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Discussion Starter #1
Hi all,

What grade/spec of gear oil are you guys using for your transaxle? Searched the net, there seems to be quite some confusion.

Some highly recommend Redline 75w90NS for LSD transaxle, but some say it grinds. Some say Mobil 1 75w90 (think for LSD too), and some say Amsoil. I'm quite confuse, which one works the best in our transaxle? My mechanic think 75w90 is too thin, and usually opted for 80w90

My newly rebuild gearbox suffering massive grind on 2nd gear after my mechanic added some sort of gear lubricant additive (not sure what for reason too lengthy to describe here) on my Castrol 80w90 filled gearbox. This seems like a bad idea, therefore I'm thinking of replacing the gear oil again. Question is which? :confused:
 

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First of all Redline 75w90NS is for non LSD transaxle. For LSD transaxle you want to use 75w90.
I had mine replaced few years ago with Redline 75w90NS on my GTV6 (non LSD) and had a major improvement. It is always a good idea to go easy on the transmission when cold, the first 10-15 minutes for the oil to warm up and depends on the climate location where you live in.

Hope you didn't damage any of the synchros at the mean time.

Giorgio
 

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Only only use the redline NS and never never add the LSD crap even if you do have a LSD. it will kill the syncros. Any mechanic worth his salt should know you only add the LSD stuff if you have a chatter problem on any car. And then you just add a tiny bit until the chatter goes a way too much and the LSD will stop working.

but the gearbox part need to have none of it. That is why there are only a few oils that seem to work. The redline NS seems to work a lot better then the Shell Spirax the only other oil to use. the redline seems to also work cold and very hot. while the Spirax seems to only work at normal operating temps (shifts like crap untill the box gets warm)

My guess is you will have to change the oil a few time to get that LSD crap out even the tiniest amount will affect shifting.
 

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So does that mean for Red Line product 75w/90NS is good, the standard 75w/90 from Redline is bad?
Not sure I would call it bad for the transaxle, but not as good as the NS. The NS is for non-limited slip transaxles/diffs, which means it does not have the additives for a LSD. The additives are to let the "clutch disks" in the LSD slip a little so you don't get the chatter when turning sharp corners with a LSD. These additives that make the disks slip also let the syncros slip more, which means it takes longer for them to sync the speed of the two gears/shafts in the transaxle, so you either have to shift slower or you get more wear on the dog gears and the syncro ring.

I use the redline NS in all my Alfa transaxles/transmissions/diffs, my verde would chatter a little in sharp corners, which let me know that disks were not completely gone. Some racers say they use the NS in their LSD because it makes the LSD work better and they don't care about the chatter on the race track.
 

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"75w/90NS is good, the standard 75w/90 from Redline is bad"
as for the box I would say yes that is true. I think anything that makes shifting hard is bad as the wear and tear will add up a whole lot faster if it shifts hard. and you end up grind a lot more.
 

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Discussion Starter #11
Not sure I would call it bad for the transaxle, but not as good as the NS. The NS is for non-limited slip transaxles/diffs, which means it does not have the additives for a LSD. The additives are to let the "clutch disks" in the LSD slip a little so you don't get the chatter when turning sharp corners with a LSD. These additives that make the disks slip also let the syncros slip more, which means it takes longer for them to sync the speed of the two gears/shafts in the transaxle, so you either have to shift slower or you get more wear on the dog gears and the syncro ring.

I use the redline NS in all my Alfa transaxles/transmissions/diffs, my verde would chatter a little in sharp corners, which let me know that disks were not completely gone. Some racers say they use the NS in their LSD because it makes the LSD work better and they don't care about the chatter on the race track.
That is some good explanation there. Come to think of it, I think that is probably what happened now. My mechanic added some addictive into the gearbox, causing the oil to be too slippery to work properly.

What do you mean by chattering? The car lunge forward?
 

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Discussion Starter #12
"75w/90NS is good, the standard 75w/90 from Redline is bad"
as for the box I would say yes that is true. I think anything that makes shifting hard is bad as the wear and tear will add up a whole lot faster if it shifts hard. and you end up grind a lot more.
Yes, I agree too. Especially if its a massive grind like mine now! Imagine how I felt like when I first heard it, knowing that I just got my entire gbox rebuild.

One question, how many quarts/liters I need?
 

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Discussion Starter #13
Oh one more thing, has anyone tried Royal Purple. Something I can get here easier than red line product.
 

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What do you mean by chattering?
The diff rapidly locking and unlocking when it shouldn't, like when going around a slow tight street corner or simular instead of unlocking to let one wheel drive and one freewheel to allow for the difference in rotation speeds of the wheels.
 

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Redline 75w90ns all the way. just changed mine on my new 75, first and last product i will ever use , excellent in cold weather excellent under hard driving.
add a tiny bit of friction modifier to relieve the chatter... its a normal thing and will not get worse or ruin anything in your gearbox. your Alfa will make many noises becuase like a breathing soul you should hear all the fluids moving etc it tells you the bloods pumping and shes healthy.

you should need about 4 bottles of redline, with about a lil less than half a bottle being left over when to the fill screw. buy 5 bottles and flush one thru first and remember to remove the fill screw before the drain screw.

buy a hand pump for a boat about 20 bux at the Local hardware store.

you should be done in about 45 to an hour....Good LUCK!
 

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Discussion Starter #17
Thanks guys!! Since so many forumer is recommending, I think redline 75w90 NS GL-5 spec should be my cure! Will not bother with friction modifier first, and see how it goes. Wish me luck!
 

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I apologize in advance for resurrecting this ancient topic again.

In my '88, street use Milano Verde I have been running with Shell Spirax HD 80W-90 gear oil for years, and years. I have never added in an LSD friction modifier, nor have I ever experienced any chatter from the good shifting transaxle. This coming Spring I am planning on doing a drain and flush with my diminishing supply of the same Spirax. Should I add in any friction modifier in or just forget about, and run with the Spirax as is "straight out of the bottle"?

The reason I ask is this question is there seems to be a lot of opinions on weather to use friction modifier or not in the Verde or Platinum's LSD transaxle. I don't recall the Milano shop manual ever calling to add in an LSD additive, maybe I missed it?

The 2nd part to my question is: when the Shell Spirax runs out I am am considering two different gear oils, either:

1) Swepco 201 80W-90 GL-5

or

2) Redline 75W-90 NS GL-5


Do either of these oils require the use of and LSD additive? No ill effects on the LSD if the friction modifier is bypassed?

I have read tons of post how wonderful the Redline NS is, but does anyone have any feedback they can share on the use of Swepco 201 in the Milano LSD transaxle?

Thanks,
 

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If it's not chattering no need to add friction modifier. Chattering won't hurt anything and the modifier can affect synchro performance, so always start with no modifier.

When I had my Milano I tried Swepco 201 and Redline 75W90NS back to back and preferred the Swepco. It's what I use in the GTV and Spider as well and I've been very happy with it. YMMV.
 
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Agree with Gubi. even on freshly rebuild LSD with higher torque ratio (additional friction plates) I never have had to use friction modifiers in the transaxle. Never had a chatter issue.

I also run the cheapest gear oil that meets the viscosity requirements. I have tried redline and others, but have found the parts store label oil to be just as effective (no syncro crunch on a fresh trans, or after 10s of thousands of miles)
 
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