Nice work Wiz!
Please do share how you machined them. Inquiring minds want to know!
Nice work Wiz!
Please do share how you machined them. Inquiring minds want to know!
I believe that they did exactly that. Look at cvtroger's photos in this blog entry. You can see the slim steel hoop around the outside, with a pattern of staking marks.Too bad Toyota didn't do that,
It appears that you can. Febest's part number is TAB-LCB. Although it gripes me to buy anything from these guys I ordered up a few sets to see what I get. I assume they'll need to be machined. Sooner or later the couplings will be NLA from Toyota, and we Previsti will need new options. And I've no idea when Febest will quit making the inserts. Perhaps they already have, and just have some inventory left.then we could just buy the 12 little rubber/bushing parts, press out the old, then in with the new.
Speculating wildly here, but they don't seem to be aware that the OD of the sleeve has to fit into anything. Since Toyota never made the rubber inserts a replacement part, and as far as I can tell never made the earlier couplings a replacement part, I suspect that they leaned towards forcing customers to buy an entire shaft to a) make more money, and b) control quality. There may have been minor mid-year changes as well. There's nothing in the FSM regarding the fit of the bolt sleeves into the shaft yokes. And they may have never made any detailed specifications available to the replacement part manufacturers, forcing them to do their own reverse-engineering, with varied results. As has been seen on this list, plenty can go wrong rebuilding one of these shafts. Same reason bicycle manufacturers got away from the loose-ball and cone bearings and went to a cartridge style. The performance is no longer dependent on the skill of some kid in a bike shop.Seems like Febest had a good idea, but it was executed/assembled with complete incompetence. It's interesting how they are using bushings that are neither 12 mm or 14.
I'm blessed to have an old Deckel FP1 with an index head. It's very versatile. Cutting the loose bits on a lathe will probably be easier, but I will need to make a bit of simple tooling. I'll give that a try when my batch of rubber bits arrive. The sleeves on the Febest parts machine easily - I assume they are just mild steel. The OEM sleeves are more precise, and may well be harder, but there's no need to machine them!I'm impressed you were able to accurately reduce diameter. I have to admit I never checked hardness, but I assumed these bushings were hardened steel. Did you install this on a bolt & spin in a lathe?
Envious, congrats!Originally Posted by pdgizwiz
Those are actually my photos, and I'll be darned if I never noticed! Nice catch. Too bad we can't get these from Toyota
Nice job finding those. I just ordered 4 sets myself, although I think I might only end up with enough to do one shaft (if I'm lucky). I see they have 2 listings for those. One is referencing Toyota part #04374-28010 (which I assume is the NLA number for the coupler set with 12 mm bushings) and the other listing is referencing Toyota part #04374-28011 (which IS the number for the coupling kit with the 14 mm bushings). Interestingly enough, both listings are for Febest # TAB-LCB, so it seems they are aware there were 2 different part numbers. So sad their production & QC (as if) people don't know what's going on.
I think it has more to do with greed. I get the quality argument (so many things to screw up here), but then why sell the coupling kits........and then $250+......really?
That's so awesome! I'm envious too. Do you have 3 phase power? I set up an old Bridgeport mill once that required 3 phase. I did the math and rigged a capacitor as a substitute (that did the job). Tim
Nope, no three-phase power. I replaced the original 410V motor with a 2 HP 220v three phase unit, and then rigged it up with a VFD (Variable Frequency Drive). The VFD takes single phase 220, converts that to DC, then converts that to 220 three phase at frequencies from 0 to 60 (or maybe more, I forget). So you get full torque at a range of speeds.
VFD units are a great way to retrofit smallish (< 3HP) industrial machines for home shop use. They take a little beard-scratching to set up, and aren't marketed to consumers, but the technical issues are workable and they're not hard to locate and buy. There's a whole forum dedicated to them, along with the other options.
I just got my 4 sets of Febest TAB-LCB bushings (24 total). I unpacked and measured them. All 24 of mine have the bigger steel bushings inside, but no taper. OD of inner bushing is also slightly above 14 mm. With a little force they might fit inside the later (94 & up) couplers, but I think I'll have some work done to these before installation. I purchased mine off Amazon for $14.95 (each set of 6) with free shipping.
IMG_3877.jpg
Kind of funny though as the boxes state "1990 - 1999" Previas on them. I guess if I wanted these for the earlier drive shafts I'd be bummed, but since I already have 2 of the more modern shafts (with bigger holes) getting these bigger bushings was nice. I'll probably toss my 91 shaft in the scrap pile once the urethane couplers fail. Tim
FYI: Although the Febest number is the same on both listings, Amazon actually has 2 listings and each listing referencing a different Toyota Part number. I ordered all of mine from the listing that referenced the Toyota number for available (14 mm) flex couplers. Perhaps this had something to do with me getting all 14 mm bushings, but I find that a bit hard to imagine as Febest has no numbers or marks on the boxes to separate the newer from the older (seems to be random).
PS: Thanks again for the tip about these.
I got a bunch of them too, and they look the same.
I also took one of my older OEM couplings and pounded the inserts out. Sheesh, they were tight! There was no sign of the crimping marks around the outsides, they were just pressed in.
And the diameter of the holes in the aluminum body are significantly smaller (around 0.4mm) than the OD of the outer steel sleeve of the new bits. So I'll either have to bore out the holes or turn down the sleeves.
I'll have to bust apart one of my other spare SADS to see what their couplings look like. I still wonder if Toyota made some number of mid-year changes.
Well, it's a good thing I enjoy this kind of thing... At least I'm confident now that I have the wherewithal to rebuild any SADS that comes my way.
I ordered the TDS-428 coupler set for the 92 shaft. I see the TAB-428 bushings are avaliable from Febest too...maybe these are for the older SADS? But they're $14 and the couplers are $18. Is it that simple to punch out/insert the bushings?
Assuming the parts are usable (correct sizing and dimensions), your way is easier by far. Guys like pdgizwiz & I are just weird.
Amen to that, Tim.
The bits I bought are from Febest directly. I bought six sets, and have only opened and inspected one at random, but it contained six of the 14mm units. They are actually a little larger than that, so I still think I'll need to turn them down a bit even to use on a newer SADS.
By no means is it simple to knock these Febest bits in and out. I don't have a good feel for how much variation there is in the parts, but given what I have on hand, some machine work is required. I turned a drift on my lathe to catch the thin steel outer rim but still pass freely through the hole in the aluminum part. I used a hammer but a press would be a much better approach to get them out, and certainly to get a new one in.
I finally got around to cobbling up the tooling I needed to finish a SADS coupling rebuild using the Febest rubber bits.
I was able to knock the old bits out of the blasted couplings of a SADS, but the replacements are just too big to go in without some work. I decided to bore the holes in the aluminum body out instead of turning the steel shell of the bits down. The shells aren't perfectly round, and there's no good way to get ahold of them to reduce their size. Besides, it's more fun to bore out the bodies, since I have the means. I had to make a fixture to hold the body by it's central bore, which is tapered from each face. My Deckel and indexing head along with a cool boring head make fairly quick work of it.
Video of the body boring process
Finished bored body:
re-bored_SADS-coupling-body.jpg
I bored the holes to around .001 - .002" smaller than the average of the rubber bit sleeves- They were as much work to knock in as they were to knock out, so I don't expect they're going to be going anywhere. Some kind of hydraulic press would be a better way to go, but that would be another project, expense, or both.
Old bits are way hammered:
old-SADS-rubber-bit (2).jpg
New bits: as received in the background, turned down to 12mm in the foreground:
reworked -SADS-rubber-bit (1).jpg
It's easier to turn these down when they're out of the body.
video of the turning process: (I tacked some random music on as the background noise of the lathe is a little obnoxious)
Here's a completed coupling:
SADS-coupling-rebuilt.jpg
Once I've completed the second one I'll put them in my '94 and give it a spin. I've no way to balance the shaft, so we'll see if that's needed or not.
Nice. I'm nowhere near as sophisticated as you are with your fancy machines. Tim
Wow, thanks for sharing those videos... Those were awesome!!! But it did give me flashbacks of taking metal shop back in 1984 and getting my thumb and index finger almost twisted off in the lathe machine when my metal shop partner turned on the machine when I was adjusting the pipe we were practicing cutting down.... Never took that class again
Boy have I missed out on some good stuff!!
Last edited by JDM VANMAN; 02-15-2016 at 07:19 AM.
The rebuilt SADS is now spinning happily in my '94 LE!
I thumb my nose at the FSM-
FSM-warning_SADS.jpg
This van is a 2WD, so it isn't as much trouble to swap a SADS as the AllTrac - there no front drive shaft to remove first. Still, every time I do this I wish I had a couple of extra hands and maybe a prehensile tail to maneuver things. The yoke has to come out - FSM view:
FSM-mounting-yoke.jpg
non-cartoon version:
SADS-yoke.jpg
I find I can leave the #5 stay in place (it's a PITA), but I remove the #4 stay (passenger side). FSM:
SADS-No4_stay.jpg
SADS_#4-Stay.jpg
The rest of the procedure has been described before, so far as what gets unbolted. When the SAD Shaft is loose, the rearward end pops off of the dampener pulley and shifts to the driver's side, then the SAD (Separated Accessory Drive) must be lifted with the SAD Shaft until it can be jostled rearwards and out. It's hard to see what's going on with a single set of eyes and hard to lift and jiggle everything just right. It seems impossible until BONK! It's free. Don't drop it on your face.
Much anguish has been expressed over the "SST" to measure the angle of the shaft and the SAD. But hey, it's a simple inclinometer - comprised of a stick with a string on it that swings past a scale. It is used to compare the angle of the main part of the SAD Shaft to the angle of the SAD housing. The front bearing of the SADS is fixed firmly to the housing, which is made of cast iron and has a convenient flat surface on it's lower edge. That lower surface can be trusted to be dead parallel to the front-most portion of the Shaft, so by comparing the two measured angles one can determine the angle that the coupling is compensating for. The FSM allows 2 degrees, and I measured mine at right around 1/2 of a degree.
Toy-inclimometer.jpg
What's needed is a way to get something to stick against the part that needs to have it's angle measured so that the string can settle down and a repeatable measurement can be made. Then measure the other part and calculate the difference.
I made my inclinometer as shown in the picture below out of bits of stuff I had laying around. Yours will certainly be different!
INCLINOMETER_DETAILS.jpg
Mounted to the shaft:
SADS-Inclimometer.jpg
mounted to the SAD housing:
SADS-Hsg_inclination.jpg
I measure the distance between the string and the level, my reference:
Inclimometer-measurement.JPG
The difference between the two measurements was about .07". The length of the swinging portion of string was 7.5". The angle of the difference is the arc-tangent of .07/7.5, which works out to around .5 degree. Well within spec.
I'm happy with the results, but I'm not likely to put a lot of miles on the van. So who knows how long it will last? Maybe another score of years and quarter-million miles. Or not.
Last edited by pdgizwiz; 02-29-2016 at 10:48 PM.
Very nice! Thank you for that awesome & detailed write-up. It makes everything crystal clear. I agree there is no good reason why the FSM forbids this. If one is careful and precise, you can get away with anything. I think Toyota is more worried about your average hack mechanic's inability to follow comprehensive instructions........that & the loss of potential profits when you don't buy their overpriced replacement parts. Tim
Thanks for that, very clever!
pdgizwiz - dude... that is pretty awesome. Wow!
The thing that I keep thinking about, after seeing what 1/2 deg looks like, is "Wow, they would seriously allow 2 whole degrees?......really?" I can't imagine it ever being off that far by chance. Even your eyeballs should be able to detect a misalignment like that. Next time I do this I'm going to employ your method (or a variation of it), but try to hit it dead on. I'll also try to rig up something to align it sideways too. Because it's conceivable that having one side of the accessory assembly further forward than the other could create the same alignment issues, yet still pass the "up/down" alignment test. Hmmm, perhaps I could use my laser level somehow. This gets the wheels turning. I'll post here if/when I do this again. Tim
I found an adjustable shell reamer on ebay for $30, so the boring process is now a one pass operation - a lot quicker and more precise.
SADS-bore_one-pass_.jpg
You should start a SADS repair business..........you can call it Happy SADS. Start out by stocking up on cores and the Febest bushings, then Previa owners can place orders for your rebuilt ones (done right), and you can charge a refundable core charge.
Reply With Quote
