Workshop - Straightening Forks
(PLEASE NOTE - THIS SECTION IS FOR INFORMATION ONLY - UNLESS OF COURSE YOU HAPPEN TO HAVE THE JIG!)
The following instructions refer to the straightening of the front fork in case of distortion. Details for this section are for the Lambretta 175 li Series 1 and 2 however there are many similarities between these models and other models of Lambretta threewheelers/Lambros.
- Carry out an accurate sight check of the damaged part. Should this show cracks, breaks or kinks due to accident, it is necessary to discard the item and replace it.
- All forks should be straightened at cold.
- Carry out the straightening and the dimensional control (see page 144). When this is done, a very accurate sight check should again be made of the straightened part. Should further cracks etc., be caused by the straightening show, or in case of doubt, replace the part.
It is very important to also carry out the following test.
- Spray abundantly the part to be examined with paraffin. After having left drip or after a quick wiping which will leave the part still damp, sprinkle over this part a quantity of talcum to cover the surface ; should any crack be present, this will immediately show up as the paraffin in the crack will be absorbed by the powder. This test helps considerably in the checking of the state of the surfaces involved.
- The jigs for this work have been designed to allow a dimensional checking of the part, as well as acting as a vice for the part during the straightening.
Straightening of the Fork Jig No: 59651
The jig consists of a base plate on which are fitted three knuckle devices for the locking of the fork in place, three slides carrying points for the checking and two sliding blocks which give the fork a further means of retainment during the actual straightening.
To carry out the dimensional control of the fork, this should be locked in the Jig, see Fig. 80. The fork can be accepted as dimensionally correct when:
1) The central slide carrying the checkpin can move freely while its two pins touch the surfaces of the link boxes.
2) The two check pins carried on the side slides ,should enter freely into the suspension box bush holes.
If a Fork is distorted proceed to the straightening in the best possible manner. A further support can be given to this through the sliding blocks. Avoid hitting the suspension boxes with the lead hammer to avoid damage.
The Straightening must be carried out at cold, and the rules given at the beginning of this chapter should be strictly adhered to.