i dont know where to get the syncromesh but to overfill it by a quart you have to take the shift tower off to put it in overfill

 

No. Manual trannys need manual transmission lube (MTL). Ever since the synchromesh-type fluids appeared on the scene (such as the GM Synchromesh fluid), drivers have had better shifting due to better synchro engagement, attributed to the specialized friction modifier used in these lubes. This specialized friction modifier is better for metallic and composite synchros in terms of shifting and life.

Manual Transmission fluids use a different friction modifier specifically designed for synchro engagement, a modifier that does NOT contain the same chemical compounds as do differential lubes.

A synchromesh fluid usually refers to a specialized fluid that contains special friction modification additives for transmissions that use mechanical synchronizer assemblies; those synchronizer assemblies may be made of carbon fiber composites, sintered metal.

You also have to consider the viscosity of the fluid that the transmission was designed for. The spectrum now ranges from ATF to 75W90 viscosities and therefore a synchromesh GL4 Manual Transmission Lubricant (MTL) can be any viscosity from 7.0 cSt (ATF equivalent viscosity) to a 75W90 type viscosity of approx. 14.5 cSt, and contains special friction modification additives for synchronizer assembly engagement with brass/bronze, or steel-steel materials.

Current MTL GL4 viscosites are:

1. ATF Series - Type; 6.5 to 8.5 cSt (Equivalent ATF viscosity; Note: ATF additive package is weak compared to most GL 4's)
2. Synchromesh Series -Type; 9.3 - 9.5 cSt (such as Amsoils MTF, Texaco's MTL, Pennzoil's Synchromesh, GM and Chrysler's Synchromesh)
3. 75W85 Series-Type; 9.8 to 11.5 cSt ( Redline's MTL, RP's Synchromax LT, Nissan's MTL, Honda MTL, Castrol Syntorq LT)
4. 75W90 Series-Type; 12.8 to 14.5 cSt (Amsoil's MTG, Redline's MT-90).

MTL specific lubes were developed for manual tranny's and transaxles, and not for differentials or industrial gear boxes. A differential lube may not kill your tranny, but it is not the optimum lube for it. A diffy 75W90 (GL5) usually has a higher viscosity than does an mtl in the same advertized weight.

Is that clear as mud, now?

 

holy cow i dont understand those numbers at all

what i think i got out of that is that i can use the Amsoil MTF is that the name of the fluid? like if i go into the local napa auto parts and say i need amsoil mtf theyll know what im talking about?

sorry for making it confusing nadirpoint but you sound like a genius with all this lubrication stuff ive noticed in several threads. i know about as much as chemical compounds in lubricant as ford does about building an auto transmission

 

what exactly does overfilling the getrag do for it?

 

so then why do 90% of people use and recomend a good 5w-30 synthetic instead of the MTL and more than 60% of maunusl tranys use ATF as per the maunual

overfilling the rag helps it lube better cool better shift better there is no downside to overfilling the rag

 

Because ignorance is bliss. Synchromesh fluids were still in development when these vehicles rolled off the assembly line, so Ma Mopar wrote down in the manual whatever would work best that was available at the time. Some people just seem to be stuck in time warps, I suppose.

Uh yeah, right. And 70% of all statistics are purely concocted rubbish. The manuals I'm talking about were printed around 17 years ago.

Overfilling allows lube to get to the front bearings in this tallish tranny that is canted somewhat rearwards in the Dodge Cummins configuration.

 

Exactly. just because it was the thing to do twenty years ago doesnt mean its still the best thing today. Wonderfull world of technology.

 

the nv4500 swap is the only way to go if you like your truck to pull well,i have spent $ 4000 so far

 

Was that $4k in 5th gear nut repairs, $4k in Syntorq fluid, or both together total so far?

 

and input shafts, i got a friend - steve with a 600hp 14v (1999) on his 4th tranny, snaped the input shaft clean off.(too many brake stands) and i think you can pull just fine with a rag.
for the record i have gear oil in mine may soon be adopting nadirpoints new technology.

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just a thought if you wanna see me shift my truck come on down to lebanon i can raeally jam the gears