Swapping front crossmembers

R

Richie R

Member
I have just picked up another Model A chassis, it's missing the front crossmember. The new chassis is a later A 30, 31 I think but my good crack free spare crossmember is a early 28 with solid engine mounts.
None of the rivet holes line up.
Is there a trick to making crossmembers fit into another chassis?
I'm happy to weld up the holes and redrill, but what hole should I make the "primary"
Is there any reference point to make sure the crossmember is in the correct place?
 
I had the same problem with my Tudor. With a lot of carefull trying all possibile hole locations I found that the two on each end going through the frame web matched. I welded all the rest, installed with the 4 end holes and drilled the rest in the crossmember. The front motor mount is a close fit and I guess I lucked out because it worked. My old mount had the solid part cut out and the newer motor mount installed. I replaced because it was a slop job and installed with hardward store bolts.

John
 
Sounds like he's not in the US so shipping a crossmember may be pricey. Also, he's building a '28 pickup so the early crossmember would give him the right radiator setting. I know you can shim, etc. but it looks like several factors are coming into play.
 
Managed to fit it today, the 4 holes on the outside of the rail and the 2 front where it attaches to the bottom of the rail lined up perfectly.
The 2 top front lined up close.
I welded up 4 of the top crossmember holes, opened up all holes in the rail to suit 8mm grade 12 cap head screws. Bolted it in tight using all bolt holes that matched, and drilled the remaining holes.
All looks good, I like cap heads, can fill up the Alan key head will filler and they look a bit like rivets.
Not happy with the lower back bolt holes, will fill the holes in the chassis and redrill to suit the crossmember. Using the chassis bolt holes as I did puts the bolt too far forward.
I think the early crossmember is near 3/4" longer than the later crossmember.
Will be removing and reworking the bottom holes later after I finish mockup.
But it's done for the time being:)
 
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Hi Al 29Tudor
Yes I know the top should be countersunk, by drilling the hole to 8mm it removes most of the hole taper. I might grinds some of the crown of the bolts to make them look less obvious.
This chassis must have been a Monday or Friday car, the crossmember holes are all over the place and not even even side to side
 
What you are going to do may cause you some problems if you are mounting a 30/31 body radiator etc to the chassis. The mounting pad for the radiator is lower on the 30/31 front crossmember. On the early cross member the radiator mount spot is flush. Thus the 30/31 radiator will be to high.When you come to fit the bonnet (hood) it will not line up. A mate of mine had this problem and could not figure out why things would not line up. In the end he lengthened the rear bottom corners of his bonnet to cover the gap at the fire wall. Of course you could pack the whole body up to suit but then you may get a large gap at the bottom of the bonnet and need longer catches. Happy Motoring.
 
Halswell said:
What you are going to do may cause you some problems if you are mounting a 30/31 body radiator etc to the chassis. The mounting pad for the radiator is lower on the 30/31 front crossmember. On the early cross member the radiator mount spot is flush. Thus the 30/31 radiator will be to high.When you come to fit the bonnet (hood) it will not line up. A mate of mine had this problem and could not figure out why things would not line up. In the end he lengthened the rear bottom corners of his bonnet to cover the gap at the fire wall. Of course you could pack the whole body up to suit but then you may get a large gap at the bottom of the bonnet and need longer catches. Happy Motoring.
Click to expand...

It's a 1929 roadster pickup I am putting together from loose swap meet parts and eBay finds, there is at least 10+ dead model A cars in this build.
I have almost everything I need now other than garage time.
Trying to use as much original parts in this build but will be automatic on the back of a Model A engine, later diff and hydraulic brakes.
 
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