Which production date can use the Toyota Kit Flexible Coupling for 93 Previa?

[Choz]

How do I determine which 93 Previas can use the Toyota brand Flexible Coupling Kit?
Question based on info from TheMAN (03-27-2014) in thread:changing flexibole compling on previa 93.
Thx Choz.

[timsrv]

According to Toyota's EPC (Electronic Parts Catalog), the change didn't take place until the middle of the 94 model year. All Previas built from 01/1990 - 12/1993 had the 1st generation shaft. Previas built from 01/1994 - 06/1997 had the improved shaft (bigger bushings). If you want to physically verify, you can do it by climbing under the van with a caliper. Just take out one of the bolts and measure the diameter of one of the coupler bushings. 1st generation shafts have 12mm OD bushings, the later shafts have 14mm OD bushings. Tim


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

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

[Choz]

Seems simple enough. Mucho thanks Tim.

[maestro123]

Im wondering whether the ID for the couplings might still be the same though. When I was at the junkyard, I noticed that I was still using the same 12mm socket on the updated shaft for the couplings as I was at home on my older shaft.

[TheMAN]

no, just no...
just because the hex head on the bolt is the same, doesn't mean the bolt is the same! Thread size, shank size, length, etc can be different, to name a few
The 94+ shaft is very different and if Toyota says it won't fit, it won't fit!

[maestro123]

Well Toyota tells us that the older shafts should be replaced completely too, when we clearly could just change the couplings, albeit with aftermarket solutions. I don't know why this was such a bad question.

I had a suspicion that the bolts might actually be identical. I got a few from the junkyard and compared it to what I had for my car. Same exact thing. Just to make sure I checked the Toyota part numbers, and those did turn out to be the same. It's PNC 37910A.

1993 Previa: http://www.toyodiy.com/parts/p_U_199301_TOYOTA_PREVIA_TCR10L-RESDKA_3702.html?hl=37910A
1995 Previa: http://www.toyodiy.com/parts/p_U_1995_TOYOTA_PREVIA_TCR10L-RFSGKA_3702.html?hl=37910A

So there may be differences in the shafts, etc., but the bolts are indeed actually the same.

[timsrv]

The ID of the bushings and the bolts may be the same, but since the bolts don't typically fail, why does it matter? A helpful tip I guess if you lost a bolt or broke one off during service. If that was your point, then thanks for the input. Tim

[maestro123]

My bad, I did a little more searching around and it appears the bushing OD sizes press fit into the shafts, so the OD sizes do matter apparently. Previously, I was under the impression that only the ID would matter since it was the bolts that actually screwed into the crankshaft pulley.

[timsrv]

Oh, I get it. FYI you could put 94 + couplers on a 91 - 93 shaft, but you would need to have all the bushing bores resized from 12 mm to 14 mm. A machine shop could do the work, but since these things are already so sensitive, I wouldn't want to push my luck with such a procedure. Not sure how much a machine shop would charge, but there are 12 "depth sensitive" bores that would need to be resized. The bore diameter would need to be precision as to maintain a "press fit". Personally I'd rather go find a 94 + shaft in a salvage yard and put the OEM Toyota couplers on that. Tim