hi all after a bit of info regarding fish plates I'm currently doing a coil conversion on my 75 series cruiser using 80 series housings and 79 series mounts/brackets I'm not sure whether to fish plate the chassis where the front coil/shock mounts weld to. 79 and 80 series are not fish plated but what they do have is a sleeve on inside of the chassis where the coil/shock mounts are. I'm not sure what purpose these sleeves actually serve But are obviously there for a reason. My problem is 75 series don't have these inner sleeves hence why I'm thinking of fish plating. So what's peoples thoughts on this?
Fish plate (1 Viewer)
- Thread starter NSALT
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Whats a fish plate?
Ok got it. I just have other names for it.
I’m unsure of the exact frame and sleeve situation you are describing. Maybe some pics would help. When I installed coil buckets on my 40 front end I used 3/16” fish (scab) plates to be certain I had something sturdy to weld to. The frame steel on a 40 is not very thick and a little on the weak side so creating a strong base to weld to was a must. A couple different welders I know suggested you want to avoid welding vertical when plating as it creates stress lines and leads to cracks. This can be done by using diamond or rounded plates, avoid fish plates with squared off ends. If you are talking about bolting coil buckets on though a sleeved boxed frame that might be ok without a fish plate.
every 70 series cruiser I know of that's had a front coil conversion always ends up cracking around the front crossmember/steering box due to the stress transferred back through the panhard mount so you may want to do some strengthening to the frame around that area