Can anyone help me identify which crankshaft my 348 has? I'm converting to stick and need to know which pilot bushing I need. Pictures of both the Powerglide and Turboglide crankshaft ends would be nice. The block has an 'HA' code, so I'm thinking I do have the Turboglide crank. The large bore extends about 1" into the crankshaft and then tapers down into the smaller bore for another inch or less.
Turboglide/Powerglide crankshaft?
- Thread starter WSSmolick
- Start date
The cranks should be the same, just put the bushing in for the stick tranny.
I remember seeing a 1972 catalogue listing for the crankshaft bushing showing " 1937 to 1972 all " boy, ya gotta hand it to GM for that kind of coverage. Hard to mess that one up.
Hey Dave! Nope; still looking for that air cleaner base.
I finally got sick of the aluminum Powerglide in the '58 and yanked it out. So now I'm doing my stick conversion. The Turboglide does have it's own crankshaft. It has a large counterbore for the large pilot of its torque converter. The regular manual trans pilot bushing will not work with this crank, however, there is a pilot bushing out there specifically designed for the Turboglide crank for a stick conversion. Problem is, I can't remember what the back end of a stick/Powerglide crankshaft looks like, so I'm not positive my crank is a Turboglide's. Anyone have a pic of a rear of a Powerglide or stick shift crankshaft? Pretty please? And actually Ronnie, I think your parts book meant that the pilot bushing will fit all manual shift crankshafts, which is the same as a Powerglide, but is machined for the bushing. You can't use the regular stick shift pilot bushing in a Powerglide crank straight-up; you have to lathe off a little from the OD.
I finally got sick of the aluminum Powerglide in the '58 and yanked it out. So now I'm doing my stick conversion. The Turboglide does have it's own crankshaft. It has a large counterbore for the large pilot of its torque converter. The regular manual trans pilot bushing will not work with this crank, however, there is a pilot bushing out there specifically designed for the Turboglide crank for a stick conversion. Problem is, I can't remember what the back end of a stick/Powerglide crankshaft looks like, so I'm not positive my crank is a Turboglide's. Anyone have a pic of a rear of a Powerglide or stick shift crankshaft? Pretty please? And actually Ronnie, I think your parts book meant that the pilot bushing will fit all manual shift crankshafts, which is the same as a Powerglide, but is machined for the bushing. You can't use the regular stick shift pilot bushing in a Powerglide crank straight-up; you have to lathe off a little from the OD.
pilot bearing
I was always under the impression that the automatic transmissions did not have a pilot bearing . The cranks were drilled to allow the nub of the converter to fit inside all of the combinations Chevy produced. The power shaft of the standard transmissions need a pilot bearing to reduce the size down to size of the power shafts. of the manual transmissions. Just my thoughts.
I was always under the impression that the automatic transmissions did not have a pilot bearing . The cranks were drilled to allow the nub of the converter to fit inside all of the combinations Chevy produced. The power shaft of the standard transmissions need a pilot bearing to reduce the size down to size of the power shafts. of the manual transmissions. Just my thoughts.
If what you say is true then that would be the only crank that Chevy made special. I highly doubt it until I see it. It's possible.
Wyatt, The bushing I was referring to was for manual transmissions. I have never seen one needed for any automatic. I rebuilt a 348 (coded turboglide) , a couple of years ago and I am 99% sure the customer put a powerglide behind it with no problems. His car was originally 283. I did not know the turboglide crankshaft was different than all the rest. Please let us know what you come up with that works , it might help someone else in the future.
Jester- right. The automatic trannies did not use a bushing in the crankshaft. The hub of the torque converter fit inside the counterbore of the crank. The manual transmission used an automaitc trans crankshaft that was further machined for a smoothe surface for the pilot bushing (so I wonder if they have the same part#?). If you go to install a pilot bushing into a automatic trans crankshaft, you'll have a tough time getting it in there and when you're done, the input shaft of the manual trans won't fit into the pilot bushing, unless you first shave off a little from the OD of the pilot bushing.
Ronnie- From what I understand, you can use a Powerglide with a Turboglide crank, but not a Turboglide with a Powerglide crank. The Turboglide has a larger torque converter hub. I know in both the '58 and '61 Shop Manuals, in the engine section, there is a diagram of a comparison of the torque converter mounting of the Turboglide vs. the Powerglide.You'll see how the Turboglide crank differs from the POwerglide crank. The diagram actually has a Powerglide torque converter on the Turboglide crank. And from that diagram, you'll see how a standard trans pilot bushing will not work in a Turboglide crank. But there is a special bushing out there for this scenario, which it looks like I need.
Ronnie- From what I understand, you can use a Powerglide with a Turboglide crank, but not a Turboglide with a Powerglide crank. The Turboglide has a larger torque converter hub. I know in both the '58 and '61 Shop Manuals, in the engine section, there is a diagram of a comparison of the torque converter mounting of the Turboglide vs. the Powerglide.You'll see how the Turboglide crank differs from the POwerglide crank. The diagram actually has a Powerglide torque converter on the Turboglide crank. And from that diagram, you'll see how a standard trans pilot bushing will not work in a Turboglide crank. But there is a special bushing out there for this scenario, which it looks like I need.
Wyatt, Maybe if all else fails, you could measure the inside bore of the turboglide crank and find someone who handles Dorman Products and buy the bushing by size. . It would be easy to determine the inside diamiter needed.
Ronnie,
The OD of the bushing is stepped- the rearward part is large; the forward part is small, like a regular GM pilot bushing. The large bore of the Turboglide crankshaft extends into the crank for about an inch. Where the step occurs from the large bore to the small bore is where the midpoint of the manual trans input shaft pilot would be, hence the bushing designed for the Turboglide crank is stepped.
The powerglide only has about 1/8-1/4" deep large bore (pretty much the rear of the Powerglide/manual trans crank has a lip to pilot the flywheel). I'm fairly certain I have the Turboglide crank; I just wanted to hear from those with the usual Powerglide/manual trans crank to confirm before I go and order this crazy bushing. Now about a flywheel-- I'll make that another post.
The OD of the bushing is stepped- the rearward part is large; the forward part is small, like a regular GM pilot bushing. The large bore of the Turboglide crankshaft extends into the crank for about an inch. Where the step occurs from the large bore to the small bore is where the midpoint of the manual trans input shaft pilot would be, hence the bushing designed for the Turboglide crank is stepped.
The powerglide only has about 1/8-1/4" deep large bore (pretty much the rear of the Powerglide/manual trans crank has a lip to pilot the flywheel). I'm fairly certain I have the Turboglide crank; I just wanted to hear from those with the usual Powerglide/manual trans crank to confirm before I go and order this crazy bushing. Now about a flywheel-- I'll make that another post.
Gearhead99
Active Member
I know, "back in the day" a shop I worked at swapped a Powerglide in place of a troublesome Turboglide. It was a basic bolt in swap.
gearhead409
Well Known Member
Back in the day
it was common practice to make this change over. most machanices didn't want to work on the turboglides. when i was 18 i had a 57 with turboglide, it went bad, i took it to my local chevy dealership for service and they even made the powerglide swap.
it was common practice to make this change over. most machanices didn't want to work on the turboglides. when i was 18 i had a 57 with turboglide, it went bad, i took it to my local chevy dealership for service and they even made the powerglide swap.
I was at a show and shine yesturday and this subject came up. What was the first production year for the tuboglide? I thought it was 57' but was corrected by another who said it was 58'
.gearhead409
Well Known Member
Dan
i wish you could have read my post before you went to your car show, 57 was the first year.
i wish you could have read my post before you went to your car show, 57 was the first year.
I will see him again...We belong to the same club...:takethat