Any MTF that Improves Notchy Shifting?

[bulwnkl]

Red Line's 75W90NS worked well in my XT-6 transaxle. That's a 25-year-old Subaru, not a trim level on a recent car. Specialty Formulations' product was better, but that Red Line fluid was very good.

I know lots of people talk(ed) up Shockproof, but it's not for transmissions and I personally wouldn't use it in that application. There's a LOT of solid 'stuff' in shockproof.

Molakule's list is a good one.

 

[Smash209]

I wonder if Ravenol MTF-1 would be a good fit here... I couldn't dig up a cSt number but I'm guessing its close to 12 or 13 as it is a 75w-85 and so it would be a little thinner (than 75w-90) however it does carry a GL-5 rating.

I believe Subaru tried to do this with their Extra MT fluid... get a bit thinner for shift feel and maintain enough protection to carry a gl-5 rating.

 

[SHOZ]

I went with ACDelco 10-4014 42291 and a half bottle of Ceratec. Really smoothed out my Gen Coupe trans.

 

[Gebo]

Go with Molakule's list. I found that just because one brand worked better in my Nissan that it didn't necessarily work in my Honda as well. I ended up using RedLine and Amsoil.

As it was already mentioned, I want to call your attention to one important fact. It may take 100+ miles of use before you will be able to judge a fluid. You can't refill it and know in 2 miles if it is better. At least based on my experience...

 

[racin4ds]

NSAIOC forums love the new(er) 75W90 NS from Redline, you just haven't looked hard enough!

"Use 1 quart of heavy shockproof and the rest 75W90NS and it will be a totally different transmission" Is what I'm told from one of the gurus over there, so I just ordered it all from Amazon today, I'll let you know next week how it works in my 08 Legacy GT Limited.

 

[mightymousetech]

Honda actually has a service bulletin for cars with slow syncros and notchy shifting. The fix is to use GM Syncromesh - Friction Modified. We always have a case or so here at the Acura dealer. Most of the time it works.

 

[Smash209]

Originally Posted By: racin4ds
NSAIOC forums love the new(er) 75W90 NS from Redline, you just haven't looked hard enough!

"Use 1 quart of heavy shockproof and the rest 75W90NS and it will be a totally different transmission" Is what I'm told from one of the gurus over there, so I just ordered it all from Amazon today, I'll let you know next week how it works in my 08 Legacy GT Limited.


Interested to know how this works out. I think the shockproof helps for a bit but then the benefits fade. Heavy shockproof flows like honey.

I wonder how long the front diff would last with synchromesh in there.

 

[racin4ds]

Originally Posted By: mightymousetech
Honda actually has a service bulletin for cars with slow syncros and notchy shifting. The fix is to use GM Syncromesh - Friction Modified. We always have a case or so here at the Acura dealer. Most of the time it works.

Syncromesh is great stuff and works real well in Honda's! I've used it for years in many Manual trans apps that call for ATF or light weight oil but the Subies HAVE to have a gear oil in them due to the shared final drive in the trans. The Hypoid gear drive would destroy straight syncromesh pretty quickly I'd assume.

 

[john_pifer]

Decided to just go with the Subaru OEM stuff. They call it "Subaru High Performance Gear Oil" (HPGO). Picked up at the dealer for about $10.5/qt. Asked if they could do any better on the price, and the counterman said "I'm already giving you a discount off the price we charge service dept. customers. For them, it's $23/qt." Wow. If you're going to have a dealer do ANY work for you, be sure you get an itemized list BEFOREHAND of the prices for everything, and shop around. That's where the term "stealership" comes from, I guess.

Got 5 quarts so I can do the gearbox/front diff, and the rear diff also. Made by Idemitsu - part #SOA427V1700. Doesn't say "GF-5" anywhere on the bottle, but the counter guy at the dealer assured me that it's what they use, and that there is not another MTF/gear oil offered by Subaru. Nothing on the bottle says "synthetic". So I'm assuming it's a conventional product.

Apparently this has replaced the Subaru "Extra S". Found a thread from a couple of years ago:

https://bobistheoilguy.com/forums/ubbthreads.php/topics/3542880/Re:_Subaru_High_Performance_Ge

On paper, it looks to have an inferior addpack to the old Extra S.

Opened up the drain bolts last night after taking the WRX on a 20-min. highway drive to warm the fluid. Letting it drain until I get off work today.

We'll see if shifting improves. It was really just the 1-2 and 2-3 shifts at high RPM that were a bit notchy. Will report back...

 

[benjy]

just look up your ride on redlines web or call them. just got lubes for tranny + diffs in my nissan frontier, shopped around + E-bay won, delivered to my door with the best price in less than a week from TCS Automotive. there are very few real synthetic lubes made today + IMO Redline is one of the BEST!!!

 

[SHOZ]

So I'm at about 2 years and 25k on the AC Delco 10-4014 and 150mL of Ceratec. It has been getting more difficult for the trans to drop into a couple of the gears. Nothing bad or grinding but I have to hesitate longer and push harder when the oil is cold. Once I drive an hour or so at 30F temps then it's OK.

What do you think is the normal service life of the AC Delco sycromesh fluids? They are not synthetics I don't think.

Should I be looking into something thinner yet? The AC Delco is a bit thinner than the 75w85 OE recommended stuff as it is.

 

[JmanG]

You mentioned the car has 30k miles which is usually when manufacturers recommend changing the mtf anyway. I recently did a change on my Civic si at 60k after having the same notchy issue.

Figured id start with the OEM fluid and shifting quality has improved 100% as well as on/off throttle trans loading and unloading.

Probably can't go wrong with an OEM fluid but my experience with conventional manual transmissions always says use the correct spec'd fluid and you can't go wrong. Although I am a little more pickier as to what mtf I use in imports as I feel a lot of the parts store brands are designed with more multi vehicle compatibility in mind rather than a quality mtf fluid.

That said, I have always had great results with the reputable brands (amsoil mtf, redline mtl, OEM fluids, Pentosin MTF2 etc) so go with any reputable brand and i think you'll experience better shift quality.

 

[Olas]

Im currently using Castrol Syntrans in a gl4 syncromesh application - shift feel equals redline at a significantly lower price point

 

[BBDartCA]

You may want to consider Motul MotylGear 75wX0. I recently did a transaxle in a non-turbo 150k mile Subie with the 75w-80 and shifting became noticeable less notchy. And a faint whine in low gear went away. Both Gl4/gl5. Yours probably requires 75w90.

https://www.motul.com/us/en-US/products/motylgear-75w90

 

[code5coupe]

The recommended fill for the ZF6 manual in my Corvette was Castrol TWS engine oil. I ran it for a decade, putting up with notchy shifting the whole time. Several months ago I replaced the TWS with Amsoil Syncromesh and am very pleased with the improvement in shift feel. Wish I'd done it a long time ago.

 

[ChristianReske]

I allways had succes in curing notchy shifting when adding a tube of Liqui Moly gear oil additive (Nr. 1040) to 2 liters of gear oil.
No matter wich viscority or brand of gear oil i used, the LM additive improves shift quality noticeably.

 

[Job]

Chevron Delo xdm synthetic and esi non syn have gl5 gl4 and mt1 ratings. No need to worry yellow metals this or that. I happened upon them while searching. WM sells the esi. May be worth a try Chevron makes good products. I got xdm at AZ store although online said out of stock. Either is in the $7 range per qt.