Rear End swap - PeachParts Mercedes-Benz Forum

snookwhaler · #1 12-10-2009, 06:02 PM

I got my replacement rear end and axles in today. I did the whole swap in under 3 hours by myself and in the rain! Thanks to DeliveryValve for his detailed "rear end write up"! That little Harbor Freight stub wrench was just the ticket. It made the job very easy.

I used his instructions and modified them. I removed the rear end and axles as one unit and installed the new rear end and axles as one unit. It was surprisingly easy. Just a lot of getting up, moving around and getting back up to move around (over and over). I never removed the tires or the brake calipers. It came right out and went right in.

The hardest part of the whole deal was getting the drive shaft hooked back up. Also, I have a bit of a shudder around 30MPH. So, I need to try the drive shaft on a different hole.

After getting the old rear end and axles out of the car.... I found out that my SEVERE clunking problem was just worn out AutoZone axles that the PO installed 20,000 miles ago. They were completely worn out. Holding one end and twisting the other, there is 1/4" of play on both of them. The old rear end turned out to be OK.

So, now I have a back up!

Also... Many thanks to daw_two for the parts! Top notch! My car is tight as new again (for a while).

winmutt · #2 12-10-2009, 06:12 PM

What do you mean by try the driveshaft on a different hole?

snookwhaler · #3 12-10-2009, 06:21 PM

Quote:

Originally Posted by winmutt

What do you mean by try the driveshaft on a different hole?

Disconnect it and move it around to the next hole on the flex disc. There are 3 possible positions to try. I could find the yellow paint on the diff. yoke but not on the drive shaft. Someone has painted the drive shaft at some point.

pawoSD · #4 12-10-2009, 10:09 PM

In the rain....must be nice!! Its SIXTEEN degrees here currently! And snowing, hard!

winmutt · #5 12-10-2009, 10:21 PM

Quote:

Originally Posted by snookwhaler

Disconnect it and move it around to the next hole on the flex disc. There are 3 possible positions to try. I could find the yellow paint on the diff. yoke but not on the drive shaft. Someone has painted the drive shaft at some point.

You think the DS and rear end are balanced.

tr1cky · #6 12-10-2009, 11:44 PM

Quote:

Originally Posted by snookwhaler

I got my replacement rear end and axles in today. I did the whole swap in under 3 hours by myself and in the rain! Thanks to DeliveryValve for his detailed "rear end write up"! That little Harbor Freight stub wrench was just the ticket. It made the job very easy.

I used his instructions and modified them. I removed the rear end and axles as one unit and installed the new rear end and axles as one unit. It was surprisingly easy. Just a lot of getting up, moving around and getting back up to move around (over and over). I never removed the tires or the brake calipers. It came right out and went right in.

The hardest part of the whole deal was getting the drive shaft hooked back up. Also, I have a bit of a shudder around 30MPH. So, I need to try the drive shaft on a different hole.

After getting the old rear end and axles out of the car.... I found out that my SEVERE clunking problem was just worn out AutoZone axles that the PO installed 20,000 miles ago. They were completely worn out. Holding one end and twisting the other, there is 1/4" of play on both of them. The old rear end turned out to be OK.

So, now I have a back up!

Also... Many thanks to daw_two for the parts! Top notch! My car is tight as new again (for a while).

I am thinking that I may have a similar problem with the clunking in an 83 SD. Now that you have it apart what would you have checked prior to the removal? Is there a way to determine bad axleshafts vs. a bad pumpkin?

snookwhaler · #7 12-11-2009, 06:51 AM

Quote:

Originally Posted by pawoSD

In the rain....must be nice!! Its SIXTEEN degrees here currently! And snowing, hard!

I have been watching the weather... You guys are crazy!

It was 85 here yesterday and today until the rain came. Now it is in the mid 70's.

Quote:

Originally Posted by winmutt

You think the DS and rear end are balanced.

Well, it looks like it is all original. But, at some point in time someone painted the driveshaft and painted over the factory paint marks. So, I could not line up the rear with the "yellow and the green". I'm going to try rotate it over to the other 2 holes and see if I can find the sweet spot. If not, I'm just going to take it in and have the thing re-balanced.

Quote:

Originally Posted by tr1cky

I am thinking that I may have a similar problem with the clunking in an 83 SD. Now that you have it apart what would you have checked prior to the removal? Is there a way to determine bad axleshafts vs. a bad pumpkin?

I have had 2 to play with in and out of the car and I have played with a few in the salvage yards.... Now I know what to look for. First of all, a bad ring and pinion (uneven gear wear) willl make some noise at any speed but the noise will "peak" at lower speeds. Say around 45 to 55 MPH. Sometimes a little lower.

I would have replaced the axle shafts first (now that I know). If you grab the axle shaft at each end and twist there should be zero play, no slop at all. My old ones had 1/4" of slop while twisting.

Also, where the axle goes into the diff. grab the "big can" and push in and out. There should be very little to no play there too (my new ones have no play at all anywhere). On my old axles (autozone crapola) the PO did not take time to install the spacers. So, there was alot of play in this area. About 1/8"!!

I'm sure this was causing noise as well.

In regards to the diff. itself... put it in the air or up on ramps (securely), chock the front wheels, put the car in Neutral and get up underneath. Grab the pinion at the rear flex disc and grab one of the axle cans on the side of the diff. While holding the can completely still, twist the pinion shaft back and forth and see how much play you got. Both of my rear ends only have about 1/32" play. It is so small that it is difficult to measure. I have seen them with up to almost 1/2" play.

I replaced the diff. mount when I bought the car at a cost of $70. So, I ruled that out early on.

tr1cky · #8 12-11-2009, 07:07 AM

Quote:

Originally Posted by snookwhaler

I have been watching the weather... You guys are crazy!

It was 85 here yesterday and today until the rain came. Now it is in the mid 70's.

Well, it looks like it is all original. But, at some point in time someone painted the driveshaft and painted over the factory paint marks. So, I could not line up the rear with the "yellow and the green". I'm going to try rotate it over to the other 2 holes and see if I can find the sweet spot. If not, I'm just going to take it in and have the thing re-balanced.

I have had 2 to play with in and out of the car and I have played with a few in the salvage yards.... Now I know what to look for. First of all, a bad ring and pinion (uneven gear wear) willl make some noise at any speed but the noise will "peak" at lower speeds. Say around 45 to 55 MPH. Sometimes a little lower.

I would have replaced the axle shafts first (now that I know). If you grab the axle shaft at each end and twist there should be zero play, no slop at all. My old ones had 1/4" of slop while twisting.

Also, where the axle goes into the diff. grab the "big can" and push in and out. There should be very little to no play there too (my new ones have no play at all anywhere). On my old axles (autozone crapola) the PO did not take time to install the spacers. So, there was alot of play in this area. About 1/8"!!

I'm sure this was causing noise as well.

In regards to the diff. itself... put it in the air or up on ramps (securely), chock the front wheels, put the car in Neutral and get up underneath. Grab the pinion at the rear flex disc and grab one of the axle cans on the side of the diff. While holding the can completely still, twist the pinion shaft back and forth and see how much play you got. Both of my rear ends only have about 1/32" play. It is so small that it is difficult to measure. I have seen them with up to almost 1/2" play.

I replaced the diff. mount when I bought the car at a cost of $70. So, I ruled that out early on.

Awesome. I will check mine out this weekend.

Gremlin hunting is tedious but quite satisfying. It makes me wonder why and how so many POs let their cars become a P.O.S.

DeliveryValve · #9 12-11-2009, 10:44 AM

Quote:

Originally Posted by snookwhaler

..... I removed the rear end and axles as one unit and installed the new rear end and axles as one unit. It was surprisingly easy. Just a lot of getting up, moving around and getting back up to move around (over and over). I never removed the tires or the brake calipers. It came right out and went right in.....

Very cool you were able to get it install in one piece. I've taken out the diff and axles in one piece, but installing them, I've never thought about installing as a whole. Good job!

Keep that diff for a long time. 2.88s are slowly disappearing. Especially low mileage units.

.

snookwhaler · #10 12-11-2009, 12:47 PM

Quote:

Originally Posted by DeliveryValve

Very cool you were able to get it install in one piece. I've taken out the diff and axles in one piece, but installing them, I've never thought about installing as a whole. Good job!

Keep that diff for a long time. 2.88s are slowly disappearing. Especially low mileage units.

.

Your write up is awesome! Pics and all. I was a little worried about getting under there at first. But with the stands in those positions, it was really solid.

The only trick with doing it "as a whole unit" was getting the drivers axle up and over the exhaust pipe and then getting the passengers axle tip (spline) around the passengers brake hose. Other than that it was a cinch. I'm keeping the old diff. for now.

Thanks again!