Jump to content
Ultimate Subaru Message Board

What are the options when the rear frame rails for the 86 brat is all rotted out?


Recommended Posts

What to do? What to do??

 

I just picked up an 86 brat in great shape but....................

 

My rear frame rails are all rotted out where the torsion bar mounts.

 

I am going to try frame rails from an 84 wagon I just got for $200

 

First attempt..

Edited by mcgyver331
correcting wagon year
Link to comment
Share on other sites

I had a brat a long time ago that had a busted torsion bar, plus the frame rail was rotted badly...

 

I did this...

http://www.indysworld.com/80s/general/USRM/mick-usrm/Strutsinrear/strut.html

 

 

 

 

I like the way you did that but the trailing arms are attached to the torsion bar mounting area too and it is sunken into the body about 1 inch. I will be gutting the bottom of the bed next week.

Link to comment
Share on other sites

I like the way you did that but the trailing arms are attached to the torsion bar mounting area too and it is sunken into the body about 1 inch. I will be gutting the bottom of the bed next week.

 

If it's that bad it'll have to be full rebuilding/strengthenig of that entire area, and redo susp mounting points, etc....

 

but, if it's that bad there, I can only image how the rest of frame rails look. short of a complete custom subframe build, it's only a matter of time before it collapses...

Link to comment
Share on other sites

I would predict what you need to do and add at least 25%...cut out, rebuild, restore more than you think you need to.

 

A board member brought his RX to my place for some turbo/intercooler fabbing, the car collapsed due to severe rust in the rear, car just sat right on the rear tires, it was crazy.

Link to comment
Share on other sites

If it's that bad it'll have to be full rebuilding/strengthenig of that entire area, and redo susp mounting points, etc....

 

but, if it's that bad there, I can only image how the rest of frame rails look. short of a complete custom subframe build, it's only a matter of time before it collapses...

 

 

 

Actually the entire rest of the car and even the rear half past the sway bar is in excellent condition. Will take some pics as I start this weekend. oh yea BTW nice Solid Axle build !!!!!!!!!!!

Edited by mcgyver331
addition
Link to comment
Share on other sites

Quite simple really rust is like an iceberg there is always more then what you see.

Buy a cheap Chinese made folder my basic one cost $60.00 Australian .

Read, up on bend radius and check dumpsters near sheet metal fab shops for free offcuts.

Beg borrow or make a Rotational jig or carefully drain liquids and gently lay vehicle on it's side maybe on some old tyre's for better access.

Cutting and welding in an easy position will make the job much easier and more likely to be finished to a high standard and not be put off because it is too much like hard work.

Use a Mig Welder and where there is an area where a duplicate of any factory flanged area is required that the factory spot welds drill a hole about 6~8mm diameter and fill with a plug weld to the underlying metal section.

As well look into edge welding along the lines of "Stitch welding as done to rally cars for additional strength.

remember to always join in new metal to a frame rail with something along the lines of a 45 degree slash cut never use a vertical weld bead on any chassis section as this will cause it to fracture beside the vertical weld.

It is actually illegal to weld vertically across a chassis section in Australia because the stress concentration will always cause a failure at that point.

Remember to treat the rail internally against rust after welding with a coating such as fish oil to break the cycle of corrosion by eliminating one or more of the required elements for corrosion such as oxygen access to the area.

Additional strengthening can also be added as well as skid sections if serious off road use is envisaged in the future at the same time.

Any brat is actually worth fixing as no manufacturer has made a replacement vehicle with the Brat's unique abilities and characteristics,at least so far

Link to comment
Share on other sites

Well started tearing into it finally. :Flame:

 

I cut out alot of rot, the mounts for the torsion bar housing and the diff holder.

 

I also pulled the tank, what a nightmare... :banghead:One of the tank's welded nuts broke free from the cross brace on the bottom of the bed. I cut a small hole up in the bed area to get to it with a 13mm. Had to use 13 due to the welds.

 

I will start uploading pics soon.

 

I have also braced the rear bumper with wood like a sawhorse just incase while I'm cutting the crap out it decides to buckle.:brow:

Link to comment
Share on other sites

Quite simple really rust is like an iceberg there is always more then what you see.

Buy a cheap Chinese made folder my basic one cost $60.00 Australian .

Read, up on bend radius and check dumpsters near sheet metal fab shops for free offcuts.

Beg borrow or make a Rotational jig or carefully drain liquids and gently lay vehicle on it's side maybe on some old tyre's for better access.

Cutting and welding in an easy position will make the job much easier and more likely to be finished to a high standard and not be put off because it is too much like hard work.

Use a Mig Welder and where there is an area where a duplicate of any factory flanged area is required that the factory spot welds drill a hole about 6~8mm diameter and fill with a plug weld to the underlying metal section.

As well look into edge welding along the lines of "Stitch welding as done to rally cars for additional strength.

remember to always join in new metal to a frame rail with something along the lines of a 45 degree slash cut never use a vertical weld bead on any chassis section as this will cause it to fracture beside the vertical weld.

It is actually illegal to weld vertically across a chassis section in Australia because the stress concentration will always cause a failure at that point.

Remember to treat the rail internally against rust after welding with a coating such as fish oil to break the cycle of corrosion by eliminating one or more of the required elements for corrosion such as oxygen access to the area.

Additional strengthening can also be added as well as skid sections if serious off road use is envisaged in the future at the same time.

Any brat is actually worth fixing as no manufacturer has made a replacement vehicle with the Brat's unique abilities and characteristics,at least so far

 

 

Definately will be cutting and welding in the new pieces in a step style and even then placing a flat brace 4+ inches in each direction over my stiches.

 

I have every intention of this bieng a long lasting toy. I have built 1 ton trucks (k5 blazer + c30 parts) and gusseted the crapola out of it.

 

I will be doing my repairs first and then lifting after due to time and $$$ constraints at the moment.

 

Thank you.

Link to comment
Share on other sites

did more on the brat today, and the frame rails from the wagon are short on the front side, boo. Just add a little more metal and off we go.

 

I have the drivers side trimmed out and fitted, I am using the wheelwell, the frame and some of the rear deck from the wagon.

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...