Im thinking about using GM SynchroMesh in my tranny...

[Reign_Maker]

Yes? No? Maybe so? Good idea? Bad idea? Waste of money?

[IJ.]

I would think it's far too light for a 154 Jake.

[MDCmotorsports]

I wouldn't go 100% with it Jake. I would go 25/75 with it.

[hottscennessey]

I've heard bad things about it - now that I've used it for 1.5 years and destroyed my second gear synchro.

[jdub]

GM SynchroMesh is for manual transmissions that specify it...RP Synchomax is a replacement for it. This weight oil is used in trannys that require automatic transmission fluid, multi-viscosity motor oil or straight grade motor oil. Read this thread for why it's not a good idea to use either in a R154:

http://www.supramania.com/forums/showthread.php?t=44485

[IJ.]

In my old steel case 5 speed I ran in the 240z I used to use a 50/50 mix of gear oil and ATF to help it shift when cold.

I still say straight Syncromax would be a bad choice for a 154 (it's one of the recommended oils for the Tremec TKO the other is Dex-III)

Also beware using anything very slippery ie: some Synthetics as the Trans needs a precise level of friction for the Syncro rings to actually work and will glaze them quickly with the incorrect oil. (Motorcraft do an add pack to restore the tranny if this happens)

[Reign_Maker]

I was given 2 quarts of the Gm stuff... Before I dumped it in, I wanted to ask...

I used to have royal purple in there, and it helped alot... I was having trouble at times from 2nd to 3rd... After RP, no more trouble... Should I just go with RP again or what would you guys recommend for the high hp/heat this tranny will take?

Jdub, Im gunna read that thread you posted, thanks...

EDIT: SyncroMax is made by royal purple? So not a good idea to put it in there?

[jdub]

Red Line MT-90.

[Reign_Maker]

Ok, I just read that thread, awesome info... Right now, my tranny is BONE dry, save for any assembly lube they used... So, I want to make sure that what I put in it is the right choice... After reading that thread, it made perfect sense why my shift got smoother... The RP... When I picked up my tranny after the rebuild, the tech told me my tranny looked great on the inside, just a tad bit of wear on the 2nd gear syncros... Im sure that was what was giving me problems, and the RP just made it "slip" easier... Im gunna look into the RedLine...

Thanks again Jdub...

[hock2k5]

Red Line MT-90.


Just picked up 4qts of that myself.

Hope it will smoothen out shifts a bit. :biglaugh:

[marc3]

in my offroad suzuki sidekick, they recommend the syncromesh even though i had always put 75w90 in it. last year when i had the t-cae rebuild with some lower gears, they said if you want it to be guarenteed, you must use this.

i did about half a km , before i dumped it, the gears were screaching and whining. i put the 75w90 that came with the calmini gears , and the screeching went away. truck goes very well without the syncromesh.
it is too lite!!

[wardog]

+1 on the REDLINE MT90 really good stuff its on my tranny and 75-90w on lsd :evil2:

[Reign_Maker]

+1 on the REDLINE MT90 really good stuff its on my tranny and 75-90w on lsd :evil2:Is this what you guys are talking about using? http://store.summitracing.com/partdetail.asp?autofilter=1&part=RED%2D50304&N=700+308712+115&autoview=sku Wardog, it says its 75-90w for the tranny... Is this ok to use in the tranny AND diff?

Oh, and before I buy it, how many quarts do I need for the tranny? The lsd?

Thanks...

[jdub]

That link is to MT-90...use it in the tranny.

Use this in the LSD...it contains the friction modifiers it needs:
http://store.summitracing.com/partdetail.asp?autofilter=1&part=RED%2D57904&N=700+400236+115&autoview=sku

They are different...Re-read the link in Post #5

Here's the service specs ;)
http://www.cygnusx1.net/supra/Library/TSRM/MK3/manual.aspx?Section=A&P=35

[starscream5000]

The 75W-90NS is a gear lube for the R154 also correct? Supposed to be a little less effective than the MT90 right?

[jdub]

RL 75W-90NS will work in a R154...it does not contain the friction modifier. MT90 is a bit better IMO...it's formulated for a tranny.

[Reign_Maker]

Thanks for the advice Jdub, I just received my 4 quarts from Summit... I cant wait to see how well she shifts...

Any thoughts on Mobile 1 synth for the new motor? I know initial break in should be done with convetional motor oil... But I have 9 quarts given to me of Mobile 1 for after break in... Yay? Nay?

[jdub]

Read post #11:
http://www.supramania.com/forums/showthread.php?t=38768

What Mobil 1 do you have? And what is the weight/grade?

[MDCmotorsports]

I say nay on the break in Jake. Ive always gone the first 1000 miles on straight 30w.

Then switched over to synthetic.

[jdub]

But I have 9 quarts given to me of Mobile 1 for after break in... Yay? Nay?

Pretty sure Jake means after he breaks the motor in ;)

[Reign_Maker]

Read post #11:
http://www.supramania.com/forums/showthread.php?t=38768

What Mobil 1 do you have? And what is the weight/grade?
Read this, read that, yur always makin me read stuff, lol... Ok, I'll read it and get back to ya...

And yeah, Jon, the synthetic is for after the break in... :icon_bigg