SADS problem as in noise only in Drive

I'm a pro wrench trying to fix a customers 91 Previa. The SADS shaft is making a noise from the front end only at lower RPMS in Drive. Shift to neutral or reverse or get up above 30 MPH and the noise goes away completely. The shaft has new off Ebay alum and rubber bushing parts on both ends and is tight and has no slop. I've checked all the mounts and none of them appear to be obviously bad. The front accessory cradle does move in sych with the noise. The noise started a few months ago and was very small and only happened when the alternator had a load on it. i.e. you could make the noise come and go by turning on or off the headlights. I had the alternator checked and its fine and as time has gone on the noise has steadily gotten louder.

I just got out there and inspected this again and it appears the passenger front cradle mount is bad....New ones are ordered will report back after they are installed.

Thanks
Rick:thmbup:

That sucks. Are you sure the flex couplers were for a 91? 91-93 have smaller bushing OD than 94 on. If the bigger wrong couplers were installed it would create a fit issue and would make the shaft a bit too long. That's the only thing I can think of. A better fix would be to find a 94 or newer shaft in the salvage yard then putting the Toyota couplers on. They are Toyota part # 04374-28010. Here's another related thread. You may want to download and read the PDF file found within. Tim

http://www.toyotavantech.com/forum/s...-shaft-removal

Well the new mounts didnt change a damn thing. Still have a noise in drive only.....The old mounts were not bad.

Further inspection makes me think the front bearing that supports the shaft is going bad. Anyone know anything about fixing or replacing the bearing shaft bearing?

Won a new SADs shaft on Ebay for $236 and it will be here next Tues will report back if it fixed the noise.

Damn, so you're the guy I was bidding against :rol:. I won one the week before for $93. About 2 years ago that same seller was selling them for $69 each. You could buy as many as you wanted on a BIN for that price. I got 11 of them. That must have tipped him off because immediately after he ended the auction. Now he sells them one at a time and starts the bidding at $92. I sold all the $69 ones and made a killing. I sure wish I knew where that guy was getting them. If he listed them correctly he could easily get $350 each (or more) for them............I know from experience :)>:. Tim

Yea! The Previa is quiet. The noise only in drive was the front SAD bearing. A new SAD shaft made it happy.

Awesome! I guess these are getting old enough to start seeing bearing failures. Thanks for the follow-up.

Just out of curiosity, what's the username of the eBay SADS seller? I just had mine go out on my 92, and need to get one.

Thanks!

It's "userid863753" but I'm pretty sure he's out. When I bought the "mother-load" a couple years ago he quit selling shortly after. I sold all of those for $350 - $500 each. Then just recently (around the time this thread started) he must have found a few more and sold those. There was no "buy it now" for this time and they all got bid up pretty high.........except for the one I managed to win. I still search eBay every couple weeks for "previa shaft" but nothing has come up (at least not the genuine Toyota ones). The one I bought I hadn't planned to sell, but could be persuaded if the price was right. I'd go $500 + whatever shipping costs (sorry but I don't think I'll be able to get one of these again). Here's a link to it on ToyotaPartsZone: http://www.toyotapartszone.com/oem/t...910-28050.html

Yeah, there's a few sites I've seen them listed for the $700-850 range, but I'm trying not to go that high. I'm probably going to go the junkyard + rebuild kit route. Unfortunately, this is my 92 that has the problem, so I can't just rebuild the current one with the kit. Thanks for the info!

Just before I found the killer deal on the Toyota shafts I replaced the couplers on my 91 with the urethane ones from eBay (If you go aftermarket you can replace the couplers on the early shafts). It's been a couple of years and over 10k miles. I haven't inspected them since the install, but so far so good (in regards to noise or other symptoms). Tim

I'm new, and I got here by a Google search for Previa drive shaft.

I have the EXACT same problem as the original poster (only have noise when the alternator creates a load).

I have the service manuals, etc, and downloaded the aforementioned pdf earlier in this thread.

I studied this entire thread, and even looked at the toyota part (which is now going for a whopping $1300!!!!)

I DON'T GET SOMETHING.... when I look at the pictures, I see a bearing, a metal shaft, and two couplings. You guys talk about it like it's a rare animal or something. What am I missing?

1. I have the original in my vehicle. Why wouldn't a sane person just buy the couplings, and bearing, and install them? Wouldn't two couplings (about 90$ - polyurethane, or 72 - aluminum) and a bearing (50$) make a ton more sense ... total 140$ max???? Why would would would someone even consider paying an outrageous 1300$?

2. If I elected to replace the couplers (if the original poster is correct, I think I only need a new bearing) -- which should I use, polyurethane or aluminum? If I am rebuilding the shaft, would you recommend replacing the couplers even if it's just the bearing that needs replacement?

3. The ebay guy selling the couplers mentions you have to balance the shaft. Huh? How would you do that?

Thanks in advance...
ron

I hear what you're saying and it sounds pretty straightforward. Well , in a way, it isn't. the 1991-93 models had a driveshaft that wasn't meant to be repaired. It was designed to be replaced. That's why the bushings for those years are part of a retrofit kit. 1994-97 models are made to be replaceable.

I remember posting about a guy that was selling the SADS shafts rebuilt and balanced for $225. That was on toyotavanpeople.com. Not sure how many he sold but he was getting them in regularly and they were selling like hotcakes. If you're replacing the couplers, I've spoken with a few Previa owners that said the polyurethane ones failed around 50-60,000 miles. My mechanic said that 100K miles is about what to expect on the aluminum ones. Sounds a bit disappointing being that my main Prev gets driven about 35-40,000 miles a year. Still that's not bad for a vehicle that is paid for and is 21 years old. I can live with that.

About balancing the shaft. My mechanic told me that they shouldn't have to be balanced unless they were damaged (ie. accident) but it would be good insurance still to have it done. It has to go to a driveline shop to be done- which I received quotes between $120-160. I'm a strong suppoerter of buying the Toyota kit as well. I tried two different aftermarket kits and both failed miserably with a year or two. The Toyota kit (which retails for a little over $200) has lasted me almost 3 years and shows no sign of failing soon.

I rebuilt a SADS with a pair of aluminum/rubber couplers and have had no trouble with it. The appear to be accurate replicas of the original parts. The rebuilt shaft runs quietly and without any perceptible vibration. I can't claim a lot of miles or years yet, so this is just one guy's experience, but I see no reason to expect anything less than OEM endurance. I'd avoid the polyurethane couplers, as they are a big departure from the OEM design.
I think so far as balance goes there's little on can do but mark the assembly before you knock the old couplers to be sure the pieces go back in the same clocking orientation as before. The couplers don't align the shaft components on an axis; that's done by features you can't replace anyway. The couplers themselves are of simple geometry and if they contribute to a balance issue, it's probably negligible. You might find a drive-shaft shop that could balance it, but they might just as easily mount it wrong and screw it up.
The couplers are available for the earlier years as well as the later. I used something similar to item 360366006681, currently on ebay (but didn't pay that much).

I have the same problem citizen Sorak reported.

It began after driving with the emergency brake on for 2 miles without noticing it.

Then, same day, the noise began.

I have replaced the SADS twice, the last time from Colorado Drive Shaft. It seemed solid and was well-installed by my buddy's very well informed shop, that did the balancing. It performed fine until the incident; just after the 1 year warranty expired.

I recognized the sound immediately.

It is a 91. Alltrac. I am wondering if anyone knows if I can just replace the couplings (maybe just the front coupling) or bushings rather than the whole unit again. And how long it takes the thing to fail: planning to drive 2000 miles around the holidays, thru lands with no Toyota shops for hundreds of miles. Already have driven it probably 800 miles, over the Sierras.

Rig has low miles: 126K. Was salvaged early in its career. Headlight lenses are discolored, ceiling is peeling, but otherwise fine. Got 25 mph this summer on straight highway driving. What a trooper.

I am short on coin and mechanically inept. Just hoping for some insight.

Thanks

Mo