GM turbo 350 question--stock trans

FED 387 · 01-21-2011, 01:19 PM

My sons turbo 350 trans(totally stock trans not hopped up in anyway) was leaking fluid out the input shaft/front pump cover area---not around the gasket or edges but thru the hole in the middle---he took it apart and found that the bushing was messed up so he went to the auto parts guy and got a replacement along with the gasket and the seal---none of this is original GM parts or available from GM any longer ----he installed everything and now he cannot get the convertor to slide back on the bushing is in the way--anyone got any ideas what the problem is??? thanx in advance Comp

Tom Goldman · 01-21-2011, 01:26 PM

The front pump bushing is a split bushing and is fussy about alignment.
even with the proper driver even the slighest misalignment will tighten the bushing to the point that the converter will not enter.
Also inspect the bushing for burrs or distortion at the edges. ....Some parts house bushings do not have much of a champher at the edge and burr easily when installed.
Also want to make sure the pump gear is not in backwards, as the drive tangs are offset in the gear.

Alan Roehrich · 01-21-2011, 01:29 PM

You need to take the pump out, take it apart, slip the front cover over the converter hub, and bump it on the outer edges with your hands. At that point, the cover should spin freely on the converter hub when the bushing and seal are lubricated with petroleum jelly. Then, reassemble the pump, while it is on/in the converter, with a hose clamp around the outside of the pump, and a couple of 5/16" pushrods are in the alignment holes in the outer edge of the pump. Use petroleum jelly and ATF as assembly lube for the bushing, seal, gears, and housing. Use petroleum jelly as assembly lube on the outer edge of the pump where the o-ring is, as well as on the input shaft, the case, and the sealing rings. Use it to hold the washer on the back of the pump, and the gasket in the case. Use a long Phillips screw driver to align the pump to the case.

FED 387 · 01-21-2011, 02:14 PM

thanx guys will pass along the info on both ideas---probably the bushing has a burr on it or no chamfer to allow the conv to slide on freely--is it possible to have the bushing in backwards or does it matter which way to go??? thanx again ----comp

Alan Roehrich · 01-21-2011, 02:22 PM

The bushing is not directional. However, it should be driven in from the gear side.

01-21-2011, 01:19 PM	#1
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,419 Likes: 525 Liked 332 Times in 180 Posts	GM turbo 350 question--stock trans My sons turbo 350 trans(totally stock trans not hopped up in anyway) was leaking fluid out the input shaft/front pump cover area---not around the gasket or edges but thru the hole in the middle---he took it apart and found that the bushing was messed up so he went to the auto parts guy and got a replacement along with the gasket and the seal---none of this is original GM parts or available from GM any longer ----he installed everything and now he cannot get the convertor to slide back on the bushing is in the way--anyone got any ideas what the problem is??? thanx in advance Comp

01-21-2011, 01:26 PM	#2
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,475 Likes: 887 Liked 865 Times in 235 Posts	Re: GM turbo 350 question--stock trans The front pump bushing is a split bushing and is fussy about alignment. even with the proper driver even the slighest misalignment will tighten the bushing to the point that the converter will not enter. Also inspect the bushing for burrs or distortion at the edges. ....Some parts house bushings do not have much of a champher at the edge and burr easily when installed. Also want to make sure the pump gear is not in backwards, as the drive tangs are offset in the gear. __________________ Tom Goldman 1500 SG , 1506 STK

01-21-2011, 01:29 PM	#3
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,107 Likes: 1,564 Liked 1,797 Times in 410 Posts	Re: GM turbo 350 question--stock trans You need to take the pump out, take it apart, slip the front cover over the converter hub, and bump it on the outer edges with your hands. At that point, the cover should spin freely on the converter hub when the bushing and seal are lubricated with petroleum jelly. Then, reassemble the pump, while it is on/in the converter, with a hose clamp around the outside of the pump, and a couple of 5/16" pushrods are in the alignment holes in the outer edge of the pump. Use petroleum jelly and ATF as assembly lube for the bushing, seal, gears, and housing. Use petroleum jelly as assembly lube on the outer edge of the pump where the o-ring is, as well as on the input shaft, the case, and the sealing rings. Use it to hold the washer on the back of the pump, and the gasket in the case. Use a long Phillips screw driver to align the pump to the case. __________________ Alan Roehrich 212A G/S

01-21-2011, 02:14 PM	#4
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,419 Likes: 525 Liked 332 Times in 180 Posts	Re: GM turbo 350 question--stock trans thanx guys will pass along the info on both ideas---probably the bushing has a burr on it or no chamfer to allow the conv to slide on freely--is it possible to have the bushing in backwards or does it matter which way to go??? thanx again ----comp

01-21-2011, 02:22 PM	#5
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,107 Likes: 1,564 Liked 1,797 Times in 410 Posts	Re: GM turbo 350 question--stock trans The bushing is not directional. However, it should be driven in from the gear side. __________________ Alan Roehrich 212A G/S