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As mentioned a week or so ago, during a commute the Jaffa threw of its power steering/AC accessory belt, something I discovered up hill on Sandgate Road through the corners at Albion. I managed to secure a replacement belt (although subsequently discovered the rejected belt had been neatly deposited on the engine undertray) and on getting home set about fitting the new belt.

I wouldn't consider myself particularly mechanically inclined but would put replacing an accessory belt well within my capabilities. I did do a little digging, and come across this document (http://www.miata.net/garage/Miata%20NB%2099-05%20Belt%20Guide.pdf) which pretty much confirmed what I expected.

So, job seemed easy enough, but didn't seem to be able to wind on enough tension on to the belt before running out of adjustment, and noticed the adjustment bolt (the long one, 12mm, M8, probably 75mm or so long) was slightly bent, with some of the thread flattened. Went for a drive, a bit of squealing, got home, opened the bonnet, belt had slipped out (towards the nose) two notches on the main pulley and the airconditioner pulley, but was fully secure on the power steering pulley.

Tried it again today, this time focussing on the right order of tightening bolts. Managed to snap the adjustment bolt. Went out, got another one. Ran through the process again (I'm totally across it now), this time the adjustment bolt's pretty much tight without all the thread being used. Belt's still loose for my liking. Go for a drive, no squealing this time but belt has slipped two notches on the main pulley and the airconditioning pulley again, sitting correctly on the power steering pulley.

So, wondering if anyone had any thoughts. I'm wondering if the power steering pump's not sitting where it should be, given it seems to be the one pulling the belt out of line. Aircon and P/S are working fine.

This is a complete stab in the dark but, are all the pullies tight and spinning freely and true? (meaning not wobbling or loose or bent)

speed freak wrote:This is a complete stab in the dark but, are all the pullies tight and spinning freely and true? (meaning not wobbling or loose or bent)

Fair question, but yeah, all spinning freely and true.

Stand on one side of the car and see if you can sight the pulleys in a line to see if they are aligned with each other. Not sure if there is enough room to see, haven't gone outside to check.

Have you got the correct size belt? It sounds like it is too big as you should not run out of adjustment.

I'd think JBT is right. Put up a photo so we can see what you're working with

gslender wrote:I'd think JBT is right. Put up a photo so we can see what you're working with

It's actually going in to get it looked at tomorrow - not the primary cause, there are some oil leaks at the front of the motor that need dealing with, and since the belts will be off I'll get this issue sorted as well.

On the belt front, yeah, the old belt actually fits within the new belt, so there's an issue there. That said, I put the old belt on and the tension felt much more like what it should, but the Jaffa threw the belt off pretty much immediately on start up. The aircon has been worked on in the last 7-8 months or so and it appears to be that pulley that's out of alignment.

I'll update once it's resolved. Thanks.

My recollection of the B6/BP set-up was that aircon is bolted in a fixed position to the block, is not adjustable and the adjustment for that belt's tension is at the power steering pump.
If the old belt fits within the new belt then there's at least one of your problems. Maybe the old belt was also too big.

Vat wrote:

gslender wrote:I'd think JBT is right. Put up a photo so we can see what you're working with

It's actually going in to get it looked at tomorrow - not the primary cause, there are some oil leaks at the front of the motor that need dealing with, and since the belts will be off I'll get this issue sorted as well.

On the belt front, yeah, the old belt actually fits within the new belt, so there's an issue there. That said, I put the old belt on and the tension felt much more like what it should, but the Jaffa threw the belt off pretty much immediately on start up. The aircon has been worked on in the last 7-8 months or so and it appears to be that pulley that's out of alignment.

I'll update once it's resolved. Thanks.

I might see you there then, Im going to plus in the morning to get my NB serviced

Hopefully you get it sorted soon.

speed freak wrote:I might see you there then, Im going to plus in the morning to get my NB serviced

Hopefully you get it sorted soon.

Cheers, actually going to JAK.

How did you go today, get it sorted?

speed freak wrote:How did you go today, get it sorted?

Heard back from the repairer - broken AC mounting bolts. Full details when I get the little fella back, which will hopefully be tomorrow.

Follow up: Jaffa safely home again, issue addressed.

As mentioned, issue was with the bolts holding the aircon compressor. One had broken and come out completely, neatly deposited on the splash tray, the other broken in situ, requiring tapping out. As a result, unit was out of alignment by around 10 degrees - it was clearly out of alignment with the engine and power steering pulleys when viewed from the driver's side, but looked fine from the passenger side.

Other than the belt throwing, other symptoms included what in hindsight was unevenly assisted steering assistance (the steering on the drive home was a revelation, it was like rediscovering some you'd loved and hadn't realised was missing) and, I suspect, a odd metal knocking when hitting sharp bumps which seemed to be absent on the drive home - I'd put it down to a number of other potential issues and was planning a day under the car tightening things.