Rear end knocking under Acceleration and upon Deceleration

StonecoreTx · 05-03-2010, 06:59 PM

Well this weekend I had some spare time and jacked up the car again for round 3.

the car won with a huge crack in the subframe!
I dont have a pic yet but It's about the same size if not a bigger gap and place as yours pictured above where the shaft meets the diff. =(

Is it possible to repair? I belive this is why my diff mounting bolt holes dont allign, and creates the clunking noise when not under load.

I'm planning on dropping the subframe and welding the crack hopfully everything will align if it's solid again? or should I hold out for another subframe?

Tripple C, what are you going to do about yours?

TripleC · 05-03-2010, 07:19 PM

I welded it back together. I Took out the diff and swapped it for a welded this weekend and finished the welding on the botom side of the subframe Rail.
I started by welding the actuall frame back together then created some 3/4 inch flat pieces of steel and welded them on to the outside of the frame for more support. I also Drilled holes in the Metal piece so i could fill in a rosette weld and make it stronger. Not just an edge or rosette weld I put on some extra leyers on for mental security.
The frame is holding great and trust me i have been beating it to death. In fact it currently isnt running but thats not because of the subframe. i have ignition or Mainly fuel delivery problems

StonecoreTx · 05-04-2010, 07:08 AM

I'm going to wait out on another subframe in better shape and reinforce it, I didn't realize how much crap that area of the subframe is... apparently it is a common problem for 2 key areas on the rear subframe 1.) right where the front diff mounting bolts and subframe meet 2.) above the diff where it connects to the driveshaft. everyone should go under the rear of their car if not already done so and check these areas of your subframe. I suspect that age and the more torque the diff puts more stress that causes these cracks.

I found tons of info and pictures in detail about this particular problem
http://www.supraforums.com.au/forum/...p?t-43162.html

TripleC · 05-04-2010, 01:03 PM

good plan on getting the new subframe. I will be doing the same time but in the mean time i am using what i have until i find one in my area.
If you had time and wanted a cage you should just try and build your sumframe into the cage. I know thats a big budget move but i dont know what kind of mechanic you are.
Weld it back together till you find yourself a new one, it takes hardly any time at all when you really think about it.

StonecoreTx · 05-12-2010, 06:06 PM

I'm not 100% sure if I want to repair my orig subframe or wait out of another one. My main concern is that maybe my subframe is twisted a bit and the front mounting bolt holes dont line up. =/ my crack is located right above the diff. seems like it's about to snap in half...

to weld or not to weld?

TripleC · 05-12-2010, 07:12 PM

Welding - not so much money (some would say free)
New Subframe - More money then welding ($150 -1500)

05-03-2010, 06:59 PM	#1
StonecoreTx Intake Join Date: Dec 2009 Location: Austin,Tx Posts: 41	Well this weekend I had some spare time and jacked up the car again for round 3. the car won with a huge crack in the subframe! I dont have a pic yet but It's about the same size if not a bigger gap and place as yours pictured above where the shaft meets the diff. =( Is it possible to repair? I belive this is why my diff mounting bolt holes dont allign, and creates the clunking noise when not under load. I'm planning on dropping the subframe and welding the crack hopfully everything will align if it's solid again? or should I hold out for another subframe? Tripple C, what are you going to do about yours? __________________ 86.5 mk3 supra 7mgte r154

05-03-2010, 07:19 PM	#2
TripleC 3" Exhaust Join Date: Nov 2009 Location: Fort Collins, CO Posts: 103	I welded it back together. I Took out the diff and swapped it for a welded this weekend and finished the welding on the botom side of the subframe Rail. I started by welding the actuall frame back together then created some 3/4 inch flat pieces of steel and welded them on to the outside of the frame for more support. I also Drilled holes in the Metal piece so i could fill in a rosette weld and make it stronger. Not just an edge or rosette weld I put on some extra leyers on for mental security. The frame is holding great and trust me i have been beating it to death. In fact it currently isnt running but thats not because of the subframe. i have ignition or Mainly fuel delivery problems __________________ 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)

05-04-2010, 07:08 AM	#3
StonecoreTx Intake Join Date: Dec 2009 Location: Austin,Tx Posts: 41	I'm going to wait out on another subframe in better shape and reinforce it, I didn't realize how much crap that area of the subframe is... apparently it is a common problem for 2 key areas on the rear subframe 1.) right where the front diff mounting bolts and subframe meet 2.) above the diff where it connects to the driveshaft. everyone should go under the rear of their car if not already done so and check these areas of your subframe. I suspect that age and the more torque the diff puts more stress that causes these cracks. I found tons of info and pictures in detail about this particular problem http://www.supraforums.com.au/forum/...p?t-43162.html __________________ 86.5 mk3 supra 7mgte r154

05-04-2010, 01:03 PM	#4
TripleC 3" Exhaust Join Date: Nov 2009 Location: Fort Collins, CO Posts: 103	good plan on getting the new subframe. I will be doing the same time but in the mean time i am using what i have until i find one in my area. If you had time and wanted a cage you should just try and build your sumframe into the cage. I know thats a big budget move but i dont know what kind of mechanic you are. Weld it back together till you find yourself a new one, it takes hardly any time at all when you really think about it. __________________ 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)

05-12-2010, 06:06 PM	#5
StonecoreTx Intake Join Date: Dec 2009 Location: Austin,Tx Posts: 41	I'm not 100% sure if I want to repair my orig subframe or wait out of another one. My main concern is that maybe my subframe is twisted a bit and the front mounting bolt holes dont line up. =/ my crack is located right above the diff. seems like it's about to snap in half... to weld or not to weld? __________________ 86.5 mk3 supra 7mgte r154

05-12-2010, 07:12 PM	#6
TripleC 3" Exhaust Join Date: Nov 2009 Location: Fort Collins, CO Posts: 103	Welding - not so much money (some would say free) New Subframe - More money then welding ($150 -1500) __________________ 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)

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