'55 Series Violent Shaking

[Jim Meade]

1755 recently rebuilt engine which runs perfectly on the vac. Tractor used to run good in all regards.
Since the engine overhaul, when in motion the tractor will sometimes, not always and not most of the time, enter a violent shaking. It seems to happen in both direct and overdrive and it seemsm to not happen in underdrive. If it starts, it will stop in a few seconds (not instantaneously) when shifted to underdrive.
Since it operates perfectly when standing still and seems to be OK in underdrive, my question is what could be causing this in direct and overdr4ive?
The hydro is full of good fluid.
It doesn"t do this all the time.
Ideas?
 

[88 Diesel]

Do you have any loose or broken bellhousing bolts? How is the chain coupler alignment?
 

[Jim Meade]

I"ll have to double check the bellhousing bolts. How would that affect it? The chain coupler is level as far as I can tell, checked it closely when installing it, too.
I"m wondering if there is a bearing or something that only affects direct and over drive. Otherwise, I"d think underdrive would be affected and it doesn"t seem to be.
 

[e]

Sounds like it could be a coupler alignement issue. Verify side to side alignement as well as up and down.
 

[darren lauer]

did you replace the throwout bearing? There is a collar or sleeve that it rides on that needs to be shoved into bellhousing and preferebly tacwelded in place..This fixed my shaking problem on my 1755 but i also had loose bolts as well.
 

[dboll]

sounds like the chain coupler sprockets are not properly aligned
 

[Ken Grimm]

Are the right engine bolts put in their correct holes so that the engine, over/under are lined up correctly with the rear sprocket?
 

[Jim Meade]

I put brand new engine bolts in. The right size.

I tweaked the coupler line up a little - very little. I'll try it and see if it changes things.
 

[hd6gtom]

Jim the high side of my hydropower is slipping and it shakes bad when I first shift it. It does not shake in UD. I only have the 2 speed but it sounds like the problem you are having.
 

[bison]

Did you check the transmission input shaft for excessive play in the front bearing at the chain coupler sprocket?
i had a 1855 with a bad shake and found upon engine removal/rebuild a lot of play in the tr input shaft.
I took out most of the shimms to get the preload to be were it should be.
The shake was gone.
Then again i had rebuild the over/under as well for good measure altough i found nothing wrong in it but the sprag was about to fall apart when i took it out(i could save that one as well by fashioning some brass rings on my lathe to hold it together and get the sideplay out).
I put 2500hrs on it since..no problems.