Has synthetic fluid helped manual transmissions?

Brianv6 · Aug 27, 2007

I heard and read several cases on how using synthetic ATF can improved shifting and sometimes extendled the life of the transmission.

I have a T-5 transmission that called for ATF for its lubrication. 30,000 miles ago I drained it and refilled it with fresh fluid. Shortly after that I would have trouble getting into 2nd gear ocosinally. Now maybe once a month it will have issues going into second. Because it uses regular ATF is it possible that syntheitc fluid could be beneficial?

Anyone have any testimonials where syntetic fluid helped in a manual transmission?

Big Jim · Aug 27, 2007

On some transmissions with certain problems it can help. In may other cases it will not help. For the cost of the fluid it's worth a try.

aquariuscsm · Aug 27, 2007

If your manual transmission has synchro issues,there`s no fluid that will help it. Transmission replacement is the only option.

My manual transmission has synchro issues and I tried RL MT90 and RP Max Gear and it was just a waste of money.

mechtech2 · Aug 27, 2007

Many manual transmissions spec ATF .
Shifting is always a tricky issue. A synthetic can cause the synchros to engage slower, as is slips a bit more and squeezes out a bit slower.
For a very good over the counter sauce - Pennzoil Synchromesh is great. It is a bit thicker than ATF, and is a dino . Good protection and shifting.
Auto dealeships have only ONE sauce to stock for power steering, auto transmissions, transfer cases, and manual transmissions. It's not because ATF is the absolute best fluid for the transmission. It is adequate and OK.

CBDFrontier06 · Aug 28, 2007

I highly recommend Redline MT-90. I've had no further 2nd gear issues since I put it in.

Tempest · Aug 28, 2007

Quote:

I highly recommend Redline MT-90. I've had no further 2nd gear issues since I put it in.

Mt-90 is very thick for an ATF spec. trans.

I am using Amsoil MTF in my ATF spec. trans which is slightly thicker than an ATF, but also has a much more robust add pack. Shifting is very good.

aquariuscsm · Aug 28, 2007

My manual transmission specs a 85W90 GL4 gear oil. MT90 seems to thin out too much when it gets good and hot. The Nissan OEM fill is Pennzoil 85W90 gear oil. Once I finish putting my new Jspec transmission in,I`ll just keep on using the Pennzoil on my fluid changes. I`ll maybe try RP 75W90. Alot of people love their gear oils.

Dave Hess · Aug 28, 2007

Amsoil ATF for a T-5 works the best.

Brianv6 · Aug 28, 2007

Quote:

Amsoil ATF for a T-5 works the best.

Can you elaborate on this statement?

dailydriver · Aug 29, 2007

MANY of the rebuilders of the T56 transmissions suggest the Mobil 1 ATF (one of the ONLY synthetics they recommend). I don't know if this also holds true for the T5.

ConfederateTyrant · Aug 29, 2007

If you need a GL-4 85w-90 replacement, then go with Amsoil MTG 75w-90 GL-4 gear oil.

lazaro · Aug 29, 2007

Quote:

I heard and read several cases on how using synthetic ATF can improved shifting and sometimes extendled the life of the transmission.

I have a T-5 transmission that called for ATF for its lubrication. 30,000 miles ago I drained it and refilled it with fresh fluid. Shortly after that I would have trouble getting into 2nd gear ocosinally. Now maybe once a month it will have issues going into second. Because it uses regular ATF is it possible that syntheitc fluid could be beneficial?

Anyone have any testimonials where syntetic fluid helped in a manual transmission?

t-5 boxes years 1985 and newer all have friction based syncros, glued lining.
and the gears ride on needle bearing cages, this is why the ATF is called for sevice.
most any ATF will work fine, I have used and seen over 500 boxes in the past 15 years, Amsoil ATF works the best for me.
could you explain the issues with second gear a little more? im sure I can nail the source

Has synthetic fluid helped manual transmissions?

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