79 - Trailing arm rebuild
#1
Racer
Thread Starter
79 - Trailing arm rebuild
Since my differential rebuild project ran into a snag, I decided to switch my attention to the next project which is the rebuild of the trailing arms.
The project entails the following:
- Removing the arms - disassembling them - sandblasting - epoxy and top coat painting
- Replace the bushings
- Do a rear bearing job
There are plenty of horror stories about removing the trailing arms but I have to admit that I am one of the lucky ones - they came out quite easily. Everything looked majorly crusty and don't know if anyone has been back there recently - may be.
To remove the trailing arm (assuming the half shafts are out which is my starting point):
- Remove the caliper, the brake line that goes from the caliper to the brake hose and the rear rotor
- Disconnect the parking brake from the hub and from the trailing arm itself
- Remove the shock absorber
- Remove/cut the cotter pin from the trailing arm mount bolts
- Unbolt the mounting nut (you need a 5/8" and 11/16" wrenches)
- Use a brass drift to push the bolt from the outside to the inside and then finish the bolt extraction using a pry bar.
- Pull the arm out - you may have to work it up and down to get it loose from its rusty alignment shims.
- Oh, use lots of Kroil (I wonder if that was my secret weapon to get everything out so easily).
The project entails the following:
- Removing the arms - disassembling them - sandblasting - epoxy and top coat painting
- Replace the bushings
- Do a rear bearing job
There are plenty of horror stories about removing the trailing arms but I have to admit that I am one of the lucky ones - they came out quite easily. Everything looked majorly crusty and don't know if anyone has been back there recently - may be.
To remove the trailing arm (assuming the half shafts are out which is my starting point):
- Remove the caliper, the brake line that goes from the caliper to the brake hose and the rear rotor
- Disconnect the parking brake from the hub and from the trailing arm itself
- Remove the shock absorber
- Remove/cut the cotter pin from the trailing arm mount bolts
- Unbolt the mounting nut (you need a 5/8" and 11/16" wrenches)
- Use a brass drift to push the bolt from the outside to the inside and then finish the bolt extraction using a pry bar.
- Pull the arm out - you may have to work it up and down to get it loose from its rusty alignment shims.
- Oh, use lots of Kroil (I wonder if that was my secret weapon to get everything out so easily).
#2
Racer
Thread Starter
Removing the trailing arm bushings
The bushings on my trailing arms have got to be the originals. There were sloppy and upon removal of one of them, half of it had disintegrated over the years.
- Using a 5/8" drill bit I worked on the flare side on the inboard side
- Using prying motions I was able to separate the two halves.
This was straightforward. I am putting a polyurethane set back on when the time comes.
- Using a 5/8" drill bit I worked on the flare side on the inboard side
- Using prying motions I was able to separate the two halves.
This was straightforward. I am putting a polyurethane set back on when the time comes.
#4
Drifting
I just did mine. Went very easy no problems. In the last pic you still have to take out whats left of the bushings.
#5
Racer
Thread Starter
#6
Melting Slicks
Member Since: Jul 2010
Location: perth western australia
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Very nice , in your first pic ,it does look like someone has been into the left arm recently , newer shield and clean looking dust shields over the bearing housing.
Right side unit seems to have newer hand brake components as well.
That's a nice hoist in you garage as well.
Right side unit seems to have newer hand brake components as well.
That's a nice hoist in you garage as well.
#7
Racer
Thread Starter
Very nice , in your first pic ,it does look like someone has been into the left arm recently , newer shield and clean looking dust shields over the bearing housing.
Right side unit seems to have newer hand brake components as well.
That's a nice hoist in you garage as well.
Right side unit seems to have newer hand brake components as well.
That's a nice hoist in you garage as well.
Waiting on some specialty tools that will allow me to disassemble the hubs remove/install rear bearings. Probably next weekend for the next substantial update.
#8
Le Mans Master
You may want to reconsider installing poly trailing arm bushings. I had to replace the bushings in my 66 and 68. I also helped two friends replace theirs. It was exciting to drive the 66 home when one of the poly bushings turned to glass and fell out. Jerry
#9
Racer
Thread Starter
The most difficult part is removing the spindle from the hub and #2 difficult part is removing the inboard bearing - however - with the two specialty tools that one can get from the Corvette vendors this job becomes infinitely easier (spindle knockout tool and the bearing splitter).
#11
Racer
Thread Starter
Some pics - not quite in order but you get the idea
#12
Racer
Thread Starter
A few more pics:
#14
Racer
Thread Starter
After sitting on this project for a couple of months, it is back on! I sandblasted the trailing arms, cleaned, primed, painted. Replaced the bearings, seals and bushings. I used the specialty tools from Corvette America X24325 Rear Wheel Bearing Setup Tool and X2478 Rear Spindle Installation Tool - you will need the bearing kits and the rear wheel spindle bearing spacers kit. You will also need a dial indicator and base to dial the correct shim in. All and all, for a serious DIY, it is not that bad of a job. Instructions are straightforward.,
#15
Drifting
I have also just finished rebuilding the trailing arms on my 77. I also relocated the parking brake cable bracket and powder coated the arms.
Last edited by persuader; 12-08-2018 at 09:56 PM.
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Lagonia (12-09-2018)
#16
Race Director
The YELLOW arrow is pointing to the sleeve that you had to stake to keep the bushing together. JUST MAKE SURE that you file or grind on any of exposed sleeve material FLAT that is ABOVE the flat surface of the special tapered washer. You want to make sure your shim lays flat against the washer ...and not have any of this sleeve poking out. It can screw with you when you go to set your toe when aligning your car.
DUB
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Lagonia (12-09-2018)
#17
Race Director
FOR WHAT IT IS WORTH:
Setting your rear wheel bearing to -0- is best if at all possible. SO setting it at .002" run out adn thinking it is going to stay t that is not going to happen....it will increase in time.
Also verify your rotor run-out is correct also. Many times it is off greatly and will need to be indexed with a shim. Failure to do so can cause for brake caliper issues due to the brake caliper as as you all know...is directly bolted to the trailing arm and are SOLIDLY MOUNTED. Unlike most other brake calipers which ride on pins and can float. SO...bearing and rotor run-outs in this area is critical.
DUB
Setting your rear wheel bearing to -0- is best if at all possible. SO setting it at .002" run out adn thinking it is going to stay t that is not going to happen....it will increase in time.
Also verify your rotor run-out is correct also. Many times it is off greatly and will need to be indexed with a shim. Failure to do so can cause for brake caliper issues due to the brake caliper as as you all know...is directly bolted to the trailing arm and are SOLIDLY MOUNTED. Unlike most other brake calipers which ride on pins and can float. SO...bearing and rotor run-outs in this area is critical.
DUB
The following users liked this post:
Lagonia (12-09-2018)
#18
Racer
Thread Starter
Thanks for the tips DUB, very nice work, btw. Nice jig you have to hold the arm in place - could've used one!
#19
Drifting
FOR WHAT IT IS WORTH:
Setting your rear wheel bearing to -0- is best if at all possible. SO setting it at .002" run out adn thinking it is going to stay t that is not going to happen....it will increase in time.
Also verify your rotor run-out is correct also. Many times it is off greatly and will need to be indexed with a shim. Failure to do so can cause for brake caliper issues due to the brake caliper as as you all know...is directly bolted to the trailing arm and are SOLIDLY MOUNTED. Unlike most other brake calipers which ride on pins and can float. SO...bearing and rotor run-outs in this area is critical.
DUB
Setting your rear wheel bearing to -0- is best if at all possible. SO setting it at .002" run out adn thinking it is going to stay t that is not going to happen....it will increase in time.
Also verify your rotor run-out is correct also. Many times it is off greatly and will need to be indexed with a shim. Failure to do so can cause for brake caliper issues due to the brake caliper as as you all know...is directly bolted to the trailing arm and are SOLIDLY MOUNTED. Unlike most other brake calipers which ride on pins and can float. SO...bearing and rotor run-outs in this area is critical.
DUB
Last edited by persuader; 12-10-2018 at 08:08 AM.
#20
Racer
Thread Starter
Trailing arms installed
I ran the grinder in the trailing arm pockets in the chassis and cleaned away loose rust. I then coated the pockets with Ospho to neutralize any remaining surface rust. I then put two coats of primer and two coats of engine enamel.
Installing the arm by myself was not going to happen. I quickly built a stand for the trailing arm out of 1" square tubing and 1.25" x 0.25" flat steel plate - it worked like a charm when supported by the transmission lift
Installing the arm was a breeze - I run floss through the trailing arm bush bolt to run it through the frame and the trailing arm - I tried to match the shims to the thicknesses of the shims I removed but really that needs to be adjusted when the alignment is done on the rear end
Trailing arms, refurbished rotors, new brake lines (both soft and hard), new shock aborbers, new strut rods - all installed.
The springs are refurbished and are also good to go. I now need to finish the rebuild of the differential case
Installing the arm by myself was not going to happen. I quickly built a stand for the trailing arm out of 1" square tubing and 1.25" x 0.25" flat steel plate - it worked like a charm when supported by the transmission lift
Installing the arm was a breeze - I run floss through the trailing arm bush bolt to run it through the frame and the trailing arm - I tried to match the shims to the thicknesses of the shims I removed but really that needs to be adjusted when the alignment is done on the rear end
Trailing arms, refurbished rotors, new brake lines (both soft and hard), new shock aborbers, new strut rods - all installed.
The springs are refurbished and are also good to go. I now need to finish the rebuild of the differential case