Replacing Steering Box & Coupler? - PeachParts Mercedes-Benz Forum

mbboy · #1 06-20-2008, 09:33 AM

Since I'm getting ready to replace the leaky steering box on my 380sl, I'm wondering if I should take the opportunity to also replace the steering coupler even though there's no indication the coupler's worn.

Looking at the steering box, I was also wondering whether it's possible to remove the pitman arm without removing the exhaust pipe that travels under it. Any advice would be appreciated.

donbryce · #2 06-20-2008, 12:53 PM

I'm not sure how similar the 380SL is to the 560SL, but FWIW, I removed my steering box and re-sealed it last winter.
I'm fairly certain the exhaust pipe needs to come off. It may be possible to do the job with it in place, but it would be very awkward IMO. It's a *****in' job even with it off. The problem is getting the box out after you have disconnected it. I don't think it will clear the exhaust crossover pipe.
As far as the coupler is concerned, you'll probably have some fun getting the splined shaft on the box out of it. I had to use a heavy hammer and some stout shafting. If you don't damage it during removal of the box, and it is in good shape, I'd leave it in.[IMG]https://www.***************/secure/PartImages/1154600510.jpg[/IMG]
It's a very beefy coupling, and I've never read or heard of one failing in service.

bwostosh · #3 06-20-2008, 01:56 PM

Old nylon is old nylon, especially when exposed to heat.
over 15 yrs, $80 now will save you $111's in the future.

mbboy · #4 06-21-2008, 10:07 AM

Thanks for the advice, guys. Nothing like hearing it from DIY'ers that have done it themselves.

Next question: since i'll have to remove the crossover pipe, should i replace it with one bearing a pre-cat, like the OE, or can I get away with just a pipe. (Do such pipes even exist, or would I have to have one custom made?)

Thanks in advance for the additional info.

meltedpanda · #5 06-22-2008, 09:46 PM

I actually think you will need to take off the manifold, this is a bear of a job without a lift

Mine is leaking too, and I have started several threads on R\R. Search under my name. I am now to the point of just pulling the pitman and replacing the inner seals while its on the car. Some have been able to do this and stop the leak. I got the kit, figure Id try that first

I also have a parts car (380) that I am going to use to practice on

mbboy · #6 06-24-2008, 08:13 AM

Quote:

Originally Posted by meltedpanda

I actually think you will need to take off the manifold, this is a bear of a job without a lift

Mine is leaking too, and I have started several threads on R\R. Search under my name. I am now to the point of just pulling the pitman and replacing the inner seals while its on the car. Some have been able to do this and stop the leak. I got the kit, figure Id try that first

I also have a parts car (380) that I am going to use to practice on

Wow! Thanks a lot for referencing that thread, Ron. One couldn't ask for a more detailed treatment of the pros-and-cons of removing and/or rebuilding a 107 steering box. Given the problems you ran into trying to get the box out, the idea of replacing the seals with the box in place sounds real appealing. Please keep us informed as you progress.

meltedpanda · #7 06-25-2008, 10:16 PM

OK kudos to whoever has removed one of these with the engine still in the car. Tonight , just for the fun of it I decided to see what it would take to get this box out of my parts car. Its an 82 380, no engine,so access was good. three bolts off the side - easy, removal of steering components, I needed to jack up the side to get tension off wheel, but fairly straight forward, I would worry about alingment afterwards. 6MM hex bolt on coupler. Mine was very tight and took all I had with lever arms to break it free, dont know how this could have been done had the engine and manifold been there. getting it out, holy s--t, took forever , had to pry it out of coupler, I literally was sitting in engine bay.
Once again, anyone that has done this with the engine and manifold in place, way to go

My next step is to take off bottom plate and see if in fact the seals I have will stop the leak I have..

gswartzfager · #8 06-25-2008, 11:04 PM

It is a bear of a job even in my 280sl. I have replaced the coupler with the box in the car, and it was not that bad. It made a huge difference in the amount of slack I had in my steering, so my vote is if you are doing to do the box, why the hell not. I mean the part is like $50 to $100 depending where you order it from. Phil right here carries it.

Glenn

mbboy · #9 06-26-2008, 06:07 AM

Quote:

Originally Posted by meltedpanda

6MM hex bolt on coupler. Mine was very tight and took all I had with lever arms to break it free, dont know how this could have been done had the engine and manifold been there. getting it out, holy s--t, took forever , had to pry it out of coupler, I literally was sitting in engine bay.
Once again, anyone that has done this with the engine and manifold in place, way to go

My next step is to take off bottom plate and see if in fact the seals I have will stop the leak I have..

Just wondering if pre-treating the coupler with Liquid Wrench overnight would have made removal a lot easier?

gswartzfager · #10 06-26-2008, 08:22 AM

Sure couldn't have hurt. Honestly mine was not that hard. I did it with the box and everything else still in the car. I did not pre-treat it, but I might have hit it for a few minutes before I went to pull it out.

meltedpanda · #11 06-26-2008, 09:11 AM

I did pre treat it, and I think it helped, if its on the car it is imperative to get this bolt in a position to get a wrench on it. there is no doubt in my mind that you must remove the exhaust on that side to remove it from the car. I am still in hopes that I can learn from disecting this unit how to fix mine whilst on the car

donbryce · #12 06-26-2008, 09:23 AM

Loosen the lower bolt (the one that clamps the coupler to the box shaft), remove it (there is a notch in the shaft that it fits through), then drive a small cold chisel (wedge-shaped end) into the flange to spread it apart a bit. Soaking in penetrant will aid in dissolving rust in the splines.
On my 560SL, there is a metal cover around the base of the steering column that is easily removed from inside the car (4 bolts). It can be slid up the column far enough to get better access to the coupling, and is the only way to get at the top bolt if you want to remove the coupling. It's a real prick to get the allen key/socket in there though, and this one is no easier to get out of the shaft than the lower one. Try it, and after seeing what's involved down there, you might reconsider the value of changing the coupling.
Not sure of your 380SL, but I had to undo the top bearing on the shaft (at the steering wheel) to allow the shaft and coupling to come up far enough to allow clearance to remove the box. This is in the MB shop manual BTW.