Rear Suspension and Rust

[zsolt]

Hello,

I noticed a rust hole on my r4 body where the rear suspension bolts on. The usual place where all r4s rusts.

So I took off the entire rear suspension to make the welding job possible.

The rear suspension was not in a very bad condition, but I decided to clean it from rust and re-paint.



I use citric acid to clean the trailing arm from inside rust, and angle grinder with 80 sanding disk for the rest.

Do you have any advice that could make the cleaning easier?

I don't have access to sand blaster (I have a "toy" version at home") and I don't want to do electrolysis.

Do you recommend me to disassembly the entire suspension to parts, or is it good enough if I paint it assembled?

The suspension is party covered with some material that is like chewing gum, is there any easy way to remove it? I am trying to scrape it off with a flat surface, but this is nasty.

Since many r4s rust bad, I guess you guys have good experience with rust repairs, could you share some tips with me?

How am I going to paint the inside surface of the trailing arm?

If I put liquid into my trailing arm, it stays there, shouldn't it leak out somewhere?

Regards,
Zsolt

 

[petak]

Hi!

Did not disassemble rear axle because i was afraid of to big job.
I have used electrolysis to clear rust and old paint from rear axle.



But still wasn't god enough so i used grinder and wire brush to shine it nicely.
For better cleaning inside of arms i have used small bolts and nuts (M3-M4-M5). Put them inside and tumbled whole day.

After that I have used straw with spray on top of it to spray cleaner/paint and wax inside arms. That straw you can find in car body/paint shops.
First sprayed cleaner and left for few hours. Then sprayed primer in same manner and left for few hours. After that sprayed black paint and left it over night. After few days sprayed body wax inside do fulfill any small hols that have left after this process.
I have put same wax in all chassis holes.
This wax is very fluid so it can reach hard execive points, and after few days hardens like a jelly

rear axle after whole proces




About axle arm draining hole you can find it on top of arm.
Here is picture. It is easier to see that to explain it with words!



Mine was full of small stones that got stacked.
Used small drill to clean it out.
But be careful nut to broke drill inside because than you will have a problem.

My plan is to frequently check this draining hole and clean it if necessary, an put wax inside arms once a year. Hope that it will be enough for preserving axle in good condition.

Hope that i have answered some of your questions. Good luck!

 

[zsolt]

Rust

Hello,

I found the draining holes after 3 days in citric acid they started to leak water through

My battery holder was also heavily rusted, now it's almost clean.



I'll put the stuff back to the lemon juice
for a few more days until I see nothing but bare metal.

I think chemical rust removal works better to clean the inner surface of the arm than electrolysis.

Regards,

Zsolt