Manual tranny fluid

[GMFan]

Greetings,

Simple question. Do you need to replace manual transmission fluid? I was reading on Saturn forums and some people claim their transmission to be smoother after new fluid. The manual says manual transmissions do not need filter or fluid services.

Secondly, the manual says to put in ATF in the manual transmission if you do work and have to flush/refill it. What is a good ATF? I guess I am willing to go synthetic since my car is driven in winter and I probably won't ever change it again. It has gone 94k miles without a flush.

Thanks all.

 

[Tempest]

Yes you need to change it. It shears, oxidizes, gets dirty, the additives wear out, etc.

As far as what fluid to get, see HERE.

 

[GMFan]

I'm pretty clueless when it comes to gear oil. I mainly know motor oil.

Is it possible it is sludged up? I just trusted the manual which said it doesn't need to be changed unless you do work on it or it has a leak. Did I wear out my transmission more because of this? I know manual transmissions are real durable but I don't know if almost 100k miles is negligence.

Looks like I will use the M/T fluid instead of ATF.

Thanks.

BTW, I don't remember the manual specifying a weight for the fluid. I guess I can do more research to find out what to use.

 

[simple_gifts]

Quote:

Looks like I will use the M/T fluid instead of ATF.


Why? There are synthetic ATF's like Redline D4

 

[Quattro Pete]

Originally Posted By: GMFan
Greetings,
What is a good ATF?

I'm using RP Synchromax in mine.

The whole issue of "lifetime" fill is highly debated. Mainly the definition of "lifetime". If your transmission dies after 100k miles, then you can certainly say that the fluid lasted the lifetime of that transmission, but what good does that do? I changed mine at 35k miles.

 

[rpn453]

Originally Posted By: GMFan
Is it possible it is sludged up? I just trusted the manual which said it doesn't need to be changed unless you do work on it or it has a leak. Did I wear out my transmission more because of this? I know manual transmissions are real durable but I don't know if almost 100k miles is negligence.


It won't be sludged, but it will be dirty and maybe worn out. You'd have to do a used oil analysis to determine what effect the long interval has had on the transmission. It might not even show any accelerated wear. I bought a 5-speed Pathfinder with 90k miles a couple of years ago and it was obvious from the black oil in the transfer case and transmission that they had never been changed. The oil in the diffs was clean, so at least they changed that. It shifted much better after changing the fluid.

GM has no reason to recommend changing it. Most North Americans would rather have a car that requires no maintenance than one that will last forever. They're almost certainly going to get rid of it before the transmission fails anyway. If you could find a non-North American maintenance schedule for that car or transmission they'd probably recommend changing it every 60k miles.

It costs almost nothing and it's easy to change, so I'd do it every 60k miles or less.

 

[GMFan]

Originally Posted By: simple_gifts
Quote:

Looks like I will use the M/T fluid instead of ATF.


Why? There are synthetic ATF's like Redline D4


Well, from that link posted by the first reply it sound like MTF is better at protecting the transmission.

 

[Jett Rink]

I've used Redline MTL in BMWs, with great results. BMW guru Mike Miller recommends this over their ATF fluid for protection purposes.

I know Amsoil makes a good fluid, too.

But, yeah, I'd certainly change it. A 30K interval should be no problem, maybe longer. I drained the fluid on my 2004 after I got it with 46,000 miles. The original fluid that drained out looked like it was ready for a change (call that a visual gear oil analysis!), but it wasn't pitch black with all kinds of debris in there. It still had an dark amber tint, for what it's worth. We've been having some sub-freezing temperatures. I'd say it takes a little more effort to shift now with the new fluid at really cold temperatures for the first couple of shifts. But after that, it is fine.

One thing about a manual transmission. It is very easy to drain and add fluid. And it is not expensive. Contrast that with servicing an automatic transmission.

 

[The_Jeff]

Most of the saturn s-series model run they said to switch out the man transmission fluid at 6k miles then never again.

Makes sense, as it would get the break in junk out of there.

Easy enough to do, it's a "why not" kind of question.

 

[Dave Hess]

My wife has a 2007 Civic EX with 38K miles and I drained/refilled the 5 seepd trans with new fluid and it made a night/day difference.

You will notice a smoother trans especially since your Saturn has 94K miles. I bet the factory fluid has thinned out and is dirty from break in.

 

[CivicFan]

When I had my Accord, I put Redline MTL in it. After that there was a lot of grinding and difficulty putting it in a gear especially the second gear. I had to replace it with what Honda recommended - 10w30 motor oil.

So before going and buying some fancy synthetic stuff I would do a little bit of research.

 

[Bill in Utah]

I changed out my 1986 VW Jetta last year @ 292k.

While it was not the prettiest looking fluid (it looked like the Mobil 1 gear oil after 40k in my Toyota), it still was working well and no metals that I could *see*.

Replaced it and still doing well @ 324k.

I've replaced the fluid in my Toyota twice (once around 22k and 64k ) and have almost 40k on this fill. I'm going to go to 60k and change it again.

The fluid I have in the box right now is still performing excellent (much better than the Mobil 1 ever did, even in the cold) so I should take it to 75k.

But, I think if I could go almost 300k on the factory fill with 1985 fluid, maybe lifetime is possible with todays oils?

Bill

 

[02zx9r]

I drained out the factory fill in my 08 corolla at 2200 miles and refilled with coastal 75W90, when I get 20-25K on the car I am going to put in the amsoil 75W90 i bought. (thanks Bill for all your help)

Depending on the type of driving you do I have seen people recommend every 30K. With the amount of highway miles that I was doing I was going to go 50-75K, but now that my daily commute has dropped from 62 miles round trip to 4 miles round trip I will probably do every 30K