Changing Transmission Fluid....Safe or not?

[Nakulbhatt87]

I've heard various rumors about changing a car's tranny fluid over time. At one point, I was adamantly against changing the fluid because I was told by a mechanic that certain transmissions, if not properly taken care of will actually deteriorate in condition when you change the transmission fluid. This was something about metal shavings that were fused to the gears would dislodge and come out, after a trans flush, leaving your transmission in worse condition than before. However, recently I've been reading around and I am now thinking about the idea of doing a tranny flush. At this point i'd like to ask you guys and give you some background to my vehicles to decide whether it's safe to do the flush on all cars.
-I have three cars in question, the first car i'd like to flush the transmission on is a 3rd gen Maxima SE with the VE 5-spd set up. The trans feels a bit gooey and very ambiguous when its started up. Other than this I don't have many complaints about the car. I have no prior maintenance records and would like to do a simple drain and fill to make the gooeyness go away and bring the tranny back to life. The vehicle has no modifications and the miles are about 120k.
-The second car is a 4th gen Maxima SE 5-spd, with engine, suspension and tranny upgrades which includes a short throw shifter, light weight clutch and aftermarket flywheel. I bought this car from an auction and have no previous service records that indicate a tranny flush of any kind. I did not do these mods Im just using the car as a daily. The transmission makes a prominent "hissing" sound when in neutral and just cruising on the highways, it has approx 111k. I'd like to do a tranny flush and fill on this car to help with the noise and loosen up the gear box it self.
-The third car in question is a 2000 Infiniti I30 with an Auto tranny, the car has just about 130k and I have previous records that do not suggest any transmission services. This car has no performance mods.
If you all can please help me make the best decision for my babies i'd appreciate it. I don't race and I primarily plan on using Mobil1 Synthetic on the manuals and some Mobil1 Synthetic ATF on the I30. I drive my cars nearly all the time, Im looking for better over all performance, response and longevity of the vehicles life/parts. I would like to know if I should even think about touching the transmission based on the vehicle's history and it's current setup. I don't want to mess anything up by doing a transmission flush. I have already checked the stickies in this section and read about the ideal-non published intervals and which brands are available, and which viscosity and procedures on doing the flushes. I really appreciate your help.

[talkinghorse]

I'm not a professional mechanic nor a transmission specialist; but, I've never heard of metal shavings being fused to gears. Based on my experience you should have no problem whatsoever changing the cars with the manual transmissions...however, I would recommend you select a GL-4 rated oil rather than the Mobil-1 you plan on using. The additive package in the GL-5 rated M-1 might be too aggressive for your transmission and it could adversely affect shift quality.

Transmission failures in automatics have been known to occur after an evacuation service has been performed (without dropping/cleaning the pan) on high mileage units that have not been serviced for a long time. Regardless on how you intend to service the transmission, I would recommend you remove the pan, inspect/clean the pan contents and replace the filter/screen if you can. There's different schools of thought on this; but if you clean the pan in the process, I believe you will be okay.

[Scottwax]

The manual transmissions will be fine. On the automatic, I'd do a drain and refill first to see if that leads to any problems like slipping. If after a couple of weeks and everything is fine, then drop the pan, clean everything and refill.

[Nakulbhatt87]

Thank you both for your responses. I am currently in the process of re-decided which brand MTF to use, thanks for the clarification on the GL-5 vs. GL-4 rating, the stickies can get a little confusing..... If you have any suggestions then it'd be much appreciated. I read the sticky about the MTFs and I know for sure that the three choices are Amsoil, Redline and Mobil but now with mobil out, i don't know what to choose. I would like to put a synthetic oil that can be trusted. Any personal experiences? I've read that the redline mt-90 is "notchier" and "is more likely to slip" or something of that sort.

[talkinghorse]

My opinion might be considered biased by some since I sell AMSOIL products: AMSOIL Synthetic Lubricants - Dealer Cost However both AMSOIL and Redline are excellent products. There are also some petroleum-based GL-4 lubes available on the marketplace. My cars are automatics, but I have sold a lot of AMSOIL "MTG" 75w-90 GL-4 gear lube to our members and the feedback has been very positive.

[Nakulbhatt87]

Biased? hahaha there's no shame in knowing everyhting about something. But since i have the expert on hand, is the amsoil safe for hondas and acuras as well? I've got a friend whos got a 2.2cl and he wants to do the flush now as well. His owner's Manual and FSM both say use 5w-30 engine oil and various forums across the internet suggest redline mt-90 or similar, so would your Amsoil GL-4 75w-90 work in his car? Also is the amsoil gear lube considered to be synthetic?

[talkinghorse]

Originally Posted by Nakulbhatt87

Biased? hahaha there's no shame in knowing everyhting about something. But since i have the expert on hand, is the amsoil safe for hondas and acuras as well? I've got a friend whos got a 2.2cl and he wants to do the flush now as well. His owner's Manual and FSM both say use 5w-30 engine oil and various forums across the internet suggest redline mt-90 or similar, so would your Amsoil GL-4 75w-90 work in his car? Also is the amsoil gear lube considered to be synthetic?

Yes, AMSOIL Gear Lube is synthetic. Here's a link to the product information. http://www.amsoil.com/StoreFront/mtg.aspx I can send you a Tech Data sheet by e-mail if you would like one.

Concerning your friend's car, Honda typically recommends a specially formulated 5w-30 synchromesh transmission fluid (MTF) for their transmissions...AMSOIL GL-4 75w-90 should not be used in transmissions requiring this fluid. The synchromesh fluids do not contain EP additives, where other gear oils do. AMSOIL offers a synthetic MTF that is a direct replacement for genuine Honda MTF...it would be an excellent choice for his application. My cost for AMSOIL Synchromesh Transmission fluid is $7.00/quart ($8.95 retail). Here's a link to the product info: http://www.amsoil.com/StoreFront/mtf.aspx

Please send me a PM if I can be of assistance.

thanks

[Nakulbhatt87]

THank you for the heads up! That's a failure waiting to happen then! So, I was hoping you could give me a price quote with shipping to 20832 for 8 quarts of the Amsoil GL-4 75w-90, and four quarts of the Honda 5w? I appreciate your help boss...

[talkinghorse]

Originally Posted by Nakulbhatt87

THank you for the heads up! That's a failure waiting to happen then! So, I was hoping you could give me a price quote with shipping to 20832 for 8 quarts of the Amsoil GL-4 75w-90, and four quarts of the Honda 5w? I appreciate your help boss...

Sent you a PM. thanks

[MaximaMark123]

Remember the old Nissan Van. I had one, manual gearbox, changed the transmission fluid at about 100,000. A thousand miles later the bearings started to make noise and had to be replaced. Different car I know but still a Nissan.

[gotcha640]

I had a 92 integra and it ran great on gm syncromesh. It's cheaper than the fancy ones that i could find.

[d00df00d]

The dislodged dirt issue is only a risk with automatic transmissions. They have filters that collect filings and deposits and such, and all that crap can sometimes cake up. If you do a transmission flush on an old, neglected transmission, there is a risk that big chunks can come off the filter and start circulating, causing problems.

Manual transmissions do not have this problem. You can drain and fill them all day without worrying about it.

Amsoil makes great stuff. Their MTG is probably the best fluid available for Maxima 5-speeds (Red Line MT-90 is a close second). For transmissions, you can just use what they recommend for your application and you'll be fine.

[Nakulbhatt87]

Thank you all for your help. At this point, im just waiting for a little more cash and a little warmer weather to tackle this project. I'll start with the manual tranny maximas and then I'll go on with the I30. The I30s my baby so once im done with my maximas I'll see how I feel about doing the flush with her. If I feel comfortable, I'll tackle the project, if not I'll take her to my buddy's shop who im sure will give me a fair deal. I'll update you all when I finish the project. Thanks again

[gotendbz1]

Originally Posted by Scottwax

The manual transmissions will be fine. On the automatic, I'd do a drain and refill first to see if that leads to any problems like slipping. If after a couple of weeks and everything is fine, then drop the pan, clean everything and refill.

how many quarts for a drain and refill for a 03 max

[guitarpro_1st]

I was thinking of getting a flush but the place that im taking it to is changing the fluid filter and gaskets so thats probbaly the best way to go eh.....

[soundmike]

Originally Posted by MaximaMark123

Remember the old Nissan Van. I had one, manual gearbox, changed the transmission fluid at about 100,000. A thousand miles later the bearings started to make noise and had to be replaced. Different car I know but still a Nissan.

Are you talking about the old Nissan van (Quest) that was a rebadged Mercury Villager?

[soundmike]

Originally Posted by Nakulbhatt87

I've heard various rumors about changing a car's tranny fluid over time...

I've had mine changed at 50, then again at 100k. No issues at all. Although these weren't full-flushes but rather drain and fills.

[talkinghorse]

Originally Posted by MaximaMark123

Remember the old Nissan Van. I had one, manual gearbox, changed the transmission fluid at about 100,000. A thousand miles later the bearings started to make noise and had to be replaced. Different car I know but still a Nissan.

Originally Posted by soundmike

Are you talking about the old Nissan van (Quest) that was a rebadged Mercury Villager?

The Quest/Villager weren't available with a manual transmission. I think he's talking about the old box-styled van that was much earlier than the Quest/Villager.

The Quest's were actually pretty solid...the engine and transmission were Nissan components, but the vehicle was assembled at a Ford plant outside of Cleveland. Some of the switchgear, AC and some other components were Ford, but the drivetrain was Nissan.

I had a '93 Quest (first year they came out)...sold it to a friend back in '02 and he's still driving it. The vehicle now has well over 200K with absolutely no serious mechanical problems...the engine and transmission have been extremely reliable with no break-downs, leaks or oil consumption to date. The vehicle has required A/C and CV joint replacement and that's about it. The vehicle has been run on AMSOIL engine oil and ATF since it was new.

[gotendbz1]

i recently drains and refills trans fluid with m1 atf and don't really notice a big difference.

[talkinghorse]

Originally Posted by gotendbz1

i recently drains and refills trans fluid with m1 atf and don't really notice a big difference.

Just because you can't feel it doesn't mean it's not doing it's job. A good synthetic fluid will reduce wear, lower operating temperatures, flow on the coldest of mornings, reduce hi-temp break-down and keep internal components clean. Improvement in shift quality is an ancillary benefit. The true benefit will be in the long-run.

[maxximaa]

so the AMSOIL "MTG" 75w-90 GL-4 is the ATF to go with then?
how about the Redline? do i just grab any model?

[talkinghorse]

Originally Posted by maxximaa

so the AMSOIL "MTG" 75w-90 GL-4 is the ATF to go with then?
how about the Redline? do i just grab any model?

AMSOIL MTG is a GL-4 rated lubricant for manual transmissions. ATF is for automatics.

Not terribly familiar with red-line products, but if you do choose their oil, make sure you are purchasing the correct fluid for your car...a GL-4 rated gear oil of the correct viscosity for manual transmissions, or an automatic transmission fluid that meets the appropriate Nissan spec (depending on the year of your car) for use in automatics.

Pls send me a PM if I can help with AMSOIL. AMSOIL offers a straight GL-4 gear oil and their ATF meets Nissan D, J and K specs.

[maxximaa]

im confused
what should i use for my 2002 SE A/T?

[talkinghorse]

Originally Posted by maxximaa

im confused
what should i use for my 2002 SE A/T?

Use an automatic transmission fluid (ATF) that meets Nissan-matic D specs. As an alternative, you can use an ATF that is Dextron-III rated.

[maxximaa]

alright, i'll check it out.

thanks,

[maxximaa]

ok so i bought automatic transmission fluid from the stealer.
guess that's good enough, right?