Diesel GT Driveshaft Upgrade

bcuster · #1 04-13-2016, 06:23 AM

Was reading through a recent thread on upgrading the SGT diesel driveshaft to a CV style driveline. It seems that every year, I am replacing the spiral pin at the hydro pump on my 782D. I have even lost the spiral pin near the engine adapter (much rarer occurrence). I have also replaced the self centering bearings twice now over the past 5 yrs. Of course, Plow Day is in 3 days, and the 782D just threw another spirol pin.

Don't know if I have another spiral pins and bushings to fix this before Sat.

Not sure why this happens yearly....

Jeff in PA and Sam Mac, is there a replacement driveshaft option for the GT diesels with the NON-splined input shaft? I'd love to buy a kit to replace everything, but I have a feeling you'll tell me that I need a splined input shaft. With a splined input shaft, what combination of parts can Jeff in PA provide, and what do I need to make it work? I don't have any stuff to do fabrication work, so a plug-and-play option is what I'd like.

Can you guys help me fix this permanently? Thanks!

Sam Mac · #2 04-13-2016, 08:12 AM

I think in your case Jeff in PA is probably your go to guy. Take a look at this thread. http://www.onlycubcadets.net/forum/s...t=43450&page=3
Pretty much the same issue your dealing with. I don't know of a CV shaft that will fit in a 782D without cutting one down and welding it back together.

Oak · #3 04-13-2016, 09:39 AM

My 882 had the hole wallered out on the pump. I put a grade 5 bolt in it....I know, never do that. That was about 5 years ago, never had a problem out of it.

Jeff in Pa · #4 04-13-2016, 09:38 PM

Quote:

Originally Posted by bcuster

Was reading through a recent thread on upgrading the SGT diesel driveshaft to a CV style driveline. It seems that every year, I am replacing the spiral pin at the hydro pump on my 782D. I have even lost the spiral pin near the engine adapter (much rarer occurrence). I have also replaced the self centering bearings twice now over the past 5 yrs. Of course, Plow Day is in 3 days, and the 782D just threw another spirol pin.

Don't know if I have another spiral pins and bushings to fix this before Sat.

Not sure why this happens yearly....

Jeff in PA and Sam Mac, is there a replacement driveshaft option for the GT diesels with the NON-splined input shaft? I'd love to buy a kit to replace everything, but I have a feeling you'll tell me that I need a splined input shaft. With a splined input shaft, what combination of parts can Jeff in PA provide, and what do I need to make it work? I don't have any stuff to do fabrication work, so a plug-and-play option is what I'd like.

Can you guys help me fix this permanently? Thanks!

I make a replacement hub for the hydro with set screws. That would help on that end and I can make the hub by the engine with set screws too.

If you go to the link Sam posted and go to page 5, those are the hubs I make that John got his 1512.

bcuster · #5 04-14-2016, 01:23 AM

Quote:

Originally Posted by Jeff in Pa

I make a replacement hub for the hydro with set screws. That would help on that end and I can make the hub by the engine with set screws too. If you go to the link Sam posted and go to page 5, those are the hubs I make that John got his 1512.

So for the front and rear couplers, those set screws go down into the spiral pin holes on the hydro pump input shaft and front of the driveshaft? What if the holes are wallowed out? Would they have to be redrilled, and different size set screws?

Quote:

Originally Posted by Oak

My 882 had the hole wallered out on the pump. I put a grade 5 bolt in it....I know, never do that. That was about 5 years ago, never had a problem out of it.

Did you replace both rear spiral pins (one for each coupler) with the bolts? I need to make a trip to TSC to see if I can find a 1/4" dia bolt long enough to get a locking nut on the end. Did you find a bolt with a smooth shank, or are your threads taking the load as well?

Quote:

Originally Posted by Sam Mac

I think in your case Jeff in PA is probably your go to guy. Take a look at this thread. http://www.onlycubcadets.net/forum/s...t=43450&page=3
Pretty much the same issue your dealing with. I don't know of a CV shaft that will fit in a 782D without cutting one down and welding it back together.

I have been in contact with Jeff. That's odd that no other CV shaft options were available. What model GTs used the CV shaft?

UPDATE: So I just went out to the garage, and noticed that the front adapter/driveshaft spiral pin (that I just replaced last summer) is almost out again.

Other than a worn self-centered bushing, what can be causing these things to fall out or shear off? They go in tight, but I suppose a wallowed hole can cause just enough slack to cause wear? Is it possible to tighten the rag joints asymmetrically to cause this?

jaynjeep · #6 04-14-2016, 02:03 AM

You must have slightly wallowed holes at the pump and or the engine coupler.. that's about the only reason I could see that you would keep beating pins out.. The couplers that Jeff in PA makes with the set screws would be a good idea.. I would think the set screws would stabilize the coupler on the shaft if it's worn at all.. It would have to be an improvement.. Diesels seem to be harder on the driveline than the gassers

Years ago we had a 125 that ate spirol pins frequently... Like Oak said.. we used a 1/4 inch bolt with a locknut as a "temporary" fix... It has been that way for 25 years...

never broke another one.. we used a long enough bolt that the shank takes the load.. not the threads. I'm not recommending that fix.. just what we did to get by and it happened to work for a long time!

Good luck with it and keep us posted

Sam Mac · #7 04-14-2016, 09:12 AM

Quote:

Originally Posted by bcuster

So for the front and rear couplers, those set screws go down into the spiral pin holes on the hydro pump input shaft and front of the driveshaft? What if the holes are wallowed out? Would they have to be redrilled, and different size set screws?

Did you replace both rear spiral pins (one for each coupler) with the bolts? I need to make a trip to TSC to see if I can find a 1/4" dia bolt long enough to get a locking nut on the end. Did you find a bolt with a smooth shank, or are your threads taking the load as well?

I have been in contact with Jeff. That's odd that no other CV shaft options were available. What model GTs used the CV shaft?

UPDATE: So I just went out to the garage, and noticed that the front adapter/driveshaft spiral pin (that I just replaced last summer) is almost out again.

Other than a worn self-centered bushing, what can be causing these things to fall out or shear off? They go in tight, but I suppose a wallowed hole can cause just enough slack to cause wear? Is it possible to tighten the rag joints asymmetrically to cause this?

The adapter that Jeff is making has both the hole for the spirol pin and set screws to help stabilize the adapter on the input shaft for the pump. You install it with the spirol pin and then tighten the set screws. Most of these pump shafts are worn and the OEM couplers are sloppy on the shaft.

Jeff in Pa · #8 04-14-2016, 09:35 PM

Quote:

Originally Posted by Sam Mac

The adapter that Jeff is making has both the hole for the spirol pin and set screws to help stabilize the adapter on the input shaft for the pump. You install it with the spirol pin and then tighten the set screws. Most of these pump shafts are worn and the OEM couplers are sloppy on the shaft.

Thanks for the help Sam

Exactly what Sam said