Tranny fluid

[Brunoboy]

Whats everyone using? I used amsoil and valvoline with no help to my grinding problem, i think i maybe leaking out of the axle seals but not sure if im low on fluid or my systems messed. I have a new mc and slave cylinder, ss line , adjusted bled and everything, it shifts ok cold but when it heats up it grinds real bad. Is this the fluid im using or not? Its not fun when the gear doesnt disengauge all the time....

 

[GVR4_1057]

NEO RHD is my favorite by far. I have tried synchromesh, synchroshift and Redline . NEO FTW

 

[Street Surgeon]

You basically have to choose between a fluid that protects your synchros, or a fluid that plays nice with your gears! The thin fluids like synchromesh are much easier on the synchros, but your gears will then be more susceptible to wear. Thicker stuff like the redline shockproof is better for protecting your gears, but tougher on the synchros. Personally on < 400hp cars I'd run lightweight shockproof in the gearbox, that's just me though.

I've found out after years of dicking around with DSM trans' that snake oils and different fluids are merely a bandaid approach that won't fix the problem. I'm a firm believer that the 1st mod you should ever do (after general maint.) to a DSM or GVR4 is purchase a built or at the very least a rebuilt trans!

 

[broxma]

Swepco 201. Available shipped from some place in Dallas for 40 a gallon. It is Porsche racing fluid as I am told. The 210 is really expensive

/brox

 

[belize1334]

DON'T use shockproof in your transmission. It's ok in the transfer case and in the rear-diff but it is explicitly not designed for your transmission. Check the comments on JacksTransmissions for an explanation.

He's right though that theres a trade-off between thinner fluids that play well with synchros and thicker ones that promote gear longevity. But, the OEM synchros were poorly designed with their organic layer so if you have a rebuilt transmission with the revised all-brass synchros you should never have to worry about trying to baby the synchros again.

The only hi-end trans fluids that I've used were BG synchromesh and Redline MTL / MT-90. The Redline stuff is fantastic. The BG is basically a ruined transmission in a bottle.

 

[Chim55117]

A popular combo around DSMSTYLE (a Minnesota DSM forum) is the Redline "cocktail". It's two parts MT-90, and 1 part MTL. You add 1 bottle of MT-90, then add the MTL, then continue to add the other bottle of MT-90 until it's full. People around here swear by it. I have the same "cocktail" in my transmission and it shifts great!

 

[Brunoboy]

Thanks for all the replies, i saw fluid drops by the tcase but cannot locate if its a leak, will low tranny fluid be a factor in why it wont disengage sometimes?

 

[BoostedAWD91]

Anyone use just redline mt-90? I'm a synchromesh fan but now that its up to $20 a quart I need to go a different route

 

[GVR4_1057]

^ More likely clutch adjustment.

The transfer cases will leak at the back where the drive shaft goes in. Actually it is the yoke but that is where the oil will drip from.

 

[Brunoboy]

Leaking tcase will caus gears to grind too? My shifter inside the car seems pretty stiff....

 

[Boostdtalon]

I use oem Mitsubishi trans fluid. I've heard the trans fluid for the Evo six speed is a nice thing to use. All the other stuff I've used hasn't impressed me. Except the redline shockproof.

 

[belize1334]

No, a leaky t-case will basically have no symptoms until it goes dry and seizes. A leaky transmission will also shift very well up until the point where the bearings start to fail and it begins to sound like death.

Grinding going into gear is synchros. It may ultimately be caused by poor clutch adjustment which results in incomplete disengagement but the actual grinding sound is a result of gears trying to mesh at incompatible speeds and that is a DIRECT result of the synchros not doing their job.

I'm gonna sound like a broken record here but I can't stress enough how good an idea it is to use the JacksTrans disengagement test. Put the car in the air so that the wheels spin freely. Put it in 1st with the clutch to the floor and rev it up. Have a friend yell out when the wheels start to spin. If this happens below ~6k rpm then your clutch is dragging and should be adjusted before it wears your synchros down to nothing.

 

[GVR4_1057]

Quoting brunoboy:
Leaking tcase will caus gears to grind too?



Sorry, I was addressing both issues.

A leaky t-case will not affect shifting but it will lock up and cause other problems.

And check clutch disengagement as stated above.

 

[MMCVR4]

I had the shift grinding before I replaced the trans/transfer case fluid with BG Synchroshift II. Worked well ever since. For the rear diff, it was a mixture of BG & Redline Shockproof.

 

[BoostedAWD91]

I think I'm gonna do a mt-90 and GM synchromesh mixture

 

[Street Surgeon]

Quoting belize1334:
DON'T use shockproof in your transmission. It's ok in the transfer case and in the rear-diff but it is explicitly not designed for your transmission. Check the comments on JacksTransmissions for an explanation.



I have three shep race transmissions, a stage 4, and two Stage 3's. When I asked him what to run in his transmissions at ~ 450whp he told me a mix of lightweight shockproof and a lil' synchromesh. I've run that mix in both of my Stage 3 transmissions and they shift like butter, that and I know my gears are covered. As far as what I run in the Stage 4 trans, well that car hasn't run yet /ubbthreads/images/graemlins/frown.gif

Now, as far as shockproof being "...explicitly not designed for your transmission" I couldn't find that on their page, they did say however that it's "Designed for wet sump transmissions and differentials with splash lubrication." Again, I've read what Jon at TRE has said about shockproof oils, and on jacks trans but it works great for me /ubbthreads/images/graemlins/smile.gif

 

[belize1334]

For everybody's benefit, here's the link to TRE's recommendations for transmission oil.

click

Also, I was apparently confusing aspects of two different tests for clutch dis-engagement and thus giving poor advice. The two correct ways to test are provided by Jack and TRE respectively.

1) With the car on FLAT GROUND, put it in first with the clutch to the floor. Rev it up until the car starts to roll forward. If this happens below 7k then you're dragging.

2) With the car in the air, let the engine idle in 1st gear and slowly release the clutch until the wheels start to spin. The clutch should be at least 2 inches off the floor at this point (3 is better). If it is not then the clutch should be adjusted.

 

[turbowop]

Quoting GVR4_1057:
NEO RHD is my favorite by far. I have tried synchromesh, synchroshift and Redline . NEO FTW



/ubbthreads/images/graemlins/werd.gif NEO is what I use as well.

 

[turbofonz]

Quoting belize1334:

2) With the car in the air, let the engine idle in 1st gear and slowly release the clutch until the wheels start to spin. The clutch should be at least 2 inches off the floor at this point (3 is better). If it is not then the clutch should be adjusted.



I'm pretty sure just in nutreal, idling the wheels will slowly move. I wouldn't say this is a good test.

I've had good luck with 2 QT's MT90 and the rest lightwieght shockproof to thicken things up.

Straigh Syncromesh is wayyy too thin. Straigh MT90 would probally be fine, but I like the shockproof for a little extra thickness.

 

[belize1334]

In neutral yes... with the clutch engaged the wheels will spin since the trans input side is spinning and friction will make the output spin too. But with the clutch in the input side should be totally disconnected. That's why it's a test of the clutch disengagement.