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While improving fasteners for transmission (center body) crossmember, I had a look at the front center crossmember brace and rear center crossmember brace...
Neither offers the rigidity of the transmission crossmember nor fasteners that qualify.
For the front I envision either boxing in the open area by welding in a plate, or fabricating a solid 3/4" Aluminum or Metal brace and using custom shoulder bolts to improve lateral support and prevent shifting.
Boxing makes a stronger brace & also prevents them from distorting from twisting action imparted on.the chassis. from acceleration, deceleration, turning and suspension activity.
Thicker material of course adds weight but is more amenable to shoulder bolts.
Front center crossmember brace...a little on light side. Improvement to be had here...If my design, to increase chassis rigidity , I would have triangulated the entire length of the open drive shaft tunnel with a plate. Rear center crossmember brace presents a different challenge in that it is held in place by chassis studs and washer head nuts incorporating integral spring washer bottom flange..so can't readily use significantly thicker material.. Probably will resort to boxxing in the bracket to increase rigidity, or if using plate steel or aluminum will.use Shoulder bolts with female threads...not sure of stud strength however.
While improving fasteners for transmission (center body) crossmember, I had a look at the front center crossmember brace and rear center crossmember brace...
Neither offers the rigidity of the transmission crossmember nor fasteners that qualify.
For tloohe front I envision either boxing in the open area by welding in a plate, or fabricating a solid 3/4" Aluminum or Metal brace and using custom shoulder bolts to improve lateral support and prevent shifting.
Boxing makes a stronger brace & also prevents them from distorting from twisting action imparted on.the chassis. from acceleration, deceleration, turning and suspension activity.
Thicker material of course adds weight but is more amenable to shoulder bolts.
Front center crossmember brace...a little on light side. Improvement to be had here...If my design, to increase chassis rigidity , I would have triangulated the entire length of the open drive shaft tunnel with a plate. Rear center crossmember brace presents a different challenge in that it is held in place by chassis studs and washer head nuts incorporating integral spring washer bottom flange..so can't readily use significantly thicker material.. Probably will resort to boxxing in the bracket to increase rigidity, or if using plate steel or aluminum will.use Shoulder bolts with female threads...not sure of stud strength however.
Removed the front center brace for inspection...
It is held in place by four zinc-plated 8-1.25 X 20 bolts...with captive lockwasher/ washer....
A removable bridge holds weld nuts in place and inserts into chassis recess above.
The brace accomplishes a lot for its size but I am able to twist it several degrees in torsion with my bare hands, so chassis flex is probably able to impart even more.
The goal is to increase torsional rigidity of the brace simply boxing in the channel by welding a piece of similar gauge steel across the entire span.
If I box area over bolt holes then may use spacers welded in place beneath where bolts would clamp over the new bottom plate.
Front-center brace....Toyota did a lot with little...boxing in the channel with a formed plate will significantly increase resistance to twisting.. This is nut brace that slips and clips into chassis...M8-1.25 nuts...in the existing chassis mount, there is no room to go to M10 nut.
Tom's Japan (discontinued) and Ultra Racing (Malaysia) sell full sets of underbody chassis bracing for the LS400, including the components you've listed. Tested and known to fit reasonably well.
It is held in place by four zinc-plated 8-1.25 X 20 bolts...with captive lockwasher/ washer....
A removable bridge holds weld nuts in place and inserts into chassis recess above.
The brace accomplishes a lot for its size but I am able to twist it several degrees in torsion with my bare hands, so chassis flex is probably able to impart even more.
The goal is to increase torsional rigidity of the brace simply boxing in the channel by welding a piece of similar gauge steel across the entire span.
If I box area over bolt holes then may use spacers welded in place beneath where bolts would clamp over the new bottom plate.
Front-center brace....Toyota did a lot with little...boxing in the channel with a formed plate will significantly increase resistance to twisting.. This is nut brace that slips and clips into chassis...M8-1.25 nuts...in the existing chassis mount, there is no room to go to M10 nut.
Here is the finished product..
Stainless steel plate used to box in the channel. Sideview depicticting curvature of brace and excellent welding job...
Prior to reinforcement I was able to twist a few degrees with my bare hands...now not at all
For optimum results, welding metal.spacers over through holes and weldimg a metal plate across the entire span
Did you paint it? If not it is just something to rust.
So I guess you would agree that the Lexus engineers did not know much. So why didn't they originally do that to that part? If it was necessary you'd think they would have made improvements.
Did you paint it? If not it is just something to rust.
So I guess you would agree that the Lexus engineers did not know much. So why didn't they originally do that to that part? If it was necessary you'd think they would have made improvements.
It will be painted.....
It is a mass produced part in a mass production vehicle...
For an engineered stamping it achieves good rigidity, but boxxing the U channel puts the ribbon on the package.
Nice welding job and all but, in my opinion, there is no way that adds any rigidity to anything. To me the most important part of those parts is to keep the driveshaft from pole vaulting the car if they were to come disconnected.
Nice welding job and all but, in my opinion, there is no way that adds any rigidity to anything. To me the most important part of those parts is to keep the driveshaft from pole vaulting the car if they were to come disconnected.
It spans to support and brace the open driveshaft tunnel
Probably also serves to hold driveshaft in place should it break free... although not sure for how long...
Replacement hardware acquired from McMaster-Carr. ..M8-1.25X20 grade 10.9 JIS Zinc plated
Nice welding job and all but, in my opinion, there is no way that adds any rigidity to anything. To me the most important part of those parts is to keep the driveshaft from pole vaulting the car if they were to come disconnected.
Repair manual depicting component as "Front Center Floor Crossmember brace...
A few images of Rear Center Floor Crossmember Brace
Rear Center Floor Crossmember Brace is made of aluminium and twists much easier than steel Front Center Floor Crossmember Brace.. While 3 mounting holes on each side, only two are used... Will box brace to increase rigidity.
The surface is shiny where mounting nuts clamp surface indicating movement..When extracting brace (rear wheels on ramps) it shifted slightly while removing nuts, suggesting it is not only there to restrain a broken driveshaft. Would replace it with a steel brace but body studs are flimsy.
11-19-17, 04:18 PM
Front center and rear center crossmember braces
