Where is the best place to buy the best quality SAD coupling kit ??

Love the business name suggestion: "Happy SADS" !
I can't say the thought of a SADS repair cottage industry hasn't crossed my mind, but I still have a day job and tend to be a little stingy about how I spend what little free time (and energy) that I have.
Now that the boring operation is trivial, the hardest part (other than the effort of getting a SADS in and out of the van) is pounding the rubber bits out and back in again. I'd have to contrive a press operation before I'd consider doing this in any quantity. Maybe that's my next project?

How much interest is out there?

The SAD thing about a business like this is if you do your job right, there wouldn't be any return business.........except for maybe auto repair shops. Even those guys probably wouldn't get too many Previas in for repair. Maybe that "Previa Only" repair guy in Seattle (Sami) would order a few a month (assuming you could get his business). As with any business, the trick is convincing clients that you're "the man" they should do business with. Even if you could get enough regulars, whatever business is there now will die out with these vehicles. I'm guessing the SADS business is already past it's peak. Just my 2¢. Tim

Very true, Tim-
And I've been down this road before with another obscure hobby. I had more time and devised a product that no one else in the world made. I sold them all over the world - as far as western Australia. But by "them" I'm talking about maybe 20 units over a period of six or eight years. I knew the market was minuscule but it was smaller than I thought. So eventually it became a PITA to get an order, and I shut down the operation.
I think all I've done is reverse engineer the process already in use by other outfits marketing replacement "revolvers". Their quality is hit-and-miss, but they would be my competition, so I'd have to meet or beat their price to get a share of the market. To make it worthwhile at those margins I'd need to do large quantities, invest in more tooling, yada, yada, yada, and at the end of the day I'd be dependent on Febest to continue making their little rubber bits. It's not a viable plan.

Anyone know what happened with the home cast revolver bushes that a guy on the yahoo group was doing? There's a pretty long thread about them, including his process, but it was never updated.

Bought the SADS bushing kit off eBay from ABCMart based on recommendations.

i have half a mind to use 3M WindowWeld on the old revolvers just to see what it's like, and if the eBay jobbers don't last, I could install them.

Thinking of buying the OEM Toyota couplings but cant find a part number , Does anyone know it?
Thanks in advance

1st page in this thread:

Quote:

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Originally Posted by pdgizwiz

The OEM part number you want is 04374-28011.

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04374-28011
this is the newer style with the 14mm bolt sleeves

Yes, the stronger SADS shafts (with the bigger bushings) came out in 94, so these should be right for yours. However, I've heard reports of some 94s having the earlier weaker shafts, so you should verify the size of your bushings before you order. Tim

http://i8.photobucket.com/albums/a23...v/IMG_0677.jpg

http://i8.photobucket.com/albums/a23...v/IMG_0680.jpg

Attachment 3926

Here is another design approach, any experiences or opinions?

http://www.ebay.com/itm/321330123915...%3AMEBIDX%3AIT

We've talked about those a few times (other threads). General consensus is they're junk. I have a set on my Previa now, but I haven't driven it enough to speak from experience. However, I find it hard to believe a 2 part urethane can match the strength/durability of aluminum with molded rubber inserts. Tim

Just installed the ABCMart aluminum revolvers. Working great brand new; we'll see how they hold up.

So before 2018 update:

SADS have had no issues.
Visual check, no cracks or anything.
Driving check - no vibrations
sound check - no sounds.

I've used the ebay SADS bushings twice. Once was on a 2wd 93 non sc and I got 140K miles out of them before I got rid of van. The second ones are on my 95 Alltrac SC It was put on at 160K miles and van now has 240k and the SADS bushings are really starting to show wear. They arent totally shot yet but on there way out for sure.

First post, Howdy all.
Unable to post quality pictures, sys froze and lost text before, so just text for now. (If someone can point me to tips on how to best post pix, I will post pictures of a new Toyota coupling kit and side by side pix of toyota coupling and ebay coupling.)
Agree with many others on this thread, best quality is Toyota part: 04374-28011
I have had 5 previas and put almost 500k miles on them collectively, and replaced SAD'S couplings with ebay coupling kits and toyota kits.
My opinion: The Toyota kit is superior, tighter tolerances, harder more precisely machined steel spools, better rubber formulation. Hands down, use the toyota kit. I have found a wide variation of quality in the ebay couplings. I had to send one version back because it was just junk, (rounded steel spool edges, inconsistent diameters, etc.).
Lesson learned quote:
"Never time to do it right? - Then always time to do it over"
Tips on install:
1. Take care not to damage or contaminate the boot and centering bearings at the end of the shaft. If it is dry and rusted/damaged, consider finding another shaft. Its health is mandatory for a balanced and smooth running shaft repair that lasts 100k miles or more. Don't get dirt or junk inside the boot and protect the shaft that goes in it. Apply new rubber compatible grease to that bearing before assembly.
2. When tightening nuts, back up both the rectangular washers and the bolt heads, or back up the other two when tightening the bolt head. This is to avoid turning the inner spool while tightening so as not to twist and put unnecessary stress on the rubber inserts. Three or more hands is best for this. Do as much assembly on the bench as possible. Don't clamp the shaft in a vice if you can avoid it.
3. Try not to bend (flex) the assembled shaft when handling or installing. Bending too much can stretch the rubber inserts to their yield point and shorten the coupling life.
4. Pay special attention to aligning the shaft with the motor and the accessory drive housing with the shaft. This is all done with the drive housing mounts. It doesn't hurt to use new mounts. If the old ones are OK, consider match marking the mounts prior to taking things apart if the last shaft was original factory, or if the last shaft install lasted over 100k miles. If using new mounts or if you believe the old shaft may have not been aligned well, take the time to adjust the housing mounts to minimize stress on the couplings' rubber parts. My first previa (91 LE) had its SADS replaced twice by the dealer at 20k miles because the shop teks suspected it of causing a minimal shimmy at accel from a stop (previa owners are used to it). The previa was new to the teks and they were not reading the shop manual so did not align the shaft properly. A terrible clattering noise results from moderate shaft misalignment where metal to metal contact occurs. I had to buy a shop manual and show it to them while asking the question "did you align it like the book says" to get my van back. I have since improved on the alignment instructions in the manual. The manual instructions use a straight edge and an inclinometer for alignment. That only adjusts partly for angular misalignment an does not adjust for the coupling being in tension or compression along its axis. You want the rubber inserts to have as little stress placed on them as practical. Misaligning the the shaft angularly results in unnecessary cyclic loading of the rubber inserts with each revolution of the shaft. Tightening the accessory drive housing mounts with the drive housing too far forward or back puts the shaft in tension or compression, respectively, and adds continuous unnecessary stress to the rubber inserts. I have found the best alignment is achieved by using feeler gauges to measure the gap between the coupling disk and the rectangular washers. Do this first when the shaft is assembled and straight on the bench with the rubber inserts in their most relaxed state. Measure the gaps all around the shaft and average the values. Use this measurement once the shaft is installed and keep adjusting the drive housing mounts until you get as close to this measurement as possible all around each coupling. Then you will have as little bolt-up stress on the rubber inserts as you can get for long coupling life.
5. Grab the SADS and try to turn it back and forth to assess the couplings’ condition during each oil change. There is a world of difference in play of worn couplings and good couplings. You can often see the beginning of cracks in a starting-to-wear coupling’s rubber inserts open up and close when you do this. It can give you a progression of deterioration to judge over time. I have seen these couplings disintegrate quite a lot before you start hearing the metal on metal contact start, so you can generally wait as long as you can before replacing the couplings. But by all means, change the couplings when you start hearing any metal clattering. That will start damaging the shaft end yokes. The centering bearings will keep the shaft running true as long as they are in good condition. If the shaft is wobbling or causing out-of-balance vibration, the centering bearings may be toast and another shaft may be advisable.

I am new to this forum so I'm sorry if I'm asking a question that has been answered a thousand times. I've read this thread on the SADS couplings. It is extremely interesting to me because I have changed the couplings on my 1991 Previa twice and need to do it again and what I have read here will help me do a much better job of replacing the parts. I would like to get better parts so the couplings would last longer. I have 395000 miles on my van and have owned it since it was new.

I would like to buy genuine Toyota couplings but the 04374-28011 part mentioned in this thread is for a 1994 to 1997 Previa. Is there any way I can used these genuine toyota couplings on my 1991 van? If not, what do you think is the best coupling option to use for a 1991?

Thanks for your help.

Sam

Quote:

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Originally Posted by samstrader

... I would like to get better parts so the couplings would last longer. I have 395000 miles on my van and have owned it since it was new.

I would like to buy genuine Toyota couplings but the 04374-28011 part mentioned in this thread is for a 1994 to 1997 Previa. Is there any way I can used these genuine toyota couplings on my 1991 van? If not, what do you think is the best coupling option to use for a 1991?

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Can you still get any couplings (91-94 or 94-97) from Toyota? If so, you might be able to get all of the bits needed to convert to the later shaft.

OTOH, the late Yahoo Previa group seemed to settle on a BMW p/n 26-11-1-225-624, used by BMW from mid-80s to late-90s in driveshafts (and thus stronger than the SADS couplers). Mehle and Lemforder make aftermarket replacements. My 91 has only 313K, and I live further north than you, so have only had to replace them once (~220K miles), but if I have to do it again will take that approach. The mod procedures are pretty simple if you are interested.

Thank you for your reply John.

I think I can still get the Genuine Toyota couplings for a '94 to '97 but as far as I can tell, Toyota doesn't provide replacement couplings for '91 to '93 year models. So I think the only way to use genuine Toyota couplings on a '91 is to convert the accessory shaft system in it to a '94 to '97 accessory shaft system. But i'm not certain about this and I don't know what is required to make the change to the later years accessory shaft or if it is even possible. Has anyone ever made this conversion to a later year accessory shaft system?

I did not know about the BMW part you mentioned but it is very interesting, especially because it is a stronger coupling and that is what I am interested in. I'm going to look up this part and see if I can get them. If you have a copy of the modification procedure to make these couplings fit a 1991 Previa, I would be very interested in that information. I think this would be the way to go. I have seen the polyurethane couplings on the internet and thought they were interesting but it seems like people on this forum are not too impressed with them. So, I am leaning away from them. I have used the Febest parts for the last two replacements I've made but they don't last as long as I would like. The original couplings lasted until 196000 miles, but they were noisy for quite some time before I replaced them. Maybe noisy starting at 150000 miles. The first Febest set lasted for 54000 miles and the second and current has lasted for about 140000 miles, which is pretty good. But this forum says the Febest parts are not as good as they used to be and I know for sure that my second set was the older manufactured Febest parts because they had some shelf life when I bought them in 2010.

Thanks again for your help. I would be very interested in the conversion for the BMW coupling parts.

Sam

Hello John,

I forgot to say thank you for the link to the BMW part.

Sam

First, there is this link to Zen Previa, in which he quotes a post from the Yahoo Previa group about adapting to a 91:

Quote:

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"...I used the BMW flexdisc part to replace the revolvers. All I needed was a piece of 3/8 steel brakeline ($3.00) to make some bushing-spacers for all 12 of the bolts. The brakeline material fit snug in the disc bushings and the inside diam. was just right for the original Toyota bolts. I cut twelve about an inch long and used them as I reassembled the new parts. The six bolt hole diam. in the BMW part matched right up with the Toyota revolvers perfectly. The BMW flexdiscs were a little thicker than the original (1/16 to 1/8 inch) so after I had the shaft back in I just adjusted the three accessory carriage mounts forward about 1/4 inch. It went together pretty well. No more SADS rattle and no more vibration, it runs out smooth.:-) And this is the best part for me, it cost me about $80.00 in parts and five hours of my time on Friday afternoon, not $1200.00. I got the new BMW flex discs (for 1987 BMW 325i, with automatic, driveshaft flex discs) from importparts.com, $37.00 each and free shipping, they came the next day. I don't know how they will hold up over the long run, but I have no reason to believe they won't hold up for many many miles. (the BMW part seems like a much heavier duty part) And I see no vibration increase on the accessory carriage. The whole van idles much smoother."

Yahoo Previa Group 5128 on Mon Apr 22, 2002 by beeman35051 - 91 dx 2wd with 137,000 miles

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[I suspect that date is wrong, but it's no longer possible to search the group archive.]

Then there is a comment from another forum thread, in 2015, that this basic procedure also works for 95 shaft couplings if the bushing sleeves are cut lengthwise to expand slightly for the larger bolt:

Quote:

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"... They are incredibly tough. Consider they are used as the actual driveline couplers to put the rubber to the road on the 3 cars! They are a tad thicker, not a problem…maybe 1/8”. The holes line up perfectly. The holes are the wrong diameter (10mm vs 8mm bolts) so ... We chose the 3/8” brake line ... and cut them into 1” pieces, total 12... [then] cut them lengthwise with a Dremel so the bolts would fit through and it was not a problem and shims the holes just fine."

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BTW, Tim (who runs this TVT list) also posted in that thread that he had used the Lemforder (BMW after-market) couplers successfully [but that was six years ago; Tim no longer has his Previa]. So that was three posts, using BMW dealer parts as well as Mehle and Lemforder after-market parts, all with good results.

Thanks for this information John. I'm going to use the BMW parts on this upcoming change. I want something better and these certainly seem much more heavy duty and these guys had very good results using them. Zen Previa sure does do a great job of posting how he did the work! I would have never been able to find this information so thank you for helping me.

I'll let you know how this works out.

I've noticed the activity of this forum seems low now which I guess means a lot of people don't have Previa's anymore. There are getting older and it is getting hard to find parts for them. I've had good luck getting close out parts at Rock Auto for 10 cents on the dollar. Air filters for one dollar, etc.

Thanks again for your help.

Sam

Hello John and All,

I have looked at the BMW coupler and one thing that is different than the Toyota original is that the 6 metal sleeves on the BMW part all stick out the same amount on each side and the Toyota parts have 3 on each side that stick out more than the other three. There is an offset.

When installing the BMW part, how do you compensate for this difference in design? Or is it just not a problem. I don't see anywhere where this is addressed.

Thanks,

Sorry, I have not had to address that detail yet: my van is at 313K, but the couplers have less than 100K. (I've only had to replace them once so far. Rubber lasts longer here (though steel does not), and the coupler load is light because I rarely use A/C.) I just recalled the posts about the topic from Yahoo's Previa forum, of which I had saved a few (because I expected to do it again some day). If someone had mentioned that as a problem, I think I would have saved the post.

Thanks John,

I try to minimize the use of my AC too and I think that is why this last set of my couplers has lasted as long. I will find out the answer to this question when I install these new ones and let you know the answer. The Genuine BMW couplers are real expensive but you can get very inexpensive aftermarket couplers from Rock Auto. I was surprised at the low cost. I'm sure the quality is lower too but it looks like these are still a lot stronger than the Febest. I will keep my Febest and buy the inserts to rebuild them. I want to see how that works anyway. But the BMW sure does look like the best way to go. Thanks again for your help. I feel like I have a chance to fix this a lot better this time. I use my van for everyday driving so these new couplers will get a lot of use.

Sam

I used the FEBI German-made couplers. Cant really comment on their durability because I've only driven them about 15,000 miles, but they are supposed to be OEM for BMW.

Thanks Previologist,

Do you remember if there was an installing issue with the different inner bushing stick out pattern of the BMW versus the Toyota style? I'm trying to understand before I buy. These look to be greatly stronger than the Toyota parts and I can't imagine them not lasting forever under such a light load as compared to what they are designed for.

Sam

there were major installing issues because the shop that installed them wasn't qualified to install an air freshener let alone a SADS coupling. Evidence suggests they didn't even tighten the bolts, and I drove it that way for several months. When it started wobbling badly I took it to a different shop and only one loose bolt was holding it in, the others had broken. No evident damage to the coupler. No problems since then, 1.5 years later.


But I can't speak to the issues you specifically mention. I'm not aware of that problem. I think there is a slightly different thickness, but I think the 2nd shop just reefed em down tight and all seems OK.

Thanks for your help Previologist,

I'm going to try these new couplers and I'll let you know what I find out. They must work because a lot of people have used them and after getting the bolts tightened, yours have been working for a year and a half and that's pretty good.

Thanks again.

I didn't drive it for about 1/3 of that time because my HG blew and I had the engine replaced. But I have driven it 15 to 16 thousand miles including crossing 2/3 of the US twice. I haven't visually inspected them lately but I have zero vibration. I'm happy with em.

I'm going to try the BMW couplers out. If they don't work out, I can always go back to Febest. Both are less expensive now than when I bought the Febest before. Only regret will be the time to do the work and I've done this two times now and also have found you tube videos on how to do it that will make it even easier. Well, not easy but not as terrible as the first time.

It's sort of rewarding when you change them out and things quiet down as much as they do with the replacements.

I replaced the SADS couplers on my 1991 Previa (396000 miles) yesterday and used the Fibi BMW couplers from Pelican parts, part number 26-11-1-225-624. The cost for these couplers was $95.00 delivered. They were made in Germany and are very high quality. The fit up was excellent when the 3/8 inch brake line sleeves were used. I used a tubing cutter to cut the brake line to make the sleeves and was able to get them all exactly the same length, I did have to use a round file to file out the inner lip the tubing cutter made on each end of each sleeve.

It took me 7 hours to complete the job; I'm not sure how it took so long but I've always been a little bit slow.

The BMW couplers should last forever; I don't see how they could ever wear out. They are not nearly as flexible as the Toyota original design so I don't know if this will be a problem or not. With the Toyota design, the couplers provide a shock dampening whenever the air conditioner compressor kicks on and off but with the BMW couplers, it is more of a direct connect. However, the SADS shafts turns true and has no vibration. And mentally, I'm not worried about wearing out the couplers anymore.

Just like mentioned before, the BMW couplers make the SADS assembly about 1/4 inch longer (.201 inches actually) and this is only because the metal sleeves in the BMW coupler don't fit into the counter sink holes on the ends of the SADS shaft. I was worried about not using those holes with the BMW coupler because they provide some strength by taking some of the shear force off of the bolts, but I don't think this will be a problem. I tightened all the bolts to 30 foot-pounds of torque and there is no slack in the fit up of the coupler anywhere. I can't see how the bolts would shear.

I did adjust the three carriage mounts (all flexible floating mounts by the way) forward by a 1/4 inch. I had to remove a little metal (1/8 inch) from the center hole on the front two mount braces so the mounts could move forward a little more. My carriage was originally mounted almost fully forward apparently. I used a Dremel. The mounts are quite substantial so this metal removal didn't weaken anything in my opinion.

Before I removed any of the mounting brackets, I cleaned up all the parts where the bolts and nuts were attached and used a yellow paint market to draw around each bolt so I could put the mountings back together like they were. This worked out real nice. It was a lot of work up front but made putting the brackets back in place a lot easier.

Thanks to everyone for helping me decide how to replace my SADS couplers. I think I got a lot better job than I would have otherwise. I hope I never have to replace these couplers again because it is just not a fun job.

My hat is off to the original designer of this upgrade and I can't imagine how long it must have taken to figure out all of the details. it is a very clever way to install stronger couplers. This took some very clear understanding of how the whole SADS shaft is designed. Just a very clever modification all together and an excellent job. I can't say thank you enough to him for sharing his idea.

I'm certain that no brake sleeves were even used in my installation (I told them to use them but they were idjits), but as long as they are torqued down it doesn't seem to matter. Mine only sheared off initially because the boneheads didn't tighten the freekin bolts.

I think it is right that this upgrade will still work without the sleeves. The only thing these couplings do is make the shaft rotate. The shaft is held in place by the bearings on each that are located inside of the drive shaft. The shaft won't fall out even if the couplings fail completely, but the accessories won't rotate.

Those brake line sleeves sure do make the couplings fit up good however. It's a perfect fit. It's amazing how clever this design is to me. It's perfect back yard engineering.