1939 series 40 crankshaft

[Guest gmorse]

Hello. This is my first time posting in this forum, so here goes:

As most of us know, Buick in 1938, series 40 only, and 1939, all models, used a Hyatt roller bearing in the end of the crankshaft as a pilot bearing for the trans. front shaft. After '39, they went back to the sealed ball bearing which is more common.

Now, seeing that my car is all together now, and I would like to do some advance planning, can anyone tell me what the diameter of the area in the rear of the crank is, where the roller bearing goes? Hopefully, quite accurately. I know this diameter is about 1 1/16 in., but if someone has one of these engines apart, could you please measure this area as accurately as possible.

Thanks in advance.

Gary

[sleeve-valve]

Hello Gary:

I just happen to have my 39 Special engine apart for a rebuild. Here's a picture of the crank end with the pilot bearing just removed. I measure right on 1 3/32" with a good scale that goess down to 64ths. I don't have anything more accurate than the scale so I can't get down to thousanths but it looks right on 1 3/32 to me. Hope this helps.

Dave

[Guest gmorse]

Hello Dave. This is just what I wanted. Thanks very much, and for the photo also.

Gary

[Guest gmorse]

Hello Dave, thanks again for the measurements. One more question, the bearing retainer. Could you send a picture of the retainer?

I have the Buick part number, but no one seems to have a picture.

Gary

[sleeve-valve]

Hello Gary:

Here's 2 pictures. The flat side goes into the crank, facing the front of the car, the dished side to the rear. It measures about 1 5/8 diameter with a 9/16 hole and is about .050 thick. Hope this helps.

Dave

[Guest gmorse]

Hello Dave,

Thank you again for the info. This is very helpful.

Gary

[danhar1960]

It's interesting to see this as all 3 cranks I have pulled out over the years have had a sintered bronze bush in them and not the roller bearings as per manual.

Danny

[Guest gmorse]

Hello Danny,

Yes, that is strange to have a bronze bushing in place of the roller bearing. It was only in the '38 series 40, and all models of '39 that Buick usaed the roller bearing. After that, and I think also in prior models, they used a more common ball bearing. Interesting that in my Buick parts manual, it lists the only replacement crankshaft as the one using the ball bearings. Apparently they did not supply any of the roller type crankshafts for replacement use. Almost like admitting a mistake!

Gary