differential ujoint slider?

[xcashewx]

ive had bad clunks in my rear end ever since i got the car. replaced the trunk mount,got better a bit. re-did all exhaust mounts/hangars, again a little better. but it still clonks every once in a while under these circumstances. i checked main driveshaft u/j, no play

stick in "2" postion, partial throttle, put in "3" about 30 mph. sounds nasty.
partial throttle about 25 mph. breifly press and release accelerator, clonks
randomly when turning and accelerating quickly

i recently had the car up on stands and i rotated the left side axle, no slop. but when i turn the right axle there was significant play from either side when turing  the wheel, about 1 inch in movement before the opposite wheel started turing.

 i was wondering if this means the u/j slider assembly  is bad, because i am about to put in new thrust arm bushings and pivot bushings, but if the u/j is the issue i want to do it all in one shot

thanks,
alex

[ja17]

Hello alex,

Make sure that the driveshaft is not moving when you rotate the wheel.  If it is it is throwing your test off.

[graphic66]

Sounds like your bolt that holds the internal universal joint in may be loose or have fallen out. My car exhibited similar sounds for a while, then bang, the UV snapped. I found the bolt laying inside the axle and the joint snapped. You may be able to pull the right axle and look inside and see if it is out or loose. The smaller 230SL axle I had in my car had a bolt, I think a 12MM socket fit it, my replacement larger 250SL axle has a bolt with an Allen style head that must be tightened with an Allen wrench. It is worth a look. The axle is easy to pull and have a look.
    What car do you have? The smaller 230SL axle appears to have a weaker, smaller U- joint in it. The 250SL axle I have rebuilt seems more robust. I have a low mileage 230SL style drum brake 4:08 axle as a spare and my 250SL3:92 rebuilt axle.
      I am up in the air as to which one to install. I think the 250SL disc brake axle will be better, even though it is probably a little higher gearing and the car will suffer slightly off the line as these cars are made to rev.
  I have the brake proportioning valve and the master cylinder for the disc brake axle.
   I would pull your axle right away and check that bolt. Probably a 3 hour job if you don't spend too much time cleaning things up and just do the job. You will need a new gasket for the axle end, or you can make one. You  may want to replace your bearings and inner and outer seals while your in there.

[xcashewx]

i have a 230sl with a 4.08.
when i spun the wheels, the car was in park.

should i consider removing the entire axle? also how much would a  used replacement ujoint assembly cost?
i found one on ebay but i dont know if its compatible.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=120474492882&viewitem=&sspagename=STRK%3AMEWAX%3AIT

[ja17]

Hello,

There are four of five different versions.  Count the splines on the end of the shaft and compare it to yours. I guess you will need to remove yours first or find one specifically from a 230SL.  Don't worry about finding a good used one when you need it. I know someone with a backyard full of them

[xcashewx]

thanks joe,
ill end up buying one here soon.
im pretty sure its the ujoint, as i dont think its right for the wheel to have as much play as it does, while he other has none
how much would these "good used" joints cost?

[auret]

Let me add my 2 cents - hopefully they are worth more. When I got my car which is automatic the shifting was hard, abrupt and there was a clunk when putting it into gear and when it changed from 2nd to 3rd and to a lesser extent from 3rd to 4th. The left rear wheel was tight and no play with rotation and the right had about 1cm rotational play and did have a slight metallic clunk when rotating it back and forth. There was no significant play in the drive shaft. I removed and rebuilt the whole rear end. This included removing the ring gear and having the spider gears checked out. All ok. The right cylindrcal bearing was not warn but spinning on the axle shaft. Replaced all the seals and bearings. The sliding coupling had insignificant wear and the right rear internal axle u-joint was tight with no play. I had the drive shaft rebuilt and replaced the flex disc. Replaced all the rubber. When I put it all back together and drove the car there was some but not satisfactory improvement. I started to think that maybe the wear in the sliding sleeve was significant and contemplated dismantling the rear end again. However, I had no time as a trip was looming. The car has always idled a little fast since I got it ( about 1300 in neutral and 1100 in drive )so I decided to do a tune up. Adjusted the valves and the linkages - no signifcant problem found. Replaced the plugs. Checked the timing out - 50 degrees BTDC at 3000 rpm! Almost 30 degrees BTDC at idle! Vacuum advance worked ok but no advance with the vacuum pipe removed. I removed the distributor to find that the mechanical advance system was siezed up solid. Managed to get everything loose and moving freely with WD 40. Put in new points and set the dwell angle to 39 degrees. Then set the timing to specs  - about 10 degrees BTDC at idle and 30 degrees BTDC at 3000 rpm.  Now idles in neutral at 750 rpm and drops to 600 in drive.

But now the good news. Almost no sound when putting the car into gear. The gear shift from 2nd to 3rd and 3rd to 4th is almost seamless now and the car is a pleasure to drive.

I must emphasize what Joe has always repeated in his threads - Adjusting the linkages, timing and the way the engine runs makes a huge difference in the way the automatic transmission performs.

Like lovers, they are intimately connected.

[xcashewx]

the transmission shifts nicely and there is no clunk engaging gear intially, which there used to be. my idle used to be about the same as yours to compensate for the a/c ,but now i have it down to 750 with no drop in gear.
the clunking is only when in motion.