MTFCA Forum

Hi, I cleaned up the frame on my 27 today. The front crossmember has wear where the bearing/clamp rides on it. The front spring in the car is 7 leaf, which apparently is the earlier design? The clamp was loose, and there was an assortment of washers between the nuts and the lower clamp plate, and still lots of room between the pin hole and the castellations on the nuts.

Anyways...reading past threads about repairing cracks on front crossmembers, it seems folks are split on welding vs replacing. I would like to weld up the work areas and grind flat, but I also don't want to weaken the crossmember too much. Any suggestions? I have TIG, MIG and a torch, so I can do it several different ways. Or should I leave it alone?

Also, what's that little screw hole for? Is there supposed to be a screw holding the apron to the bearing?

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Boy, that baby's worn. The enlarged hole for the spring bolt head wore oversize or was cut that way for a hex bolt head and the wobbling really got going. Myself, I trust welding when the welder is trustworthy. That said, the wear from the mount is fierce and is frankly worthy of replacement if you can do it.

Do some research and you'll arrive at what the correct spring should be, and when you get it, make sure it has the correct center bolt.

Yes, the screw hole is for the front apron.

It can be done,just depends on your skills and the way you like best. Idealy a NOS crossmember with the right rivoting tools is the way to go but sometimes you don't have that option. Make for dang sure your radiator mounting holes are the exact measurement when welding is being done.Heat draws and moves things a bit.
This is the chassis that is now under my finished open exspress pickup It was split in 2 and had a large hole in it.

I have plenty of front crossmembers in good condition, $30.00 plus the ride if you need one.

Hank

Rivets and the tool to mash them are not expensive, and neither are the NOS cross members. I enlisted a neighbor to help with the installation, but two helpers would have been better. You want one person to back up the rivet with a heavy weight against the back end, another to hold heat on the business end to keep it soft, and the third person with the hammer and tool to mash it. Put the piece in solidly with bolts, and replace them one at a time with rivets.

Jim Dix (Big Flats Rivet Co.) has the tools and the rivets.

This wasn't so bad, but in some places it would have been easier having a third person holding the backup weight.

We used clamps to hold the backup weights, but again, in some places...


The NOS cross member was the only replacement I needed. The braces were good enough to keep. It's easiest to rivet the back brace on the cross member out of the car then install them together.

I think we did a pretty good job for a couple of amateurs.

Because of family "issues", I almost always work alone. For riveting frames. I have a chunk of old steel about 3/4 inch thick, inch and a half wide, and about six inches long. I drilled a couple dimples near one end to sit over the rivet heads and C-clamp it in place with two small but fairly heavy C-clamps. Between the clamps and the frame rails and the weight of the steel chunk itself, it does a fine job of backing up (bucking?) the rivets.
The reason for a couple dimples is sometimes one needs to place the iron piece slightly to the right, sometimes slightly to the left, depending upon the placement inside the frame.
Often, one must plan ahead and do a row or even two rivets in a specific order. The steel chunk needs to reach across one rivet location to reach another. Do the long reach first with the interfering hole left empty. Once done, move to the next in order. The other option if needed (not the preferred method), is to place some small object to raise the far end of the steel chunk so it can angle down a bit to the dimple in the steel chunk over a rivet in the way. Not the preferred way because the wide gap and extra object between the steel chunk and frame rail makes it a bit less solid and stable. But I have done that several times with great success.

Jim Forbes

you will not find a nicer guy to deal with than Hank, and the stuff he has is mind boggling. Grab a good crossmember while he is offering.

That front cross member can be built up and last for the next 50+ plus years. If you are a decent welder you can build it up with several stringers, tie them together and you won’t have to do a lot of smoothing out with with a disc grinder.
Some cross members have the rivets welded over and patched up but if the rest of your cross member is still in good shape building it up, smoothing down would be the way to go if it were mine.
Finding a better cross member can be done also but more work than necessary in my way of thinking.

Thanks for the replies. I'm not going all out on this car to fix everything perfectly....instead, I'm doing my best to get it back on the road, looking good, to get some enjoyment out of it. So, replacing the crossmember is something I'll leave to a future owner. The existing crossmember is in really good condition everywhere else, the brackets and rivets are real nice, and I'd rather not mess with them.

I did some grinding and welding, I decided to use MIG. I still need to flip the frame over and fill in around the hole on the bottom side, and finish the hole. I assume it wants to be 9/16" square, like the hole in the rear crossmember (which is in great condition). I built up where the locating nubs apparently used to be, to keep the bearing from moving sideways. It's not real pretty under the bearing, but it's a functional repair that will go unnoticed by most folks looking at the car.

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welded in the bottom, and filed out the hole. I think it'll work.

The frame rails seem to be about 1/32" closer together now at the radiator holes.

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Excellent

the holes should be 21 1/2" apart, and the frame is often spread some. When spread, there is a trick to closing it up. Do you still need to close it more, or is it truly too narrow now?

As best I can measure, it's dead on 21-1/2" center to center. I guess it's good.

Very nice craftsmanship, your an asset to the hobby.

Jim, exactly what I would have done, nice job! Dave

Squirrel wrote: ↑

Sun Jun 14, 2020 11:35 am

The clamp was loose, and there was an assortment of washers between the nuts and the lower clamp plate, and still lots of room between the pin hole and the castellations on the nuts.

Jim, that could be a front mount for a TT (Ton Truck). Somehow one ended up on my '25 car chassis and I have the same issue where the castle nuts are really far away from the cotter key holes.