Beginning with the 2004 model year and continuing to the present, Chevy Colorado, GMC Canyon and 2006-up Hummer H3 four-wheel-drive trucks have had various changes made to the 4L60-E TPD-model transmission components.
To allow for front-driveshaft clearance.
The 1-2 accumulator assembly has been elongated (Figure 1) to move it farther away from the pan rail.
The valve-body casting has had the rear corner near the pressure-control solenoid cut off (Figure 2).
The pressure-control solenoid has been rotated so the solenoid connector is closer to the valve body (Figure 3).
A new filter has been designed with an angular corner (Figure 4) to allow clearance for the newly positioned pressure-control solenoid.
The transmission oil pan has been made concave on the front-driveshaft side (Figure 5) to allow for clearance between the front driveshaft and the oil pan.
All components changed from the TPD model can fit any 4L60-E series transmission. The above-mentioned vehicles must use the TPD-model components.
- The TPD-model sump filter. . . . . . . . . . . . . 24226101
Note: Filtran has a filter available for the TPD-model 4L60-E.
While servicing a 2005-07 Chevy partial-hybrid truck (PHT), a technician tries to replace the auxiliary-pump filter (Figure 6). However, the shop finds that the filter is not available separately; it comes only with the pump from GM at a cost of $835.
The pump, made in Germany by Bosch, is sold only as a complete assembly with the filter. The auxiliary pump is necessary because when the PHT comes to a stop, the engine shuts off. The auxiliary pump keeps the forward clutch pressurized so there is no delay in taking off when the driver steps on the accelerator pedal.
The auxiliary-pump filter now is available separately from SPX Filtran.
Check with your parts distributor for availability; the SPX Filtran part number for the filter is 806741.
After overhaul there was no forward movement, yet reverse functioned normally. Various gear-ratio-error codes were present. The technician also complained that when the pump was bolted down, the geartrain was locked up.
During the overhaul procedure, the stator-support shaft was replaced; Allison calls this part a ground sleeve. The technician failed to press the shaft all the way into the pump-cover housing. This removed the end play and misaligned the C1-clutch feed holes.
Make certain the stator-support shaft is pressed all the way in (Figure 7). The C1-clutch passages are also identified in Figure 7.
Once the pump is assembled after stator-support replacement, air-check the C1 clutch to ensure that the pump-cover feed holes (Figure 8) line up with the C1-clutch-drum feed holes. The C1 feed oil travels through the clutch backfill valve through the pump cover and then between the stator-support shaft and the ring tower.
November 2011 Issue
Volume 28, No. 11
- 2004 & later GM ‘T’ truck: 4L60-E TPD-model changes
- 4L65-E M33 partial-hybrid transmission: Auxiliary-pump filter
- Allison 1000/2000 series: No forward movement
