Manual Trans gear oil recommendation

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Thanks for the input.

Here is day 2 update, so far about 50 miles on the new fluid.

Cold start, now it will go into 2nd and 3rd gear if I double clutch it. Again 1st gear needs to be a complete stop.

After 15 minute drive, everything smooth as it was before.

I would say it has definitely improved from the day before. Still not the way I want it, but I am willing to wait and see.

Thanks
 
Definitely recheck the fluid level and run it for 3k or so miles.
If after 3k miles and you're still not happy, then try other fluids.

In no specific order, try these which will cover you for the next 30k or so miles:
RoyalPurple Maxgear
Redline 75w90NS
Silkolene Silktran Syn5
Torco RTF
Castrol Syntrax
Motul Motylgear/gear300/gearbox
Synlube MT

Also don't rule out clutch or transmission problems. Inspect/lube/bleed/adjust any and all linkages/hydraulics/cables/levers/pedal........
 
Redline 75w90 NS + FM was definitely the next choice on my list.

FWIW, I also flushed the hydraulic system, brakes/ slave cylinder while I was at it. I am pretty sure I did the flush correctly as I used a power bleeder and this is the same procedure I have done at least a dozen times.

In any case, the slush box shifts perfectly once it is warmed up so I am pretty sure it is fluid consistency related.
 
well, your tranny is more tolerant of diffy lubes than most. Diffy lubes and MT lubes are entirely two different beasts:

From Redline Website:

quote:
All oils are slippery, and with most lubricated components, the slipperier the better, but this is not so with manual transmissions. The synchronization of shifting gears requires friction to transfer energy from the synchronizer, which is locked to the input shaft, to its mating surface attached to the gear to be locked in as the drive gear. Few modern transmissions use sliding gears to change gearing other than for reverse gearing. Synchromesh transmissions have the gear pairs constantly in mesh. The drive gear is selected by using the shift forks to slide a synchronizer ring, which rotates at the same speed as the input shaft, in contact with the selected drive gear. Once the drive gear is brought to the same speed as the input shaft, the locking ring on the synchro assembly is allowed to slide over and lock into the drive gear.

The time this process takes depends on how easily the synchro ring moves and the rate of frictional energy transfer between the two synchronizer surfaces. Higher viscosity lubricants slow the sliding of the synchro ring on the input shaft and require a longer time for the oil to be squeezed out from between the mating synchronizer surfaces. After the lubricant is squeezed out, the coefficient of friction of the lubricant determines the rate of frictional energy transfer between the two surfaces. Slippery lubricants such as hypoid gear oils and ATFs can take too long to synchronize the gears, which promotes synchronizer wear.
Click to expand...
 
that sums it up very well perhaps this should be bookmarked since the questions about hypoid and MT lubes comes up all the time.
bruce
 
Give motul gear 300 a try if you're having cold shift issues. I tried MTL-R initially in my Audi A3, and it had terrible cold shift issues. It is much better with Motul Gear 300.

Dave
 
I'm pretty sure your integrated gearbox/diff is the same that's used in VW's and Audi's. The best lube for cold weather is Castrol TAF-X. It is dual GL-4/5. It is the stock fluid in VW/Audi and is the only fluid that Lotus reccomends for their box. It's very clear looking and very expensive. You can get it from a Lotus dealer for about $15 per .5 liters. It's also available from VW for around $26 a liter, called G52. It has a high viscosity index, around 220 or so. I compared it cold with the Motul gear 300 and it was thinner and gave much better cold shifting performance. After trying several lubes in my VW tranny, I went back to the stock fluid since I couldn't use 2nd gear at all when the temp was below 50.
 
Actually the TAF-X has a VIE of 200

Pour point of -51
Flashpoint of 224
Density @ 15C .864
Viscosity@ 40C 76.0
Viscosity @ 100C 14.0

what I don't understand is that Motul Gear 300 has the following specs . . .

Viscosity grade 75W-90
Density at 15°C (59°F) 0.900
Viscosity at 40°C (104°F) 72.6 mm2/s
Viscosity at 100°C (212°F) 15.2 mm2/s
Viscosity index 222
Flash point 200°C / 392°F
Pour point -60°C / -76°F

I'm almost starting to think that the OE stuff isn't TAF-X. Looking at the specs, it would indicate that the Gear 300 is the better cold weather performer.

Dave
 
Yeah, I don't know. I compared specs and thought the motul would be just as good also. Whatever the VW fluid is, it's a great 75w-90 for the cold.
 
Hi guys,

Another update.

The transmission was still shifting badly even after a couple hundred miles, no improvement from before. So I started to think....

The factory shop manual calls for 2.7 liter of the transmission fluid, which equals to about 2.85 quarts. Thinking back about when I filled the fluid I didn't even measure the amount of the fluid I put in... I just filled the box until the fluid started to come out of the filler plug....

Well, that was 4 quarts of the stuff I put in.

So tonight I decided to drain some of the fluid out, just to try anything. I drained out about 1 quart of the stuff and went for a test drive. Immediately the gears engaged a lot lighter and I was able to shift into first gear even when the car was still rolling.... WOW!

The real test will be tomorrow morning at a freezing 45 degree (we have a cold front) will keep you guys posted on this!

Just in case I ordered some factory stuff that is flown in from Germanly at $55 a quart!!!! What a rip off! Worst comes to worst I am putting the factory stuff back in.

So I am guessing that since I over filled the transimission with fluid the synchros were just soaked in the fluid and prevented it from spinning properly? Are the components of the transmission normally completely submerged in the fluid or semi?
 
Yes overfilling is not good for the behavior of the gears. It creates to high pressure inside the gearbox.

I promise you that you will see improvent if you give MTL-R an chance.
 
Castrol TAF-X the one we can buy here in Sweden is not playing in the same elit division as MTL-R do.

Its a big difference between the baseoils.
 
"I promise you that you will see improvent if you give MTL-R an chance."

jbl, no one's a bigger fan of MolaKule's gear oils than I ... but you can't really promise one will work in a given application. These applications tend to picky and what works for one does not necessarily work in another.

I often tell people who are experimenting with different syncromesh fluids that they had better be prepared to drain it out if it isn't working well ... then replace it with something else.

In some (like my Nissan 6-speed) there seems to be enough manufacturing variations to cause problems in one ... while another identical application works very well.

mrpcar, I honestly thought that MTL-R would have been ideal for your Porsche application. Sorry to hear that it isn't the 'miracle' fluid for you many of us believed it would be.

--- Bror Jace
 
Final update,

First I want to thank everyone for their contribution to my little "gear oil journey"...

Your devotion and eager to help is very much like the air cooled 911 guys on the rennlist.com there are few boards out there that can come close to the knowledge and the willingness to share information as I have seen here.

Went out for a drive this morning, the gear box is a 100% improvement compared to when I overfilled it. Unfortuntely it is still a little hard to shift to 2nd, but after a 3 minute drive it was fine. Well... it must be my synchros are shot, so no matter what magic fluid I put in, it is going to be the same. The previous idoit owner must didn't know how to drive the **** car... so

Boys and girls, moral of this story is... read the f&%&% manual..... The problems I was experiencing was 100% due to the idoit me doing the old school way of filling it until it come out of the filler plug.

Now I am happy with what it is, I guess I will return the $55 quart stuff from the dealer and deal with the restocking charge.

Thanks again for all of your help.

Robin
 
I'd still say a bit of the cold shift issue is due to MTL-R. I ran it for awhile as well at the proper fluid level, but it was never as fluid as stock at cold temp.

Motul Gear 300 worked very well though and only shows a slight cold stiffness for the first mile. Has a very similar smooth hot feel just like MTL-R.

Dave
 
Bror, your right. I was refering to my gearbox as it have some trouble to engage the gears smoothly. Especially the third gear. Now its completely fine.

But i havent the problem only if the car was cold or not.

Mrpcar, sorry to hear that your gearbox is felling ill. If you are lucky it can maybe improve with MTL-R. Nothing to loose to give it some more time.

Best luck.
 
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