steering and suspension Cleaning 45 Years Of Grunge Off Diff? Power Washer?

[prezucha]

 

 

Hello,

I dropped my rear suspension and diff ('67 1600-2) yesterday to replace all bushings and upgrade the springs, shocks, and sway bar.  My question is what is the best way to clean 45 years of grunge off the diff and other parts.  It's about 1/2" thick in places!  Would a power washer be a good idea?  Also, do I need to be very careful about getting water in any areas?  Where the 1/2 axles bolt on? Where the driveshaft attaches? 

 

I've taped plastic bags over these areas for now but I'm just wondering if the seals would protect against dirt, grime, degreaser, water, soap, etc, by themselves?

Thanks!

Paul

 

P.S. Photos appear larger than I wanted and at the beginning of my post, not at end where I intended...

[Mike_B]

Harbor Freight soda blaster. Works great on years of built up greasy crud, but is very gentle on the metal. This is how I'm doing my rear subframe / diff.

[M3M3]

pressure wash away!!  

[tjones02]

I've used Gunk, or Simple Green, or purple "Super Clean" (don't get Super Clean on bare skin) and a parts cleaning brush at home, or tapped up the vent on the diff and taken it all down to my local coin opp car wash and used their pressure washer.... Do not use any scrub like Scotch brite unless you want to repaint where you scuffed. Hot water and Simple Green with a parts cleaning brush and a red rag works OK. If you repaint any of it, or even spot in a few areas, use Würth Satin Black Trim Paint for an EXACT color match. trust me, this paint can blend in so well that many times I can't even tell where it was.

 

Cheers and HTH,

[jgerock]

A gasoline powered pressure washer is the way to go.  

 

 

 

 

[prezucha]

Thanks all!  I can borrow a pressure washer from a friend. This will be good and easier for under the body too!  Thanks for the tip tjones for the paint!  Are you here locally in the San Fran area? 

 

Since I have some attention, what is the best undercoating to use?  My body and underneath is in quite good shape but it would be nice to protect it with something...  once I power wash it...

 

Paul

[jgerock]

I would not apply rubberized undercoating unless you really want to.  To most folks, spraying on undercoating means they want to "hide" some flaws.

 

A few years ago, when I was shopping for my 1st 2002, I flew out to CA and visited some places that were selling 2002's.  Some shops had cars that had fresh rubberized undercoating applied all underneath.  I walked away.  My comments are not meant to say that ALL shops in CA offer Vintage BMW's as tarted up rusty cars.

[prezucha]

I see what you mean about possibly hiding rust, etc.  What are the alternatives?  Body color paint?  I assume that the underside has to be near perfect clean for normal base coat paint to adhere well.  This is what was there originally, correct? I will be painting the car this summer so I guess painting the underside Sahara now would be a good thing...  How clean is clean?  This will not be a show car (with me doing it) by any means but I do want to do the best job I can... 

[jgerock]

One alternative is to use truck bedliner "spray on" coating under a top coat of color.  I'm pondering what to do for the underside of my 69 when it comes back from the body shop.  

 

Applied correctly (uniformly), undercoating looks and performs very well as a stone guard (and noise reducer).  Griot's Garage sells spray on undercarriage detailer.

 

 

[Koblenz]

POR 15?

[tjones02]

Yes, I'm in the North Bay and work at Casey MotorSports in Petaluma (linked in my signature). From NK sedans, '02s and Coupes street rats, and daily drivers to award winning restorations, but the bulk of what we do is still daily modern BMWs ans Minis. Most of our '02 customers come from all over Northern California.

 

If at any time you want a shop to do any of the work on your car we'd be glad to help.

 

If you have any powder coating done bring some of the Wurth paint with you and ask them to match that.

[rey949]

Just spit on it and power wash away the grime. The spitting part really helps...

Rey

[schoir]

I've had good success using POR-15 on the underside of the car.  It does take quite a LOT of effort to remove the factory-applied tar-like coating, but once you get it off and degrease the surface it's a rewarding job.  All it takes at that point is to scuff the paint and grind off any loose rust, then apply the POR-15.  If you are so inclined, you can follow that up with any color coat, including Sahara.  Sahara over POR-15 will be a lot more impervious to the elements than the Sahara (or any other topcoat) alone.

 

Here is the driver's side rear floor pan section being scraped to get rid of the tar coating:

 

Here is what the scrapings look like:

 

Here is the passenger side rear floor pan, almost (but not quite) completely clean and degreased.  It will also have to be scuffed up for the POR-15 to get some good "bite".  If there is some surface rust, the POR-15 will stick especially well there.  You can see the forward passenger side floor pan in the background.  That section has already been covered with POR-15:

 

Regards, Maurice.

 

 

[prezucha]

POR 15 is a great product but IF you ever wanted to remove it I think it would be next to impossible...  But why would one ever want to remove it???

[eurotrash]

Gasoline IN the pressure washer = even better.   hahaha

 

I load the parts up and set them on the grate in the DIY carwash.  They have filtration for this kind of goo.  My driveway doesn't.

 

A gasoline powered pressure washer is the way to go.  

Edited March 27, 2014 by eurotrash