6T70 Sun Shell 2011, used and ready to install. Fits the 6T70. Ships fast from the USA.
When a 6T70 loses reverse, 3rd and 5th at the same time, most people blame the 3-5-Reverse waved plate, and usually they are right. Sometimes the teardown shows something else: a sun shell with a cracked or separated weld. This used GM sun shell came from a 2011 6T70 and is for owners and shops who have found that shell broken, its splines worn, or its gear teeth damaged by debris, in a Chevrolet Equinox, Malibu, Impala, Traverse or one of the other GM front-drive models built around this transaxle.
The 6T70 makes its six speeds with three simple gearsets and five clutches, shifting clutch to clutch under TCM control. A sun shell is the thin, welded drum that carries torque from a clutch into a sun gear, so the gear can be driven or held from outside the gearset. The windows in the shell let fluid through and the welded joint takes the full load of each apply. ATRA's 6T70 seminar lists a broken shell weld under the same complaint as the waved plate, no reverse, 3rd or 5th with P0776, P2723 or P2715 possible, which are the ranges that use the 3-5-Reverse clutch. ATRA also notes that a new shell comes with the number 3 thrust bearing, which tells you that bearing should be replaced whenever the shell is.
ATRA's first step is to unplug the transmission. In failsafe the unit should give you reverse; if reverse engages that way, the problem is electrical or hydraulic and the shell is not the cause. If reverse is still missing, the next suspects are the waved plate, the shell and the case cover hub rings, and the unit has to come apart. Our 6T70 common problems guide covers each of these, and the Equinox shift problems guide explains how to separate a mechanical failure from shudder, harsh 1-2 and adapt complaints that do not need hard parts.
This shell is listed for the 2011 6T70. ATRA says the no reverse, 3rd or 5th failure mainly hit transmissions built before the 2010 model year, so a 2011 part belongs to the later Gen 1 production, before the 2013 Gen 2 control update. The 6T70 and 6T75 share the same basic layout, but a separate 2011 6T75 sun shell is listed for heavy-duty units. Compare the spline count, tooth count and weld area with your old shell, check the RPO code (MH2 or MH4 for the 6T70, per ATRA), or send us your year and VIN. Browse more 2011-era parts on the 6T70 model page.
| Fits | 6T70 2011 |
| Part type | Sun Shell |
| Condition | Used |
| Brand | GM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Both cause no reverse, 3rd or 5th, so you only know for sure on teardown. A broken weld or separated shell is visible once the gear train is out; a waved plate failure leaves plate pieces in the clutch pack. Replace the waved plate with the updated part either way.
Yes. ATRA notes that a new shell comes with the number 3 thrust bearing, so install a fresh one with this used shell rather than reusing the old bearing.
Do not assume it will. Many 2013 and later units received GM's Gen 2 update. Compare splines and tooth count with your old shell or send us your VIN to check.
They are listed separately. Buy the one that matches your RPO code and compare it to your old part before installation.
Fill with Dexron VI, check the level hot, clear codes and complete a drive learn so the TCM adapts the 3-5-Reverse clutch.
