Manual Transmission Flush

[97K15004WD]

So, I have a MT in a Nissan 2.4L (five speed) from 2004 Xterra I'm currently working on.

https://bobistheoilguy.com/forums/threads/permatex-thread-sealant-51813-or-teflon-tape.370520/

I want to run through and "flush" the trans. I know I don't need to, just want to clean it out.

I have a synthetic GL-4 lube I could use for this, before I put in the correct lube.

What do you guys think?

 

[MrStamper]

Don’t put any oil spec not approved by Nissan in there. Brass syncros will go kaput.

 

[benjy]

manual trannys are best served by Redlines great real synthetic lubes or our sponsor HPL. dis ALL my drivetrain lubes 6 spd man included in my 2011 fronty V6 SV + gained 3 mpgs. generally flushing is not used just drain after a good drive when lubes are warmer!! dont rush it + jacking accordingly to aid complete drainage!

 

[tnt_motorsports]

in a MT you don't need to flush IMO. Drain & fill is more than enough. Use the correct fluid and move on.

Just my $0.02

 

[slacktide_bitog]

Your best option seems to be Triax Synergy Gear 75w90 GL4. You can buy it from Amazon or directly from Triax.

 

[97K15004WD]

I already have the correct oil. I want to use something to flush the case out before I put in the correct lube.

 

[slacktide_bitog]

I already have the correct oil. I want to use something to flush the case out before I put in the correct lube.

The only kind of flush worth doing is just doing a few drain and fills, maybe 3-4x, with a little driving in between.

I don't think they even make a flush product for manual transmissions

 

[qdeezie]

As for flushing, play it safe. Do a few short term drain and fills with properly spec'd lubricant. Something like every 90 days for a year if driving regularly. It's more costly, but there aren't any regrets tied to this approach.

 

[MRC01]

Drain it when warm just after driving will help ensure a more complete drain and get more contaminants out.

 

[IndyIan]

I already have the correct oil. I want to use something to flush the case out before I put in the correct lube.

Was the oil silvery coming out? If not I would use nothing, just refill. If it was like silver and glittery, just more of the correct oil is probably safest. Next I would use is some non "energy conserving" conventional engine oil and let it drain for quite a while.

 

[ammolab]

Some of your non spec “flush” would then remain in the case.

Surely that would do more harm than that the ounce of old gear oil.

 

[MolaKule]

So, I have a MT in a Nissan 2.4L (five speed) from 2004 Xterra I'm currently working on.

https://bobistheoilguy.com/forums/threads/permatex-thread-sealant-51813-or-teflon-tape.370520/

I want to run through and "flush" the trans. I know I don't need to, just want to clean it out.

I have a synthetic GL-4 lube I could use for this, before I put in the correct lube.

What do you guys think?

No need to flush. The fluids for those years were about 10cSt in viscosity and GL-4's, so Amsoil MTF, Redline MTL® 75W80, or even Pennzoil Synchromesh should function properly.

 

[4WD]

manual trannys are best served by Redlines great real synthetic lubes or our sponsor HPL. dis ALL my drivetrain lubes 6 spd man included in my 2011 fronty V6 SV + gained 3 mpgs. generally flushing is not used just drain after a good drive when lubes are warmer!! dont rush it + jacking accordingly to aid complete drainage!

Flushing would net 5 mpgs

 

[meep]

Instead of flushing, you could let it drip another 20 minutes.

 

[Oliveoil2]

OMG!!! Drive it for 20 min and drain! Refill with recommend MTF. I like RedLine.

 

[SHOZ]

I used some Redline Lightweight Shockproof Gear Oil once. It didn't work out and it's pea green. I filled with some normal fluid and ran a month and you couldn't even tell I'd changed it from the color.

So I filled it with some naphtha paint thinner and shifted through all the gears with the wheels off the ground for about 10 minutes. Then drained that out and let the trans sit with the drain plug out over night.

 

[y_p_w]

There's really no need. The "steady state" for a manual transmission is little bits of metal floating in the fluid. Within a few hundred miles you'll be right back where you started.

I do remember back when I had my 1995 Integra GS-R, I did a few weird things just because I could. It spec'ed 10W-30 motor oil for the transmission and once I just did three changes within 2000 miles. But that's when I could get it for less than $1 a quart and it took 2.4 quarts. I don't think it did much for it.

 

[Revving2Redline]

Flushing would net 5 mpgs

5 !!! Well I guess it's possible as most energy lost on the Dyno is from the transmission. Kinda wondering @4WD what type of horsepower gains? 20 ?

 

[4WD]

5 !!! Well I guess it's possible as most energy lost on the Dyno is from the transmission. Kinda wondering @4WD what type of horsepower gains? 20 ?

Only if it’s REAL synthetic

 

[Revving2Redline]

Only if it’s REAL synthetic

is there any other type? if so, not in my repertoire.