That's exactly how I wrecked my back Andrew.
Drop kickin' Road Ranger gearboxes and Spicer twin plate clutches around the workshop won out eventually.
Tell your tight arse boss that as an employer, he's got a duty of care for his men and to get a new certified gearbox jack and a wheel trolley.
That should piss him off mate.
We used to use one of these for lifting the gearbox's until I first hurt my back, which pissed me off, after that I refused to use it.
The boss then bought one of these, it makes the job easier, but it is still bloody heavy work.
At the same time I asked if he could get one of these, so I didn't have to lift the heavy mongrels of clutches into place, he refused, which pissed me off.
Then 4 weeks ago I went into work and after 10 mins I could barely walk, I went home, and didn't move from the bed till I could get into the doctor, who signed me off work for a month, which really pissed the boss off
. I'm meant to be going back on Friday on light duties. Here's the funny part, I'm not allowed to lift any more than 4kg, so apparantly I'm not even allowed to go for a piss without a helper
.