Bellhousing Cover

**Roy B.** · February 5, 2004, 10:43 PM

Re: Bellhousing Cover

Me I would ether repair the part or wait and find the original part. I've sold used parts over 30 years mostly C1's and it took educating buyers about first, second and third designs , plus what logo's meant to sell my parts to people that would take the time to listen. Most people won't , all they could see was dirt , grease and that the parts didn't look pretty. Then if you told them you were asking more then a repro because it was a real original, they walked away. I can see using a repro. if the need is there to get your Corvette running or safe but then if a original parts comes along why pass it up? Many people may have seen my 55 Corvette and yes, my out side mirror is not pretty , but usable till I can find a better real one. Yes I have used repro's but when I was able to replace it with a real one I then sold the repro. Even to day , it's easier to find some nos parts to buy because people are happy or don't wont the trouble replacing thier repro parts.
To me that is the fun part like a treasure hunt, and the excitement of it all. But that's me !

**Joe S.** · February 5, 2004, 11:14 PM

Re: Bellhousing Cover

Good points Roy and I agree with most of it. I've really enjoyed the mystery behind this current project as well as going on the hunt for correct items. I won't bore anyone with the time or money I've already spent on NOS items or having things restored, either by someone else or myself. You, and many others, have been doing this way longer then I so you know all about that part of it I'm sure.

There is also to me a point where for something simple as this, in my newness to the project, expect a $10 part claiming to be "correct", to be just that. To me, this was a simple cost/benefit issue that I decided to give a try.

Also because of my newness, and my real question that I asked, is the one that I already had, an original. That was what I was trying to determine. Just because it came with the car when I bought it, doesn't mean it came with the car in 1963. AS a picture is worth a thousand words, I was hoping someone would look at it and help determine which is correct, or that neither one is correct.

Thanks,

Joe..

Joe's 63 FI Convertible

**Joe L.** · February 6, 2004, 12:39 AM

Re: Bellhousing Cover

Joe------

Here's the deal:

The original cover that you have pictured is the original-configuration piece. It was GM #3788422. GM #3788422 was discontinued in January, 1976 and replaced by GM #354497. The latter piece is the new cover that you have pictured. It's the only one that's been available from GM for pre-1982, 12-3/4" bellhousings for the last 28 years. As far as I know, the original configuration piece is not reproduced, either.

Here is an perfect example of something that I spoke of recently: ORIGINALITY versus FUNCTIONALITY. The replacement cover has a critically important improvement made to it and that critically important improvement is the 2 small tabs that you noted. These tabs are designed to clasp onto the oil pan's rear seal lip. In doing so, they prevent inward deflection of the center portion of the cover. Even slight deflection of the cover at this point will result in interference with the crankshaft flange since the crankshaft flange is normally in VERY close proximity to the cover. When this occurs, one will experience an inconsequential but STARTLING racket. Often, this will occur when one drives through a puddle of water and the slight force of the water against the cover deflects the cover just enough to contact the crank flange, but it can occur with no apparent instigating factor, too (perhaps, wind pressure).

Having experienced this "phenomenon" myself, I wouldn't even consider use of the original-style cover. The original style cover is best stored for "historical reference".

By the way, for those that are interested, the bellhousing cover for cars equipped with 14" flywheels (bellhousings "444", "621", and "497") followed a different "path". First used on Corvettes in 1966 for big block applications, it was originally GM #3843943 and it's still available under that same part number today. However, many years ago the specifications for this part were revised and the tabs were added. So, if one has an original cover, PRODUCTION or SERVICE, from 1966 to about 76, it will not have the tabs. Later PRODUCTION and SERVICE covers WILL have the tabs. The ones WITH the tabs are the ONLY ones that you will EVER find on my car. The ones without the tabs are for "historical reference" or the scrap metal bin.

**Joe S.** · February 6, 2004, 05:48 AM

Re: Bellhousing Cover

Joe,

How do you sleep at night (or maybe you don't)?

Thanks a bunch for the info. As always, very helpful. The information you've provided and helped me with is better than any books I've purchased and I appreciate it.

In some cases, do you mind if I copy sections of the various responses and use them on my website? It might also be helpful for others doing similar work.

Thanks again,

Joe..

Joe's 63 FI Convertible

**Christopher R.** · February 6, 2004, 08:10 AM

Re: Bellhousing Cover

Funny you should mention this. I have experienced the racket you speak of. Scared the heck out of me. Thought I really screwed something up this time.

Can I use one of the later service bellhousing covers with tabs on my '62 with the stock 14" flywheel, 10.5" clutch, and the stock 3779553 (cast) bellhousing?

**Roberto L.** · February 6, 2004, 09:04 AM

Re: Bellhousing Cover

Hello Joe, do you know the aprox. price for 3899621's cover which you mentioned still in GM cats?

Thanks, Roberto, NCRS #30019, RMC

**Shannon Burgess** · February 6, 2004, 11:53 AM

Re: Bellhousing Cover

Joe,

I'd like to thank you for this write-up describing the reasons for the tabs on the bellhousing cover. I just got my '69 reassembled after replacing the clutch, bellhousing, and rebuilding the Muncie and am experiencing the terrible noise that you have described here. The car has been sitting for a couple months because I've been putting off tearing everything back apart to find the cause. I think you may have just saved me many hours of frustrating troubleshooting.

Thanks for all your contributions to this forum. The next time I'm in San Jose for business I'll buy you a nice dinner as payback!

Shannon

**Joe L.** · February 6, 2004, 04:39 PM

Re: Bellhousing Cover

Chris-----

No, you can't. However, the design of the C1 clutch bellhousing and bottom cover should make them much less susceptible, if not "immune" to the problem I described. I suppose that it's still possible, though, if the bottom cover gets distorted. Nevertheless, the 63+ style covers can't be used and, as far as I know, no revison to the C1 parts were ever done.

**Joe L.** · February 6, 2004, 04:45 PM

Re: Bellhousing Cover

Joe-----

Sometimes, if I happen to "catch a nap" during the day (someting, incidentally, I could not do before I retired), I get so "refreshed and energized" that I end up staying up late.

Also, I have no objection, whatsoever, of any of my ramblings being used on your web-site.

**Joe L.** · February 6, 2004, 05:04 PM

Re: Bellhousing Cover

Roberto----

No, I don't know the approximate price of the GM #3843943 cover. However, I DO KNOW the exact current GM list price for the piece, so that will have to do. It's $20.61.

**Craig S.** · February 7, 2004, 02:30 PM

Re: Bellhousing Cover

Joe - I think you must be even happier since your retirement...more wit Lately I have been so busy at work I haven't even had time to read the board much....I am envious.....Craig

**Roberto L.** · February 8, 2004, 07:59 AM

Don't worry... THANKS *NM*

Bellhousing Cover

Bellhousing Cover

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment