Need advice on tightening pinion gear, 1974 75 hp Chrysler

[speed29668]

Thanks for reading this post. I am replacing the seals on a 1974 75 hp Chrysler. What is the correct procedure for tightening the pinion gear nut? I have attempted to torque down the nut to 85 ft-lbs as called for in the manual. After I reach 20-25 ft-lbs the shaft will not turn by hand, as if the bearings are binding. When the nut was first removed it did not feel overly tight and was no where close to 85 ft-lbs. I snugged it to 7 ft-lbs and it turns as freely as it did originally at that particular torque. Let me know what you think. Thanks.

 

[Bob in Calif.]

Re: Need advice on tightening pinion gear, 1974 75 hp Chrysler

Are you sure the manual doesn't say 85 INCH pounds? The only thing I can think of that calls for an 85 ft. lb. torque setting, is some propeller nuts! If I was you, I would read it again and then check with somebody else who has a Chrysler manual. I don't have any of those.

 

[ob]

Re: Need advice on tightening pinion gear, 1974 75 hp Chrysler

speed, The 85 ft. lbs. torque for the pinion gear nut is correct.If bearing is in a bind you'll have to change shims to attain torque value without binding.There is a significant load on pinion gear that requires this torque value.Good luck

 

[speed29668]

Re: Need advice on tightening pinion gear, 1974 75 hp Chrysler

Thanks everyone.<br /><br />How does shimming work with the pinion gear and bearings on the driveshaft? I haven't installed the propshaft yet, I am dealing solely with the drive shaft right now. I removed the driveshaft to remove a seal in the lower unit. The driveshaft was not very stiff and turned easily before removing it. When installing the old nut for reassembly, it won't come close to 85 ft-lbs before the driveshaft becomes extremely hard to turn by hand, as if the bearings on the shaft are too tight. The manual does call for a new nut but I want to make sure everything else is right before ordering this nut ($16.00). Does the new pinion gear nut have a locking feature making it much stiffer, requiring a larger torque just to turn it on the threads? Would this make up most of the 85 ft-lbs of torque? Right now the nut doesn't require more than 20 ft-lbs before the bearings are too tight. Thanks for reading what is not the most exciting post.

 

[ob]

Re: Need advice on tightening pinion gear, 1974 75 hp Chrysler

Speed, there should be a shim on the back side of the pinion that establishes enough clearance for bearing to turn freely after nut is torqued.Was there no shim?Maybe not.Don't know who worked on it last.If you are not familiar with procedure to set up pinion gear a manual would be of help.If none are present you'll have to attain the right shims from dealer.

 

[speed29668]

Re: Need advice on tightening pinion gear, 1974 75 hp Chrysler

OB, <br /><br />I was able to gain some clearance by moving the upper-driveshaft bearing up the driveshaft a bit. It wasn't 100% seated against the snap ring, bringing the pinion end of the shaft down some. It's a lot better, but still too tight to be acceptable. The pinion bearing is a roller bearing that is pressed onto a cyclindrical tale coming off the back of the pinion gear to make the gear and bearing one piece. It looks like there is a shim sandwiched between the gear and the bearing. But it looks as though more shims between the gear and the bearing would cause the bearing to be pressed farther into the race making the bearing tighter. There were no shims evident when removing the pinion gear from the shaft. <br /><br />Thanks.

 

[ob]

Re: Need advice on tightening pinion gear, 1974 75 hp Chrysler

Speed , is this a tapered roller bearing?If so I'd wager race has worn enough to create a need for reducing shims or replacing bearing.You may not have a 0-1" outside mich ,but I was wondering how thick is the shim between gear and bearing?