I've heard rumors that synthetic motor oil is bad for a manual transmission. What are the reasonings for this? I have about 3k km on the Royal Purple synthetic I put in when I replaced my tranny, will I have caused any damage? Switching to honda MTF today. Thanks!

 

why not just get honda mtf in the first place?

honda trans' are finnickey about what you put in them sometimes...

 

there is NO downside to a good synthetic oil

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zrickety &raquo;</TD></TR><TR><TD CLASS="quote">there is NO downside to a good synthetic oil</TD></TR></TABLE>

in your motor.

your transmission should have MTF, preferably from Honda

 

my manual says that 10w-30 is perfectly fine for the transmission. seeing as i've only run oil in it for 2 1/2 years, i'd say it's ok. but to each his own



Modified by zrickety at 3:06 PM 10/29/2008

 

Supposedly, synthetic won't let the synchros do their thing correctly. I Tried synthetic in my old '90 Si for a while. The only thing I noticed besides slightly smoother shifting in sub-zero temps was and occasional crunch. I switched to MTF after a while.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zrickety &raquo;</TD></TR><TR><TD CLASS="quote">my manual says that 10w-30 is perfectly fine for the transmission. </TD></TR></TABLE>

Read it again. All of my manuals state it is OK to use 10w-30 if necessary but it should be changed out for MTF as soon as possible.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sgallagher &raquo;</TD></TR><TR><TD CLASS="quote">

Read it again. All of my manuals state it is OK to use 10w-30 if necessary but it should be changed out for MTF as soon as possible. </TD></TR></TABLE>

exactly. In the owner's manual and in the Helms manual.

 

I've always used synchromesh in every manual tranny I've ever had, including the honda. It's been working great so far.

 

So Royal Purple is bad to use?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zrickety &raquo;</TD></TR><TR><TD CLASS="quote">my manual says that 10w-30 is perfectly fine for the transmission. seeing as i've only run oil in it for 2 1/2 years, i'd say it's ok. but to each his own
</TD></TR></TABLE>

In my Helms it states 10W-30 or 10W-40 for the tranny. It does not mention anywhere to use the MTF. I believe this was around the mid to late 90's they started using the MTF. I would be surprised if you had an original Helms, first edition, that states anywhere in there to use MTF.

 

But to reply to the original question. I have heard not to use synthetic in the tranny, but I have nothing other than someone else's opinion on that.

 

I could see an argument if Honda MTF was about $20 a quart... but its not so why on this earth not use it?

 

in my experience, synthetics save cars...engines, transmissions, whatever. i have run it off and on in most of my vehicles. when i was younger, i had an 86 trans am that overheated coming home one night. i drove it until it wouldn't move. then i let it sit for 20 min and started it again. drove it about 1/4 mile before it overheated again. i did that like 4 or 5 times until i found a phone and called my parents. long story short, mobil 1 saved the car and i only had to replace the radiator.
i challenge anyone that says synthetic is bad to show me any kind of test or review that proves it

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zrickety &raquo;</TD></TR><TR><TD CLASS="quote">in my experience, synthetics save cars...engines, transmissions, whatever. i have run it off and on in most of my vehicles. when i was younger, i had an 86 trans am that overheated coming home one night. i drove it until it wouldn't move. then i let it sit for 20 min and started it again. drove it about 1/4 mile before it overheated again. i did that like 4 or 5 times until i found a phone and called my parents. long story short, mobil 1 saved the car and i only had to replace the radiator.
i challenge anyone that says synthetic is bad to show me any kind of test or review that proves it </TD></TR></TABLE>

Mobil 1 =

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dman03GT &raquo;</TD></TR><TR><TD CLASS="quote">I've always used synchromesh in every manual tranny I've ever had, including the honda. It's been working great so far.</TD></TR></TABLE>


i usually tryto use mtf but this synchro mesh fluid took my 2nd gear grind almost completly away...

 

double post, sry

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HOODLOVER &raquo;</TD></TR><TR><TD CLASS="quote">
i usually tryto use mtf but this synchro mesh fluid took my 2nd gear grind almost completly away...</TD></TR></TABLE>

Yeah I've experienced that too, I had a Mustang with a 3650 which were known for grinding third and reverse and synchromesh cured it.. ever since then that's all I run.

 

Syncromesh cured my 2nd gear grind, and lessened my 3rd

 

Ive used syncromesh and Honda MTF in the past. I like both. Currently im running royal purple and haven't had any issues with excessive noises or grinds. Gets a in my book

 

haha, I should have known that another thread about tranny fluid would go wild.

My main shaft bearing is likely kaput, as the gearbox makes some awesome noises during acceleration, especially in high gear. I was wondering if the royal purple could have worsened this problem, but it's likely that it hasn't done anything bad.

Funny thing is, the synchros are fine - it shifts well and i've only had second gear grind once, and it was probably my fault. Would it be worth replacing the bearing, or should I just go get an SI tranny?

 

look for an si trans... and if that needs bearings... well then you woulda had to replace em anyways

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vtecRIPPIN992 &raquo;</TD></TR><TR><TD CLASS="quote">look for an si trans... and if that needs bearings... well then you woulda had to replace em anyways </TD></TR></TABLE>

friends screen name lol never signed back out that hater! that was me

 

nothing wrong with a good synthetic. take a look at http://www.bobistheoilguy.com/forums there's lots of good info on there.

 

I've used Pennzoil Synchromesh, RP Syn., Amsoil 5w-30 Syn. MTF, 10w-30 motor oil(forgot which brand) and Honda MTF.

I've noticed no issues except for with the RP synthetic MTF in my old '90 Accord LX and the regular motor oil in my D15B VTEC 88 Civic with DOHC ZC transmission

At first the RP in the Accord worked fine but after a couple thousand miles the transmission started grinding and got worse(especially when cold). A switch to Pennzoil Synchromesh fixed that problem. Seems like the issue with RP is it probably breaks down quickly. With the motor oil in my Civic, during cold days(like &lt;40 degrees F) it would just grind a bit but once the temperature of the transmission went up it worked fine.

As far as Honda MTF and Amsoil MTF, I've never had any problems at all. If anything, I'd probably just stick with Honda MTF since it's half the price of the Amsoil MTF.