ChairmanMeow7 Posted May 16, 2009 Share Posted May 16, 2009 Shortly after I bought my Toy a couple of years ago , the alternator went. I replaced it with a heavy duty 160 amp alternator I got off E-Bay. Since replacing it , I have tightened it 3-4 times. And I have also had it tightened at about 3 different garages , including a Toyota dealer. It still seems to loosen up 3-4 times a year (and I've only been driving about 5k a year). I'm getting so frustrated , I am about to have them tack weld it in place , but of course that would create huge problems if I ever needed to change it on the road. I also have been thinking of seeing if I could have some sort of "pusher" bracket fabricated with a bolt that would "push" on it to keep tension on it so it couldn't (at least very easily) loosen up. Any suggestions ? Quote Link to comment Share on other sites More sharing options...
Bodybagger Posted May 16, 2009 Share Posted May 16, 2009 (edited) Yes. Remove the adjustment bolt and clean the holding bracket and alternator with acetone. Place Locktite 242 on the mating surface between the alternator body and the holding bracket, and on the threads of the adjustment bolt. You could also try placing a neoprene washer between the alternator and holding bracket. If this doesn't hold it, maybe you should remove the holding bracket and grind a series of small notches in it. Or sand it shiny smooth and place it next to some dirty metal getting welded and the weld spatter that gets all over it will bite into the alternator and provide friction. Be sure to apply Locktite 242 (or permatex blue thread locker) to the bolt threads. Edited May 16, 2009 by Bodybagger Quote Link to comment Share on other sites More sharing options...
Shoprat Posted May 16, 2009 Share Posted May 16, 2009 Here's another thought ! Could be a lousy stretchy belt. Try another brand of belt an see what happens. I have heard Dayco are about the best. John Quote Link to comment Share on other sites More sharing options...
Gulfstream Greg Posted May 16, 2009 Share Posted May 16, 2009 Here's another thought ! Could be a lousy stretchy belt. Try another brand of belt an see what happens. I have heard Dayco are about the best.John I have had the same problem from time to time. Can't remember the brand of belt but I know the alternator was not coming loose. But every 1000 miles or so it would start to slip. Quote Link to comment Share on other sites More sharing options...
ChairmanMeow7 Posted May 16, 2009 Author Share Posted May 16, 2009 Thanks for all the suggestions ! I thought that maybe because it was a HD alternator , rated at quite a bit higher amps than the stock alternator , that it was creating more torque and causing the problem. I don't beleive it's the belt stretching , although that is definately something to keep in mind ! I say that because when I tighten it , I push it up the "arc" slot on the bracket a little bit. But after a while , it seems to work it's way back to the end of the "arc slot" to where it can't loosen up and further.... I will try the threadlocker 1st , and then maybe (if need be) the neoprene washer. As a last resort , I may try to grind the slots on the bracket and maybe even the mating surface on the alternator. (or if I only do 1 of them , which surface would be better to grind the slots on) ?? Do you think grinding them by hand would be sufficient , or would I be better off taking them (the bracket and alternator) to a machine shop and have them mill a bunch of small equally placed slots on both surfaces (thus ensuring a good fit). My only concern would be the cost involved , but if I had to resot to this , I am certain it would solve my "problem" (especailly if all the slots matched up perfect). I had actually thought of this option before as well. But I realized the tack weld would be a quick "fix" , but most likely create problems down the road.... Quote Link to comment Share on other sites More sharing options...
ChairmanMeow7 Posted May 16, 2009 Author Share Posted May 16, 2009 Oh ...... I just had it tightened a yesterday by the mechanic I had install and charge my new AC compressor , and replace the tranny pan gasket and a fitting on the tranny that was leaking. Anyhow , I drove it about 25 miles , and the AC and tranny seem to be fine. But....... Darn belt is loose again after I just had it tightened !! I'm DEFINATELY gonna try the threadlocker as this is getting pretty frustrating ! Quote Link to comment Share on other sites More sharing options...
Maineah Posted May 16, 2009 Share Posted May 16, 2009 Mark the alternator with a black marker when it's tight I think you will find its the belt and not the alternator moving. Mine does the same thing at high Rpm's. A larger alternator is more likely to slip the belt because it will use more power to charge the batteries and the field is much heaver. (the rotating part) Quote Link to comment Share on other sites More sharing options...
futar Posted May 16, 2009 Share Posted May 16, 2009 This brings back memories of my first toyhome which was a four cylinder. I marked the position of the pulley. It was definitely the belt stretching. I finally bought an ultra premium belt. That seemed to help. I often wondered if the belt was too narrow. If I didn't sell it I would have changed to wider pulleys and belts. My next four cylinder and my six didn't have that problem. . Quote Link to comment Share on other sites More sharing options...
ChairmanMeow7 Posted May 17, 2009 Author Share Posted May 17, 2009 This brings back memories of my first toyhome which was a four cylinder. I marked the position of the pulley. It was definitely the belt stretching. I finally bought an ultra premium belt. That seemed to help. I often wondered if the belt was too narrow. If I didn't sell it I would have changed to wider pulleys and belts.My next four cylinder and my six didn't have that problem. . So when you say ultra premium belt , would you agree Dayco would be the way to go ? What if a Dayco is not available. Any other ultra premium brands to try ? Quote Link to comment Share on other sites More sharing options...
Bodybagger Posted May 17, 2009 Share Posted May 17, 2009 As a last resort , I may try to grind the slots on the bracket and maybe even the mating surface on the alternator. (or if I only do 1 of them , which surface would be better to grind the slots on) ??Do you think grinding them by hand would be sufficient , or would I be better off taking them (the bracket and alternator) to a machine shop and have them mill a bunch of small equally placed slots on both surfaces (thus ensuring a good fit). I would take a cold chisel and hammer a cross hatch pattern into both sides of the holding bracket. The aluminum body of the alternator is soft and it would serve little purpose to put a pattern into it. It should absorb the ridges from the pattern you put on the holding bracket. You want raised ridges in the hard steel of the bracket. Not cut valleys. Quote Link to comment Share on other sites More sharing options...
Maineah Posted May 17, 2009 Share Posted May 17, 2009 I think the next time I replace my belt I am going to try an agricultural belt they are designed for large torque loads. They usually are green and often called fractional horse power belts but don’t let that fool you. Mine right now is bow string tight but still slipping at high RPM so it is getting replaced before I take off again. It is not a real good ideal to tighten a belt as tight as you can because it is hard on bearings and in the case of our Toyotas the water pump bearings. Quote Link to comment Share on other sites More sharing options...
WME Posted May 17, 2009 Share Posted May 17, 2009 Once a belt is let slip to long it becomes glazed on the sides of the v and slips more, of course more glazing means more slipping an so on. I have machined groves in side the pully to help give the belt traction. Also there limits to how much power a belt can transmit, thats why there are dual belts on the large RVs with high amp alternators. It takes a little more than 1hp to run a Toy stock alternator at full output. It takes over 3 hp to turn a high output alternator. Quote Link to comment Share on other sites More sharing options...
Maineah Posted May 17, 2009 Share Posted May 17, 2009 Once a belt is let slip to long it becomes glazed on the sides of the v and slips more, of course more glazing means more slipping an so on.I have machined groves in side the pully to help give the belt traction. Also there limits to how much power a belt can transmit, thats why there are dual belts on the large RVs with high amp alternators. It takes a little more than 1hp to run a Toy stock alternator at full output. It takes over 3 hp to turn a high output alternator. Yep 5,000 miles and a great polish it also takes a lot of power to accelerate the moving parts. Frankly I think the alternator needs to have a larger pulley as it seems to be a common problem. Quote Link to comment Share on other sites More sharing options...
futar Posted May 18, 2009 Share Posted May 18, 2009 Sorry, I have "old timers disease" and can't remember what premium brand. It was over 16 years ago. There is something I remember. I noticed the pulleys were highly glazed so I burnished them which helped. I also remember buying a belt that was a monkey hair wider. Quote Link to comment Share on other sites More sharing options...
ChairmanMeow7 Posted May 18, 2009 Author Share Posted May 18, 2009 I would take a cold chisel and hammer a cross hatch pattern into both sides of the holding bracket. The aluminum body of the alternator is soft and it would serve little purpose to put a pattern into it. It should absorb the ridges from the pattern you put on the holding bracket.You want raised ridges in the hard steel of the bracket. Not cut valleys. And what's the purpose of the cross hatches in the back side of the bracket ? Just to help hold the bolt in place ?? Quote Link to comment Share on other sites More sharing options...
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