Pagoda SL Group
W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: cascadia on June 14, 2008, 11:06:09
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I lost my differential yesterday ('65 230SL 4 spd), the drive shaft is turning but the car has no movement. What's the best approach here? I do have a lift but limited knowledge in this area.
Bob in Portland
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I had the same issue a few years ago. In my case the splined universal had sheared off. I had a long-running thread on the diagnosis and replacement of the differential entitled "Replacing my 230sl differential..." located here:
http://sl113.org/forums/index.php?topic=1642
There is a post by Joe Alexander (I think 4th reply) showing the exploded parts diagram with the part in question.
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Great info, thanks. One question, though, if the splined universal has indeed sheared off on mine, is it worth a try to just replace that part of the driveshaft?
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It would not be as cost-effective as replacing the entire rear axle... which you can probably do yourself. Opening up the differential and replacing the universal (which are prohibitively expensive as a stand-alone part) is quite an involved job.
You can swap out the entire rear axle and then open up your old unit at your leisure, at which point you can always decide what to do with it. Make sure you keep your hand-brake assemblies (cable and aluminium housing units) as they are expensive to replace.
On the other hand, after all these years, my old axle is still awaiting my leisure time lying in the back of the garage... :(
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Thanks Waqas, your first hand knowledge saves me a lot of guesswork!
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Bob, you're most welcome. I look forward to future installments of your "Barn Find" thread.
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Originally posted by cascadia
Thanks Waqas, your first hand knowledge saves me a lot of guesswork!
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Theres a rear axlr on EBay Though I hope in your case it's not that serious, I had a similar problem a few months ago and it turned out only to be a broken universal joint inside the rear axle pivot. Good luck!
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Did they have to tear into the differential to get to it though?
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Hello Bob,
Sometimes the attachment bolt for the splinned universal just comes loose. Other times as mentioned, the spline simply shears off. You can go in through the right axle tube to check for the loose bolt. Rmove the axle and take a look in with a flashlight. If if is still in place and tight, a diff. removal is in your future. Plenty of good used units around since many owners are swithching do different ratios these days. If you decide just to replace the universal let me know I have some good used ones laying around here.
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In case you choose to inspect the splined universal as Joe suggests, here is Joe's excellent "Rear Wheel Bearing Tour" where axle removal (from each tube) is covered:
http://sl113.org/forums/index.php?topic=4487,tour
FYI-- Removal of the entire rear axle does not entail removing the individual axles. You simply remove the springs, disconnect the shocks and brakes, and then lower the entire differential/axle assembly. There is a specific procedure for this that has proven reliable for most people (see one of Joe's posts in my "Replacing..." thread linked below).
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Thanks for the advice everyone.
Joe, if, after removing the right side axle, I see the UJ's attachment bolt is indeed loose, is it just a matter of then removing the axle tube to get at it? Also, this is a limited slip rear, I forgot to mention that earlier, not sure how much of a difference that may make.
One other little detail I've noticed is that previous to the rear end failure, the car was sitting high in the rear with quite a bit of positive camber, which I thought was due to the weight difference from me having removed the soft top assembly and spare tire from the car. Now the car is sitting level with zero camber. Related?
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quote:
Originally posted by cascadia
Also, this is a limited slip rear, I forgot to mention that earlier, not sure how much of a difference that may make.
Wow, you got a great deal on that car! I would try to repair it, as these axles are very hard to come by.
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One other little detail I've noticed is that previous to the rear end failure, the car was sitting high in the rear with quite a bit of positive camber, which I thought was due to the weight difference from me having removed the soft top assembly and spare tire from the car. Now the car is sitting level with zero camber. Related?
Not likely, unless you really did "lose the differential." When these cars are raised and lowered from the rear axles, they tend to have very positive camber until the car is moved (allowing the rear suspension to fully settle). Different levels of petrol in the tank?
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quote:
Not likely, unless you really did "lose the differential." When these cars are raised and lowered from the rear axles, they tend to have very positive camber until the car is moved (allowing the rear suspension to fully settle). Different levels of petrol in the tank?
Yes, normally these cars settle down into normal camber range within 500 feet of driving after being on a lift. I thought it was strange that it still displayed this positive camber after several miles.
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Wow, you got a great deal on that car! I would try to repair it, as these axles are very hard to come by.
I was surprised to discover the limited slip rear, it doesn't show up on the datacard, apparently this car's rear axle has been out before!
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Hello Bob,
If the bolt is found to be loose, recover it with a magnet and clean it up, I believe it may have a lock washer also, but I always add some locktite before re-installing it. It can be re-installed with the axle together in the car just by using a long 1/2" extensions and a torque wrench. Get the right side axle housing as level as possible first. Some cars had a 17mm hex bolt and others used a 8mm head allen bolt.
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Well it's worth a try, I'll give it a shot. I'll use the 'rear wheel bearing tour' as a guide, that's going to be a lot of help. I'm about to head out of town so I won't be able to jump into it until the beginning of July. I'll update the post once I have some new info.
Thanks!
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Ok, one more question here. I had a chance to get the car up on the lift today and have some observations I want to run by the group.
With the car in the air, out of gear, turning the wheels will turn the driveshaft as well, and the wheels turn in the same direction. Limited slip, right?
With the car in the air, in gear, turning the wheels will not turn the driveshaft as well, and the wheels turn in opposite directions.
With the car still in the air I started the motor, engaged first gear and observed the driveshaft turning the wheels. Dropped the car to the ground and tried it again, now just the spinning driveshaft, no wheel movement.
Probably "rear axle 101" to most, but a mystery to me! What does this suggest?
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Hello,
Loose bolt may be allowing splinned shaft to slide in and out depending on the orientation of the axle halves? You may get lucky and just have a loose bolt. Proceed with the plan.
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How do you know it's a limited slip rear axel? There's nothing different as far as outward appearance to tell you that it is. The only clue is the two wheel marks you get if stuck in the mud or loose gravel if you spin the wheels. There is a small tag on the dif housing that says to use special oil printed in German. I have one of these units so I know they look just like a regular axel.
The forward bite coming out of a corner is something you have to exprience to apreaciate just how much difference they they really make. I've only seen 2 or 3 in the last 20 years.
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Hello Dan,
Frank Cozza has one in his W113 also.
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I'm assuming it is based on the behavior of both wheels turning in the same direction when it's on the lift. Of the 15 or so I've sold, I've only had one other with the lsd rear, and it exhibited the same wheel rotation characteristics while on a lift. All the other ones had wheels that turned in opposing directions.
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I hope some pics will help explain.
Download Attachment: (http://images/icon_paperclip.gif) spider.JPG (http://www.sl113.org/forums/uploaded/jeffc280sl/2008617133549_spider.JPG)
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Download Attachment: (http://images/icon_paperclip.gif) univspline.JPG (http://www.sl113.org/forums/uploaded/jeffc280sl/2008617133610_univspline.JPG)
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Download Attachment: (http://images/icon_paperclip.gif) univallen.JPG (http://www.sl113.org/forums/uploaded/jeffc280sl/2008617133628_univallen.JPG)
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I found a little time to work on the car today to try to get that axle shaft out and have a look inside. I have the brakes torn off and the backing plate loose. The car is on a lift with the right side of the axle jacked up independently to make it more level. I built my angle iron "puller" per the photos in Joe's rear wheel bearing tour. I'm using a 3lb sledge hammer but the axle doesn't want to come out. My question is how hard and how long am I supposed to be banging on this? I'm at about a dozen blows from both sides and thought I'd stop and post the question to the group before I mess up anything.
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Hi Bob,
The axle shafts are not usually that tight and should come out with a little positive persuasion. I must admit that I have always used a slide hammer and no more that half a dozen blows have been necessary, in fact the bearing usually starts to move after two or three good hits. Joe’s tool should be fine for the job but you may need to use two hammers to try and hit both sides at the same time. If that doesn’t work you may need to buy or borrow a slide hammer. When removing the right hand shaft don’t try to pull it out in one go, once loose just pull it gently until it hits the internal circlip then give it a good pull and it will come out.
Good luck
David Brough
1969 280SL Auto with A/C & 3.46 Axle
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Well, I gave it a few more tries today, it's not budging. Then I started thinking maybe I didn't get the axle assembly level enough when I lifted the car and could that have anything to do with it? I put the brakes and wheel back on the car, lowered it down and rolled it a bit to get the car to sit level again.
The rear end wasn't settling down to level, it had the same excessive positive camber as before the failure. On a hunch I started the car, put it in gear, and sure enough, now it moves.
So whatever is causing this positive camber is allowing for the car to move, and as I experienced before, when the rear did go level, no axle engagement.
Per Joe's previous post, it sounds like I still need to get in that right side axle tube to look for the loose U-joint bolt that could be causing this, but is it possible that this stuck camber condition is what is preventing the axle shaft from releasing?
Bob
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Hi Bob,
Under normal circumstances it’s the axle bearing just behind the brake back plate that needs to be released, the splines that fit into the UJ are normally just a hand push fit. However, given that you have a problem in there it is possible that something has damaged the joint between the axle shaft and the UJ. If that is the case I’m not sure how you’re going to release it with anything other than brute force or complete removal of the axle and cutting off the rubber boot to see if you can see anything wrong in there. The obvious seems to be the locating bolt fouling things up. A replacement axle may prove to be the easier approach.
David Brough
1969 280SL Auto with A/C & 3.46 Axle
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Hello, Bob,
The fact that the car drives again would suggest to me that nothing serious has happened in there. Probly, the securing bolt has just come off.
Get a bigger hammer to persuade the shaft to move! I destroyed the front tool on my sliding hammer and the shafts (both) did not budge.
I was stripping the axle anyway and I got the shafts out in the end by knocking them out from the inner ends. I would say persevere and you will get there.
naj
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Hello Bob,
Sorry I have not been up to date on this thread. The "rear axle tour" uses a later W113 car with disc brakes on the rear. If I recall the drum brake cars require removal of some other parts. The emergency brake pulley fasteners at the brake plate (two 10mm nuts) in addition there is another bolt on the other side of the backing plate. It goes through the axle housing and into the pulley casting and this bolt is parellel to the driveshaft (possibly 12mm). Make sure these three fasteners are off also.
Sounds like you have a loose bolt in the diff. All the banging and the camber change probably allowed the spines on the universal assembly to re-engage!
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Hello All,
Yes, the "rear axle tour" mentions those extra e-brake and backing plate bolts, I made sure those were removed.
It looks like I'm going to try the 'bigger hammer' approach. It's a little counter-intuitive to me, one of the things I love about these cars is how almost every element is elegantly assembled. I've de-trimmed a few of these cars for paint and learned to appreciate that nothing needs to be forced apart. The way they go back together is equally refined.
Will give it another go, if nothing else I'm getting good at drum brake disassembly!
Thanks!
Bob
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Gave it another shot today. Had about 3 friends stop in throughout the day, each time I enlisted their help with a 3lb sledge, each of use hitting the angle iron on either side of the hub in unison. No go. I'm starting to trawl Craigslist for donor cars, here in Portland there's always a couple on CL at any given time. What models and years would interchange?
Bob
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Sorry to hear that. Perhaps the 'loose bolt' or whatever else is causing the problem is also obstructing the axle from sliding out. Not sure about this, but it might be useful to slide over the axle boot (without damaging it) and inspect that end for something obvious.
Most axles from the 113/111/108 series should work just fine. The only differences are axle ratio and drum vs disc brakes. Your original should be drums with 3.75 rear ratio (not sure about the limited slip though). The ratio should be inscribed somewhere on the diff housing (my 3.75 has a "3/75" inscribed on the diff rear in a semi-circular machined face).
There have been many many discussions about the relative merits of the various diff ratios, so search away. If you switch to a disc setup, you will need a rear proportioning valve in addition.
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Yes, mine is 4.08 so there's room for improvement with a swap. I looked at a 64 190D finner project for sale today, but the ratio was 4.10, I'd like to go lower.
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Hello Bob,
Did you remove that 13mm bolt on the back side of the backing plate, the one inside the opening in the lower shock bracket?
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Hi Joe,
Definitely did remove it, the brake backing plate is swinging loose.
Bob
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Just an engineer's logical thought process... absolutely zero practical experience with rear axels and differentials except for my work on my '65 Chevy Heavy Duty (C20) pick-up's axels and bearings.
The axel splined end uses slip fit (or slight press fit) into the differential U-joint.... typical and standard in most similar applications. The axel splines will therefore be forced out with relatively mild force --- i.e. the 3 lb slege approach among others.
Since it's not budging with that approach, nor with both sides of the bar being hit simultaneously (for symetric unbiased torque at the splines), it means that the splines "fit" (mating splines) are cinched up so to speak... friction is all that's holding them together unless the splines have been "twisted". If just friction, then more force is needed to overcome it... so why limit the hits with a 3 lb sledge???... gee, I use a 32 oz (2 lb) hammer just for nailing.
If twisted, plus friction, the force required is greater yet, since the sliding friction is greater... but that's all.... so more force is reqiured over a greater distance of sliding along the splines to dislodge.
Now, if you can't get the axel out by the 3 lb. sledge approach, and have to consider replacing the differential / axels anyway, then why limit the dislodging effort to a 3 lb sledge? Go for a couple of guys that can handle a 20 lb sledge each and bang on the bar (might need a heftier bar though) on both sides simultaneously 'til the axel begins to move off... then keep banging 'til it's free.
What's to lose but a few calories and perhaps some skin from a knucle or two? If you break something in the process it's still no loss as you're going to replace the differential anyway if you can't get the axel out... and even then you may find you have to replace it if you're unlucky.
The curious part is why you get engagement with high positive camber condition then no engagement with normal camber.... but that's internal to the differential.
Brute force is necessary to unstick frictional forces when those forces are high... no matter what may be causing the high frictional forces... even if somebody used super glue once upon a time on the splines... or some other adhesive, it's still a force issue. So.... more force is needed than you've been using.
Get a couple of 30 lb sledges (local tool rental joint) and have at it! What am I missing here that that 'solution' hasn't been tried before resorting to puchase of another differential?
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Hello Longtooth,
The most common point resistance is the tight fit of the wheel bearing in the housing. Maybe some heat at that point around the housing would allow the assembly to pull out.
Another alternative is to rent a giant slide hammer tool commonly used for axle removal. Such extremes are not usually needed.
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My mechanic loaned me his heavy duty slide hammer, the thing looks like it's from the bronze age, I just got done with about 10 minutes of it. Will apply some heat around the housing and see if that helps.
Bob
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Hi Ja17... very good point, and better than mine ... re:
quote:
The most common point resistance is the tight fit of the wheel bearing in the housing. Maybe some heat at that point around the housing would allow the assembly to pull out.
Yer right, of course. Heating the housing sufficiently will expand it, reducing the frictional compression of housing on bearing outer race. But the housing has a lot of conductive (heat conductive) metal mass, so heating it sufficiently may be problematic.
Another similar approach is to shrink the bearing's outer race... squirting some super coolant on it(I don't know what's available)... or doing both (heating housing and cooling bearing race)... plus pounding while doing this.
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Hello Bob,
I have never heard of one being so difficult!
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quote:
Originally posted by ja17
I have never heard of one being so difficult!
That's what most people I've spoken to say as well. It couldn't be the circlip that's hanging things up could it?
Bob
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Hello Bob,
Thats what I'm thinking also. Once they get out of their groove they can cause all kinds of difficulty. At some point you should be able to overide that pesky clip!
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Would it help if I removed the road spring and compensating spring and angled the axle tube up? I seem to remember a thread here where someone said that's the procedure for getting the shaft back in.
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Hello Bob,
Having the axle hanging at an angle could cause problems. I would let it down on the ground and place a jack stand under the end of the housing and try to extract it then.
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Is removing the swivel pin and taking off the right axle casing complete with the axle shaft an option?
naj
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quote:
Originally posted by naj
Is removing the swivel pin and taking off the right axle casing complete with the axle shaft an option?
naj
Naj, wouldn't the 'stuck' right axle prevent the axle shaft from coming off?
Or does the universal simply slide out from the other end (diff side) once the axle shaft is removed? In this case, the axle and the universal would need to be separated on the bench (with axle shaft stuck in-between). Not sure if this is easier... but my assumptions may be wrong.
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quote:
Originally posted by waqas
wouldn't the 'stuck' right axle prevent the axle shaft from coming off?
Or does the universal simply slide out from the other end (diff side) once the axle shaft is removed? In this case, the axle and the universal would need to be separated on the bench (with axle shaft stuck in-between). Not sure if this is easier... but my assumptions may be wrong.
The right casing would come off with the axle shaft. If the UJ retaining bolt has come off then it would pull out with the casing and shaft. If not, only the 'pesky' circlip would have to be dealt with. As I said earlier, I was not able to remove the axle shafts before stripping the casings.
Once they were free from the center pumpkin, the shafts were easily removed by knocking the inner ends with a wooden block and club hammer.
naj
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Bob.... I am late to this thread and hate to comment after the good ideas have not worked. My thoughts are that you have a broken outside race in the wheel bearing and it has expanded enough to become very stuck. I cannot imagine the circlip or anything else preventing the axle from coming out with what you have already done.
So, what next? I see two options; borrow the big slide hammer again and pound until something gives (what I would do) or remove the rear end from the car, split the axle housings and then take the right housing to a shop with a big press to press it out. I would doubt that removing springs or changing the orientation would help.
Heat might help but brute force should also work.
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Thanks for the advice. I think I'll take the car off the lift, tuck it in the corner and keep going with the slide hammer, for the moment brute force is my simplest option :)
Bob
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Bob, I had a similiar problem years ago on customer's car. The sliding sleeve that the right side axle slips into had broken into several pieces and the small cylinderical bearing and pieces of the sleeve were jammed, holding the axle in the sleeve. Have you tried pushing the axle back in ? Will the right side of the axle pivot up and down ? I had to cut the axle off just inside the bearing and remove the right side tube. After removing the tube i could remove the snap ring that holds the sliding sleeve together, letting the axle and broken sleeve parts come out.
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I have tapped inward on the axle shaft with no noticeable results. My mechanic who loaned me the slide hammer recommended equal impact in both directions for this problem. Maybe it's just a matter of perseverance. The right side won't pivot, it's stuck in the positive camber position. Somehow, this position allows gear engagement because when the rear went out the car finally sat level. Now that it's stuck again, maybe I should drive it until it goes out and back to level? Might help with getting that axle shaft to release.
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Hi Bob,
You might want to try removing the compensating spring, road spring and the shock absorber then you can see how the axle tube pivots, or not as the case may be. You will need an axle stand to support the right side tube and will also have to remove and plug the brake hose on that side. You may also need to loosen off the hand brake cable. The road spring is easy but the comp spring is a bit more difficult. If you haven’t done it before Waqas has a good post showing the spring compressor to use.
A combination of up and down movement on the axle tube whilst rotating the axle shaft might help to understand/feel what is going on. As part of this you could chock the left wheel and or put the car in gear or park. I’m not sure if this will show anything but at least it’s another option to continually hitting everything with ever bigger hammers. Ultimately, you may have to drop the whole axle and cut off the rubber boot. In any event it sounds like you may have to remove the right hand tube which really means the axle has to come out anyway. If the problem is a UJ bolt that has come completely loose then you should be able to separate the tube axle and UJ together. If not and the whole things stuck then cutting the boot and delving inside may point the way forward.
David Brough
280Sl Auto with A/C & 3.46 Axle
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Ok, here's an update. It took about a month of looking on Craigslist but I was able to find a replacement axle assembly. It came from a 63 Fintail so all of my drum brake parts swap over, ratio is stamped D 3/9, which I guess is 3,96? Owner claimed it's been gone through, we'll find out, paid $250 delivered to my door.
My mechanic offered to let me use his shop and tools, and he was a big help when it came time to remove the compensating spring, we used his plasma cutter to fashion the removal plate per Wagas's instructions. Also, his transmission jack was excellent for supporting and dropping the whole thing down. I'm keeping my springs, pads and strut, most everything else looks like a direct swap. This axle does have studs instead of threaded holes but it doesn't bother me much.
Ironically, I was able to drive the car the 7 blocks from my shop to his, my camber specific functionality problem seems to be absent for now. If I could have removed that right side shaft I think I could have fixed my problem, but after a few straight days of trying to get it out I decided my time is worth more than the money to replace it.
Here's a couple of pics from today (Friday), on Monday we'll install the replacement, pictured below. Thanks to all of the great information on this forum I think I understand the approach but feel free to let me know if I'm headed toward certain disaster 8)
Bob in Portland
(http://www.sl113.org/forums/uploaded/cascadia/2008815225351_axle1.jpg)
(http://www.sl113.org/forums/uploaded/cascadia/2008815225843_axle2.jpg)
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quote:
Originally posted by cascadia
.../...I'm keeping my springs, pads and strut, most everything else looks like a direct swap
Bob, just a hint.
Hoisting a Mercedes from the sixties in the manner shown in your picture puts a severe stress on the rubber front subframe supports.
The weight of the front suspension and the engine hangs in these parts, extending them, they are designed to be compressed.
The compensating coil spring is not the same on a Fin W111 as on a W113 Pagoda. A Pagoda coil has eleven windings
and the metal is 11.9mm diameter, part No 113 329 0301.
Just like in your (lower) picture. So, swap that one over to the Fin axle.
.
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Success! The swap went smoothly, the compensating spring being the only real pain to deal with. I logged about 20 miles today, everything seems to be swell. Thanks for all of the advice!
Bob in Portland
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Great news!
Now you can take your time with the old axle to figure out the problem. (don't get rid of it!)