Frame Restoration

[Steve Little]

Hi.
We were just about to start the restoration of a 1945-early 1946 frame, when my co-worker (who is younger than me, and into all things computor) suggested that we should document how we work through our process and put it on a web forum.
We see a lot of butchered frames come through here, but this frame is going to be an easy job.
The top section of the frame is in pretty good shape but has a couple of small bends in the tubes.
The backbone and the intermediate backbone, and down tubes all have some slight bends from a head-on accident.
There is a pretty decent nick in the front of the neck and my guess is that the rear leg on a springer has been smashed back onto the neck. The part that sepperates the springs, has been smashed back into the frame at the upper section of the neck. This has bent the backbone downwards at the top engine mount.
And the 2 downtubes are bowed out toward the front.
For the record all downtubes and backbone tubes on any big twin frame should be straight...(except for the 1941 Bent style frame
1945-46 frame restoration 007.JPG
I will add some more pictures later.

[Steve Little]

1945-46 frame restoration 002.JPG1945-46 frame restoration 019.JPG1945-46 frame restoration 004.JPG1945-46 frame restoration 026.jpg
The bottom tubes on this frame have been broken and re-welded in 5 places and are integrally unsafe.
The rear Trans/engine mount is broken off and not supplied with the frame. The rear trans mounts have been stripped of all threads and the low fender support is cracked from both sides. The seat post has been broken and welded in two places.

[Steve Little]

1945-46 frame restoration 001.JPG1945-46 frame restoration 005.JPG1945-46 frame restoration 006.JPG1945-46 frame restoration 007.JPG

The front engine mount had been ground by someone to try and get a engine back in it.
In order to get a accurate engine deck reading, I had to run a file across the two pads of the front engine mount and take the high spots off.
By putting the face of the file on both pads it will stop the file from making a worse job of the uneven surfaces.
The 3/4" plate that is bolted to the rear engine mount is wash ground both sides and is used to measure the deck heights. Knuckle is 1.625" and Pan is 2" from the rear engine mount, down to the front engine mount.
The plate is also used to measure the angle of the rear engine mount to the seat post. The seat post angle of this frame measured at 74 degrees and 10 minutes. Harley designates this angle at 74.4.
The rear engine mount looks like it should be rigid, but the rear engine deck bends quite easily....from a construction point of veiw.
The box of small metal objects are called "Slip gauges" and it is the most professional way to measure a gap. It is common toolroom equipment
The right side pad of the front engine mount measured at 1.550 and the left at 1.540. This is why someone was grinding away at the front engine mount. It would not accomadate a Knuckle engine as the rear head would be hitting on the seat post well before the rear engine deck had settled on the rear mount.

[Steve Little]

I am having to make a couple of edits and add pictures quickly because the forum times out and I have to retype.
Hope its making sense

[Robert Luland]

Steve, write your post in word and the cut and paste and you will do away with the time out problem. Bob L

[Steve Little]

Thanks Bob. I will do that. I have typed out some replies in the past and have had to re-type them when a timeout happened. How long is the time out from inactivaty.
Can I cut and past pictures in the same way or are they constricted to the file manager of the forum?
Regards Steve

[Robert Luland]

No, the pictures still have to be entered at the post. Bob L

[TimR]

Steve, I to had an impact with a solid object (very large rock) with my 1942 UL and the frame suffered similar damages. The backbone and intermediate backbone bent up, both front down tubes bent out. Upper motor mount broke. Both tubes broke below the sidecar loops. Seat post tube cracked. I rode the bike before dismantling, 45 MPH hands off the bars and it tracked straight down the road. So much for people using that as a guide to prove that they have a straight frame. With the way the frame bent I have a hard time understanding how the MoCo bent the 1940-41 frames without disturbing the rest of the frame.

DSCN0508.jpg

[Robert Luland]

Because the rest of the frame was locked down in a frame table to make sure it didn't move.

[Steve Little]

Hi Tim.
We had a pretty good thread on this issue a couple of years ago.
One of the contributors thought he had seen a document that instructed dealers to bend frames with a sledge hammer and hard wood. But no one was able to come up with said document.
Personally I have never seen a frame that looked like it had been altered by a dealer.
It was probably a urban myth, or maybe some of the old timers of the past were trying to make rational sense of the true factory "Bent" frame was like it is.
Harley made two changes in 1940. The "foreward sweep" springer that was produced from 1936 through the 1940 production run. It was changed to a True inline springer for the 1941 production run. The other change was the heavier 16 inch wheel. I believe the combination of these two changes culminated in severe handling problems at high speed. The factory had to make a quick change to the frame to increase stability and slow down the steering. This was achieved by altering the neck angle from 25 degrees to 28 degrees by way of pre-bent backbone and down tubes. This meant that early 1941 "Bent style" production frames had pre bent tubes before assembly. The backbone of that perticular frame would have been cold forged. We do similar cold forge tube press here, for the rear downtubes of a swing arm frame.
Regards Steve

[Steve Little]

For those of you who are a little delicate or squeemish, now might be a good time to turn away.

[Steve Little]

Except for the front engine mount, the rest of this section is junk.

We will cut the front engine mount away this frame section and clean out the tube. Then it will be set up in the mill and we will lightly cut the damage to the decks so that it can be bolted to the jig when we start to re-asemble the frame.

I had a laugh.
I was standing there getting my energy back and looking at this junk section on the floor, and the young guy who works with me pipes up and says, "Ive seen some guys on ebay who would list this as a good start to a frame restoration"

[Steve Little]

These frames are very fragile in this state.
If it drops off your work bench in this state, you can create hours of needless work.
I place a mandrol through the sidecar lugs and have a pipe spacer between them to hold lugs in the correct postion. It also gives strength/support to the front of the frame.
For the same reason I have deliberatly left the cheap Tiawan toolbox bracket in place to give a bit of bracing to the rear end.
I also put a brace between the axle carriers for support.
This frame is 1945-early 46 and the seat post area and the sidecar lugs are electrode welded.
Frames from 1945-1947 are not as delicate as the 1936-1944 frames.
The earlier frames (with the brazed seatpost assembly) are more prone to cracking when in this dissasembled state.
A good practice is to always have the frame, well supported when working on it. Any year.

Although the pictures are not in sequence....they just put themselves where they damn well liked... I think you will be able to work out which picture I will be explaining.
In the pictures I have ground down the seat post tube until it got to the crack. You can see that the welder failed in his attempt at penatration. The next shot is ground down to the original HD weld. Hopefully you can see the sepperation line in the bright finnish of the steel. This the guide you are aiming for. Then I used a drift and knocked out the brass bush. Then ground the factory weld off the top of the seatpost cluster and drift out the remaining seat post material.
Even though these posts have been added over a day and half, the real time up to this stage is about 3 hours work.

[c.o.]

I'm following this thread with great interest Steve. Thank-you for taking us through this job.

[hdkh1947]

Thanks Steve for the awesome thread! Wish I was there to help and LEARN! Thanks for sharing your knowledge.
Jonathan