Alternator Tin Questions, Early vs. Late, Fastener, Gasket Options

[frank_c]

The alternator tin on my '76 914 was damaged due to the PO not installing the alternator bracket leaving only the tin and the adjuster bracket to hold the alternator in place (IMG:style_emoticons/default/sad.gif) . I have three questions related to replacing this piece of tin:

1. Early vs Late tin
I see that there are two tin part numbers; early: 021-119-281D, late: 022-119-281
When I searched for the later part number, I found a replacement on eBay and placed the order. I did not have the tin piece from my car in my had at the time to compare the two, but later noticed that the circular opening is different between the early and late parts (see 2 photos below). Searching for photos of the two part numbers, it appears the eBay seller tagged the post with the late part number, but the tin is actually the early part.

So first question - why is there a difference, and can I use the early tin on my '76 2.0? Or do I need/should purchase the correct later tin?

Early Tin 021-119-281D:


Late Tin 022-119-281 (damaged area circled):


2. Wrong Fastener?
When I was removing the tin piece, I noticed something that appeared odd to me about the bolt for the hole circled in red in the image below. First, the bolt was difficult to remove for the entire length of the thread. Second, it was an M8, while all the other tin fasteners are M6 (and PET doesn't list an M8 in this area). Third, it was an M8 fine-thread - which is not very common on these cars.

I suspect that the tapped hole in the fan housing was originally an M6 that was damaged at some point, and someone drilled & tapped it for an M8. Can someone confirm? I searched fan housing photos I was able to find online, but it's difficult to tell. If it should be an M6, I'll probably install a time-sert (because these types of things bother me).



3. Gasket for Alternator
PET shows a "Gasket for Alternator" (see #6 in screen shot below) - part number 021-903-203. As far as I can tell, this gasket is missing from my car. Does this go in the front or back of the alternator? How important is it to the cooling function. If important, where do I get one ? I thought it would be available at 914 Rubber, but I don't see it. None on eBay as well.

[rfinegan]

Stripped carriage bolt hole and missing plastic gasket/adapter to face of the alternator other the stamped bracket. There is also a paper gasket for the back cooling cover bolted to the back of the alternator.

Quick fix could be a flat washer so the carriage bold does not pull through and goes into the flat mount and U barked with alternator finished with the bolt/ lock washer and nut. As you found out, this keeps the bolt from tuning when tightening and secures the front stamped mount at the same time. A tack welded washers place will be better and file for square hole.

[914Sixer]

Use either one. Early does not require trim ring. Later was made to use 75 Amp bus alternator from 1975 on,

[frank_c]

Use either one. Early does not require trim ring. Later was made to use 75 Amp bus alternator from 1975 on,

Thanks for that info - it saves me from having to acquire both the later tin and the seal/trim ring.

Taking another look at PET, I see that there are actually two different part numbers for the plastic seal (I missed that at first):

Early: 021-903-203
Late: 022-903-203

Searching for the 021 (early) part number yields nothing. I can find vendors and images for the 022 part number.

So is there actually a seal/trim for the early tin, but it's not really needed?

[frank_c]

Stripped carriage bolt hole and missing plastic gasket/adapter to face of alternator other than bracket?

Not sure I understand the question, but yes - the tin was damaged at the carriage/pivot bolt due to the alternator being installed without the U-shaped pivot bracket behind it. And, surprisingly, it ran like this for short time before the tin gave way and the belt started to squeal, which allowed me to discover this mess when I went to tighten the belt.

[914Sixer]

I have some used sealing rings, not sure IF early or late.

[mgphoto]

Get some gasket paper at your local flaps and trace the cover and cut the gasket yourself.
Helps seal the cooling at the rear of the alternator.

[frank_c]

Ok, after some more searching, I think I'm now starting to understand the differences in the two sets (early/late) of alternator tins and their respective seals.

From the photos below you can see that the shape of the later seal changed to fit the shape of the later tin.

There are some good photos of the later tin & seal, as well as how all the pieces fit together when assembled on the following Samba site:
https://www.thesamba.com/vw/classifieds/det....php?id=2631258


Early tin (021-119-281D) and seal (021-903-203):

As posted by @914Sixer , the early tin was for the smaller 50 Amp alternator. The seal was different due to the smaller diameter of the pulley opening in the tin. This alternator replacement thread has some good photos of the early tin and seal (copied below): http://www.914world.com/specs/alternator_replacement.php

Early Tin:


Early Seal:




Late tin (022-119-281) and seal (022-903-203):

The larger opening in the later tin was to accommodate the cooing fins on the larger 70 (75?) Amp alternator for the bus (thanks @914Sixer ), but works for both 50 & 70 Amp units. See photos below showing both.

Late Tin:
Note: Circled opening is for oil dipstick on bus. This opening is not present on my 914 tin.


Late Seal:


Late Tin & Seal Assembled with 50 Amp alternator:


Late Tin & Seal Assembled with 70 Amp alternator (notice dipstick location)

[frank_c]

I have some used sealing rings, not sure IF early or late.

@914Sixer ,
Based on the recent photos I posted of the early & late sealing rings, which ones do you have available?