Hello, My lady drives a 2012 C350 4matic Coupe (204.388) engine type 276 with 128,xxx miles. We had it in for its 110,000mi service 3-22-19 and, somehow, they reported nothing about the front shaft u-joint; nor anything else covered by warranty. The warranty expired 6-29-19. We had the vehicle back in for its 120,000mi service on 7-15-19 and they told us the front prop/driveshaft u-joint was rusty and seized up and gave us a $1,900.00 estimate to replace it. My initial reaction was that's BS. But I did a little research and inspected it myself and discovered the needle bearings were failing. However the short span from the last service(97 days) led me to investigate further....and to no surprise discovered multiple other services that turned out to not have been performed as described over the last 90,000+ miles but that's for another post.
I made the decision to replace the prop/driveshaft myself and ordered one from WholesaleImportParts.com for less than 1/3 what the dealership quoted. It arrived the next day(7 days ago) and I went to work. After carefully marking the position of the old shaft I cut it out. Then removed everything I can possibly see that could be in the way of installing the new one incl the top bolt on the differential and also loosened the cross tunnel transmission mount and currently have the trans weight on my floor jack. Over the last 7 days I have scoured the internet for instructions on how to get this shaft in place. The best video I've found was a 2012 E350 4matic and in it the mechanic said he had to lower trans and swing it to the drivers side to get new shaft in. The best guidance I have read anywhere is on here from a couple members saying lower trans as far as you can, and brute force did not help but precision parts alignment was key. So I decided to become a member and see if anyone can help me complete this install.
I currently have a small approx 1.5" block of wood between the trans and the passenger side of the tunnel holding trans towards driver side of tunnel. During my last attempt to install new shaft I was able to get it about halfway onto the splined output shaft on the transfer case but no further, which led me to think the two shafts were just a couple degrees off. The output shaft was angled as far as it would go at the 10:30/11 o'clock position. The u-joint end of the shaft was resting on top of the front diff mounting plate and beside the manifold collector flange so it would not go any lower until the shaft seated allthe way onthe output shaft allowing it to clear the mounting plate so I tried raising the jack a couple pumps to raise transfer case(and output shaft) but it didnt help. I almost removed the wood block but didnt out of fear that the tranny would swing back toward passenger side and damage the new shaft. My questions are: Does the transmission need to be moved towards the drivers side of tunnel to get new shaft in? and Approximately how far can transmission be lowered without damaging the lines, linkage etc...?? I would guess I had it down about 2.5-3"from its original position in my last attempt. I have to get this thing together by Tues morning or we'll get stuck renting another car or worse I'll have to shuttle her back and forth to work lol..... any guidance will be greatly appreciated!!
*sorry so long just wanted to get all the facts out