|
|
|
#1
|
|||
|
|||
Cracked frame. W126 owner alert.
I have seen this now three times. On one particular 300SD the sub-frame actually broke completely off of the frame on one side at both mounts! Although the car was able to limp home it was a rather unexpected, catastrophic failure for the owner.
In my case I was servicing the front brakes yesterday and noticed the undercoating bubbling near the rear sub-frame mount. I figured I would scrape all the loose bits of and reapply undercoating to the area. When I removed the loose coating I was disturbed to see a rather extensive crack. See photograph. I had used a wire wheel on a mini grinder to expose the crack as seen in the photograph. I also cleaned up the mount horn to see if there were any cracks there. On the two previous cars the cracks I saw were actually at the bottom of this horn where the horizontal 1/4 inch steel plate, that the sub-frame mount bushing bolts to, attaches to the thinner frame material of the vertical sections of the horn. This is why I used the wire wheel to expose the steel here as well. I welded up the crack and reinforced the mount horn then gusseted the horn to the frame at the 1/4 inch plate. Although the left side was not cracked as far as I could tell I also did the same procedure there. Second photo is of preventative maintenance repair to driver's side (identical to repair on right except no welded crack). Although there was some obvious pocking from corrosion at the crack it was nowhere near serious enough to cause the issue. Indeed the car that completely failed had pristine steel when compared to mine. I have no idea why this is failing on these cars but three is now cause for concern. All were SD's. I only observed and did not repair the others. I would like to say that anyone with a W126 should pay close attention to this area any time you are servicing brakes or removing a front tire for any reason. If you see bubbling, cracked, or loose undercoating remove it to expose the steel underneath. Pay particular attention to the bottom of the frame horn and the area just forward of the horn where it attaches to the frame.
__________________
I don't know the same things that you don't know. Shayne 85 W126 SD OM617.951 87 409D 650S OM617.913 93 E34 Touring M50B25TU 02 E46 Sport M54B30TU |
#2
|
||||
|
||||
I think I have a crank in mine now that I see the pics. But I blew it off not thinking much. I will look again for sure!
__________________
1991 560 SEL / 185k miles 1992 750il / 17k miles - project car |
#3
|
||||
|
||||
30 years of rough road can do that.....we just had the rear trailing arm fail on one of our SDs.....cracked right across the bottom and bent at a severe angle. Car will likely be retired at this point.
__________________
-diesel is not just a fuel, its a way of life- '15 GLK250 Bluetec 118k - mine - (OC-123,800) '17 Metris(VITO!) - 37k - wifes (OC-41k) '09 Sprinter 3500 Winnebago View - 62k (OC - 67k) '13 ML350 Bluetec - 95k - dad's (OC-98k) '01 SL500 - 103k(km) - dad's (OC-110,000km) '16 E400 4matic Sedan - 148k - Brothers (OC-155k) |
#4
|
||||
|
||||
I posted a few days ago about my SD... the crossmember cracked where it attaches to the outer frame...
__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread "as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do! My drivers: 1987 190D 2.5Turbo 1987 190D 2.5Turbo 1987 190D 2.5-5SPEED!!! 1987 300TD 1987 300TD 1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere! |
#5
|
|||
|
|||
High milage fatigue? Cars with very high total milage have always raised questions in my mind. That also is a very large and heavy car.
The 300d 123s are not reporting many cracking issues that I am aware of. Your repair looks adaquate and a good ideal to brace up the otherside at the same time as you did. Rust can get this particular location as well. We have an identical model low milage gas parts car here with a mint interior. It has corrosion failed on the drivers side at the same location. Euro lights and a great engine and transmission. We could not pass it up for 100.00. |
#6
|
|||
|
|||
Could be. Not sure on the other cars I saw that failed/cracked but I have 334,000km on mine.
__________________
I don't know the same things that you don't know. Shayne 85 W126 SD OM617.951 87 409D 650S OM617.913 93 E34 Touring M50B25TU 02 E46 Sport M54B30TU |
#7
|
|||
|
|||
i have seen it on an early '80's 280S. it cracks where the rear part of the front subframe is attaches to the frame rail of the unit body.
__________________
________________ punkinfair |
#8
|
||||
|
||||
W123 and W126 sub frames are configured differently... The W126, of course is bigger and heavier. I've helped change out he rear sub frames which were badly corroded. Of course, southern cars have a better chance of surviving longer due to the lack of salt that they encounter. Northern cars should be reviewed periodically to ensure they are not "falling apart".
__________________
Pete Williams, President emeritus - MBCA-International Stars (Eastern Mich.) Now Wi. & Az. 1985 300D Manual 4 speed Green Hen's tooth 1979 MGB triple black Az car nice 1969 back 1/2 of MGB (Az home built trailer) 1991 Volvo 245 Wagon Nice AZ Restored Gold Brick 1983 Jeep CJ7 37,600 Miles Summer use only |
#9
|
||||
|
||||
What's a "crank?"
|
#10
|
||||
|
||||
Quote:
|
#11
|
||||
|
||||
Structural cracking would seem to be widespread on W126es, it is looking like.
|
#12
|
||||
|
||||
Well....most of them are a minimum of 20 years old with most being much older at this point....there's no telling what 300k of environment and vibration will do to welds....I doubt MB intended for people to be driving these cars for 30-40 years and 500,000 miles.
__________________
-diesel is not just a fuel, its a way of life- '15 GLK250 Bluetec 118k - mine - (OC-123,800) '17 Metris(VITO!) - 37k - wifes (OC-41k) '09 Sprinter 3500 Winnebago View - 62k (OC - 67k) '13 ML350 Bluetec - 95k - dad's (OC-98k) '01 SL500 - 103k(km) - dad's (OC-110,000km) '16 E400 4matic Sedan - 148k - Brothers (OC-155k) |
#13
|
||||
|
||||
mine has 422k and the odo stopped working about 3 years ago
I know I have seen some fishy looking rust in that area. But rust is my SD's major problem. There is a section under the right rocker, behind the front wheel, where I can actually stick my arm up to mid bicep in a hole between the rocker and floor.. kinda hard to describe... it's got rust real bad. I hope to sell it in the spring I may have to rob it for parts and send it to scrap.
__________________
08 R320 CDI current Past 95 E420 87 300D Turbo 5spd 90 300TE 83 300SD 85 300TD 92 400E 85 190D |
#14
|
||||
|
||||
That looks like a spot where I was tempted to jack up the car, but decided not to because of uncertainty. Maybe some shade tree mechanics were lifting the car at that spot which led to failure.
__________________
'81 300SD |
#15
|
||||
|
||||
Answer
This issue is common in Michigan salt.
Who has the most rust and still drives Who has the most rust and still drives .
__________________
ASE Master Mechanic asemastermechanic@juno.com Prototype R&D/testing: Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician. Noise Vibration and Harshness (NVH). Dynamometer. Heat exchanger durability. HV-A/C Climate Control. Vehicle build. Fleet Durability Technical Quality Auditor. Automotive Technical Writer 1985 300SD 1983 300D 1984 190D 2003 Volvo V70 2002 Honda Civic https://www.boldegoist.com/ |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|