48RE Sun Shell, used and ready to install. Fits the 48RE. Ships fast from the USA.
If your Ram 2500 or 3500 with the 48RE still pulls away in 1st but loses 2nd, 3rd and reverse all at once, or a teardown turned up a cracked shell, chewed-out lug slots or flakes of steel in the pan, the sun gear driving shell is the part you are looking for. This is a used factory 48RE driving shell, pulled from a running transmission and ready to go back into a rebuild, so you are not paying new-part money for a stamped steel piece that rarely wears out unless something else broke first.
The 48RE main box is a Chrysler Simpson geartrain: two planetary sets that share one sun gear. That sun gear rides inside the driving shell, held by a snap ring on each side with a thrust plate on the back face. The front (direct) clutch retainer has drive lugs that drop into the slots around the rim of the shell, and the front band wraps that same retainer. So the shell is the only link between the sun gear and the parts that drive it or hold it. When the front band clamps, the shell holds the sun gear still for 2nd. When the front clutch applies, it turns the sun gear for 3rd and for reverse. Because 4th is the overdrive unit added on top of 3rd, a failed shell takes out the top gears too.
The RE family has no input speed sensor, so a broken shell usually does not set its own trouble code. The diagnosis comes from which ranges are lost, not from a scan tool.
Check the fluid hot in Neutral first, because low fluid alone can cause slipping in every range. If 1st holds but reverse and the upper gears are gone, a pressure test at the front servo and front clutch taps tells you whether the hydraulics are applying. Good pressure with no engagement points at a mechanical break, and the shell is a prime suspect. Our 48RE Cummins failure points guide covers what breaks in these units under diesel torque, and the 48RE pump failure guide explains how to tell pump-related pressure loss from a hard-part failure.
This listing is a 48RE sun shell carrying the A618 family reference that Chrysler used for the 47RE and 48RE. The 48RE went behind the 5.9L Cummins in 2003 through 2007 Ram 2500 and 3500 trucks. No production year is marked on this listing, so lay your old shell next to the photo and compare the lug slot count, overall depth and hub before installing. The photo shows the shell with a sun gear seated in the hub; if you need the gear and the shell together, message us before ordering to confirm. If you are unsure, send your year and VIN and we will check it. We also stock a 2005 48RE sun shell, and everything else for the unit is on the 48RE parts page.
| Fits | 48RE |
| Part type | Sun Shell |
| Condition | Used |
| Brand | OEM |
| Reference | A618 |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
It is a factory 48RE shell, and the 48RE was used behind the 5.9L Cummins in 2003-2007 Ram 2500 and 3500 trucks. No year is marked on this listing, so compare it to your old shell or send your year and VIN and we will confirm before it ships.
The photo shows the shell with a sun gear in the hub. If you need both pieces, message us before ordering and we will confirm exactly what is in the box.
The classic pattern is 1st still working while 2nd, 3rd and reverse slip or disappear, usually with steel debris in the pan. Overdrive goes too, because 4th depends on 3rd working in the main box.
New snap rings every time, plus the thrust plate and tabbed thrust washer if they are scored. Check the sun gear bushings and both planetary carriers, and replace the front band and front clutch frictions if they took damage.
Mopar ATF+4. Chrysler lists roughly 14-16 liters for an overhaul fill, depending on the cooler, so fill, run it and check the level hot in Neutral.
