5-sp shifting issues
 

This '89 D250 is my third Dodge Cummins, and my first with a manual transmission. The truck has only 93,000 miles on it, and the original owner said Dodge recalled it when it had
4x,xxx miles to replace transmission, clutch and pressure plate. I'm ignorant as to why the recall occurred. Anyway, having no experience with these manual transmissions, it seems that this one is pretty hard shifting - you can shift easily from 4th to 5th, but 2-3 is very slow and often will either grind or bump hard if I try to shift with what I'd consider a normal speed, and 3-4 is slow, but a bit faster than 2-3. Am I expecting too much, or is there something that needs to be done to make shifting a little faster and easier? I'll appreciate any help.

2 3 is a harder shift on mine too.

Is there a different fluid you could run for a better shift Richie? I dont know much about teh rags...

over fill by one quart and a good synthetic 5w 30

do they use 5w-30 or gear oil?

I Know the shop manual calls for 10w-30 for what its worth.

5-30 no gear oil to thick

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same idea the 5 just flows better when its cold

Synchromesh makes them shift much better. It's close to the same viscosity as 5-30 motor oil but with the necessary FM formulation to let the synchros do their job better. In any case, the Getrag does not like to shift quickly. At least half your problem is probably technique.

The recall was probably for one of the the runs that came shimmed too tight from the factory.

so 5-30 synthetic is the way to go on these huh?

Thanks for all the input; by the way, what is 'Synchromesh', and where do you get it? That is a product that I'm not familiar with. And how do you overfill the transmission by one quart?

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? :tu:

holy cow i dont understand those numbers at all:argh::argh::argh:

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:tttt:

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. :rolleyes2:

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.

getray is junk,
 

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? :lol88:

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:w2: 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