How hard is a differential swap?
 

Hey, all:

jim16671836 has come to my rescue with a used diff from his parted-out '71 220D. But I'm curious as to just how difficult a job it is to do the replacement. Has anybody done this? Are there any special tricks, dangers, etc.?

I'd just like to have an idea what I'm getting myself into before I start. ;)

I look forward to your response! Thanks!

Did you try a search?
 

There are a lot of posts on this subject.

Here's one:

http://www.peachparts.com/shopforum/vintage-mercedes-forum/18857-differential-ratio-swap-w114.html

Hey, Chuck:

Yeah, I did search a couple different ways, but somehow I missed the link you posted. Thanks a lot! :)

Tell me what your running in your gasser, is it a stick shift? My message to you and post on the other thread on this subject was to use a lower ratio if youhave a stick shift, if automatic tranny forget it. Check that the gear ratio stamped on thelower ear of the differential is the same or lower than what you currently have. Early NA diesels generally use a higher ratio and you'd be setting yourself up for a poorer fuel economy and higher engine wear if you intall a higher ratio
And the usual things one runs into are replacing the rear flex disc, watch out for cracks in the boots on the half shafts might be a good time to replace them (the shafts usually, not the boots) if necessary as most of the work is done getting them out of the differential
And replace fluid with a good brand synthetic 75/90W lube to keep it happy a long time!

Diehard: Yes, mine has the four-speed floor shifter. I will make a note to check for the gear ratio specs...you say it's stamped right onto the unit, no?

I'm almost certain to find some more worn-out bits while I'm up underneath there, most likely included exactly the stuff you mentioned...you're right about it being a good time to swap that stuff, so as not to have to rip everything apart twice.

When changing the fluid in a diff, is there some sort of cleaner (like "motor flush") I can run through it before refilling with a quality lube? Just to make sure any sludge is washed away? Just curious.

Thanks for your input on this...it's most appreciated! :)