Fan belt adjustment with early-style (pre-1980) "extra-bolt alternator"

[lostmarbles]

I just made a discovery and it involves this picture from my 1977 B and 2B engine manual:



As you can see ........It suggests that you should "throw away" one of your "adjustment-slot bolts" as soon as "belt wear" requires you to move your alternator "out wide".

Is this what other people have done?

(I've looked at this image many times before but never noticed the way the alternator has been mounted until now....... And it comes as quite a surprise!)

I ask because I have always liked my older-style alternator's "more solidly-engineered mounting system" and thus have always kept all the original bolts in use. And recently I even extended my slot to allow more belt adjustment while still retaining both bolts. Because without this extension - I've always felt I had to run my belt too loose. (I've never EVER considered discarding a bolt!)

I'll show you what I mean...........

This is my alternator before the extension:



And this is my alternator after I extended the slot in the top bracket:

 

[Poser]

All F/2F alternators in the USA only utilize one belt tensioning bolt for the alternator. The alternator on your diesel is not like anything that we received over here.

I have ran only one tensioning bolt in all of my vehicles for 20+years now without any issue.

I cannot imagine that you would have an issue doing the same, especially if the manual states to do so.

 

[lostmarbles]

And I've been trying to track down which cruisers got my type of alternator. So I'd be eternally grateful if owners of cruisers with this same "extra-bolt-type alternator" can post replies here with details of their vehicle model & year. (Posting a picture as well would be better still .)

This alternator is externally-regulated and seems to be only on 1979 or earlier trucks - And probably only on diesel trucks too (since it has a vacuum pump hanging off the back)

So maybe used on pre-1980 BJ40, BJ45 and HJ45 trucks only?

Here's the only other one I ever spotted on ih8mud - and that is fluffybunny's 1977 HJ45:

 

[lostmarbles]

.........
I have ran only one tensioning bolt in all of my vehicles for 20+years now without any issue.

I cannot imagine that you would have an issue doing the same, especially if the manual states to do so.

Thanks Steve. .......Your answer is full of sound logic.

But unfortunately " logic" and "cruiser work" don't automatically go "hand-in-hand" for me.

(Like the people that build themselves bumpers from 1/4 inch plate!)

 

[Joe Egolf]

I'll try to remember to look at my set up tomorrow , pretty sure I have 3 bolts

 

[lostmarbles]

I'll try to remember to look at my set up tomorrow , pretty sure I have 3 bolts

It would surprise me if you are one of the "special few" with the "extra bolt" Joe.

I reckon yours should be like Theo's(tmarx):



Or Andrew's (Brisveganbj42):





(As you can see - I've been snooping around quite a few builds... He he)

 

[amaurer]

It would surprise me if you are one of the "special few" with the "extra bolt" Joe.

I reckon yours should be like Theo's(tmarx):

...

Or Andrew's (Brisveganbj42):

...



(As you can see - I've been snooping around quite a few builds... He he)

Mine definitely has a single bolt, smart money says so does Joe.

(Interesting 3B headers on brisvegansbj42's though...)

In the EPC a 1973 (first diesel year I could find) HJ45 appears to have the two-bolt style, as do 1974 BJ40s (first BJ40 year I could find). Trying to look at 1975 or later however doesn't appear to be fruitful, as the EPC (online version) displays a graphic with text claiming "1980+" and showing a one bolt style...

 

[lostmarbles]

Mine definitely has a single bolt, smart money says so does Joe.

(Interesting 3B headers on brisvegansbj42's though...)

In the EPC a 1973 (first diesel year I could find) HJ45 appears to have the two-bolt style, as do 1974 BJ40s (first BJ40 year I could find). Trying to look at 1975 or later however doesn't appear to be fruitful, as the EPC (online version) displays a graphic with text claiming "1980+" and showing a one bolt style...

Thanks Drew.

(I like to keep my BJ40 looking standard and I'd like to locate a spare alternator too. So knowing which models came out with my style/type should help me there.)

 

[Falco80]

Hi Tom, my 79 BJ40 is exactly like yours was and I don't really see a problem with using just one adjustment bolt.
I do think Toyota could have made the bracket a tad longer from the factory though.

Good job on your bracket!

 

[Coolerman]

Interesting find. It looks like a combined US 1F and 2F face plate with the two clocking positions. Leads me to wonder if that face plate would fit the US version alternator. That would allow an alternator fitted with it to fit either engine. Nope, not logical at all but like you said...

 

[lostmarbles]

Hi Tom, my 79 BJ40 is exactly like yours was and I don't really see a problem with using just one adjustment bolt.
I do think Toyota could have made the bracket a tad longer from the factory though. ..Good job on your bracket! ...

Thanks Dan. "Original BJ40s" like ours must be getting pretty rare these days.

I admit I had a complete "brain block" for removing that bolt". And this must have cost me a bit in fan belts over the years too - Because every time the belt got loose & flapped around excessively - I just replaced it. And I seem to remember these belts have always been expensive ...... Like $NZ70 upwards!

Interesting find. It looks like a combined US 1F and 2F face plate with the two clocking positions. Leads me to wonder if that face plate would fit the US version alternator. That would allow an alternator fitted with it to fit either engine. Nope, not logical at all but like you said...

If I find one to hold as a spare I'll be able to investigate such things quite easily Coolerman.

I've already bought a 27030-54013 alternator (supposedly off an early 80s Hilux). I've found it still uses a 10mm pivot bolt but the width of its pivot-gap (also called "mounting bore distance") is only 97mm when my original is 106mm. Pulley diameters look the same but the Hilux Vee belt size is smaller. And most importantly - the pulley groove ends up too far rearwards (using my original block mount). And I suspect this Hilux alternator is 55A (whereas my original is just 35A). ... This alternator was cheap enough but the non-standard modifications required to mount it have turned me off the idea of holding it as a spare.

Interestingly - the EPC says I can look in wrecking yards for 1977 to 1980 Dynas and Coasters for my original-style alternator: