300DT rear axle replacement
 

The big reason the PO had the low price was a bad passenger side axle.
'85 300DT with 193k.

Got the parts due in and next week it should be warm enough to change it out.

Ive done quite a bit of mechanical work and can see from the most excellent writeups here that the rough part of the job will be getting the jack under the pumpkin.

The obvious question is ... what else should I be looking for while Im under there ?

I am thinking of changing out the steel fill plug to brass and will be using 75/90 oil for the refill. Any other suggestions ?

Nothing really... Just be sure the vehicle is properly supported, use spacers on the new axle and be sure to remove the fill plug before you remove the drain plug. I used a little dab of anti sneeze on the plugs. The whole procedure is not that difficult. Especially if you follow one of the DIY threads in the Resources area.

In regards to the spacers.. You may have to get new ones to make it a tight fit. If you are using "used" axles be sure the boots are in good shape before you replace the axle.

I have done a lot of work under there and I have never had a hard time getting a jack under the diff.?

When I did my rear axles ('84 300D) I didn't find it the least bit necessary to drop the pumpkin, instead I just took about a 1" length of 3/8" keyway shaft and slid it inside the back of a socket for the diff cover bolts. Put the socket on the bolt head, slide the keyway out a bit so you've got something to grip and turn it with a small 3/8" wrench. We're only talking about a couple of bolts that you can't fit a ratchet on and once you break them free they're easy to loosen by hand. Again no worries with reassembly, diff cover bolts don't need that much torque and the top ones aren't likely to ever see much pressure from gear oil.

Dunno if getting around the suspension is different on the DT, the other thing I did was not mess with the fill plug while under the vehicle. I do understand the logic of why pull the cover if you can't refill it, but honestly with the cover off and in a vise you can apply breaker bars, heat, whatever is necessary to get the plug free. I'm a big guy and it took me leaning on a 3' extension to get the plug out, I don't think it would have been easy under the car.

I'm not mb savvy enough to tell you if your job is the exact same as mine was, but it really wasn't hard. The c-clips are nice enough to have tabs on them you can grab with pliers, not like those bastard jeep c-clips that sit flush. I didn't have my vice-grips handy, I think those would have been ideal, but a busted pair of needle-nose still got the job done in under 10 mins...

http://www.peachparts.com/Wikka/W123RearAxles

Dave

Beware the c-clips
 

Comedy. :D


Perhaps stronger wire for the c-clips is in order? Slightly smaller guage than a wire hanger will do, I filed the hanger down a bit to thread it through then grabbed with a pair of needle nose. I've heard both sides on the ease of removing these little !@#%$, it's obvious how I greeted. Still, nothing to panic over.

Also, getting the shims in there so the axle is nice and snug. Replaced the passenger side with a JY example several weeks ago and refilled with synthetic in an attempt to loosen some of the internal gunk around the case. So far, so...


FNHB

Your right fn... kinda like getting the jack out is the hard part of doing a brake job. Somewhat sick sense of humor here.

Incredible writeup Dave, thanks for the link. Should be required reading for your thoroughness and safety pointers. Too many trust a hydraulic jack. I had one pop while changing motor mounts on a 350 Chevy. The only reason Im typing is ... the car and motor were blocked !!

If you dont have time to do it safely... then ya dont have time to do it !

Im expecting virtually zero motion up and down.

Any spec on the tolerance for the in/out play ??

in/out play?
 

If you're referring to the axle play at the diff? then nooooo. You want this snug like a bug after replacing the c-clip, I've read of bad things happening when any play is left here. Gear wear at abnormal rates. The benefit of grabbing a unit from the wrecker is it already has it's required shim so no modding or anything when you install it. This detail was rather cloaked when I was researching, but had both the old shim and replacement shim so was prepared to yank it if seemed suspect.


FNHB

The manual tells you that the Retainer Clip should go in without much effort; but after it is installed there should be no in and out play.

Checking for the in and out play is easier to see if you watch the Retainer Clip while you try to move the Axle in and out.

I am doing this repair right now.

The only major problem I am having are

1. Missing tools :rolleyes: mostly the 22mm allen socket.
2.Broken tool :D I broke my torque wrench.
3. Differential drain plug.

I just had a post earlier about the plug being stuck. Heating with propane and using the jack against the force of the car also did wonders.

I purchased a set of axles from CVJ and I am looking forward to putting them in.

I'm hoping for a painless install after I gather my last remaining socket and torque wrench tomorrow. This is the first real "hard core" repair I have done on my car. If I can tackle this then from this point forward it is only easier.

Also, Dave you guide has been indispensable for me. I am very grateful for it.

A minor update ... yes it warmed up but it was still pretty cold at least for me.

In the interim Ive managed to do a pretty good update on my metric tools to include the infamous 14mm / 9/16 allen wrench.

One tool I picked up which Ive added to the tool rental is a great Flexx tool.
Mine is the Astoria 5000, the latest version. The box has a broken hinge but
for the price I paid its most liveable with. Auctions can be a grand place to shop.

As a side note, anyone renting this from me will have a differential plug wrench along with the CV boot tool. Great time to change out the fluid and the wrench might encourage it being done while the boots are being replaced.

From what I see using this can be done without pulling the axle but Im sure more knowledgeable folks here can confirm that.

You have to pull out at least one end. But if it were me, I'd pull the axle out to work on it better.