No more flex discs
No more flex discs
I came across a thread listing the Spicer yoke 3104-27 matches the Mercedes' 27 spline 722 transmission output and differential input. Seal is Timken #473445, the differential is SKF #16900.
The main benefit I can think of is eliminating the flex discs. They can be upgraded to the larger W126 V8 discs to handle "superturbo power", but if you're going to do that it will still need a custom or cut W126 driveshaft. It would also be a good option for a 5-speed job missing the driveshaft.
If one were to go this route, couldn't a single straight shaft with a slip yoke be used? If there is a u-joint on each end, I don't see the need for a center bearing or 3rd u-joint.
Yes this is from Austin's 300CE here in Bakersfield. Looks like a great option.
I don't see why not would be a problem and definitely cheaper if a straight shaft is used. He spent 700 bucks to make his two piece drive shaft here locally.
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(10-26-2009, 11:24 AM)DeliveryValve Yes this is from Austin's 300CE here in Bakersfield.
(10-26-2009, 11:24 AM)DeliveryValve Yes this is from Austin's 300CE here in Bakersfield.
(10-26-2009, 06:30 PM)SurfRodder Does he have a 4 spd? I'd be interested to see if the resonance vibe is missing/reduced/worse with this setup.
(10-26-2009, 06:30 PM)SurfRodder Does he have a 4 spd? I'd be interested to see if the resonance vibe is missing/reduced/worse with this setup.
Do you guys think this will work on a W124 chassis as well? I'm upgrading from the 185mm to 210mm differential, and the drive shafts are different lengths.
(10-27-2009, 01:57 PM)Tymbrymi Do you guys think this will work on a W124 chassis as well? I'm upgrading from the 185mm to 210mm differential, and the drive shafts are different lengths.
(10-27-2009, 01:57 PM)Tymbrymi Do you guys think this will work on a W124 chassis as well? I'm upgrading from the 185mm to 210mm differential, and the drive shafts are different lengths.
AWESOME info - thanks for posting.
I have two new flex discs (spendy little buggers) for my W210...but I'd rather have greasable u-joints...and I do have a nasty vibration going on that I'm hoping to eliminate at some point.
Beers,
Matt
nice!
I like that the flange you have puts the U-joint closer to the transmission.
this is a different application but last week, I received my custom spicer short shaft for the G-wagen. It goes between transmission and transfer case and is 10.7" long.
has about 1" of slip joint play. at that length, every 1/4" matters and balance is critical to keep the vibrations down.
-C
Would this work on a 240D's four speed manual? I'm using my 240D for parts to convert my new 300D, and if I can get a 'real' driveshaft and U joints for the car for at/near the same price as having the 240's driveshaft shortened the requisite four inches, I'd probably go that route instead.
So does anybody know how to add a slip joint into this mix? Sounds like we would have to change the output flange of the transmission....
A slip yoke that would fit and function would either be a gift from On High or a product of 'real' engineering. Seeing as how Mercedes never used them in this era, I'd say probably not.
But that's no huge deal - unlike a solid axle the differential stays put and the axles move, so there's no need for a slip joint. If there was a need, there'd be one in the stock system. Otherwise we'd all be eating flex discs left and right, especially the way some of us drive...
So, rereading the posts, you'd use the same yoke front and back? I think the elimination of three expensive wear items, in addition to the slack this would take out of the driveline, would be worth the effort for my 300D conversion.
(11-18-2009, 12:40 PM)CID Vicious But that's no huge deal - unlike a solid axle the differential stays put and the axles move, so there's no need for a slip joint. If there was a need, there'd be one in the stock system. Otherwise we'd all be eating flex discs left and right, especially the way some of us drive...
(11-18-2009, 12:40 PM)CID Vicious But that's no huge deal - unlike a solid axle the differential stays put and the axles move, so there's no need for a slip joint. If there was a need, there'd be one in the stock system. Otherwise we'd all be eating flex discs left and right, especially the way some of us drive...
I suppose the real test will be doing it. But as said, in a typical solid rear axle, the differential yoke can change height relative to the body/frame as much as six inches, thus the need for a slip joint. In the Mercedes it would be fractions of an inch, if that.
Hmm...what about taking it to the ultimate stage...Torque Tube! Is this very hard to accomplish, I know it's mainly used in FE/RD sports cars (RX8, Miata, Corvette, Porsche 944, etc). I doubt it would be worth the extra effort, but just to put the idea out there...
I feel like if you had no slip yoke, a torque tube would really be the only way to do it. Maybe you could rip one right out of a miata and lengthen it?
U joints would probably wear out pretty fast without any way to reduce vibration, twist, or slight play.
Probably makes more sense just to adapt the drive shaft to the V8 discs, instead of going to all this trouble
(11-19-2009, 10:25 PM)dropnosky I feel like if you had no slip yoke, a torque tube would really be the only way to do it. Maybe you could rip one right out of a miata and lengthen it?
U joints would probably wear out pretty fast without any way to reduce vibration, twist, or slight play.
Probably makes more sense just to adapt the drive shaft to the V8 discs, instead of going to all this trouble
(11-19-2009, 10:25 PM)dropnosky I feel like if you had no slip yoke, a torque tube would really be the only way to do it. Maybe you could rip one right out of a miata and lengthen it?
U joints would probably wear out pretty fast without any way to reduce vibration, twist, or slight play.
Probably makes more sense just to adapt the drive shaft to the V8 discs, instead of going to all this trouble
makes sense, like you say, someones got to try it or the guy who's done it should post
I think its a great idea, I really hate those rubber discs, and also how the center u joint is un-serviceable.
I have another question though, so we know there is minor movement in this driveshaft since both ends are anchored, and this is about removing refinement and improving responsiveness.
Couldn't you just eliminate the flex discs and put in a metal blank? The shaft already has a U-joint so that kind of movement is already covered. What if you were to make a couple of aluminum discs and just make it a hard connection at either end? Wouldn't that achieve the same result without having to completely re-engineer the shaft?
True. Easily made at a machine shop from steel plate. Would be the ticket for an existing application, I'm more thinking for converting the 300Ds. Since you're paying X amount to alter the existing shaft anyway...you know, I think it needs to get hashed out, cost of new, u jointed straight shaft vs. cost of altering a used shaft and using new stock parts.
Alteration- $200
New flexes- $90
New center support- $20
So right there you're already at least $300 in the hole. A new steel driveshaft with a slip joint costs around $300 add $100 for the Spicer yokes and you're looking at around $100-200 over the conversion cost.
I'm sure it would save money in the long run too. $20 u-joints instead of $45 flex discs and no more center support bearing.
http://www.actionmachineinc.com/steeldriveshaft.aspx
1310 Series: 3" x .083 DOM tubing with SlipYoke $240 - $265
this was the option I went with for my OM617 swap:
see the thread here: http://www.4btswaps.com/forum/showthread.php?t=7751
(11-18-2009, 11:52 AM)Tymbrymi So does anybody know how to add a slip joint into this mix? Sounds like we would have to change the output flange of the transmission....
(11-18-2009, 11:52 AM)Tymbrymi So does anybody know how to add a slip joint into this mix? Sounds like we would have to change the output flange of the transmission....
(11-18-2009, 11:52 AM)Tymbrymi So does anybody know how to add a slip joint into this mix? Sounds like we would have to change the output flange of the transmission....
(11-18-2009, 11:52 AM)Tymbrymi So does anybody know how to add a slip joint into this mix? Sounds like we would have to change the output flange of the transmission....
The stock driveshaft has a slip joint. If you don't have a slip joint it will murder your transmission, your differential, and your U-joints. Just because the pumpkin doesn't move on the order of inches and feet, when you zoom in to half-thousandths (bearing tolerances), everything still moves a WHOLE LOT! Just throwing that out there...
It's for sale... already sold the trans.
He's looking at $500 bucks for the driveshaft, 3.69 ASR diff (has a LSD carrier) and a throw in 3.07 diff. All fitted in his w124.
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After looking at seal options for the 3104-27 yokes, I've decided that the best solution is to have the smooth seal surface of the yokes turned down to the same O.D. as the stock trans output yoke and diff yokes.
The trans output seal for a 16v manual trans is 65x40mm and the diff seal is 70x40mm seal. These are published seal measurements. I have yet to measure the actual O.D. of a trans output yoke and pinion flange. While you can come up with a very close match to the rear diff seal that will work with the Spicer yoke, it's a non-directional seal. I have yet to find a suitable seal for the manual trans. The MB 16v getrag trans seal (which is shared by other MB manual transmissions) is designed for a counterclockwise app and the pinion seal is for clockwise use.
After seeing a lot of slip yoke discussion on this thread, I should mention that a steel driveshaft can be made with reliable, vibration-free slip yoke integrated. This is pretty much the only option. Installing a DS without any slip yoke is plain stupid.
U-Joints need to be installed in pairs, to cancel out phase differences. The odd thing is that Mercedes driveshafts have a single u-joint in the center. If you install a single joint on the front, it should be 90 degrees out of phase with the one in the center to avoid resonance.
Mercedes seems to have build their cars so that the engines and diffs are exactly in line (to avoid wheel hop due to the center u-joint), I think it's an odd way to design a car. With two (not three) u-joints, you would have more flexibility in mounting the drivetrain components. You could, for example, lower the engine a bit to relocate the roll radius.
Here's another option:
http://www.superturbodiesel.com/std/Thre...5#pid58525
Found a possible idea for a slip yoke in our automatics, but I'm having trouble finding some information.
http://www.amazon.com/Strange-U1661-Tran...sbs_auto_1
This shows that it is 27 splines, but it doesn't show dimensions. Also noteworthy, it fits the TH350 transmissions, so that is a possible source for a driveshaft as well.
Still would need to use a yoke on the diff. I hope that this works out, would make the driveshaft issue for my build disappear.
EDIT:
Found this with some information, shows the diameter of the transmission shaft in question is 1.176", the yoke is 1.172."
http://www.actionmachineinc.com/slipyoke.aspx
Do you know the diameter of the 722 output shaft?
I don't think a slip yoke will work for an output shaft that is made for a yoke flange, but if you're able to get a spline match you're closer to finding a spline yoke that will fit.
Well I suppose that there is only one way to find out, there are many sources for TH350 transmissions, plus 700R4s which are later upgrades for TH350 applications. All I need to do is to find a driveshaft for a TH350 at a pull-a-part and try it in a MB automatic transmission. Plentiful on both sources there. However I'd imagine that the diameter of the output shaft on the 722 is close to 1.172" since that yoke is known to work on the 722 transmissions.
My thoughts are, and someone correct me for missing the obvious, is if one can put on a u-joint flange with a new seal (mentioned above) a slip yoke should also work?
For my application, since I'm using an independent suspension, I don't really need that much travel of the yoke, I'm just wanting a bit of travel since my application is a truck application.
(02-08-2014, 12:42 PM)EmJay Well I suppose that there is only one way to find out, there are many sources for TH350 transmissions, plus 700R4s which are later upgrades for TH350 applications. All I need to do is to find a driveshaft for a TH350 at a pull-a-part and try it in a MB automatic transmission. Plentiful on both sources there. However I'd imagine that the diameter of the output shaft on the 722 is close to 1.172" since that yoke is known to work on the 722 transmissions.
My thoughts are, and someone correct me for missing the obvious, is if one can put on a u-joint flange with a new seal (mentioned above) a slip yoke should also work?
For my application, since I'm using an independent suspension, I don't really need that much travel of the yoke, I'm just wanting a bit of travel since my application is a truck application.
(02-08-2014, 12:42 PM)EmJay Well I suppose that there is only one way to find out, there are many sources for TH350 transmissions, plus 700R4s which are later upgrades for TH350 applications. All I need to do is to find a driveshaft for a TH350 at a pull-a-part and try it in a MB automatic transmission. Plentiful on both sources there. However I'd imagine that the diameter of the output shaft on the 722 is close to 1.172" since that yoke is known to work on the 722 transmissions.
My thoughts are, and someone correct me for missing the obvious, is if one can put on a u-joint flange with a new seal (mentioned above) a slip yoke should also work?
For my application, since I'm using an independent suspension, I don't really need that much travel of the yoke, I'm just wanting a bit of travel since my application is a truck application.
SO guys, been thinking lately about how nice a straight driveshaft would be (with a slip yoke in the middle of course), anybody know if the spicer yoke will fit in my trans? I swapped a 4-speed in my 300D a while ago and the driveshaft I have is just a little too long and kind of causes vibrations and stuff and I figured if I'm gonna get it shortened I might as well just get a new one made, and this seems like a better option with the spicer yokes and whatnot
Instead of putting the slip yoke in the middle, has anybody attempted putting it right after the transmission or before the differential, connected directly to the U-joint?
That is what I intend to do, unless it would be a bad idea for some reason. Otherwise, it seems it would be easier and cheaper to do it that way.
Using a U-joint connected slip yoke similar to this.
The main thing I am concerned about is that since the center bearing will be eliminated, the entire weight of the driveshaft will be supported by the transmission and differential. Even with an aluminum driveshaft, there will most likely be more weight hanging off the transmission. I am not too worried about the differential side, but I am hoping the transmission would be able to handle the extra weight without issues.
(05-04-2015, 11:40 PM)Matej Instead of putting the slip yoke in the middle, has anybody attempted putting it right after the transmission or before the differential, connected directly to the U-joint?
That is what I intend to do, unless it would be a bad idea for some reason. Otherwise, it seems it would be easier and cheaper to do it that way.
The main thing I am concerned about is that since the center bearing will be eliminated, the entire weight of the driveshaft will be supported by the transmission and differential. Even with an aluminum driveshaft, there will most likely be more weight hanging off the transmission. I am not too worried about the differential side, but I am hoping the transmission would be able to handle the extra weight without issues.
(05-04-2015, 11:40 PM)Matej Instead of putting the slip yoke in the middle, has anybody attempted putting it right after the transmission or before the differential, connected directly to the U-joint?
That is what I intend to do, unless it would be a bad idea for some reason. Otherwise, it seems it would be easier and cheaper to do it that way.
The main thing I am concerned about is that since the center bearing will be eliminated, the entire weight of the driveshaft will be supported by the transmission and differential. Even with an aluminum driveshaft, there will most likely be more weight hanging off the transmission. I am not too worried about the differential side, but I am hoping the transmission would be able to handle the extra weight without issues.
(05-04-2015, 08:19 PM)sassparilla_kid SO guys, been thinking lately about how nice a straight driveshaft would be (with a slip yoke in the middle of course), anybody know if the spicer yoke will fit in my trans? I swapped a 4-speed in my 300D a while ago and the driveshaft I have is just a little too long and kind of causes vibrations and stuff and I figured if I'm gonna get it shortened I might as well just get a new one made, and this seems like a better option with the spicer yokes and whatnot
(05-04-2015, 08:19 PM)sassparilla_kid SO guys, been thinking lately about how nice a straight driveshaft would be (with a slip yoke in the middle of course), anybody know if the spicer yoke will fit in my trans? I swapped a 4-speed in my 300D a while ago and the driveshaft I have is just a little too long and kind of causes vibrations and stuff and I figured if I'm gonna get it shortened I might as well just get a new one made, and this seems like a better option with the spicer yokes and whatnot