Amsoil Differential and Transmission Oils Review

[gravitylover]

Originally Posted by venturaII

I've already done the diff once around 30K with Mobil1 GL5...I think 80W-90 weight or thereabouts... I didn't do it again this time...I'll let to go a little longer. I just wasn't happy with the trans fill and wanted to try something else. I think the Redline is slightly better than the Toyota LV75W GL3, and the Amsoil a bit worse; certainly no better. Funny how everyone has different preferences....'feel' is such an interpretive thing.

I used the Lucas fluid in the tranny and it's been great. It doesn't crunch into 2nd like the stock fluid did but it's a little grabby until it warms up, after that - smooooth. It's not so good in the rear diff though, there's a hesitation almost like a slip, that's disconcerting. I couldn't find Redline locally so I grabbed a couple of quarts from the dealer this morning and it's going back to the stock fill tomorrow.

[venturaII]

Originally Posted by gravitylover

I used the Lucas fluid in the tranny and it's been great. It doesn't crunch into 2nd like the stock fluid did but it's a little grabby until it warms up, after that - smooooth. It's not so good in the rear diff though, there's a hesitation almost like a slip, that's disconcerting. I couldn't find Redline locally so I grabbed a couple of quarts from the dealer this morning and it's going back to the stock fill tomorrow.

I bought my Redline on Amazon. Which Lucas lube did you use in the transmission?

EDIT: Nevermind...I looked up Lucas Synthetic SAE 75W-90 Gear Oil, and it's rated as GL5. No bueno.

[Alpha86]

Have you ever run Motul fluid in the trans? I'm about to switch to that since this Redline 75W-90 isn't much better than stock, especially in the cold. Wondering if I should try Amsoil next year after Motul.
Also have the Perrin shifter bushing, along with the Whiteline trans mount insert and MTEC shifter springs.

[Spuds]

Originally Posted by Alpha86

Have you ever run Motul fluid in the trans? I'm about to switch to that since this Redline 75W-90 isn't much better than stock, especially in the cold. Wondering if I should try Amsoil next year after Motul.
Also have the Perrin shifter bushing, along with the Whiteline trans mount insert and MTEC shifter springs.

If you are asking me, I haven't run Motul or Redline so I can't give you a comparison unfortunately. If you don't wind up liking the Motul, I don't see why you shouldn't give Amsoil a try based on my experience with it. If the Motul knocks your socks off, I would stick with that for a while.

[gravitylover]

Just the first 2 miles back on the stock rear diff fluid was MUCH better.

[strat61caster]

Originally Posted by Alpha86

Have you ever run Motul fluid in the trans? I'm about to switch to that since this Redline 75W-90 isn't much better than stock, especially in the cold. Wondering if I should try Amsoil next year after Motul.
Also have the Perrin shifter bushing, along with the Whiteline trans mount insert and MTEC shifter springs.

Been 30k miles each on OE and Motul, then ~15k on Redline, then ~10k on Royal Purple (dropped the trans to fix the TOB and had to use whatever was on the shelf on Sunday to get to work on Monday), surprisingly royal purple in the tranny felt pretty great for about 5k miles, then felt the same as the others and I couldn't really tell the difference. Interested in the Amsoil but I'll probably just go with what's cheap when I look again in a few weeks.

Stock, Motul, Redline in the diff all feels the same to me, the gears do all the work and the oil just keeps stuff lubed.

[Tristor]

I love AMSOil and it's all I run for engine oil. But after significant testing, I can say that I've had better results with Motul in the diff and Redline in the trans (ATF) for predominantly track usage in Texas (where higher temperatures occur and I don't deal with low-temp conditions). YMMV, but just wanted to throw that into the thread. I have switched away from AMSOil except for my engine oil.

[autoracer86]

I just ordered amsoil for my transmission to replace motul gear 300 after reading it might cause damage to the brass synchros. I am still using gear 300LS in the diff though but might swap it out for amosil severe gear

[Bonburner]

Originally Posted by autoracer86

I just ordered amsoil for my transmission to replace motul gear 300 after reading it might cause damage to the brass synchros. I am still using gear 300LS in the diff though but might swap it out for amosil severe gear

I've used Motul's Motylgear for about 40k miles, then motul gear 300 for another 40k miles. With a few track days here and there with the gear 300.

Synchros still seem to behave the same as day one.

Not sure where u read gear 300 is hard on brass.

https://azupim01.motul.com/media/mot...0_20221014.pdf
Suitable for any type of seal and yellow material used in gearboxes design.
Anti-corrosion, Anti-foam, Anti-emulsion.

[autoracer86]

Originally Posted by Bonburner

I've used Motul's Motylgear for about 40k miles, then motul gear 300 for another 40k miles. With a few track days here and there with the gear 300.

Synchros still seem to behave the same as day one.

Not sure where u read gear 300 is hard on brass.

https://azupim01.motul.com/media/mot...0_20221014.pdf
Suitable for any type of seal and yellow material used in gearboxes design.
Anti-corrosion, Anti-foam, Anti-emulsion.

I was reading it on this forum. Gear 300 seems super popular so it was surprising to hear their gl4/gl5 formula might be problematic for our cars. I’m going to switch it out just for piece of mind. I don’t have any personal data myself to back anything up.

[spcmafia]

Update: While replacing my TOB, I replaced all fluids to AMSOIL (Coming from MOTUL) and boy does the car feel so much, so much better. No more notchy gears. Smooth shifting all the way through. The car feels more engaging in every possible way.



I highly recommend to use the EZ-Packs. I couldn't find it for the Differential oil, but for the transmission it was super helpful.

[Ohio Enthusiast]

Originally Posted by spcmafia

I highly recommend to use the EZ-Packs. I couldn't find it for the Differential oil, but for the transmission it was super helpful.

Do you have a transfer/siphon pump? I grabbed a 4 oz one when I did my trans and diff swap for $12 and it made the process really easy. Actually looking at the EZ-Packs makes me think it would be annoying to use as the clearance around the trans is pretty tight (unless I'm missing exactly how it's supposed to work).

Thanks for the recommendation on the Amsoil fluids, though. I used Redline and wasn't impressed with the shifting quality (overall I preferred the OEM fill).

[spcmafia]

Originally Posted by Ohio Enthusiast

Do you have a transfer/siphon pump? I grabbed a 4 oz one when I did my trans and diff swap for $12 and it made the process really easy. Actually looking at the EZ-Packs makes me think it would be annoying to use as the clearance around the trans is pretty tight (unless I'm missing exactly how it's supposed to work).

Thanks for the recommendation on the Amsoil fluids, though. I used Redline and wasn't impressed with the shifting quality (overall I preferred the OEM fill).

I got a Penzoil transfer pump that I got from Amazon and it worked wonderfully for the differential.


With the transmission, I inserted the EZ Pack tip and then held it with one hand while I rotated the bottom bag up towards the engine bay, there was plenty of room since as it empties it becomes easier to maneuver.



Though the pump is handy, it can become a little messy with residual oil left on the hoses or inside the pump.

[Ohio Enthusiast]

Originally Posted by spcmafia

I got a Penzoil transfer pump

I got the same one

Originally Posted by spcmafia

With the transmission, I inserted the EZ Pack tip and then held it with one hand while I rotated the bottom bag up towards the engine bay, there was plenty of room since as it empties it becomes easier to maneuver.

Gotcha, that makes sense. Thanks for the details!

Originally Posted by spcmafia

Though the pump is handy, it can become a little messy with residual oil left on the hoses or inside the pump.

Agreed. I tried to be careful and drain the excess fluid in the pump and hoses back to the bottle and any minor leftovers into the drain pan, but still made a bit of a mess.