TM 10-3930-659-20 17-12.    FORKS REPLACEMENT (Con't). WARNING Use extreme caution when handling heavy parts.  Lifting device Is required  when  parts  weigh  over  50  lb  (23  kg)  for  a  single  person lift, over 100 lb (45 kg) for a two person lift, and over 150 lb (68 kg) for a three or more person lift.  Keep clear of heavy parts supported only  by  lifting  device.    Failure  to  follow  this  warning  may  cause serious Injury or death to personnel. 9. Remove bar (12) and two spacers (11) from carriage assembly (1). 10. Repeat steps 6 and 7 to remove right fork (3). b. INSTALLATION WARNING Use extreme caution when handling heavy parts.  Lifting device is required  when  parts  weigh  over  50  lb  (23  kg)  for  a  single  person lift, over 100 lb (45 kg) for a two person lift, and over 150 lb (68 kg) for a three or more person lift.  Keep clear of heavy parts supported only  by  lifting  device.    Failure  to  follow  this  warning  may  cause serious Injury or death to personnel. NOTE When both forks are Installed, they should be approximately 15 In.  (38 cm) apart. 1. Attach suitable lifting device to right fork (3) and position fork on carriage assembly (1). 2. Remove lifting device from right fork (3) and apply a coat of grease to bore of fork. WARNING Use extreme caution when handling heavy parts.  Lifting device is required  when  parts  weigh  over  50  lb  (23  kg)  for  a  single  person lift, over 100 lb (45 kg) for a two person lift, and over 150 lb (68 kg) for a three or more person lift.  Keep clear of heavy parts supported only  by  lifting  device.    Failure  to  follow  this  warning  may  cause serious Injury or death to personnel. 3. Install bar (12) halfway through carriage assembly (1) to install right fork (3) on carriage assembly. 4. Remove lifting device from right fork (3). 5. Repeat steps 1 through 4 for left fork (2). 6. Install two spacers (11) and end caps (10) on bar (12) with two new locknuts (9). 17-42