the street. These are completely different and non overlapping environments. You cannot have both out of any oil.
Everybody seems very concerned about their oil. If you are that concerned then use the oil appropriate for the driving situation.
My 575 Maranello box only gets to 140 F with around town driving. This is with 90 degree outside Florida weather. The gear oil cooling circuit does not come on until the temp reaches 190 F. |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1312
Registered: 4-2002
| | Posted on Monday, May 19, 2003 - 11:31 am: | |
Just talked to a RedLine sales engineer. He apparently has some famaliarity with these early transaxles, as he asked me if they use Porsche syncros (they do). He said that these syncros really don't like "friction modifiers", which is what positrac additive is. He said that he would use their 75W90NS w/o any additive. I've been using it with some additive. Despite not having any friction modifiers, he said they aren't getting any chatter in the older Porsche transaxles. The 75W90NS is a GL-5 oil, but he thought it would be superior in this application to their GL-4 oil (MT-90), because their GL-4 oil has some friction modifiers and is actually a little more 'slippery' than the 75W90NS.
The difference in GL-4 .vs. GL-5 isn't related to how slippery it is, but rather the GL-5 stands up to what he referred to as "high pressure".
What was interesting is that syncros work better with *thin* oil, not thick. That's why these trannys will shift better when warm. As the oil thins, it squeezes out of the syncros easier and allows the syncro to grab and consequently do it's job. However, he didn't recomment deviating from the manufacturer's recommendation in viscosity. (i.e. a thinner oil may shift better, but could cause other problems.)
Not mentioned so far here is Swepco 201, which is what Porsche uses (or used?). I've heard some F-car owners claim it works well. |
Robert W. Garven Jr. (Robertgarven)
Junior Member
Username: Robertgarven
Post Number: 141
Registered: 2-2002
| | Posted on Monday, May 19, 2003 - 10:27 am: | |
I use AGIP 75 90 LSX (made for limited slip differentitials, it is what the factory and AGIP recommends. It come in 5 gallon jugs great after the are empty for a cool garage trashcan with large AGIP logo. It is fully synthetic AGIP #
516-876-0318
Italian translation of AGIP saying:
The dog with six legs is a friend to man with two. |
Ali Haas (Aehaas)
New member
Username: Aehaas
Post Number: 6
Registered: 5-2003
| | Posted on Monday, May 19, 2003 - 10:14 am: | |
I just got off the phone with a tech from Mobil 1. He told me that their GL-5 75W90 gear oil will be corrosive to yellow metals. It is not intended for sychro transmissions. They wated to make a GL-4 vesion that could be used in these cases but the people upstairs told them there was too little a market to bother.
aehaas |
G. J. Germane (Germane)
New member
Username: Germane
Post Number: 22
Registered: 7-2002
| | Posted on Sunday, May 18, 2003 - 4:09 pm: | |
I previously used Agip Fels in the gearbox of my 87 MY 328. I used Mobil 1 when I last replaced the oil, about four years ago, with a resulting noticeable improvement in the 1-2 shift. The gearbox operation under all conditions seems smoother with the Mobil 1, also. |
pete (Pete_peter)
New member
Username: Pete_peter
Post Number: 34
Registered: 12-2002
| | Posted on Sunday, May 18, 2003 - 10:00 am: | |
I have owned several Ferrari's from old to new.
I've always used GL-5 in everything (non synthetic) and never had any problems.
Just my 2 cents.
(I did have a problem with Mobil 1 in my 348 gear box, shifted worse actually, I then switched back to just a non synthetic and it shifted much better. Again, I'm not sure why) |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1307
Registered: 4-2002
| | Posted on Saturday, May 17, 2003 - 6:26 pm: | |
Except I'm not convinced that GL-5 is indeed recommended on the older cars because of:
a) Potential for corrosion. Rumored but not confirmed for Mobil 1, probably a certainty for some brands.
b) *LESS* slippery is better for syncro life.
c) The slippery-ness of GL-5 is necessary for a hypoid ring & pinion, which the older cars don't have.
I'm currently using RedLine 75W90NS w/ a very small amount of posi additive. This is a GL-5 oil, but they specifically state that it is brass compatible to 300 deg. I'm thinking about changine to RedLine MT-90, which is what the company recommends for syncro gearboxes, as the coeffiecient of friction is variable w/speed and allows the syncros to 'grip' better just before engagement. |
JRV (Jrvall)
Intermediate Member
Username: Jrvall
Post Number: 1467
Registered: 11-2002
| | Posted on Saturday, May 17, 2003 - 12:50 pm: | |
>>>It appears that the GL-4 oils have this desireable characteristic, but GL-5 oils don't - they're just plain slippery all the time. <<
GL-5 is reccomended because "it's slippery all the time" to prevent rapid and premature wear to the gears, bearings, and especialy the Ring & Pinion.
and like mentioned, Lmtd Slip Diff additive is very highly recomended whether it's in the oil or needs to be added.
|
Paul Jeffery (Peajay)
New member
Username: Peajay
Post Number: 43
Registered: 4-2002
| | Posted on Saturday, May 17, 2003 - 11:59 am: | |
Hans
Interesting findings, so what oil do you use ?
And what is the quantity by the way? there appears to be a typo in the owners handbook.
Paul |
Dave Helms (Davehelms)
New member
Username: Davehelms
Post Number: 14
Registered: 5-2003
| | Posted on Saturday, May 17, 2003 - 12:07 am: | |
Mobil 1, 75w90, but be careful about the source. When it is purchased in bulk form (30gal. drum) it dosnt come with the posi additive, in all of the qt. containers that I have found it does come with the additive. Been using it in every diff, and trans except for the old cars that required 140w, and have had nothing but great results. |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1298
Registered: 4-2002
| | Posted on Friday, May 16, 2003 - 8:24 pm: | |
Ken: I'm glad you said whale oil, not sperm oil. I'd hate having to try to produce in quart quantities. |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1297
Registered: 4-2002
| | Posted on Friday, May 16, 2003 - 8:20 pm: | |
Was just re-reading some Redline info. Apparently the ideal syncro lubricant has a 'variable' coefficient of friction, that varies in relation to the relative rpm difference in the parts involved. i.e. - It's very slippery when the parts are moving past each other at high speed, but as the speed difference lessens, the lubricant gets less and less slippery. Redline has charts showing this characteristic. It appears that the GL-4 oils have this desireable characteristic, but GL-5 oils don't - they're just plain slippery all the time.
Fascinating stuff. Now, class, tell me which will make the spaghetti slide down easier - butter or olive oil? |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1293
Registered: 4-2002
| | Posted on Friday, May 16, 2003 - 6:58 pm: | |
The problem that I originally faced when changing my gearbox oil was whether to use GL-4 or GL-5 oil. Contrary to popular belief, one is not a superset of the other - they are different specs. As my 1975 owner's manual didn't specify, I turned to some RedLine documents that I had. I surmised that the *transverse* engine cars (308/328) need GL-4, while the 348 and newer cars need GL-5. Going on that assumption - which I'll get into in more detail - I took a warning on Mobil 1's web page perhaps more literal than others might.
(- Link removed because it was very long and caused F-Chat scroll bars to go screwy. Just search www.Mobil1.com for the Data Sheet on their gear oil -)
There is a passage that reads:
================================================
Application
Mobil 1 Synthetic Gear Lubricant is suitable for all automotive applications where lubricants meeting API Service GL-5, are recommended. It can also be used in rear axles where an API Service GL-4 lubricant is recommended. It should not be used in any *TRANSMISSIONS* requiring an engine oil or automatic transmission fluid, or GL-4 performance level.
=================================================
Note that the emphasis on "transmissions" was theirs, not mine, and recommends not using Mobil 1 in TRANSMISSIONS requiring GL-4 oil. From this, I combined the warning from RedLine that many GL-5 oils can be corrosive to brass syncros and bushings, and rumors from P-bug owners of syncro corrosion, and thus became wary of Mobil 1 in my precious 'Dino'saur gearbox.
I'm going to try to post in more detail what Redline has to say generically about these specs. But in crude summary, GL-4 oil has a special co-efficient of friction that is slippery until squeezed out - as in a syncro cone engaging - and then will grip. This allows better shifting, and less syncro wear, as the syncro is no longer slipping in that final moment before engaging. GL-5 oil is specifically made for Hypoid differentials, which is not what is in the transverse engine cars. Apparently there is a 'shearing' action in hypoid gears that tends to wipe the oil off. GL-5 is made to stand up to this. But it is also a bit too slippery for syncros, as well as *usually* (there are exceptions) corrosive to brass. Throw into this big mess is the need for special positraction additives - which need to be added to both GL-4 and GL-5 specifications for limited slip applications. However, most of the oils on the market already have the additive mixed in. Positrac additive further screws up gear syncronization, as it adds even more slipperiness that tends to prevent the syncros from locking up to complete the shift.
What we need to do is shoot the Ferrari engineer that combined a positrac diff with a gearbox. They're incompatible. At least it's better than early Lambo Miuras that had the gearbox sharing oil with the engine! |
Ken Ross (Kdross)
Member
Username: Kdross
Post Number: 356
Registered: 2-2002
| | Posted on Friday, May 16, 2003 - 6:14 pm: | |
I believe that I have whale oil in my 308QV.
Ken
|
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1292
Registered: 4-2002
| | Posted on Friday, May 16, 2003 - 5:52 pm: | |
Steve: I've got to dig out my info. I did a bit of research when I originally changed my oil, as the old 1975 owners manual didn't really state what to use - other than a specific (Shell? Agip?) oil. ie, no generic specification.
I'll be right back. |
david handa (Davehanda)
Member
Username: Davehanda
Post Number: 728
Registered: 5-2001
| | Posted on Friday, May 16, 2003 - 5:29 pm: | |
Nothing seems to make the "2nd gear syndrome" go completely away, but I have had the best results with Mobil 1 (I have heard Valvoline Syn gear oil is good too). I have used Redline and another I can't remember off hand, and it didn't help at all. |
Frank Parker (Parkerfe)
Intermediate Member
Username: Parkerfe
Post Number: 2302
Registered: 9-2001
| | Posted on Friday, May 16, 2003 - 4:13 pm: | |
I have used RedLine gearbox oil in my Ferraris for years and have been very happy with it. |
Steve Magnusson (91tr)
Intermediate Member
Username: 91tr
Post Number: 1788
Registered: 1-2001
| | Posted on Friday, May 16, 2003 - 4:01 pm: | |
Hans -- Can you give a clue/link where to find that "not in a synchro gearbox" Mobil1 gear oil recommendation? (I tried looking -- really...) |
Hans E. Hansen (4re_gt4)
Intermediate Member
Username: 4re_gt4
Post Number: 1287
Registered: 4-2002
| | Posted on Friday, May 16, 2003 - 3:42 pm: | |
Some differential oils are not formulated for brass syncros, and can be corrosive to them, especially at high temps. (Ref: Redline oil technical papers) Where I'm going with this is that I've heard Porsche owners claim to have syncro degradation from Mobil 1, and Mobil *specifically* states not to use Mobil 1 gear oil in a syncro gearbox. (Ref: Mobil website) It's too bad, because I've heard that shifting is greatly improved with Mobil 1. |
JRV (Jrvall)
Intermediate Member
Username: Jrvall
Post Number: 1452
Registered: 11-2002
| | Posted on Friday, May 16, 2003 - 11:21 am: | |
The brand is up to you.
Ferrari's require a minimum of GL-5 grade oil. |
TomD (Tifosi)
Advanced Member
Username: Tifosi
Post Number: 3648
Registered: 9-2001
| | Posted on Friday, May 16, 2003 - 11:06 am: | |
I think most use mobil 1 gearbox oil |
Paul Jeffery (Peajay)
New member
Username: Peajay
Post Number: 42
Registered: 4-2002
| | Posted on Friday, May 16, 2003 - 10:59 am: | |
A simple question this time, what type of oil is required for the gearbox, synthetic or regular mineral? I am guessing the synthetic because it is three times the price, so that would be normal Ferrari pain level !!
Any advice on brand and grade etc. ? |