StratfordShark

I'm trying to adjust the tensioner, but it's really difficult getting access to the locknut from under the car, even with stubby wrenches.

Please can anyone confirm the size I should be using? The instructions with Kempf tool say the locknut is a 19mm, but putting a 19mm on it it's obviously too big.

If I try to put a 17mm ring over the adjusting nut then it won't go past the nut (presumably the tightening nut is 17mm?).

I've tried getting an open 17mm wrench on the flats of the locknut but it's so hard to find a position where I could actually turn it with all the belt runs down there. I think I got a wrench on it once, but it didn't want to undo and of course being a stubby I had less leverage.

So what's the best tool to use to get the locknut loose on an S4, and what are the relevant sizes?

I'm so close to completing this job. have plugs out, engine at TDC, and have confirmed with Kempf that the belt is too loose (I was getting belt warnings at kickdown)

Many thanks

the flyin' scotsman

I use a short open spanner out of a Honda m/cycle tool kit despite having a tool chest full of Snap On tools.

17mm at one end, 19mm at the other.

StratfordShark

Thanks Malcolm. So that implies the locknut is 19mm? But I'm almost certain mine is smaller as a 19mm ring doesn't have any purchase on it, and the nut looks in good condition
.

Bill51sdr

Both locknut and adjustment bolt are 17mm.

davek9

Yes they are both 17mm, try a gear wrench it will give you more angles.

the flyin' scotsman

Sorry Stratford I wasn't clear; 17mm is the size.

StratfordShark

Thanks, and also thanks Davek9 for gear wrench suggestion. I'd completely overlooked that I have a nice set of those!

StratfordShark

I finished the re-tensioning today. The locknut moved easily with a long wrench, and after it came free I could undo it by hand. It was awkward getting a wrench on the adjusting nut but by threading through the various pulleys (mostly coming at it from above, but with me under the car if you get my drift) I gave it a total of half a turn or so which put the Kempf tool on high side of window, where it remained after a complete revolution. Feel a little happier about the belt now but will have full replacement done soon.

I thought I was on a roll and would then get block drain plugs free but no such luck...