Another question that we often get regards the fitment of the Dodge Ram 2500 and 3500 front driveshaft. Most customers want to know if certain shafts that we offer will fit their manual transmission or automatic transmission trucks. As with the Ford F-250/350 front shafts, any shaft for any model will fit any other provided that the length and the connection point at the front differential is the same. When it comes to Dodge Ram front drive shafts, the shaft uses either the serrated AAM flange, the Dodge 7290 universal joint (also known as the Dodge big u-joint), or the Spicer style 1330 universal joint.
The constant velocity (CV) flange is the same on all models from the mid 90's to at least 2012. This flange uses a 3.125" female pilot with a 4.250" bolt circle diameter. This is the four-bolt flange that is part of the CV assembly that bolts to the transfer case.
Note: To get the bolt circle diameter of your flange, measure center of bolt hole to center of bolt hole diagonally.
Prior to 2003, both front drive shafts for the Ram 2500 and 3500 used drive shafts that attached to the front differential via a pinion yoke that cradles the u-joint. This u-joint is typically the 7290 series or the 1330 series.
Dodge 7290 Big U-joint
The 7290 uses inside clips/snap rings that clip on to the actual universal joint bearing caps and keep the u-joint centered inside of the yoke ears. The bearing cap diameter is 1.126" and inside lock-up (where the clips/snap rings make contact with the inside of the yoke ears) measurement is 2.622"
Spicer-style 1330 Series U-joint
The Spicer-style 1330 u-joint uses outside clips/snap rings that fit into machined grooves in the yoke. These snap rings sit on the 'outisde' of the u-joint bearing caps, keeping the u-joint centered in the yoke. The bearing cap diameter is 1.062" and the width (with caps in place) of the u-joint is 3.622".
Dodge Ram 2500 Front Drive Shaft Measurement/Identification (~1997 through ~mid-2004)
From about 1997 to around mid-2004, the Dodge Ram 2500 front drive shafts used u-joints as the connection point at the front differential. That is, there was no serrated, four-bolt flange. At this point, you'll want to determine which type of u-joint your drivehsaft uses (see above).
To determine your measurement, simply measure from the flat flange surface at the transfer case to the center of the front u-joint under the truck (with the vehicle at ride height). This gives us the running/installed length measurement. If you've already removed your front drive shaft, then you'll want to collapse the drive shaft all the way and take the same measurement. This give us the flange to center, collapsed length measurement. If the shaft is removed, measuring like this is more accurate since it is easier to fully collapse the shaft as opposed to trying to guess the running length. The accordion-style boot makes it difficult to determine the midway travel position.
If your Dodge Ram 2500 is mid-2004 or newer, simply follow the instructions for the Ram 3500 with serrated flange for measurement instructions.
Dodge Ram 3500 Front Drive Shaft Measurement (2003 through at least 2012)
From about 2003 to at least 2012, the Dodge Ram 3500 front drive shaft has used the AAM serrated flange as it's front differential connection point. These are very distinctive and easy to identify. Here is an example of what it looks like:
These driveshafts are probably the simplest to measure since we're essentially just measuring from flange face to flange fact. To determine your measurement, place the flat of your tape measure on either flange surface and measure to the other flange surface with the truck at ride height. This gives us our flange to flange, running/installed length measurement:
If you've already removed the front driveshaft, then collapse it all the way and measure flange to flange:
A few tips:
If your drive shaft is missing, you can still determine both the running/installed length measurement as well as the universal joint type. Since the 7290 u-joint uses inside clips/snap rings, the front differential pinion yoke will not have machined tabs to keep the u-joint centered. This is the job of the c-clips/snap rings that clip on to the u-joint. If your front shaft uses 1330 series u-joints there will be machined tabs in place to keep the u-joint centered since it has no way of doing this on its own.
Likewise for the newer models with the serrated flange: if your shaft is missing entirely, just measure from flange surface to flange surface under the truck. This measurement is normally around 32", 34 3/4", or 38". Let us know which measurement you came up with and we can direct you to the correct front drive shaft for your Dodge Ram 2500 or 3500. I hope this helps you guys out. If you have any questions, feel free to contact us at either firstname.lastname@example.org or call (501) 626-0570 and we'll be glad to answer any questions you may have. Have a great day!
Justin from ProShaft