New second hand super low 2.5t floor jack


Skirts lifted high!
Since the last couple of days, T-Rex has started to make some weird noises... When accelerating I hear a "fluttering" noise coming from the transmission tunnel just under the gear shift. It gets pretty loud when I accelerate more than just a gentle throttle opening. It has been getting worse and yesterday evening going to higher grounds to watch the lunar eclipse it made the noise nearly all the time. Surprisingly when coming back home later and driving downhill, the noise was practically non existent.

Got her in the workshop and lifted her skirts high enough to sit on axle stands. I invested last week in a new second hand 2.5t super low floor jack to replace my two dinky 1,5t ones which are a pain to use as they don't jack very high, so I have to work round the vehicle with pieces of wood to finally get a decent height.

Pulled the exhaust from the cats back to give open access to the driveshaft after having also removed the metal heat shield. First checked the two flex discs at either end and both look in perfect condition, so that's a problem area which doesn't need further investigation. I'll be also changing the transmission rear rubber support as I get some clunks when shifting into R or D. This seems to solve this noise problem.

Now having a nice view on the transmission shaft from front to back, a first visual doesn't show much. When twisting the shaft there is a slight knocking noise. I made a video (not very good quality) but you can hear the knock. I may try making something tomorrow with my GoPro which is hanging around in a drawer somewhere


What should I do? Remove the transmission shaft from the vehicle and take a closer look on the workbench? The parts look original and she's got close to 300'000 km on the clock, so they could be worn out. Also hoping it's not something more dramatic going on in the transmission

 

From comments by those in the know, it would seem the U joint and support bearing are shot. Just need to know exactly what needs changing and perhaps if it's not a DIY operation, I'll dismantle and bring the complete drive shaft unit to my local dealer to do the work or find a reputable independent workshop specializing in servicing transmission shafts. I know of one but its over 1h drive from here

 

 

 

Hey 503C43////AMG thanks for the links. I had not yet looked around on the net for some 'How To' videos. That just arrived with perfect timing.
BTW how's the white coat doing?

 

Next step will be the removal of the drive shaft, before checking the worn parts (central support bearing most likely). Hope the U joints are still OK otherwise I will be needing specialist help. To be on the safe side, I'll also change the front and rear flex discs and the transmission rear support mount.

Stay tuned...

 

Believe me Dennis; that's absolutely wrong info. for sure..!,

i'v been used "722.631" many times with very long period,

on all "C43 & C43/55" without any issues..!?!,,

any "722.6" need to be serviced well, that's the point to keep it strong & healthy all the time..

-;ZAYED;-

 

+1

 

Yup Denis, I agree that the early 43's had bearing problems, but MB upgraded the faulty parts and later year models had no longer any problems, if serviced regularly.

 

Been studying up on my E63. So far fixed a small section of sagging headliner, replaced the head bolts, swapped out to all LED lighting, installed a lowering module, and replaced air boxes with the ROW air boxes. Next up is replacing fuel pressure sensor and fuel filter. So far the E63 has been almost as easy to work on as the C43.

It will take me some time to get to the level of white coat I was at with the C43 but I am enjoying it as I progress along

 

So pulled out the drive shaft this afternoon. Easy job which took less than 30 minutes all in. I prepared all the necessary tools beside me under the vehicle: ratchet with 19mm, 17mm, 15mm and 13mm sockets and a short extension bar. Placed a piece of wooden plank between a small floor jack to support the weight of the transmission as the first thing to do is remove the transmission rubber mount. This gives a full access to the bolts and nuts holding the flex disc on the end on the three finger pronged transmission spocket. With all the six bolts removed, I moved to the rear and unscrewed the six bolts holding the flex disc on the "pumpkin". I then removed the two small cross braces just under the transmission shaft. Those braces/brackets are probably there to hold the transmission shaft from falling on the ground should some dramatic failure occur. Lastly I removed the two bolts holding the central support bearing. With that done, some gentle tapping and wiggling to free the shaft on the two ends and be prepared to see and feel it fall on your breast. Job done and then onto the workshop bench.

Some people say to mark the two separate drive shafts so they can be reassembled in the same position as they were disassembled. In my case and probably other MB shafts, the two parts have markings stamped in the metal, so realignment is no problem if you respect the markings.

Dismantled and cleaned the parts (yes I'm sometimes a bit crazy as I like working with clean parts even when worn) and started to check the two flex discs and the transmission support mount. Looking closely I did find several small hair line cracks in each flex disc and the support mount was cracked in one place. I'm very happy having looked at these parts and apart from the clunk I sometimes heard when shifting gears to R from P or N, I didn't expect the hair cracks in the flex discs. I did look at them in situ recently, but it's very difficult to spot the cracks are they are covered either by a fixing bolt or the three pronged sprocket.

I then pulled off the central bearing using a three finger extractor. This is a very handy tool and it is designed to either pull out from the outside of the bearing or with a set of reverse fingers pull out from the inside of the bearing race assembly.

Passed round the MB dealer and ordered all the necessary parts which will be available tomorrow morning.

Stay tuned for the reassembly.

Drive shaft as seen on the vehicle after having removed the heat shield which normally covers all this area keeping it relatively clean and most important dry on the bearing and U joints


Shafts separated and the central support bearing still attached to the lower shaft


Flex discs front and rear with several hair cracks if you look closely...


Transmission rubber mount cracked at the upper edge on the left of the rectangular support


Bearing extractor. Its a 'Facom' made tool (French) which has a lifelong warranty. Excellent tools but bloody expensive!

 

No way, normally

 

thanks for the warning. Be assured that I never work under a vehicle without it being secure 100%. The little floor jack I talk about is just supporting the rear of the gearbox...

 

I fetched the parts from the dealer this morning and gawd damned found they forgot to supply the central bearing So everything is now on hold until Thursday, as tomorrow is Swiss National Day and everything is closed.

The new flex discs manufactured by SGF are supplied with new nuts, washers and bolts and all covered in nice blue loctite. Looking closely at the ones I removed, I noticed they were manufactured back in 1998, so they are the originals and I guess it's normal that after 19 years of service they need to be changed. Also noticed on the old ones the rubber was very very dry.

 

Avoid "Febi/Meyle/Trucktec", they're mostly fake (Turkish/Chinese) crap..,,

stick with "OEM" or "SGF/SP" or "Lemforder/Boge"..

-;ZAYED;-

 

While waiting for the central shaft bearing to arrive tomorrow, I noticed that the sound insulation surrounding the transmission tunnel was hanging down and needed glueing. Part of the insulation it was rubbing against the drive shaft (tell tale signs on the shaft). So how do you glue the insulation and get it to hold in place when it's upside down? Contact glue, a floor jack and some pieces of wood You can also see that the underside is clean and rust free

See my solution in the photo and which for the time being works fine.


Sometimes a simple solution is the best

 

Yeah, what kills our cars is driving in the winter on salty roads. The clean underside does not mean she doesn't have any rust elsewhere. She unfortunately does and I'll make a couple of photos to show you...
As I'm keeping my Queen, she'll be in the bodyshop during next winter for rust repairs and a full paint job.

 

I'll never understand why my C43 has 312k miles on the rainy southeastern US roads and zero rust.

 

Simple. No salt!!!!

 

+1,

Aside of that; now here we have (48°C) & Humidity (37%)..,,

we are really toasted..

-;ZAYED;-

 

Stay alive man

 

And to keep Kowalski happy regarding rust eating away our queens, I'm dedicating this photo to him. That should give him plenty to say IMO...

Left driver's side at the rear under the jack mounting hole

 

Damn, damn, damn

After reassembling everything and getting her back on her wheels last night, I just returned from a small drive round the block this morning. The noise is still there On small throttle openings no noise at all, but when accelerating harder the noise begins. Definitely need to make a video later today. I'll also plug in my diagnosis programme to see if any codes are shown

All very frustrating and tiring as we are in the middle of an unpleasant heatwave which doesn't help the thinking process...

 

Did you check if one of insulation sheets around the driveshafts need to be tight or something..!

-;ZAYED;-

 

Yes all the rust spots will be cut out, new steel plates welded in and full bodywork repaint next winter