Better drive belt tensioner bolts (non-S/C)

[TheMAN]

Most of us here have a 91 (90) to 93 Previa, since more of them were sold and now they're relatively cheap to buy used. Maintenance and repair on these vans are not easy as many of us have discovered.
One of the stupidest things I've encountered are the drive belt tensioner bolts... instead of hex bolts like what is common on many other cars, it's a bolt with a wing on the head... like a wing nut. That's great when the bolt is brand new and clean, making it "easy" to adjust a belt by hand. Well these vans are quite old now and either the bolt is now all grimy or is rusted like crazy.

Mine was the latter... rusted like crazy. My alternator finally died 2 weeks ago after 340000km. It has lived a good long life. The bearings have seized and it stopped outputting any voltage. With all the rust there, it took me more than 2 hours to take it off, and then many more hours to slowly (using pliers) to twist that stupid "wing nut" tensioner bolt off as I didn't want to cut the bolt off, making be having to replace the "T" piece that connects the tensioner bolt to the alternator (requires a junk yard trip). So, after taking it off, I replaced the tensioner bolt with one from a junk pile of bolts of the same length and a 12mm hex head... I believe that bolt came from a Corolla.

The A/C compressor's tensioner bolt is the same way... I haven't messed with it yet, but it's something inevitable because the belts will eventually wear out (I didn't replace either belt as they're still in good shape). Good thing is, the 94-99 Previas no longer have the wing nut style tensioner bolt on the A/C compressor. It is now a hybrid hex head/torx bolt, making it easy to adjust the belt with using a simple socket. I spotted a 94 non-S/C Previa at the Pick-n-Pull recently, so I went yesterday just to grab the updated bolt and not rusted bracket.

Most of you probably don't need anything but the updated tensioner bolt.... so here are the part numbers:
90119-08A25 Alternator tensioner bolt (superseded the original wing nut style bolt, officially per catalog)... 90-96 non-S/C Previas can benefit from this... the late 96-99 non-S/C (doesn't exist in USA/Canada) has this better bolt from the factory
can be found on 96-2000 3RZ-FE RZN18* 4Runners (alternator/water pump tensioner bolt), 96-04 2RZ-FE/3RZ-FE RZN140/RZN150/RZN196 Tacoma (alternator/water pump tensioner bolt), 93-98 3RZ-FE RCK10 T100 (alternator/water pump tensioner bolt), and 2000-2006 Tundra (proportioning valve bolt)... outside of North America, can be found on 88+ Hilux, LiteAce/TownAce, Qualis, Fortuner, Granvia, Coaster, Land Cruiser, Land Cruiser Prado, etc.

88446-28010 A/C compressor tensioner bolt with lock washer (no official supersession in catalog, but can be used in lieu of wing nut style bolt).... this is a Previa specific bolt.... 94-99 non-S/C Previas have this

These bolts can be had for less than $10... it's worth it!
I ran out of time yesterday trying to find the proper alternator tensioner bolt and it was too hot anyway... so I'll go find it in a few months when it's cooler... tons more 4Runners/T100s/Tacomas in the yard than Previas. I got my main objective achieved for the time being

If anyone wants pics, it'll have to wait

[TheMAN]

Oh, and if you need to replace the little connector piece the tensioner bolt goes into, you don't have to buy the entire A/C compressor bracket... based on the European parts catalog, you can order 88442-28010, which is that piece... the US catalog does not show this!

For the alternator, that piece is listed in the catalog, which is 16385-76030

This should be especially useful for those of you who either don't have the time to go to the junk yard or not any where near a wrecked 94+ Previa

[TheMAN]

It's almost 5 years since I last posted about this. I ended up never finding the time to go back to the junk yard to find the updated style alternator tensioner bolt from a wrecked Tacoma/T100/4Runner, so I just bought a brand new one instead. It's pretty cheap from the dealer.

Here's pics of what I got from the junk yard 5 years ago, plus the new bolt I bought. I went through the trouble of marking down the part numbers for reference.


The two non-wing nut tensioner bolts, for both the A/C Compressor and Alternator. The A/C bolt is 10mm longer with a captive lock washer

...and has a torx head machined into the hex bolt. The alternator bolt has just a standard hex head, with no captive lock washer.

[Previologist]

Thanks. I'm determined to get back into a Previa this year and I remember my old 91 (RIP) was a pain