what awd tranny is this?

[ed1380]

picked it up at the junk yard. my guess is 1g because of the mechanical speedo

any help would be appreciated

Thanks

 

[etay89]

that seems like a 2g awd tranny

 

[JusMX141]

W5M33-2-NPXV = 91-94 T/E/L AWD 5-speed 6/90-2/94

 

[twicks69]

Justin is correct it is a 1g AWD transmission. The VIN code further down the bellhousing will tell you a year, 10th digit is a letter, referring to the year it was built.

Tim Zimmer via Evo Phone

 

[ed1380]

I remember reading something about the 1g having a very favorable gearset. Is that right or am I confusing something

 

[92EagleAWD]

i dont think its much different than a 2g if at all.

 

[ed1380]

Justin is correct it is a 1g AWD transmission. The VIN code further down the bellhousing will tell you a year, 10th digit is a letter, referring to the year it was built.

Tim Zimmer via Evo Phone

I finally had the chance to look and it's a 91. What are the chances that it'll have the larger 3rd and is it possible to tell without taking it apart? And what else do you have to swap besides these parts? And when you said 3rd and 4th needs to be replaced. Is that just the gear on the input shaft, or also the matching gear on the intermediate shaft?

The weakest parts in your 95-99 transmission (torque capacity wise) are the 3rd/4th hub and slider assembly and the stock center differential.

The 3rd/4th hub and slider assembly likes to either implode the hub or explode the slider after ~400TQ. It is only a matter of time if you do any sort of load in 3rd or 4th with this kind of torque. The fix to this is to use the late 91-early 92 3rd/4th gearset conversion which utilizes a late 91-early 92 3rd gear, 4th gear, hub and slider/keys/springs, shift fork and shift rail/rail end. You can always swap out the following parts for Evo 1/2/3 parts: 3rd gear, 4th gear, 3/4 shift fork, and 3/4 shift rail/rail end.

The Evo 1/2 OEM transmissions utilized single synchro versions of the Evo 3 3rd/4th gears that had the same gear ratio. The Evo 1/2/3 had a mixture of shift forks utilized from the factory including solid steel ones without shift pads, with plastic shift pads of varying sizes. The best ones were the Evo 1 solid steel shift forks, but they are non-existent unless you find an Evo 1 used transmission. The 1990-early 1992 transmissions used an aluminum version of this 3rd/4th shift fork design for wear life, at the cost of breaking under very hard shifting. The Evo 1/2 also used forged shift rail ends on all 1/2, 3/4 and 5/Rev shift rails and had to be used as a matched set with the Evo 1/2/3 shift selector or you needed to clearance the shift selector and rail ends to work properly. The Evo 1/2/3 shift rail ends worked best with late 1991-1999 shift selectors and still sometimes require a bit of clearance work to function properly. The late 1991-early 1992 3rd/4th shift rail had a heat-treated rail end that was stronger in design than the 1990-mid 1991 but is not interchangable unless you do a shift selector conversion and complete shift rail conversion with other parts involved. The late 1991-early 1992 and Evo 1/2/3 3rd/4th shift rail can be used in late 1991-1999 transmissions when used with a matching gearset from an Evo 1/2/3 or late 1991-early 1992 DSM.

The 1990-early 1992 DSM and Evo 1/2 utilize the same diameter 3rd/4th synchros and hub/slider assembly whereas the mid 1992-1999 used a larger diameter synchro with a substantially thinner and inherently weaker design hub and slider assembly. The Evo 3 used a very thick slider and the same hub as the Evo 1/2 and early DSM stuff and had a bit more clearance for oiling to the 4th gear synchro as the Evo 3 double synchro 3rd/4th assembly needed a bit more space to get proper oiling. You can use an Evo 3 3rd/4th double synchro gearset with a late 1991-early 1992 3rd/4th hub and slider but you will need to have the 4th gear and 3rd/4th hub machined for additional clearance and oiling, otherwise you will end up with a torched 4th gear synchro almost immediately due to lack of oiling.

The Evo 1/2/3 3rd/4th gears are "stronger" than the late 1991-early 1992 DSM gears only on the fact that they have a lower tooth count and more meat on the root radius of the gear teeth. The gear tooth angle is still the same as the late 1991-early 1992 DSM gears.

The center differential is the other weak link in all DSM's and Evo 1/2/3 at around the same power levels as the 3rd/4th hub and slider before the two spider gears either explode or the cross-shaft shatters. Common wear items that should be replaced are the spider gear shims, the lower pinion gear brass shim and the upper pinion gear oiling washer. The upper pinion gear oiling washer has a tendency of wearing out and then microwelding itself to the upper pinion gear and center diff cover causing catastrophic failure to the differential or at least the upper pinion gear and center diff cover. If the wear is excessive it will also place the spider gears and lower pinion gears into risk of failure from excessive gear lash, resulting in spider gear washer failure (and case damage) or splitting the lower pinion gear brass oiling shim. If the pinion gearset gets damaged in any way, you need to replace the entire pinion gearset as they are not available as separate pieces from Mitsubishi. I would recommend having the center differential serviced and upgraded to a minimum of a Torrington bearing upgrade for the upper pinion gear by having the center diff cover machined for the additional clearance required to run a Torrington bearing and oiling shim, and replace the spider gear washers and lower pinion gear brass oiling shim as a longevity upgrade. The 2-spider diff can only hold so much power and abuse before it fails, so upgrading to a 4-spider center diff is a must if you want to keep streetability while having increased torque capacity. Most vendors just machine down the stock crappy cross-shaft to incorporate 4 spider gears while TRE and myself have designs that utilize a better material custom machined 4-spider cross shaft that will be able to capacitate substantially more power without failure. To do the modification for a 4-spider center differential upgrade, you will need an additional pinion gearset (two more spider gears required), a 4-spider cross-shaft and a machined center differential housing to fit the 4 spider gears. The benefit to a 4-spider center differential is the ability to not sacrifice streetability while increasing torque capacity without failure. The benefit of a welded center differential is taking the spider gears and stock cross-shaft out of the equation and having a beefy "locked" differential at the sacrifice of streetability as the welded differential will bind the front/rear wheels during turning or unequal wheel speed causing substantially more wear on your other drivetrain parts.

A blown or damaged center diff and a welded center diff will put alot more wear on the output shaft splines and transfer case input sleeve splines causing premature failure of the parts. A blown or damaged center diff will also burn out your viscous coupler.

Other common wear items that should be replaced are the input shaft and intermediate shaft tapered roller bearings, 1/2 and 3/4 shift forks, 1/2 and 3/4 hub and slider assemblies, and synchros. 1st and 2nd gears also get worn out over time the most as they are the most-used gears for street cars. The dog engagement teeth for the synchros to engage with the associated slider will cause gear popout or grinding while engaging the gear; it is not just as simple as a worn synchro replacement if the gear is grinding in almost every circumstance. Gear popout is common with worn out gear dog engagement teeth or worn out slider engagement teeth. Gear grinding at any rpm is normally a worn out hub and slider or a severely worn synchro, while gear grinding at higher rpm is normally a worn out synchro with the potential for a worn out hub and slider from continuous grinding gear engagement.

Shifting issues can either be from worn out shift forks, worn out hub/sliders, worn out gear dog engagement teeth, worn out hub/slider keys, broken or popped out hub/slider springs, or excessive end play on the input and/or intermediate shafts.

With that said, it is very important to replace the input shaft and intermediate shaft tapered roller bearings on both ends of the shafts and then properly preloading the two shafts to tighter-than-OEM-spec tolerances. Each builder uses their own specs based upon power levels that the transmission will see. By increasing the preload on the input shaft you can also have the transmission slow down itself a bit to aid in high rpm shifting taking some of the load off the clutch and synchros to shift into gear as the input shaft will use friction to slow itself down a bit. By increasing the preload on the intermediate shaft you can allow for less deflection of the intermediate shaft under load or under increased temperatures which would cause case expansion resulting in the reduction of preload under increased temperature.

If you intend on doing alot of continuous load use in 3rd or 4th, it is imperative that you either service your transmission regularly, replace the 3rd/4th gearset/fork/rail for the heavy duty late 1991-early 1992 or Evo 1/2/3 parts along with tossing the aluminum shift fork as the expansion of aluminum will be greater than the steel parts under increased temperature resulting in substantially increasing the friction and potential binding of the 3rd/4th shift fork on the engagement surface of the 3rd/4th slider. This will result in permanent shifting issues and the potential for failure of the hub/slider or shift fork. If you are making ALOT of power or doing continuous load even with the heavier-duty 3rd/4th stuff, it would be wise to have an external transmission cooler fabricated up and have the return line spray onto the 3rd/4th hub and slider and 4th gear assembly to aide in cooling the parts down and maintaining lubrication to high-stress parts.



So....with that said, you can either take your chances with a stock transmission, or you can have it upgraded to suit your needs while having it gone through and inspected so you can replace the worn out parts before there is a failure that can easily cost alot more money than a rebuild.

Personally, if I was building it, I would recommend a stage 3 transmission that uses a custom chromoly steel 4-spider cross-shaft center differential, and a heavy-duty 3rd/4th gearset. If you are intending on shifting normal and not trying to put your hand through the stereo on 3rd gear shifts, go with the HD aluminum shift fork and have the 3rd/4th shift rail machined to incorporate a second roll pin (double-pinned 3rd/4th fork). If you don't know how to shift gently, then I would recommend getting an Evo 3 steel shift fork AND learning how to shift softer -- your transmission will last longer.

Along with all these things, don't forget to replace the clutch fork, clutch fork pivot ball, throwout bearing and have a properly functioning/bled/adjusted clutch hydraulic system to ensure that the clutch is properly disengaging, otherwise you will just put more wear on your transmission resulting in premature failure of more parts.


I hope that this long-winded tech response will give you more background into the workings of the AWD transmission so you make an informed decision in your purchase of an upgraded transmission. Like I said, you are playing with fire using a stock used transmission if it is not up to spec; especially if the bearings are worn on the input and intermediate shaft or the oiling shims in the center differential. It will only be a matter of when it fails, not if it fails.

I search alot

 

[twicks69]

In this circumstance, you would either tell by the shape of the 5th gear cover and 5th gear assembly, the markings on the 5th gear teeth (would have three notches), and then confirm by opening up and disassembling.

 

[ed1380]

I got a picture of the cover.

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sent from my Galaxy S while street racing and doing awd burnouts