jimq

try tapping it in gently. There is probably a burr in the way. I had to do that with mine after somebody buggered mine up. The 10mm worked fine then.

ilko

Rod, you and I are in the same boat unfortunately. I tried replacing my belts last night and as it turns out, mine's in even worse shape than yours. Looks like I'll need a new alternator. I don't see how I can possibly salvage this thing. It's completely round on the inside. Worst thing is that there is no way to really tap the triple square bit in it because there's only about 2" of space between the hood latch release and the bit when it's inserted.

JasonAndreas

What about buying a short tap and some tapping fluid and threading the hole? Then all you need is a (strong) bolt that you can grab onto with vice-grips.

ilko

Hey Jason, I'm having a hard time visualizing what you're suggesting. Can you please explain? Thanks so much!

JasonAndreas

A left-handed tap will thread the inside of the shaft. You can then screw in a bolt or whatever and hold the shaft steady while you undo the nut. I guess I would be a little concerned with amount of torque required to undo the nut which could snap the bolt (or whatever) while loosening the nut. Obviously the best thing is to buy a new alternator shaft but if your stuck. A left-handed tap is only a few bucks at the hardware store.

When you replace the alternator and you want to remove the shims, etc. I've heard of people using an air compressor and an impact wrench to break that nut loose without any other tools.

rdean

Well there is no lite tapping the 10mm bit into this hole. I just can't see how it was ever a 10mm fit to begin with. So my plan is as follows. I need a NYS inspection, my brother in law owns a car restoration biz and also does my inspection. They are "experts" so I'll ask for their thoughts/solution. Secondarily I'm considering to cut a slot to insert a blade to stabilize the shaft to loosen the nut. What are the "listers" thoughts on this approach ?

ilko

I thought about tapping it in, but that would involve removing the bumper and lowering the engine. Too much work IMO.

I started a thread on this in the 993 forum and have gotten a few interesting ideas: https://rennlist.com/forums/993-foru...ment-woes.html

Used your photos too, hope you don't mind

altarchsa

+1
elbee knows the "trick", and provided some really great photos to boot. I had a little trouble getting the standard 10mm star in mine because it was also damaged like yours, maybe not quite as badly. You can probably drive the bit into the end of the shaft, and "reform" the spline by wiggling it around a little, with a little persuasion from a hammer if necessary.

UUhhh, just be aware that if it doesn't work, it's a new alternator (= $$$) or source a replacement shaft out of a used one and R & R (= time).

rdean

As indicated in prevous posts, I took my RSA to the experts to have a look see at the alt shaft and 24mm nut.
Firstly, they have a Snap-On Fiber Optic to view the shaft bore, that determines what we are dealing with. It is diffinitely buggered up. The mechanic (Terry) explains that there remains formed teeth at the base, however the lead ini s stripped and peened. So he takes the 10mm bit (the one that I said would never fit) and aligns and gives a couple of taps, its a no go. Next a sharp tool to dig some of the buggers out. Puts the 10mm bit back in with a rod thru the lid latch hole, a couple of lit taps seats the bit, next is a couplse of HARD WHACKS (while I am cringing) and the bit sinks in. All is well, the bit fits, 24mm nut is loose. Next task is to disassemble the fan and remove the alternator to sand blast the shaft bore to clean it up.

Yikes with a smile

elbeee964

And that's why they (rightly) call themselves, Pros.

ilko

I fixed it last night using the simplest of methods... I stuck a screwdriver through one of the fan's rectangular openings and jammed it against the alternator. That prevented the fan from moving. The 24mm nut came off with very little effort (I had soaked it in penetrating oil for a few days). Thanks to geolab for the suggestion - it worked great.

Dsqr964

ilko, I had the same issue, the problem will be putting it all back together, you will still need the T10 tool to tighten everything up (you don't want to run the risk of damaging the windings in the new alternator with the screwdriver).
Like many of the others here I had to find the tool then alter it to fit in the space between the body and alt. shaft. A grinder does wonders -D²

elbeee964

Ilko, if you're still in the factory dual-pulley configuration, the fan's pulley doesn't care what preload is on the shaft nut.
The alternator pulley's grip to the alternator shaft, however, does rely on the shaft nut's preload.

If you're reinstalling the crapped-end alternator, I'd throw some LocTite on the nut & shaft's threads, tighten it to what you can get, let it cure overnight, and monitor as you can to whether the alternator pulley and washer are rotationally slipping under the nut.

(This, figuring you'll know soon enough if the other worst case scenario - the nut breaking free of the LocTite - takes place. But I'd reckon the LocTite will work fine given any non-trivial torque.)

Of course, if you're on the fence re just grabbing up a new alternator to put all this aside, I'd say, "Do it."

mojorizing

If you're keeping the alternator, I would fix the end of the shaft such when you break a belt you can change it out on the road with tools you have. Just imagine trying to do what you're doing now out on the freeway, or back roads. If you can't change the alt belt on the road , always keep in cellphone range, upgrade your insurance to cover towing, and bring something to read while you wait.... maybe "War and Peace"

C24FUN

I was sure I had a tool for this in my kit. I checked and sure enough there it was. It even has a handy extension. Now, this kit was bought from a Japanese part-out but I am fairly certain it is correct for this car ('90 964).

Cheers!

Jim