correct transmission covers ?

[kehughes]

Another question about which is correct for a '50. Which year did HD switch the cover? the one on the right has the 33-49 underneath, no date code.

Hope some of my questions help some others as well. I appreciate you guys' help.

[1950Panhead]

Sand cast covers were used from 36 to mid 50, date and 33-35 inside.
Die cast covers were used from mid 50 to 64, no date, 33-49 inside.
Early 50's use sand cast, late 50 use die cast.
Jerry

[kehughes]

looks like from what you say, I need to go with the one on the left for early '50. However, the transmission case that I have is date code G 9 with vented boss, but I don't think it is sand cast. Im not the best at recognizing, but just seems to have a cleaner finish. It has not been polished, still natural. I'll post some pics this evening.thanks 50

[Speeding Big Twin]

I do not know exactly when the cover was changed from 33-35 to 33-49. And even though Palmer indicates the later casting number only appears on the inside, that is incorrect because sometimes it appears on the outside.

On page 277 Palmer states covers with casting number 33-49 inside were used for mid-1950-1964. But he does not mention this newer cover on page 594 in his 1950 First Year of Features. And neither does he mention the early cover in his 1950 Last Year of Features. However, one problem there is that the lack of mention in those two lists does not necessarily mean anything because his FYoF lists, as well as his LYoF lists, are not always complete.

On page 595 Palmer shows a 1951 prototype but it is the same bike used as a 1950 prototype and has serial number 50EL1001 (I have photo) and an early trans cover. On page 596 he says the mid-50–64 trans cover is on the 1951 production model police bike shown on that page and I agree. But I don't know the serial number of the cop bike so I can't even speculate as to whether or not all 1951 models may have had one of the newer covers.

Also, as I indicated above it would seem Palmer was only aware of 33-49 being inside the cover. But some covers have 33-49 on the outside as shown below:

1950mid64est1.jpg

1950mid64est3.jpg

I do not know which of the two newer covers appeared first. And I do not know what EST means.

You have a trans case with date code G 9 and vented boss. But anyone could have drilled the boss and G 9 could indicate casting in July of either 1939 or 1949. Can you post photos of the underneath of the case and also of its left side.

And can you post a photo showing the underneath of the cover at the left of your above picture. It is hard to be sure from your photo but I have to wonder if that cover at left could be a pre-1947 model.
Eric

[kehughes]

Oh, no doubt the left cover is pre '47. It is date code I 5 . I didn't realize there was a change in '47. What was the change? I need to make sure I have the correct cover.

Also, I didn't get a chance to post pics last night but upon further inspection, I do think it is sandcast. Concerning the G9 date on the case, 1939 or 49 would be sandcast, but I was pretty sure a '39 did not have a boss at all and '59 would be coded without any letters.

thanks for the replies.

[Speeding Big Twin]

For 1947-later models the gear shifter lever pointed down instead of up so the two bosses near the upper front left of the trans case were flattened as original, either by machining or design, as opposed to earlier cases which had rounded bosses as original. At below left is a case with rounded bosses cast in September 1945 and at right is a case cast in January 1947 which has flattened bosses:

1945septemberhlwkg.jpg

1947januarygkae.jpg

However, sometimes you'll find early cases with flattened bosses because they were done that way by someone at a later date.

Date codes for top covers started as early as June 1938 but I won't be surprised if I see one from as early as April of that year. The latest example I have is from March 1949.

Photos I have indicate there were at least two changes to the top cover around 1947:
1. Casting number 33-35 went from being indented to being raised and on a rectangular plate. According to Palmer page 277, 33-35 was indented only but that is incorrect and my photos indicate it was indeed later raised and on a plate, with the change probably occurring at some point in the 1947 calendar year.
2. Early covers only have one relief at the left edge and it is directly below the gear shifter lever shaft hole as shown below on a cover cast in March 1946:

1946marchbgkg.jpg

But late covers have a second relief on that same edge as per the next cover which was cast in March 1948:

1948marchbaty.jpg

I used the March 48 example because it shows the two reliefs clearly but other pictures I have indicate the second relief first appeared at some stage in the latter half of 1946, possibly for the 1947 models.

However, sometimes you'll find early covers with two reliefs but the second one may have been done at a later stage and therefore may not be original to the cover.

And something else needs to be mentioned regarding date codes: the letter I was not used at times in 1948-49 because of confusion with the number 1 and so the letter M indicated December for those two years. But there may be exceptions to this because the letter I has appeared on a few parts that do indeed seem to have been cast in 48-49. I can't explain it yet and it's something I'm trying to resolve.

Concerning your G9 case, regardless of whether it was cast in July of 39 or 49, just because the vent screw boss is drilled doesn't necessarily mean Harley drilled it. It could have been a replacement case for a pre-1940 model machine and therefore the boss would not have originally required drilling but it may have later been drilled by someone other than H-D.

Examples I have of BT trans case date codes for 1959 consist of numbers only, with the year sometimes indicated by two numbers: 1 59; 3 59; 5 59; 6 59; 7 59. But sometimes the year 1959 was indicated by only one number: 10 9; 11 9.

If you post photos of the entire underneath of your G9 case and also of its left side then we may be able to tell you if it was cast in 39 or 49. And check the insert for the mounting bolt underneath near the right-hand side. Is the insert bronze or steel?
Eric

[kehughes]

Great post! very helpful info. Looks like I'm in need of the correct cover. The battery on my camera is dead, but I looked at my case and the 2 bosses on the left side are flattened(looks cast that way).

Back to the 33-35 "I 5" gearbox cover. I actually got it off of a '36 case. Was there any difference from a '36 and '46 cover? Im wondering if it could be a '36 cover vs a '46 cover. I still have that case and would like to keep it with the case if so.

Thanks

[Speeding Big Twin]

The two bosses on the upper left side of your G9 case may have been cast that way but you can look at other things to help determine if the case is 39 or 49:
1. As I mentioned in my previous post, check the insert for the mounting bolt underneath near the right-hand side. A bronze insert indicates a 39 model case and a steel insert indicates a 49 model case because the insert changed from bronze to steel around 1943-44.
2. At some point in 1949 there was a change to the casting around the outside of the two mounting stud holes on the left side. The first case below was cast in July 49 (G 9):

transg9copy.jpg

The next case was cast in Feb 49 (B9):

transb9copy.jpg

The date codes aren't clear in these pictures but I have close-ups of them in my photo collection. Notice the July casting is beefier than the February casting around the outside of the two mounting stud holes on the left-hand side of the case.

If your G9 case has the beefier castings then that indicates it was cast in July 49 as opposed to July 39.

Was there any difference between a 36 and 46 cover? Yes. Palmer indicates on page 277 there were at least three types used for 1936 models:
1. First type (early-36) has a rounded outer surface over the shifter gear area. It has holes exiting both sides for the shifter cam shaft. Across the top on the outside it has cast-in raised characters EX 1337.
2. Second type (early-36 and mid-36)—according to Palmer—has the aforementioned rounded outer surface and holes exiting both sides for the shifter cam shaft. But it does not have EX 1337.
3. Third type (later-36 and 37) has holes exiting both sides for the shifter cam shaft. But it does not have the rounded surface over the shifter gear area and does not have EX 1337.

I have photos of the first and third types but no pictures of the second. Anyway, on your cover I see none of the characteristics of the three 1936–37 types. Also, date codes of the sort we are dealing with are not known to have appeared on the top covers before some time in the 1938 calendar year. Therefore code I 5 indicates your cover was cast in September 1945. And I would imagine your I 5 cover has its 33-35 indented and not raised on a plate.

In my previous post I mentioned a second relief appearing on the left edge of some later covers, apparently beginning in the latter half of 1946, possibly for the 1947 models. But I forgot to include that for 1936–37 models, a similarly-positioned second relief appeared on the first and third type of covers and possibly on the second types and it extended higher up than the relief I've seen on 1947 and later models.

For 1938-46 model covers there seems to have originally been one relief only on that left edge, although some covers from that era may have had a second relief added at a later time and that's another thing I'm still investigating.
Eric

[kehughes]

Another outstanding post Eric. Thank you again. I'll be looking for a correct 50 style cover.