modelbuilder Posted May 15, 2018 Report Share Posted May 15, 2018 (edited) My friend has just lowered his body onto a rebuilt chassis and is having self doubt about his work. To start with, he is a brilliant engineer and has been very methodical in the process of repairing the chassis. He built the most amazing jig prior to removing the rear chassis etc. The chassis and cross members are all new from the t shirt back. Having seen the jig arrangement and the way he measured everything prior to starting the removal of the original rusty sections, I cannot believe that he has misaligned anything. The floor to chassis mounting points have only needed a couple of spacers as have to rearmost mountings. However the cross member that goes under the spare wheel well is at least a couple of inches away from the replaced boot floor. We are wondering how good the shape of the replacement floor is. Also the mounting point in the first photo there is at least a couple of inches gap between the body and chassis. I would be interested in any comments from anyone who has an unrestored car or from anyone who may have experienced similar problems during a rebuild. Thanks, Rodders. PS the title is not a figment but fitment! Edited May 15, 2018 by modelbuilder Quote Link to post Share on other sites
stuart Posted May 15, 2018 Report Share Posted May 15, 2018 Judging by the angle of the rear end of the chassis to the boot floor he has managed to "Hog" the chassis.I will give you a ring and explain later. Stuart. Quote Link to post Share on other sites
Marc R Posted May 15, 2018 Report Share Posted May 15, 2018 Hello Stuart, I am interested to understand also the concept of an Hog Chassis and the solution.... if you explain and share on the Forum Thanks' and best regards Quote Link to post Share on other sites
tr graham Posted May 15, 2018 Report Share Posted May 15, 2018 Speak with Stuart ,the angle of boot floor to chassis is wrong 3/8” is a better guide Quote Link to post Share on other sites
stuart Posted May 16, 2018 Report Share Posted May 16, 2018 Hello Stuart, I am interested to understand also the concept of an Hog Chassis and the solution.... if you explain and share on the Forum Thanks' and best regards In essence when replacing the trailing arm sections and the "T" shirt section (Usually required) and often also sections of the rear legs of the chassis its very easy for the chassis to warp upwards at the rear, some more than others thus producing what you see in the above picture. Normally the boot floor when viewed side on with the shell sat on the chassis would be pretty much parallel to the rear chassis leg just slightly closer at the tail end.The clearance at the front of the spring bridge where the parcel shelf mount is around 3/16" to sometimes 3/8" depending on the shell.Also at the rear of the car there shouldnt be that much of the rear chassis legs showing from behind 1/2" to 3/4" is usual. Stuart. Quote Link to post Share on other sites
Ragtag Posted May 16, 2018 Report Share Posted May 16, 2018 I agree with Stuart although I thought the term 'hogged' was used to describe the rear chassis sagging down rather than raising. Anyway, I have a brand new CTM '6' chassis in my garage (assuming 5 and 6 are the same) and I've taken a measurement for you. The chassis is pretty much flat until it starts to kick up, just in front of the rear diff bridge. With a straight edge under the chassis below the spring/diff bridge, the base of the chassis kicks up by 90mm at the rearmost point. Hope that makes sense!!! Quote Link to post Share on other sites
graeme Posted May 17, 2018 Report Share Posted May 17, 2018 (edited) I wonder if the restorer has taken all his measurements from the original chassis which may have already been hogged. Consequently, creating a perfect reproduction of a hogged chassis. Not good news whatever has happened. Graeme Edited May 17, 2018 by graeme Quote Link to post Share on other sites
RogerH Posted May 17, 2018 Report Share Posted May 17, 2018 Hi Chris, in aerospace Hogging is where the centre of the fuselage is raised above the cockpit and the taiplane Sagging is where the centre of the fuselage is below the cockpit and tailplane When I got my new chassis back in the 90's from a shed in Birmingham I also found my back end was seriously too high. I ended up cutting the chassis just forward of the diff rear support. This caused the diff attachment points to move rearwards so the rear bridge had to be removed and re-positioned. Roger Quote Link to post Share on other sites
Marc R Posted May 17, 2018 Report Share Posted May 17, 2018 Hello Stuart, thanks' for this education note. Best regards In essence when replacing the trailing arm sections and the "T" shirt section (Usually required) and often also sections of the rear legs of the chassis its very easy for the chassis to warp upwards at the rear, some more than others thus producing what you see in the above picture. Normally the boot floor when viewed side on with the shell sat on the chassis would be pretty much parallel to the rear chassis leg just slightly closer at the tail end.The clearance at the front of the spring bridge where the parcel shelf mount is around 3/16" to sometimes 3/8" depending on the shell.Also at the rear of the car there shouldnt be that much of the rear chassis legs showing from behind 1/2" to 3/4" is usual. Stuart. Quote Link to post Share on other sites
Marc R Posted May 17, 2018 Report Share Posted May 17, 2018 Hello RogerH, good point to clarify Hogging vs Sagging for a French guy like me. Best regards Hi Chris, in aerospace Hogging is where the centre of the fuselage is raised above the cockpit and the taiplane Sagging is where the centre of the fuselage is below the cockpit and tailplane When I got my new chassis back in the 90's from a shed in Birmingham I also found my back end was seriously too high. I ended up cutting the chassis just forward of the diff rear support. This caused the diff attachment points to move rearwards so the rear bridge had to be removed and re-positioned. Roger Quote Link to post Share on other sites
stuart Posted May 17, 2018 Report Share Posted May 17, 2018 I wonder if the restorer has taken all his measurements from the original chassis which may have already been hogged. Consequently, creating a perfect reproduction of a hogged chassis. Not good news whatever has happened. Graeme When I talked to Rodney he confirmed the guy had taken all his measurements etc from the chassis when he removed it and then repaired it to them hence the problem. Stuart. Quote Link to post Share on other sites
Waldi Posted May 17, 2018 Report Share Posted May 17, 2018 You can find the chassis dimensions in the brown bible. Waldi Quote Link to post Share on other sites
len1 Posted May 17, 2018 Report Share Posted May 17, 2018 (edited) My heart goes out to the builder of the chassis...that's an awful amount of time and energy invested...to no avail...I hope he can summon the energy to peserve and correct the error. Len Edited May 17, 2018 by len1 Quote Link to post Share on other sites
modelbuilder Posted May 18, 2018 Author Report Share Posted May 18, 2018 Thanks for all the replies and a special thanks to Stuart who, as usual, is always there for the best advice. Rest assured, Peter will correct the problem and in due course I will report back with the outcome. There is no substitute for experience! Weve all made, what in hindsight, is an obvious mistake. Rodders, ( without a TR after 54 years ). Quote Link to post Share on other sites
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