Mazda 5 MTX - AMSOIL GL-4 MTF vs. GL-5 gear lube

Status
Not open for further replies.
Number_35

Number_35

Joined
Jul 7, 2014
Messages
5,156
Location
Winnipeg MB CA
Hello all -

I'm changing out the rear diff fluid in my '97 Mazda MPV 2WD, and manual transaxle fluid in my '09 Mazda 5.

The MPV specs GL-5 80W if temperature will be < 0 F (-18 C), and 90 otherwise. Not wanting to do seasonal changes, I'll picked up some AMSOIL synthetic gear lube in 75W-90, rated GL-5. No controversy there.

The MT fluid for the 5 is a bit trickier. I would like to use the same fluid but understand that the GL-5 should not be used in an MT rated for GL-4; apparently some of the GL-5 additives can damage the yellow-metal synchro gears.

The owner's manual for the 5 states that GL-4 or GL-5 is acceptable. 75W-90 is recommended for year around use, and 80W-90 for temperatures > 50 F (10 C). So far so good ...

However, the factory service manual for the 5 has a range of VIN numbers for which GL-4 or GL-5 can be used, and a range for which only the GL-4 can be used. My vehicle's VIN indicates that GL-4 or GL-5 will be OK. Interestingly, the higher VIN range is for GL-4 only.

1st question: Would it be better to go with a GL-4 fluid to be absolutely safe?

2nd question: I notice that AMSOIL does make a dedicated GL-4 MTF in 75W-90. Would this be a better choice than the GL-5 general purpose 75W-90 gear lube in a manual transaxle?

Bear in mind MTF is hard to find up here. If I'd seen it in the shop where I bought the gear lube, I would have chosen it for the MTF instead.

Thanks in advance for your feedback!
 
Originally Posted By: Number_35
1st question: Would it be better to go with a GL-4 fluid to be absolutely safe?

Better? Yes. Necessary? Apparently not. But still better.


Originally Posted By: Number_35
2nd question: I notice that AMSOIL does make a dedicated GL-4 MTF in 75W-90. Would this be a better choice than the GL-5 general purpose 75W-90 gear lube in a manual transaxle?

Yes.


Any Mazda dealerships near you? If so, what do they use?
 
As an aside: Kudos to you for your MT Mazda 5!
cheers3.gif
 
Originally Posted By: d00df00d
As an aside: Kudos to you for your MT Mazda 5!
cheers3.gif



Ah, many thanks! It's our 8th Mazda, and the 7th with a manual tranny. Still miss our old '90 MPV with the RX7 5-speed. It's great to have another van with an MT.

I covet your RX8 - they are apparently a phenomenally-handling car.
 
When i had a Mazda i used 75w90 Ford Motorcraft manual transmission fluid. It is full synthetic and GF4 rated for manuals.

It's excellent stuff. you can get it at any ford dealer at the parts counter. most of the RX8 guys run this stuff. It's super high VI (211) and has a very low pour point (-65F)

https://www.fcsdchemicalsandlubricants.c...ion%20Fluid.pdf


For the MPV diff SVG 75w90 would be great.
 
Last edited:
Nissan and Hyundai have great GL4 MT 75w85 fluids.
Ford, GM, Mopar, ... also have some GL4 MT lubes.
Amsoil MTG and Redline MT85 or MT90 are great choices.

Availability and cost are what you have to research, but I do recommend a GL4 for the manual.
 
Guys, thank you all for some excellent information.

I thought I'd try to look for Redline first. It had outstanding on-line reviews.

As it turned out, there was a vendor (a small speed shop I've been past hundreds of times) less than a mile from my house. Picked up three quarts after work, and hope to change out the fluid this evening.

Will keep you posted on the results. Thanks again! I feel much better about adding an MTX-specific fluid with the proper GL-4 rating.
 
Originally Posted By: Number_35
Guys, thank you all for some excellent information.

I thought I'd try to look for Redline first. It had outstanding on-line reviews.

As it turned out, there was a vendor (a small speed shop I've been past hundreds of times) less than a mile from my house. Picked up three quarts after work, and hope to change out the fluid this evening.

Will keep you posted on the results. Thanks again! I feel much better about adding an MTX-specific fluid with the proper GL-4 rating.


Did you get the Redline MTL for the MTX?
 
[/quote] Did you get the Redline MTL for the MTX? [/quote]

I bought three quarts of Redline M-90 (75W-90) and installed it earlier this evening.

I was relieved to notice that the old stuff didn't smell like sulphur, indicating it likely was GL-4 not GL-5. The fluid coming out was the colour of fresh motor oil, and there were no metal filings on the magnetic drain plug. It was in there not quite two years and just over 30K km. It performed fine, although the transmission was always a bit notchy.

It likely didn't need to be changed yet (I can't find a maintenance interval in the owner's manual or factory service manual) but I like to change the brake fluid & tranny fluid every two years.

Anyway, did a short test drive this evening. The tranny feels great now! Very smooth, sort of like the shifts are slightly cushioned somehow. No notchiness at all.

It was expensive (C$23.99/US quart + 13% tax) but well worth it just for the driving pleasure.

Will get Jr over to switch his elderly Protege over to RedLine. I'm a convert.

Thanks everyone for the recommendations. RedLine was the 1st 75W-90 I was able to find, and I'm very happy with it.
 
Just a heads up, that is probably a bit thick for your climate. That isn't a good shifting cold weather fluid.

Enjoy the new fluids!
 
Originally Posted By: badtlc
Just a heads up, that is probably a bit thick for your climate. That isn't a good shifting cold weather fluid.

Enjoy the new fluids!


Oh no! I've good luck with synthetic fluids in the winter though. It's +25 C here today - winter seems a long way off. I'll enjoy the RedLine for at least the next several months.
 
Originally Posted By: Number_35
Originally Posted By: badtlc
Just a heads up, that is probably a bit thick for your climate. That isn't a good shifting cold weather fluid.

Enjoy the new fluids!


Oh no! I've good luck with synthetic fluids in the winter though. It's +25 C here today - winter seems a long way off. I'll enjoy the RedLine for at least the next several months.


It might not be terrible. I have the MTL in my Mazda MTX (75W-80) which is a fair amount thinner than the MT-90 you are using. Even with this thinner fluid when it gets below -15C, you definitely notice it in 1st and 2nd gear for the first 3 or 4 shifts.
 
Originally Posted By: badtlc
Just a heads up, that is probably a bit thick for your climate. That isn't a good shifting cold weather fluid.

Enjoy the new fluids!


Yep, I suggested a thinner fluid as well:

Quote:
For Canadian weather I would choose a 12 cSt or a 10 cSt fluid.

Same Performance Improvment Packages, slightly different viscosities.

Take a look at Specs for these:

http://www.redlineoil.com/product.aspx?pid=45&pcid=7

http://www.redlineoil.com/product.aspx?pid=140&pcid=7

Educational Paper on Dedicated MT Fluids:

http://www.bobistheoilguy.com/forums/ubb...sio#Post1231182
 
So far, so good, two months into a mild winter. Shifting remains excellent w/ the Redline in the '09 Mazda 5. Will try to drive the car when if/when the weather gets cold. I don't think we've even hit -30 C so far.
 
It does look like shift feel with 75W90 in winter survives well so far.

For your year round weather,this heavier 75W90 is fantastic/superb for the transmission durability.

The previous OCI's of 30K km is too short a duration. You should be able to double or triple the OCI without injuring the transmission components within, I suppose.
blush.gif
 
Quote:


1st question: Would it be better to go with a GL-4 fluid to be absolutely safe?


Yes.

Quote:

2nd question: I notice that AMSOIL does make a dedicated GL-4 MTF in 75W-90. Would this be a better choice than the GL-5 general purpose 75W-90 gear lube in a manual transaxle?


Yes, or Redline MT-90. Either would be appropriate for a manual transaxle.

Hypoid Diffeential lubes are thicker than dedicated MTF's and don't have the specific friction modification chemistry for synchro assemblies, making shifting difficult.
 
Status
Not open for further replies.

Similar threads

T
  • Locked
70W-80 GL-5 MTF for Subarus
Replies
12
Views
864
MolaKule
ThatNavyGuy
2021 MX-5 Miata 6MT Gear Lube
2
Replies
22
Views
684
dfarr67
Fabulous50s
SHAES-429 vs GL 4 OR GL 5
Replies
1
Views
155
fantastic
MolaKule
  • Locked
Updated List of MTF's (both GL-4 and GL-5)
2
Replies
35
Views
10K
Ruturaj
N
Substitute Motul Gear 300 75W-90 for BMW G1 75W85?
Replies
1
Views
663
oldhp
Back
Top