When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I want to completely clean/degrease the inside and outside ofboth trailing arms.
I tried brake cleaner but it is very hard to get it inside properly. There this black tar stuff inside. I think it’s a kind of underside protection that has dried out somewhat. It’s also very rusty in there.
Already have the POR15 products and some cans of Eastwood internal frame coating.
Will the bearing seals deteriorate or will there be no problems?
The rear bearings were replaced by the previous owner. So in fairly good condition I think (No noises when driving etc.)
I would not recommend immersing them in anything as the seals may become compromised and allow whatever product you are using to flow into the bearings and attack the grease.
In a perfect world, you’d fully disassemble the arms, then you could find a company that would electrochemically strip them. However, since they are assembled, I’d get some wire brushes and mechanically clean them. If you have an air compressor, you could get an inexpensive sand blaster but you’d need to duct tape to protect the seals. A wire brush on an electric drill will cut the time down significantly.
I would not immerse the T/A assembled into any kind of solvent, The inner housing is filled with grease, and that woud ruin your grease and the grease around your bearsings, UT would also probably eat away your seals. I would recommend going the rest of the way and disassembling the T/As, clean it all up, get new bearings and do it up right. It is not an impossible job. IF need be a machine shop can set your bearings for you.
Taking short cuts at this point is well pointless. You already have them removed so just rebuild them, trying to just clean and paint is lipstick on a pig. If that is your only option than use a wire wheel on a drill to clean them the best you can than apply paint from a rattle can. I wouldn't mess with Pro-15.
2020 Corvette of the Year Finalist (performance mods)
2019 C3 of Year Winner (performance mods)
2016 C3 of Year Finalist
I would just spray them with simple green and let it soak , then scrub them. Then clean the residue off with acetone or xylene. THen paint. Unless you are trying to make your car pristine and look like it just rolled off the assembly line, manually cleaning them will give you good results
Unless you are a full-up gearhead like some of us who are willing to dedicate time and expense to learn how to do the job correct and have all the proper tools needed, I would not recommend tackling rebuilding the arms with one caveat. That caveat is that you should take them to a machine shop where they can, with a proper dial indicator, measure the axial play in the bearings.
When new, the factory set these at 0.003-0.008”. When rebuilding, we shoot for 0.001-0.0015”. If yours measure more than 0.008”, then you need to think carefully about your long term goals with the car. I will just about guarantee you will see other posters give you specific recommendations along the lines of “if more than 0.00X”, then change them” so I am not going to give you a hard number but instead offer this to consider:
These bearings will not last forever but properly set up, will last a long time. As mentioned above, they were originally set up at the factory in the 0.003-0.008” range. Bearings do wear so irrespective of what the actual play value was when new, a bearing will, after, say 50,000 miles, exhibit a bit more axial play than when new. A bearing setup on the tighter side (let’s say 0.003”) may exhibit a value still within the OEM specification range whereas a bearing that was setup at 0.008”, will exhibit a value outside of the specifications.
So does this mean that if you measure the play and find, say 0.010”, does this mean they need to be replaced? Not necessarily, but this is where you need to think bigger picture. How many miles do you intend to drive the car? Where do you plan to drive it? How concerned are you that you might experience a bearing failure - being stranded far from home?
If they measure out at 0.008” or less, mechanically clean up the arms, treat the bare metal with DX579 phosphoric acid based cleaner and rattle can paint.
If they measure more than 0.008” and you want increased confidence against a failure, then either rebuild them or obtain a rebuilt set.
If they measure more than 0.008” and you are willing to accept some risk, clean them as above and check the play again down the road. The mileage you accrue until remeasure will depend on the amount of play you have now. As a recommendation, I would offer 5000 miles if you measure 0.010” and 1000 if you measure 0.015”.
BTW - one of my “bucket list” items is to sit in the stands at Eau Rouge for the Belgian GP!
I will try the Simple green method (here it's called 'Dreft'). Maybe that will be enough.
Rebuilding the bearings will be a problem I think... The prvious owner (or workshop/garage) did something strange to the bolts... Will send a clear picture.
Oh and I bought a stiff nylon chimney brush, gonna try it out tomorrow.
Interesting.
Well you're overseas, that kind hurts you with this stuff since you're probably limited on resources and experienced mechanics. Based on your last thread on differentials I would say you are stuck between a rock and a hard place. Sorry I am not trying to negative here but you are getting involved with with work that is critical to drivability and safety of the car.
Looking at those arms there are 2 apparent issues.
1- The arms appear to need attention
2- They were worked on already but some inexperienced mechanic.
When I get in arms like this they are usually damaged by the previous workers more so then age. Looking at how they cut the axle flange to access the anchor lock, I can only imagine how the bearings are setup.
Cleaning and painting those arms in that condition is a waste of time since nice looking black arms can lock up bearings as much as rusted looking one.
Again just trying to be direct not critical with my choice of words.
You were willing to pull the trailing arms off the car so you must have some mechanical aptitude. There is nothing magic about the fact these are off a Corvette. The mechanical principles involved in the repairs are used on thousands of European cars every day. A good mechanic how works on BMWs or VWs or Skodas every day can do this job if they are provided some specific instructions and they are willing to listen and work with you.
We can walk you through the process of rebuilding the arms if you want. To do the job correctly, you’ll need/have access to:
Shop press (20 ton preferred but 12 or 15 ton will work)
Bearing splitter
Dial Indicator (and magnetic mount)
Micrometer
Bearing setup tool
Torque wrench
A means to determine parallelism of the bearing spacer (machine shop)
The alternative is to, as we say, bite the bullet and buy a complete pair of rebuilt arms. Shipping across the Atlantic (we call it the Pond), will run you about $200 and I believe you have a VAT that will tack on another 20% so figure a pair of arms here in the States is $1000 plus a $600 core charge and you are looking at around $2100 USD but you’d get net $400 back once the cores are back here. However, given the condition of the axle flanges, the rebuilder would reject those so you might get a net $150 return.
Given those costs, you have quite a bit of room, budget wise, to rebuild yours. You’ll also have the satisfaction of knowing you did it but that may or may not appeal to you.
We’re here to help. Let us know what you want to do.
Trailing arm cleaning
