Rear end knocking under Acceleration and upon Deceleration

cre · 02-19-2010, 06:26 PM

I'd consider just cutting an opening large enough to fit the head of a spanner and not welding the nut in place.... I can't recall how well fortified that area is though; Some minor reinforcement may be needed if you want to keep the access port open.

TripleC · 02-19-2010, 06:33 PM

Cre on in my hunting for the answer i have seen a few Broken Subframes in these exact spots. Now i am sure those guys had tons of power i an looking to be between 375 what i have now and 500 so i am not sure if i should or shouldnt weld something in. Right now i am considering Welding a Nut to a Rectangular piece of metel and sliding that in to the opening i create. I think this would help hold it in position, Make it so i only have exterior welding to do and be effective in securing it for future removal when and if it is needed. I think i will do a write up on it so everyone can see what i did if they encounter this situation

cre · 02-19-2010, 06:41 PM

The stock nut isn't welded in; it sits inside a metal box which is welded in. I suppose there may have been some revision or early version where the nut wasn't free, but none of those I've worked on have been welded directly in. Putting the nut free in a piece of U channel and tacking that down, similar to the stock arrangement, might not be too difficult.

A break in the place you're talking about isn't a power thing... it's a torque and excess play thing. Your diff's been pounding on it like a slide hammer... this could have happened in a Honda. Time to start going over the car and torquing all the critical fasteners... start with the subframe fasteners next.

TripleC · 02-19-2010, 08:14 PM

What if i welded it to one of the far ends of the u channel. wouldnt it act like a lever and hold the bolt in place if i offset it to one side. this way it could move a little and not need to be welded in but would also secure the nut for install and removal. I could then drill a hole in the bottom and fill it between the Piece of Uchannel and the Bottom of the Subframe.
I am not sure how to break away the cap inside the frame i guess ill just have to use a large srew driver and some pliers to get it out. Punching it from the bottom is also an option since the hole will serve mainly to scoup out the pieces.
Here are some pictures of the subframe.
Should i drill into the side of it or should i go from the bottom next to where the original mount is and hope my custom angled nut piece (LMAO)will fit in and work

cre · 02-20-2010, 04:28 AM

Welding the nut to a floating piece of U channel is not a good idea. If the clamping surface is uneven you increase the likeliness of the nut placing an uneven load on the fastener with the U channel acting as a lever; I'm certain this is the reason for the original method of construction.

I would go at it from the side myself. It depends on how large of an aperture you need and what you're using to cut with and weld with though.

TripleC · 02-22-2010, 02:48 PM

SO S### hit the fan on Friday when i went home. I looked at the project at hand and with more light realized that the worst that could have happened did. Subframe Broken in Half.

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So since this is going to be my Drift car and sometimes Daily vehicle i figured i will just weld the subframe back together and Fix the broken Cap for the Square nut thats in the subframe. i welded a nut to a piece of Steel and fit it into the Frame which worked perfectly and i put the circle that i cut witht he hole saw and filled in the gaps (plus i laid down a little extra metel for good looks. LOL). I had to do the same thiing to the other side as it was originally like this (past owner never fixed) and definetly added to the broken subframe i had. I used a Grade 8 Washer from Home depot to fill the hole this time which was easy'r then the orignal frame and thicker. (i finished this entire project in about 6 hrs)All in all I am going to drive it hard this week after the snow melts and see if i can get the frame to crack again if it does i will reweld it again and put in some extra metel in to get it to hold the subframe together.

02-19-2010, 06:26 PM	#1
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	I'd consider just cutting an opening large enough to fit the head of a spanner and not welding the nut in place.... I can't recall how well fortified that area is though; Some minor reinforcement may be needed if you want to keep the access port open. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-19-2010, 06:33 PM	#2
TripleC 3" Exhaust Join Date: Nov 2009 Location: Fort Collins, CO Posts: 103	Cre on in my hunting for the answer i have seen a few Broken Subframes in these exact spots. Now i am sure those guys had tons of power i an looking to be between 375 what i have now and 500 so i am not sure if i should or shouldnt weld something in. Right now i am considering Welding a Nut to a Rectangular piece of metel and sliding that in to the opening i create. I think this would help hold it in position, Make it so i only have exterior welding to do and be effective in securing it for future removal when and if it is needed. I think i will do a write up on it so everyone can see what i did if they encounter this situation __________________ 1JZGTE ,R154, Hallman Boost Controller, HKS bov, HKS Mushroom top Air Filter, HKS Front Mount Intercooler, Greedy Turbo Timer, PLX300 AFC, Custom Divorced Y-pipe, Custom Intercooler Pipeing, RS-R Concept Exhaust, Optima Red Top Battery, Strut bar Brembo Rotors, A1 Traction arms, Megan Coilovers, Stern ST 2 wheels rear 265x30 r19 - front 245x35 r19, New Front Lip, 18 x 8 and 18 x 9 MRR HR2 with whatever for Drift treads 2 additional C12A turbo's(Extra)

02-19-2010, 06:41 PM	#3
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	The stock nut isn't welded in; it sits inside a metal box which is welded in. I suppose there may have been some revision or early version where the nut wasn't free, but none of those I've worked on have been welded directly in. Putting the nut free in a piece of U channel and tacking that down, similar to the stock arrangement, might not be too difficult. A break in the place you're talking about isn't a power thing... it's a torque and excess play thing. Your diff's been pounding on it like a slide hammer... this could have happened in a Honda. Time to start going over the car and torquing all the critical fasteners... start with the subframe fasteners next. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-19-2010, 08:14 PM	#4
TripleC 3" Exhaust Join Date: Nov 2009 Location: Fort Collins, CO Posts: 103	What if i welded it to one of the far ends of the u channel. wouldnt it act like a lever and hold the bolt in place if i offset it to one side. this way it could move a little and not need to be welded in but would also secure the nut for install and removal. I could then drill a hole in the bottom and fill it between the Piece of Uchannel and the Bottom of the Subframe. I am not sure how to break away the cap inside the frame i guess ill just have to use a large srew driver and some pliers to get it out. Punching it from the bottom is also an option since the hole will serve mainly to scoup out the pieces. Here are some pictures of the subframe. Should i drill into the side of it or should i go from the bottom next to where the original mount is and hope my custom angled nut piece (LMAO)will fit in and work Attached Thumbnails __________________ 1JZGTE ,R154, Hallman Boost Controller, HKS bov, HKS Mushroom top Air Filter, HKS Front Mount Intercooler, Greedy Turbo Timer, PLX300 AFC, Custom Divorced Y-pipe, Custom Intercooler Pipeing, RS-R Concept Exhaust, Optima Red Top Battery, Strut bar Brembo Rotors, A1 Traction arms, Megan Coilovers, Stern ST 2 wheels rear 265x30 r19 - front 245x35 r19, New Front Lip, 18 x 8 and 18 x 9 MRR HR2 with whatever for Drift treads 2 additional C12A turbo's(Extra)

02-20-2010, 04:28 AM	#5
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Welding the nut to a floating piece of U channel is not a good idea. If the clamping surface is uneven you increase the likeliness of the nut placing an uneven load on the fastener with the U channel acting as a lever; I'm certain this is the reason for the original method of construction. I would go at it from the side myself. It depends on how large of an aperture you need and what you're using to cut with and weld with though. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

02-22-2010, 02:48 PM	#6
TripleC 3" Exhaust Join Date: Nov 2009 Location: Fort Collins, CO Posts: 103	SO S### hit the fan on Friday when i went home. I looked at the project at hand and with more light realized that the worst that could have happened did. Subframe Broken in Half. So since this is going to be my Drift car and sometimes Daily vehicle i figured i will just weld the subframe back together and Fix the broken Cap for the Square nut thats in the subframe. i welded a nut to a piece of Steel and fit it into the Frame which worked perfectly and i put the circle that i cut witht he hole saw and filled in the gaps (plus i laid down a little extra metel for good looks. LOL). I had to do the same thiing to the other side as it was originally like this (past owner never fixed) and definetly added to the broken subframe i had. I used a Grade 8 Washer from Home depot to fill the hole this time which was easy'r then the orignal frame and thicker. (i finished this entire project in about 6 hrs)All in all I am going to drive it hard this week after the snow melts and see if i can get the frame to crack again if it does i will reweld it again and put in some extra metel in to get it to hold the subframe together. __________________ 1JZGTE ,R154, Hallman Boost Controller, HKS bov, HKS Mushroom top Air Filter, HKS Front Mount Intercooler, Greedy Turbo Timer, PLX300 AFC, Custom Divorced Y-pipe, Custom Intercooler Pipeing, RS-R Concept Exhaust, Optima Red Top Battery, Strut bar Brembo Rotors, A1 Traction arms, Megan Coilovers, Stern ST 2 wheels rear 265x30 r19 - front 245x35 r19, New Front Lip, 18 x 8 and 18 x 9 MRR HR2 with whatever for Drift treads 2 additional C12A turbo's(Extra)