Looking at buying My First Diesel

[cat3176]

Hey everyone. Im looking at buying a 1993 Dodge D350 w/ cummins 12v and a getrag 5 speed. Does anyone have any suggestions on performance parts? Ive got a few ideas but am still new to the diesel side. So far all I know that has been done to it is they turned the pump up and cut the muffler off. I heard a few bad things about the getrag 5 speed, can anybody put some facts out there on this for me. Thanks

 

[Whit]

this info from Dan the gear man


When off-warranty 1989-'93 Dodge trucks with blown Getrags started coming in our shop in 1996, it was obvious a simple rebuild wasn't going to be the solution. These trucks came with a 7 year-70,000 mile warranty which must have caused Dodge a fortune in transmission warranty claims because nearly 75% of these trucks we have seen had one to four transmissions replaced under warranty. With that kind of track record, you know the factory part just isn't up to the job. In addition, many of the parts required were not available and those that were had a gold-plated price tag.

Our inspection of failed Getrags revealed that excessive heat and insufficient lubrication were causing the transmissions to literally self destruct from bearing failure. At that point, I started doing research on the Getrag design and service procedures, looking for possible ways to modify it for better lubrication and cooler operation. My research showed the basic problem of premature failure with the gearbox was probably a combination of premature pilot bearing failure, use, bearing preload, basic design, type of lubricant and the power of the Turbo Diesel. We considered installing an external oil cooler and using synthetic lubricant. Our conclusion: while an oil cooler might prolong transmission life, we would still see bearing failures due to the modest size of the preloaded bearings; the use of a single tapered roller bearing on the front of the main shaft to handle radial, lateral and thrust loads; and drivers who would power up hills with heavy loads in fifth gear.

The only contributing factor to Getrag failures that is easy to remedy is the clutch pilot bushing. Why Dodge used a pilot bushing in the first place is a mystery, but a simple flywheel modification that any competent machine shop can perform permits the installation of a heavy duty, sealed ball pilot bearing.

 

[Whit]

here is some more good stuff from Cummins Express

Dodge 4x4 Cummins Diesel Automatic to Manual Conversion Information

NV4500 and NV5600 Conversions on 1989-2002 Dodge 4x4 originally equipped with automatic transmissions. This is not quite so simple as it sounds because of transfer case incompatibility. For all trucks with NP205 transfer cases and most newer models with NP241 transfer cases, the transfer case input shaft is only a 23 spline and the manual transmissions have a 29 spline output shaft.

With the NV4500, you can install a Torque King 23 spline output shaft although this is not as strong as the 29 spline shaft. The best option is to install a 29 spline input shaft in the transfer case. This is pretty straight forward with the NP241, however it is not so simple with the NP205 found in 1989-1993 trucks. For these models, the bores for the input bearing and transfer case adapter must be enlarged by a machine shop to accept a larger bearing and seal, plus you will need to get a 29 spline female coupler shaft to join the transmission output shaft to the transfer case input shaft. Our QK2001 has the pieces required to convert your 23 spline NP205 to 29 spline.

In addition to the transfer case modifications, you will need a new flywheel, flywheel bolts, clutch assembly, clutch bolts, bellhousing (NV4500 only), clutch fork, clutch hydraulic system, clutch pedal, brake pedal, transmission mount, transfer case linkage, and hardware. You will need to cut the cab floor/carpet to accept the shift tower, rewire the backup lights and cruise control. In most cases you will also need to have driveline modifications done. Some models will also require crossmember relocation. NV5600 conversions in 1989-1993 trucks will also need a new flywheel housing. and custom starter as will first gen trucks using 1994 and newer bellhousings.

Unless you have a donor truck to cannibalize most or all the parts from, this is one expensive conversion. NV4500 conversions will run $6,000-$7,000 for all new parts and NV5600 conversions are even more expensive.

 

[cat3176]

Thanks for the really good info on the trans and the conversions. It is very helpful. Thanks