Desperation +Hammer+ confined space is not a good combo.
Suggest you wait for a few comments to help avert a disaster.
What happened to the ratchet strap idea?They are cheap ,safe and controllable.Harbor Freight has them, less tan $20 with your 10% off coupon:
3300 lb. Capacity 2 in. x 27 ft. Heavy Duty Ratcheting Tie Down 1 Pc
Get the free mini flashlight while you are there. It fits in your mouth (!) so you have both hands free while you are crawling around under the car like a lizard.
Take your time & be safe !