Can I run the engine with the driveshaft disconnected or will it cause any damage
Damage to what?
id say yes as nothing turns relating to gearbox, back axle and such.
if your getting a suspended tow then the angle of lift may not do your oil pressure much good,but i dont see why not if your sitting parked with no driveshaft bolted on.
if it unbolted from rear of box then no worries,if its unbolted from the diff,then dont hit any gears or the prop will spin.
thanks Diesel Dog , it was towed and now I want to empty the loaded box so need to run it so the taillift wont run down the batteries , save me a lot of headaches ,
Gidders the answer to your question is all there, damage to gearbox , diff
No offence intended nedflanders.I wasn’t being facetious.I didn’t quite understand your question.You need to detach prop for a suspended tow to avoid gearbox damage but you can still run engine to provide air for brakes or whatever.It won’t damage clutch.
No offence Ned but your don’t sound like you know what your doing , DONT Start the engine unless the prop is removed completely from the gear box and the diff or the diff end is well ■■■■■■■ and be very careful not to knock it in to gear it it is ■■■■■■■ .
Thanks Gidder , I should have explained more clearer,
and thanks Dan , its not the first time of recovery but the first time I wanted to start a truck during or after recovery prior to it been towed, so yeah not a clue did I know what I was doing,
Its been towed and its completely removed and ■■■■■■■
Their is bad batteries on it so saves me bringing in a unit to keep a charge on the batteries while I use the tail lift for a while to get the load off her
To be clear: if the propshaft is still connected to the gearbox it will rotate if the engine is running regardless of whether the gearbox is in gear or in neutral. It will attempt to thrash about the disconnected end whether that is at the diff flange or a sliding joint. If it has been ■■■■■■■ then it has most likely been done so only to prevent it falling onto the road, not to prevent it from rotating; which needs to be done much more securely.
Meerkat explanation.
If propshaft is disconnected from diff don’t start it.
If disconnected from gearbox, you can start it.
If drive shaft removed, you can start it.
The only reason you have to disconnect a prop shaft,or half shaft when being towed is because you have no lubrication to the mainshaft.
When the engine is running the layshaft is in constant motion and throws oil up on to the mainshaft,syncros and shift forks.
When the vehicle is towed the mainshaft is turning due to the prop rotation but it has no splash feed from the layshaft because you have no rotation from the input shaft or a gear selected.
The layshaft sits in the oil bath at the bottom of the gearbox and is the only supplier of oil to the rest of the box.
To tow a truck a short distance without disconnecting the prop either run the engine at tickover or hold in the clutch and engage a gear.
Both will keep the layshaft turning and splash feed the mainshaft.