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| | | | Joined: May 2005 Posts: 215 Shop Shark | | Shop Shark Joined: May 2005 Posts: 215 | Hello all, just finished installing my rebuilt SM420 using Novak kit.
Everything went well, but I have a few issues
Before connecting the driveshaft, I have her a start to make sure everything was smooth. In neutral, I see the u-joint connector on the back of the tranny spinning a little. Clutch feels great, smooth shift all gears
But when I put in reverse, the u-joint connector rotates the same direction as 1st and 2nd
Also, when I did connect the u-joint, and in neutral, it act like it's in gear and I cannot push the truck
I did install new shift bushing and I think I read that the problem may be in the tranny cover with the rods not being aligned. I plan to call Novak tomorrow, but if anyone has advice before that it's much appreciated | | | | | Joined: Dec 2015 Posts: 2,063 Big Bolt Forum Moderator | | Big Bolt Forum Moderator Joined: Dec 2015 Posts: 2,063 | I would pull the bolts out of the top cover and see if you can lift it a tad and see if the shift forks are where they need to be. It sounds like something is not lines up properly.
with the top off, you should be able to make sure it is in neutral and spin the rear yoke by hand. | | | | | Joined: Apr 2002 Posts: 2,168 A teacher, but always an apprentice. | | A teacher, but always an apprentice. Joined: Apr 2002 Posts: 2,168 | Lou,
I have a similar problem with my 420 where it rotates in neutral at the output shaft. My sneaking suspicion at the moment is the pilot bearing is egged from my installation. It was a bear to push into the crank and I think it's pinched. I'm going to pull the bearing and the 420 and try an old spare to see if it is the culprit. But for now I'm still sanding, sanding , sanding! | | | | | Joined: Jun 2011 Posts: 5,096 Crusing in the Passing Lane | | Crusing in the Passing Lane Joined: Jun 2011 Posts: 5,096 | Pilot bushings are cheap, way less than the grief caused by improper installation, check it upon first trans. Installation when it is easy to replace. Do a test fitting with a spare input shaft.
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
| | | | | Joined: May 2005 Posts: 215 Shop Shark | | Shop Shark Joined: May 2005 Posts: 215 | Got it up and running today
Wrestled with the cover and smashed my finger by the shift did
Drove around for a bit
Very smooth and well worth the clutch and rebuild
| | | | | Joined: Dec 2006 Posts: 1,154 Shop Shark | | Shop Shark Joined: Dec 2006 Posts: 1,154 | I've had my Novak sm420 for over a year it's great. Had the rear end changed to 3:38 new u- joints and drive shaft and clutch assembly. Couldn't be happier Novak is a great company and nice people.
Steve | | |
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