Straight edge and gauge bar for measuring intermediate shaft end play on a 48RE so you can select the right spacer before final assembly.
If you are rebuilding the overdrive unit on a 48RE behind a 5.9L Cummins, or on a 46RE or 42RE from the same family, there is one measurement you cannot eyeball: the intermediate shaft spacer. This set is the straight edge and gauge bar that do the job of Chrysler special tools Miller 6311 and 6312. With them and a dial caliper you get a real number off the bench, and that number tells you which selective spacer goes in before the overdrive unit is bolted back onto the case.
The RE transmissions carry their overdrive section in a separate housing at the back of the case, with its own planetary, overdrive clutch, direct clutch hub and output shaft. Chrysler's factory procedure for the RE family stands the overdrive unit upright with the output shaft unloaded and the internal parts pushed rearward. The gauge bar (the 6312 piece, which the manual calls the gauge alignment tool) slides down through the sun gear and the planetary and into the pilot bushing in the output shaft until it bottoms on the planetary shoulder. The straight edge (the 6311 piece) lies across the face of the overdrive case. You then drop the depth rod of a dial caliper through the slot in the straight edge until it touches the top of the gauge bar, lock it, and read the distance. That reading goes against the spacer chart in the service manual, and the chart gives the spacer thickness.
The same straight edge is used again for the next step in the manual: measuring down to the clutch hub thrust bearing seat at four points 90 degrees apart and averaging them to pick the overdrive piston thrust plate. One tool, two selective parts.
If the overdrive unit is coming apart, you need it. Any time the planetary, output shaft, direct clutch hub, overdrive clutch or the thrust parts are replaced, the old spacer is no longer guaranteed to be correct. Before you commit to a teardown, work through the failure points in our 48RE Cummins transmission problems guide and the Ram 2500 Cummins 48RE problems guide so you know what the overdrive section is likely to show you.
The tool is listed for the 42RE, 46RE, 48RE, NAG1 and NV5600 from 1998 up, with vehicle coverage of Ram LD and DH trucks 2009-2021; Dodge Challenger, Charger, Durango and Magnum 2006-2014; and Jeep Wrangler JK 2011-2018 plus Grand Cherokee, Liberty and Patriot 2006-2014. For the 48RE specifically, that means the overdrive unit out of a 2003-2007 Ram 2500 or 3500 with the 5.9L Cummins. A measuring tool does not wear a part number on your truck, so the real check is the procedure: if your service manual calls for tools 6311 and 6312, this set is the match. It does not replace the dial caliper (Chrysler's C-4962 or any equivalent depth caliper), which you supply. Everything else we carry for this unit is on the 48RE parts page.
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Together with a dial caliper they measure intermediate shaft end play in the overdrive unit. The reading is compared with the spacer chart in the service manual to choose the selective spacer. The straight edge is also used to measure for the overdrive piston thrust plate.
No. The set is the straight edge and the gauge bar. You need a dial or digital caliper with a depth rod, which is what the factory procedure uses with these tools.
The listing covers the 42RE, 46RE and 48RE, and the RE family uses the same overdrive unit spacer selection procedure. If your service manual calls for tools 6311 and 6312, this set does that job.
If the overdrive unit is apart and any part in the stack has changed, measure. Frictions, thrust parts, a planetary or a hub can all shift the result, and the old spacer may no longer be correct.
Too thin leaves excess end play, which shows up as clunks and gear noise. Too thick preloads the thrust bearings and washers. Either one can bring a fresh rebuild back.
