Hisun 700 Rear Driveshaft to Engine Boss Removal

[djl]

Hi All.  The splines are pretty well worn where the rear driveshaft fits into the adapter (boss?) on the rear of the engine.  I have a new driveshaft / adapter / seal to install but am having difficulty loosening the nut holding the adapter onto the transmission output shaft.  I purchased a chain-type vice grip tool thinking that I could get it around the adapter to prevent it from turning but have not had any luck getting it in there yet (very tight space).  What approaches have you used that have worked?  Thanks!

[aefron88]

Impact gun would be my first thought. The nut isn't staked is it?

Otherwise you could pull the cvt cover off and try getting a big strap wrench to hold the secondary from turning.

Assuming your 1 way bearing is working you could also remove the spark plug, put a rope in the cylinder and jam it close to TDC. Put it in gear and that should keep the driveline from turning.

[djl]

Hi aefron88.

No the nut is not staked.  I got it apart yesterday by using a piece of motorcycle tire inner tube (for grip), a pair of oil filter vice grips, a block of wood and an impact gun.  A complex operation. 😆  Once the nut was removed, the boss would still not come off so I used a pair of vice grips and a ratchet strap to apply some tension and struck the side of the boss with a punch and 4lb hammer.  🙃  Inside the boss I found what I initially thought to be the remains of a plastic washer, but after reviewing the parts diagrams I am convinced that it was an excess of loctite that had hardened and bound the boss to the splined shaft.  I removed and replaced the oil seal (put a wipe of gasket maker on the outer circumference to be safe) and installed the new boss without issue. Had to reuse the oil filter vice grips to get it torqued to spec.

Thanks!

[travbmo]

2 hours ago, djl said:

Hi aefron88.

No the nut is not staked.  I got it apart yesterday by using a piece of motorcycle tire inner tube (for grip), a pair of oil filter vice grips, a block of wood and an impact gun.  A complex operation. 😆  Once the nut was removed, the boss would still not come off so I used a pair of vice grips and a ratchet strap to apply some tension and struck the side of the boss with a punch and 4lb hammer.  🙃  Inside the boss I found what I initially thought to be the remains of a plastic washer, but after reviewing the parts diagrams I am convinced that it was an excess of loctite that had hardened and bound the boss to the splined shaft.  I removed and replaced the oil seal (put a wipe of gasket maker on the outer circumference to be safe) and installed the new boss without issue. Had to reuse the oil filter vice grips to get it torqued to spec.

Thanks!

hi i have the same thing going on .i think its the remains of a rubber o ring 

 

[travbmo]

3 hours ago, djl said:

Hi aefron88.

No the nut is not staked.  I got it apart yesterday by using a piece of motorcycle tire inner tube (for grip), a pair of oil filter vice grips, a block of wood and an impact gun.  A complex operation. 😆  Once the nut was removed, the boss would still not come off so I used a pair of vice grips and a ratchet strap to apply some tension and struck the side of the boss with a punch and 4lb hammer.  🙃  Inside the boss I found what I initially thought to be the remains of a plastic washer, but after reviewing the parts diagrams I am convinced that it was an excess of loctite that had hardened and bound the boss to the splined shaft.  I removed and replaced the oil seal (put a wipe of gasket maker on the outer circumference to be safe) and installed the new boss without issue. Had to reuse the oil filter vice grips to get it torqued to spec.

Thanks!

hi i have the same thing going on .i think its the remains of a rubber o ring 

 

[Ben1098]

Hate to tell you the "excess loctite" you find is actually sealant.  The new installed seal stops oil on the OD of the cupped spline coupler.  The inside spline(s) ALSO needs to be sealed.  Clean BOTH spline(s) surfaces of ALL crumbs and oil.  Goop it up good.....as in using a wooden tooth pick to "wet" the splines.  The washer needs a good bead also on BOTH sides and the shaft and cup spline area.  Last, it is best to use a new nut as the nut is a "locking thread" that cuts away some of the output shaft threads (and some of the NUT threads).  Be generous with the waterproof grease to lube the new cup spline and the driveshaft ball spline.

[djl]

Hi Ben.  Thanks for the info.  I lubed the splines using Lithium grease. I applied a good bit of gasket-maker to the washer where it contacts the splines in order to prevent an oil leak.  I did not apply any gasket marker to the outside (nut side) of the washer. I did re-use the old nut. I intended to use waterproof grease to seal up the splines on both ends of the driveshaft (enough to completely fill the cavity) to prevent water from getting in. If I find any oil contaminating the waterproof grease I will know what to do to fix it.  🙂