Buy the bronze bushing.
409 pilot bearing
- Thread starter jd63
- Start date
Do you have a p/n for a bronze bushing? the bushing I got from napa was bronze coloured.
I had to have OD turned down to fit the crank for the 409 marine engine.
I had to have OD turned down to fit the crank for the 409 marine engine.
Long story but don't make the mistake that I just did. I'm not a motor guy, what I know about the mechanics of a motor can be stored in a sewing themble and I'm embarresed to tell this story but if it will keep somebody else from making the same costly mistake.........
The bronze bushings that are available will not fit in some of the cranks. They are just a tad to big. Whatever you do make sure that you have the bushing turned down so that it fits and can be driven in without distorting. I just when through this and came close to distorying an engine. Over the Christmas holidays I had some time and decided to switch the motors in my '61SS. BTW...These ain't run of the mill motors, they are '61 409 motors!! I had removed one motor and as I was hooking the other motor up to the crane I noticed that it did not have a pilot bushing, I went to the local parts store, bought a bronze bushing, it wouldn't go in the crank, I went to the local Chevrolet dealer and bought one of the bearings, it wouldn't go it so I called the local guy that does my motor work and he says no problem just come by and I'll give you one, they are all the same. So, I take mine with me and they are the same size as his, he says my crank probably has a burr in it so he chucks the bushing in the lathe and turns a taper on it so that it will start. I go home, drive the bushing in as far as he tapered it and it started to get really tight. Well, most people would stop at this point but by now I'm pissed and I can't get it back out so I drove it as far as it would go. In doing this I guess I distorted it cause when I put the motor in the car it would not go quite all the way on the transmission. So, doing what I've done a thousand times, I put the bolts in the transmission and pulled the transmission up. I wasn't thinking what I was doing when I did this, it pushed the crank forward. When I fired the motor I heard it and shut it down, probably ran 15 to 20 seconds. It welded the thrust side of the rear main bearing to the crank!! My motor is now back in the shop being repaired, cost me dollars and time. As Forest Gump's mother says..."Stupid is as stupid does"
I'm no rocket scientist, but what I would do, is measure the bore size on the crankshaft with a telescopic gage. Then, I would shop for a bronze bushing to fit. You may have to have the bushing O.D. machined for the proper press fit.
Make sure the bushing also fits the transmission stub, before you install it.
Randy
Make sure the bushing also fits the transmission stub, before you install it.
Randy
Wow !! Tommy, what a horrible experience. I haven't built an engine for a manual shift car in over 20 years so I haven't run into that problem, but I am building one now for myself that will be manual trans. When my parts are ready, I will take a bushing with me so the machinist can install on a work bench, in case the bushing needs some work on the lathe. If its not too late maybe you could have your machinist measure final O.D. of your bushing and maybe others might get some guidance from that. If that's not possible, I will do that when the time comes. Thanks for sharing your experience. Probably saved me a 150 mile round trip to the machine shop later. No reason not to put the bushing in before assembly. Its just one of those "unexpected" problems. Thanks again.
Ronnie,
I almost contacted you when I was having the problem to see what you thought I should do. I've never had to replace a pilot bushing before. I bought the motor already assemblied so it wasn't the shop that usually does my works fault. I don't think I done any damage to anything other than the rear main bearing but the crank has to come out and while there was very little metal in the pan and I didn't see any in the filter, the motor has to be cleaned up, the crank checked and put back in. Takes time and cost money. You can bet the new bushing will fit in the crank and the transmission input shaft will slide nicely in the bushing before the motor goes in this time.
I almost contacted you when I was having the problem to see what you thought I should do. I've never had to replace a pilot bushing before. I bought the motor already assemblied so it wasn't the shop that usually does my works fault. I don't think I done any damage to anything other than the rear main bearing but the crank has to come out and while there was very little metal in the pan and I didn't see any in the filter, the motor has to be cleaned up, the crank checked and put back in. Takes time and cost money. You can bet the new bushing will fit in the crank and the transmission input shaft will slide nicely in the bushing before the motor goes in this time.
Just to set the record straight, I did build a QA engine for a guy from Ft. Worth, 8 years ago. He picked the engine up and took it home, installed it, then trailered the car back here for initial start-up. Either the crank had a bushing in it or the guy installed it, I don't know, the subject never came up. There was no shaking or vibration when the clutch was released so there was a bushing installed,, I just don't know how it got there. Not that it matters, but it is sorta interesting,,, the guy bought a '64 Belair at a swap meet with a bare block in the trunk. VIN on block matched the car. Car was unrestored but in fantastic condition. I remember him saying that he paid a premium price but in the end , he was happy.
I had the same problem when I built my 63 Biscayne. The engine is a QB 409 so you would think the pilot bushing would be simple but the standard bushing did not fit. The standard bushings have an OD of 1.094 but I think the bushing I used was a Dorman Part number 690034 with an OD of 1.060.
It was a few years ago but looking at what is available I believe that is what I used?
Bill
It was a few years ago but looking at what is available I believe that is what I used?
Bill
Good info. Bill, Thanks
The original was part number 3752487 and was 19/32 ID X1 3/32 OD X 3/4.
Be advised though, that not all cranks are drilled the same. If you have a truck crank it can have several different diameters depending on wh ch trans it came with in production..
Be advised though, that not all cranks are drilled the same. If you have a truck crank it can have several different diameters depending on wh ch trans it came with in production..
Best to measure the crank bore. 
I just looked a little farther and the Dorman site shows it as being used on automatic to standard shift conversion. If a crankshaft is replaced who knows what you have.
http://www.dormanproducts.com/itemdetail.aspx?ProductID=18310&SEName=690-034
963ChevroletBel AirV8 327 5.3L (5358cc)Only Used For Automatic Transmission Conversion; Powerglide to Manual Transmission; O.D. 1.060"
1963ChevroletBel AirV8 409 6.7L (6704cc)Only Used For Automatic Transmission Conversion; Powerglide to Manual Transmission; O.D. 1.060"
1963ChevroletBiscayneL6 230 3.8L (3769cc)Only Used For Automatic Transmission Conversion; Powerglide to Manual Transmission; O.D. 1.060"
1963ChevroletBiscayneV8 283 4.6L (4638cc)Only Used For Automatic Transmission Conversion; Powerglide to Manual Transmission; O.D. 1.060"
Bill
http://www.dormanproducts.com/itemdetail.aspx?ProductID=18310&SEName=690-034
963ChevroletBel AirV8 327 5.3L (5358cc)Only Used For Automatic Transmission Conversion; Powerglide to Manual Transmission; O.D. 1.060"
1963ChevroletBel AirV8 409 6.7L (6704cc)Only Used For Automatic Transmission Conversion; Powerglide to Manual Transmission; O.D. 1.060"
1963ChevroletBiscayneL6 230 3.8L (3769cc)Only Used For Automatic Transmission Conversion; Powerglide to Manual Transmission; O.D. 1.060"
1963ChevroletBiscayneV8 283 4.6L (4638cc)Only Used For Automatic Transmission Conversion; Powerglide to Manual Transmission; O.D. 1.060"
Bill
dean409
Well Known Member
I agree about using a bronze bushing, though we've always used the roller in performance BBCs. The one that came out of the crank measures 1.061-1.064", the O'Reillys bronze is 1.092-1.096", the Jegs roller is 1.093-1.099". I'm supposed to bang squeeze .031"? I don't think a big hammer and a running start down hill would do it.
Bruce at Show Cars said he's heard this a few tymes and always suggests a machine shop trip. The truck motors are common for hi-perf applications, so why doesn't someone offer a solution for this? My brother's '58 Impala 409 passenger block used the common off the shelf pilot bushing. Sheesh!
Bruce at Show Cars said he's heard this a few tymes and always suggests a machine shop trip. The truck motors are common for hi-perf applications, so why doesn't someone offer a solution for this? My brother's '58 Impala 409 passenger block used the common off the shelf pilot bushing. Sheesh!
You need to read the post I made just before yours, from what I see the bushing is carried by most parts stores?
Bill
dean409
Well Known Member
I just looked a little farther and the Dorman site shows it as being used on automatic to standard shift conversion. If a crankshaft is replaced who knows what you have.
http://www.dormanproducts.com/itemdetail.aspx?ProductID=18310&SEName=690-034
I hit this link, how did I not come across this on my searches? By this info, it tells me that the motor was converted from an auto to a stick? So this was a standard part? We bought a shed of dubya parts n stuff from a guy back in '79 who was supposedly parting out a school bus and a truck.
http://www.dormanproducts.com/itemdetail.aspx?ProductID=18310&SEName=690-034
I hit this link, how did I not come across this on my searches? By this info, it tells me that the motor was converted from an auto to a stick? So this was a standard part? We bought a shed of dubya parts n stuff from a guy back in '79 who was supposedly parting out a school bus and a truck.
Just watch for the quality. My napa had a bronze colour to it but was steel
Holy Moly!!!! I always thought a crank was a crank was a crank. Wrongo!!! 65 parts book has 4..........61-62, 63 400HP & 425HP, 63-64 340HP and Z-11. They give ID numbers but don't have time to check if that's in the casting number of the crank. More later...............
Maybe the 63 H/P cranks were made out of different material. I can't imagine a crank for M/T and a different one for A/T??????
Maybe the 63 H/P cranks were made out of different material. I can't imagine a crank for M/T and a different one for A/T??????
Now,Add in the truck crank,and we have at least 5 409 cranks.What we need now is measurements for the pilot bushing hole in the crank.I read somewhere that there were differences in the 409 cranks due to the lighter[?] cast piston/rod combo's in the truck and 340 hp car,as opposed to the high compression fodged pistons.Is that the case,or just another "urban legand"?
