I am rebuilding a RO 70 terex fixed bent rod in Perkins 403d-15 which rolled over into foundation excavation and hydrolocked .
Previous owner jury rigged to sell at an auction the other damages I found being ,
The pump flanges broke off hydrostatic transmission mount which I rewelded .
Check all motor mounts which support pump to bell housing
This one had cracked missing bolts which allowed pump to vibrate and crack cast steel flanges off poor design .
It also has a "tin" belly pan also which doesn't protect pump which is close to it and provides little protection.
There is a plastic coupler on flywheel which engages pump splines. They are ok but can fail strip cause low or no power to pumps .
Not impressed with quality design of this machine.
Good luck with yours .
A video of repair of roll over is on my you tube "Mitzvos Golem" channel .