Fan belt needed for a 72 GT Automatic (was "Opel Driving from CA to MA right now")

[Skip]

There is a GT in Arizona on route to Massachusetts from CA with a squeaky fan belt. I need to get the size quick for him but I cant find it in the 71 Opel Service manual…or here. Can someone tell me what size fan belt is needed for a 72 Automatic? - Thanks for the quick response!

[namba209]

Skip, I know this may sound facetious, but why can't they go to an auto parts store and use the original belt for a comparison, borrow the tools, if they don;t have them and change out the belt at the store. Plus get an extra, just in case.

[Skip]

Good point. I think because he wants it on hand in the event that it happens vs taking the time to do it on the spot at the parts store?

[Gary]

"Squeaky" fan belt may be able to be fixed by a simple adjustment. Have them also check the alternator bracket for worn/missing rubber spacers.

[booeman]

Originally Posted by Skip There is a GT in Arizona on route to Massachusetts from CA with a squeaky fan belt. I need to get the size quick for him but I cant find it in the 71 Opel Service manual…or here. Can someone tell me what size fan belt is needed for a 72 Automatic? - Thanks for the quick response!

they need an extra belt for sure but if it's just squeaking a bar of regular soap rubbed on the side that rides on the pully, with the engine off, should stop the squeak.

[mschmalenberg]

The belt squeal may not be a bad belt, the alt. or water pump could be going bad and causing the belt to slip.

[SpringGT]

Skip, the last alternator belt that I bought that I can find a receipt for is a Gates 8361. It is a '73 W/ a standard transmission and no air pump, but I think that most GT's use the same-sized alternator belt. Mine also has AC, but that is a separate belt. HTH
Bob

[jvandyke]

I just got a belt for my '70 GT (but with a '75 or so 2.0) and it's loose. It's a duralast 15365, says 1,1 cm (sic , instead of .?) 92,5 cm (sic).
Anyway, wondering if I need a bit smaller one. Alternator is at the end of it's adjustment and belt is on the loose side, working, but loose. Guess I'll reinstall the rather crappy looking old but tight belt rather than run a new but looser belt. Ugh, same deal with oil filter, got handed a "long" one first time out, didn't realize it until after I primed it too.

[Anonymous D]

There are 2 sizes of Opel 1.9 fan belts.

The main variation, is with the type of lower alternator bracket: Iron ("early" '68-70) and Aluminum ("late" '71-'75).

These lower brackets are matched with the upper bracket, and in cases where the upper bracket has been mixed with the wrong lower bracket, it's possible that an original Opel belt will either be too tight or too loose.

[Lindsay]

Originally Posted by jvandyke I just got a belt for my '70 GT (but with a '75 or so 2.0) and it's loose. It's a duralast 15365, says 1,1 cm (sic , instead of .?) 92,5 cm (sic). Anyway, wondering if I need a bit smaller one. Alternator is at the end of it's adjustment and belt is on the loose side, working, but loose. Guess I'll reinstall the rather crappy looking old but tight belt rather than run a new but looser belt. Ugh, same deal with oil filter, got handed a "long" one first time out, didn't realize it until after I primed it too.

AutoZone.com - Get in the Zone!
1970 Opel GT
Specifies Duralast 15365 ($8.99) 36.5" long.
And 15371 Gaterback ($11.99) 36.5" long.

AutoZone.com - Get in the Zone!
1971 Opel GT
Specifies Duralast 15355 ($8.99) 35.5" long.
And 15361 ($11.99) Gaterback 35.5".

Checked my assortment of GT V-Belts. All (3) are 15355 except for an old Gatorback Sleeve, 15361. I would try 15355, 35.5" Effective Length or try 153360, 36.0" Effective Length. Currently using 13555 V-Belt with lower aluminum alternator bracket and stock style alternator. Still have slot in upper bracket to tighten belt if required.

[jvandyke]

Well, 92.5 (and I deciphered the number off the old belt and found a 925 in it) would be 36.4" if you ignore the decimal. I guess I'll try and find a shorter one although I did run the new "longer one" into work today and noticed nothing amiss, no noises and ameter read consistent (like it wasn't slipping).
When I adjusted the belt (for noise) a few weeks ago I swear a found a deflection amount (.5"?) somewhere but when I look through my manuals now all I see are references to a tool of some sort and 45lbs. This longer one at max extension is certainly pushing the extreme of slack so, that's not cool I guess. Can't tell what material my upper bracket is made of; a magnet might help. The bushing is there but looking pretty sad and there's a hint of play in the thing, could not tighten it up at bushing end, allen wrench told me that's as tight as it gets and when I wiggle it you can see the play is around the bushing, not the "bolt". I'll look for a shorter belt and put it on, easy enough to do, thankfully. Old one had some chewed up edges otherwise looked fine. I'd guess the PO put on the long one as I just did, trouble with mixing motors and chassis I guess. Back to the parts store. I'm amassing a collection of "near miss" parts over here. Oil filters and belts. I will need to bring to a meet of some sort and pass them out. Can't abide throwing out new parts.

Got a Duralast 15355 1,1cm x 90cm (shorter than the 15365).
It fits. I have a cast iron upper alternator bracket (magnet stuck) not sure of lower but probably aluminum since the shorter belt fits. But the longer will work (at least on my motor) in a pinch, I ran it for quite a while as did the PO apparently.