Best manual tranny fluid

I was looking at getting some Red Line MT-90 for my X-Runner's tranny but ran across some Royal Purple Synchromax. Anyone have any experience with either or recommend one over the other?



Thanks!



J.

Reply 1 : Best manual tranny fluid

Any of those help with cold weather shifting?

Reply 2 : Best manual tranny fluid

I am using full synthetic oil from Lucas oils. very happy so far



cheers

Warts

Reply 3 : Best manual tranny fluid

mine shifts like butter on -20c mornings. it only gets notchy after warm up. for this reason im thinking about thicker oil. anyone else try this?

Reply 4 : Best manual tranny fluid

Quote:

Originally Posted by jboogie I was looking at getting some Red Line MT-90 for my X-Runner's tranny but ran across some Royal Purple Synchromax. Anyone have any experience with either or recommend one over the other? Thanks! J.

Do not put the mt-90 in your tranny, unless you like the smell of gear oil. I put it in and I would constantly smell gear oil. I think it was coming out of the breather and getting into the cab, because it was not leaking. Get the redline MTL, if your going to change it.

Reply 5 : Best manual tranny fluid

amsoil severe gear gl5 shifts easier and smoother now. goog stuff

Reply 6 : Best manual tranny fluid

(to jboogie)



if you run straight redline mtl, you MAY experience problems. it is too thin for the specs on your manual tranny. mt -90 would be the choice as far as viscosity is concerned. it is a 90 wt lube .(or you could try a blend of the two, but read up on that in detail first)

your manual tranny calls for a 75-90 wt lube .(but you probably knew that)

(to scott aw)

I have tried conventional gear oil, redline and amsoil. I have had the best luck with redline so far, it has improved shift quality in all seasons. but for me it looks like nothing will totally fix the clunky notchy shifting i experience, more so in cold weather.

good luck and hope either one you choose works for you.

Reply 7 : Best manual tranny fluid

I will change mine soon and I plan on using M1 75W-90 synthetic.

Reply 8 : Best manual tranny fluid

I put 75w-90 Quaker state full syn in at 20K a over a year ago. Its only slightly more than the convential stuff, and not overpriced like the others.



Wanted better flow/protection when well below zero. Not much noticeable diff most times, she has shifted like butter for over 3 years anyway. Changing all fluids to full syn (except LSD) my winter mileage became slightly better.

Reply 9 : Best manual tranny fluid

Quote:

Originally Posted by demoncleaner I put 75w-90 Quaker state full syn in at 20K a over a year ago. Its only slightly more than the convential stuff, and not overpriced like the others. Wanted better flow/protection when well below zero. Not much noticeable diff most times, she has shifted like butter for over 3 years anyway. Changing all fluids to full syn (except LSD) my winter mileage became slightly better.

Demoncleaner, what did you use for the rest? 75W-90 all around?

Reply 10 : Best manual tranny fluid

Quote:

Originally Posted by sechsgang Demoncleaner, what did you use for the rest? 75W-90 all around?

Yep, same stuff in tranny, transfer, & front diff.



LSD rear diff thou went with 80w-90 semi-syn/conventional blend" for LSD and non-LSD applications", no friction modifier. Spins both wheels, no chatter. Staying with this setup for future.

I've can remember many posts from guys who went with full-syn 75-90 and had LSD chatter, sometimes even with friction modifier.



Edit, I see you got TRD Off-road, so you dont have to worry about any LSD chatter issues. I'd search if 75-90 fullsyn ok for your setup.

Reply 11 : Best manual tranny fluid

some great info in here.



Since my transmission blew its reverse gear at 17k miles, I've noticed that the warranty replacement has been VERY stiff when cold. I live in Texas, so cold == above freezing.



Once the trans warms up, it shifts smooth and easy, but until then 1st and 2nd are damn near impossible to select.



I would expect this from a brand new transmission, but I've put about 1400 miles on it since it was replaced, and it still does this.



It actually snowed (real snow, not sleet) last night, and this morning it was damn near impossible to get into gear after backing out of the driveway.



It's so tight that if I'm sitting on flat, start the engine w/ the parking brake released, leave the trans in neutral and release the clutch, the vehicle starts crawling forward and a noticeable drag is placed on the engine... that lasts about the first 6-8 seconds the truck is running, and then there's a noticeable "release" if I push the clutch in for another minute or so. After I can get it in gear and get going, it will finally slot 1st and 2nd with no issue after about 3 miles of driving.



As such, I figure it's probably wearing down some tight parts and putting lots of metal in the oil, so I will likely change the fluid in another 1000 miles or so...



I'm a big fan of RedLine, (I run it in just about everything, though I use Mobil 1 in the Taco engine because I can find it in gallon jugs easier than I can find RL in quarts) so I'd probably want to dig up some RedLine synth for the transmission.

Reply 12 : Best manual tranny fluid

Bought my '07 one year ago. Trans shifted fine not notchy at all except for the non-syncro'ed first.

Last Nov changed fluids to synthetic. Went with Redline MT-90 in the transmission (and 75w90 NS in all the rest). Thought this would be good for the cold winters here in MN.

Not sure I'd do the MT-90 again. Don't feel the shifting is as smooth as it was with the OEM fluid in all gears. May try another synthetic this summer. Only 10k on the truck but it should be broke in fine.

Did the exact same change in fluids to Son's 99 (95k on it) and he feels the same way. Shifted smoother with the OEM non-synthetic fluid.

I know a lot of people like the RL but we'd not do the MT-90 again.........For what's it's worth from MN.

Reply 13 : Best manual tranny fluid

Hopefully I can clear a few things up here...

Quote:

I was looking at getting some Red Line MT-90 for my X-Runner's tranny but ran across some Royal Purple Synchromax.

Synchromax is for transmissions that use a light weight oil. It is essentialy the viscosity of ATF, very thin. You should not use this in a transmission calling for 75W-90 gear oil.

Quote:

Do not put the mt-90 in your tranny, unless you like the smell of gear oil. I put it in and I would constantly smell gear oil. I think it was coming out of the breather and getting into the cab, because it was not leaking. Get the redline MTL, if your going to change it.

Redline MTL is gear oil, same as MT-90. It is a thinner 70W-80 GL-4 fluid. MT-90 is 75W-90 GL-4. If you were smelling gear oil with MT-90 and not MTL, then it must have been overfilled at one point.

Quote:

Quote: Originally Posted by sechsgang Demoncleaner, what did you use for the rest? 75W-90 all around? Yep, same stuff in tranny, transfer, & front diff.

Normal 75W-90 gear oil can be used in the tranny (as manual allows GL-5), but with the LSD additives usually included in off-the-shelf gear oils, it is usually too slippery for optimum shifting.

Quote:

Since my transmission blew its reverse gear at 17k miles, I've noticed that the warranty replacement has been VERY stiff when cold. I live in Texas, so cold == above freezing. Once the trans warms up, it shifts smooth and easy, but until then 1st and 2nd are damn near impossible to select. I would expect this from a brand new transmission, but I've put about 1400 miles on it since it was replaced, and it still does this.

I had the same problem with a new manual trans replaced by the dealer. The problem was, the dealer filled the replacement tranny with bulk 80W-90 gear oil (I asked). As soon as I put MT-90 in, cold shifting was back to normal.



Hope this helps.

Reply 14 : Best manual tranny fluid

Quote:

Normal 75W-90 gear oil can be used in the tranny (as manual allows GL-5), but with the LSD additives usually included in off-the-shelf gear oils, it is usually too slippery for optimum shifting.

So what would you suggest instead? 75W-140 maybe? It's thicker, so probably not as "slippery"?