alternator adjustment??

Hey guys-
on the 87 2.5 (and 4.0 is the same, I guess), is there any adjustment for the alternator? Everything I've read says you adjust the belt tension by the PS pump. I never had any problems with this until I rebuilt my 2.5. In putting all the accessories back on the block out of the car, I noticed that the alternator and bracket would only fit on one way, even though the bracket is slotted, as if you could slide it back and forth. After that, the belt was always too tight. I mean, I can get it on there, but I have to get the lip over the PS pump and bump the starter. And the PS pump is adjusted all the way in. I've loosened all the alt. bracket bolts and can't get any movement out of it to help me out; I guess I could buy a little longer belt, but I'm confused...any help out there?

Thanks
Tom

Is this a new belt? I know it can be a little difficult sometimes to get over the pully but shouldn't be that bad. Do you have the belt on correctly? I only have experience with 4.0l so maybe someone with a 2.5 might help a little better.

No, the old belt. Definitely on right. In the past, I'd have a lot of space to spare. Yeah, I could force it on there, but like I said the PS pump is full-on as close as it can go.

MjTjNJ said:

No, the old belt. Definitely on right. In the past, I'd have a lot of space to spare. Yeah, I could force it on there, but like I said the PS pump is full-on as close as it can go.

Click to expand...

I guess the simple question is this: Can the alternator on 87-90 2.5 or 4.0 be adjusted?

Well I am not sure on the 2.5 vs 4.0 differences, or the 87 vs 93 year differences... but I just pulled my alternator on my 93 4.0... There wasn't any adjustment I could see that would make the belt any tighter (as long as you rebuilt it using the same pulley size...).

The alternator I have had 2 bolt locations, one at the top of the alternator and one at the bottom. They bolted onto the engine at two specific location so unless you left one of the mounting locations un-bolted (which I highly doubt) I don't see how the alternator could cause any change in belt tension. :dunno: Did you order a alternator rebuild kit or did you just pull it apart and clean it, then re-assemble? As I said, the only thing I can think of would be a different pulley size. Could be a different pulley size either on the alternator or anywhere along the belt path. Did you replace any pulleys while you had the belt off? (I know I replaced all pulleys while I had the belt off as the bearings were shot on most of them)

As you have a Renix, that means you should also have a CS-130 Delco-Remy (GM) alternator.

The CS-130 has been used on hundreds of different applications, and there are numerous different sized pulleys out there.

So, if you got a reman CS-130 at some point, say from a GM vehicle, the pulley might be larger than the OEM size, and that would give you the exact problem you are experiencing.

When I had the engine out for a rebuild, I didn't change the alternator, and the belt went on tightly (had to nudge it over the ps pump rim and bump the starter). I kept all the accessories and pulleys (except a new water pump). The belt was probably tight enough at that point, so I tightened up the PS pump there and off I went, even though I thought it was strange.

A few months later, the original alternator went (bearing) -- was it because the belt was too tight? I don't know, but I'm concerned. I have no idea why the belt I used before the engine rebuild doesn't slip on with a couple of inches to spare anymore. I am completely baffled. Thinking of buying one for an application that is a couple of inches longer.

Was the water pump pulley larger than the stock one? if the water pump is the only part that was changed and the belt was tight after the swap... then that might be related to your issue.

Or since the power steering pump bracket is also the belt tensioner (at least on the '93 it is) are you sure your PS pump is installed correctly and is able to adjust properly? Not sure why that would have changed when you pulled the engine... but it's an option I suppose

I appreciate the thoughts; when I changed the water pump, I re-used the stock pulley; I did change the PS pump (and again under warantee since), and it seems to slide all the way back and forth, from nearest adjustment to furthest. I just seem to remember something funny (possibly that it was slotted and only went on the block in one position) about the alternator. I got a belt that's a couple inches longer, I'm just going to chalk this one up to "duh, I don't know" and move on! LOL