Rear Spring Mounting Questions

Pilotdave

Pilotdave

Well-known member
While chasing a light body lean to the driver's side, I discovered that some of the nuts on the rear spring u-bolts (8 leaf spring) were finger loose. Also that the u-bolts are too long so that the cotter pins don't pass through the castle nuts when nuts are tight. I'm planning to re-work (or replace) the bolts to eliminate that issue.

I did some exploratory tightening using lock washers until I can correct the u-bolts. Given the lean, I tightened the passenger side nuts first, then the driver's side. The passenger side center bottom plate is snug against the cross member. However, there is about 0.25" separation between the driver's side center bottom plate and the cross member. The lean is pretty much gone.

So a couple of questions:

1. Should there be any gap between the cross member and either center bottom plate? (I'm going to check the height of the plates to make sure that the correct ones are installed.)

2. If there is a gap, what's needed to eliminate it?

Thanks much.
Dave
 
Pilotdave said:
While chasing a light body lean to the driver's side, I discovered that some of the nuts on the rear spring u-bolts (8 leaf spring) were finger loose. Also that the u-bolts are too long so that the cotter pins don't pass through the castle nuts when nuts are tight. I'm planning to re-work (or replace) the bolts to eliminate that issue.

I did some exploratory tightening using lock washers until I can correct the u-bolts. Given the lean, I tightened the passenger side nuts first, then the driver's side. The passenger side center bottom plate is snug against the cross member. However, there is about 0.25" separation between the driver's side center bottom plate and the cross member. The lean is pretty much gone.

So a couple of questions:

1. Should there be any gap between the cross member and either center bottom plate? (I'm going to check the height of the plates to make sure that the correct ones are installed.)

2. If there is a gap, what's needed to eliminate it?

Thanks much.
Dave
Click to expand...




1. Should there be any gap between the cross member and either center bottom plate? No (I'm going to check the height of the plates to make sure that the correct ones are installed.) If my memory is correct and if you are working on your Tudor, I'm pretty sure that they should be 17/32"

2. If there is a gap, what's needed to eliminate it? Correcting whatever it is that is out-of-specifications. The Spring Clips (rear U-bolt) were all the same however the repros are not the same as original.


There is something else that is often overlooked and that is the square hole in the top of the rear crossmember and the fit of the tie-bolt (A-20920) head. If the head of the tie-bolt is allowed to move away from centerline, it will allow the body to lean when the Clip Bars are tightened.
 
Since Ford used transverse springs instead of two springs per axle, model A's have a tendency to lean to the drivers side. I think the springs, over years of being driven, usually by just the driver, the spring looses it "set". The front spring on my coupe was new and it didn't have a lean on the front. I tried a lot of things to eliminate the rear lean on my 28 coupe, which was about 3/4" measured from the bead of the rear fenders on each side. I reversed the rear spring and it did nothing which really surprised me, as I thought it might lean to the passenger side, but it didn't. I still don't understand why that didn't make any difference. I tightened the passenger side U bolt first and real tight, before tightening the drivers side nuts, also no help with the leaning. What I did to eliminated the lean was to grind down the top leaf to about 1/2 the thickness on the passenger side. That was a lot of effort as spring leaves are very hard metal and it takes a long time to grind one down. BTW, the square bolt head holding the spring together WAS in the hole in the rear frame crossmember and I do have original shocks on the car.
Rusty Nelson
 
BRENT in 10-uh-C said:
1. Should there be any gap between the cross member and either center bottom plate? No (I'm going to check the height of the plates to make sure that the correct ones are installed.) If my memory is correct and if you are working on your Tudor, I'm pretty sure that they should be 17/32"

2. If there is a gap, what's needed to eliminate it? Correcting whatever it is that is out-of-specifications. The Spring Clips (rear U-bolt) were all the same however the repros are not the same as original.


There is something else that is often overlooked and that is the square hole in the top of the rear crossmember and the fit of the tie-bolt (A-20920) head. If the head of the tie-bolt is allowed to move away from centerline, it will allow the body to lean when the Clip Bars are tightened.
Click to expand...


Brent, I'm confused. Are you saying that the Spring Clip Bars should be bearing (i.e. no gap) against the crossmember? (and thus not necessarily fully bearing on the spring?) If so I have to disagree - sounds like almost a sure way to have a loose spring.



-
367736
 

Attachments

  • Copy of Rear spring in place.jpg
    Copy of Rear spring in place.jpg
    71 KB · Views: 293
Interesting. Back in the 60's the "rake" was the big deal. I had a 32 olds powered 5 window, 8:20's in the back and 650's in the front and put a 2 or 3" block on top of the rear spring. When I parked I always got out and pushed up on the driver's door to "level" it out. :D:eek::cool:
Paul in CT
 
Thanks for all the input, guys.

I should have mentioned that this is a 400A, not our Tudor! Based on the JS, I believe the 8 leaf spring is correct. Per the catalogs, the center bottom plates should measure 0.625". I haven't yet lowered the spring to count, but it APPEARS to be short at 1 leaf....maybe 2. Looking between the spring and the cross member I can see 6 leaves. But there could be more - won't know until I can lower the spring out of the cross member.

So given the input from Brent/Randy and the use of the incorrect, oversized center bottom plates, I'm wondering if the spring might be a little loose in the cross member with the center plates used to try to take up the slack resulting from the (possibly) under-leafed spring. The center bottom plates currently appear to be bearing directly on the spring surface and, at 3/4 of the possible spots, on the cross member. This would be counter to what I'm reading above.

Are the center bottom plates supposed to be 0.625 for the 8 leaf spring?

Thanks again!
Dave
 
An easy way out (if the car rides good) would be to put 1 or 2 short springs on the BOTTOM of your spring pack to make up the distance you need for the bottom plates you have. You could do this WITHOUT removing the spring if the center bolt is long enough ad the head is secured in the frame.
A picture of yours like the one above would help.
Paul in CT
 
Interesting idea, Paul. Ride seems okay though on really rough roads there's a fair amount of loud banging noises that might be related to the spring's thickness.
 
Pilotdave said:
Thanks for all the input, guys.

I should have mentioned that this is a 400A, not our Tudor! Based on the JS, I believe the 8 leaf spring is correct. Per the catalogs, the center bottom plates should measure 0.625". I haven't yet lowered the spring to count, but it APPEARS to be short at 1 leaf....maybe 2. Looking between the spring and the cross member I can see 6 leaves. But there could be more - won't know until I can lower the spring out of the cross member.

So given the input from Brent/Randy and the use of the incorrect, oversized center bottom plates, I'm wondering if the spring might be a little loose in the cross member with the center plates used to try to take up the slack resulting from the (possibly) under-leafed spring. The center bottom plates currently appear to be bearing directly on the spring surface and, at 3/4 of the possible spots, on the cross member. This would be counter to what I'm reading above.

Are the center bottom plates supposed to be 0.625 for the 8 leaf spring?

Thanks again!
Dave
Click to expand...



Dave, All vehicles using the 8 leaf spring should be using the taller (1-1/8") Spring Clip Bars (A-5708-A) or bottom plates as you refer to them. The 1/2" difference between these and the shorter (5/8" or O.625") is significant for sure - which are currently in place?

How difficult is it to check if the spring thru bolt is properly seated in the crossmember on a 400A?

Good luck.
 
Randy - it has 1.125" plates. I misread the catalog (or my brain deliberately flipped the data!) when I claimed that 0.625" plates were correct. It also makes sense that thinner springs use taller plates!

Checking the bolt head location on the 400A requires removing the back seat bottom cushion and then a piece of fabric that covers that area - as I recall. I'm not sure how the fabric is attached.
 
Last edited:
A few years ago my 400A leaned to the driver's side. I "assumed" the front spring was the culprit even though it had 3000 miles on the restoration. After replacing it twice and tightening the passenger side U-bolt first, it still leaned. I thought I had checked the frame before restoration but went through measuring and comparing rail to rail every foot. Was ok. Didn't think about the stout rear spring until being the last resort. It was relatively loose! Had the right bars but may not have been torqued-up at the begining or the u-bolts allowed movement of the castle nuts. At any rate I removed the spring and disassembled it. Took a sheet of cardboard and drew a profile of each leaf and noted the position. Flipped each leaf and was amazed at the distortion on the driver's side. Since it was a NOS eight leaf I thought maybe I could re-mount it 180 degrees but a lot of effort if I end up with a passenger side lean. Next I thought maybe it would even out if I alternated every other leaf. Again, they likely would not seat to each other very well. I ended up putting a NROS spring on since its show days were long over. Resulted in eliminating the lean and is level. Did make sure the nuts were tight and cotters lined up with castle nut slots.
 
More good stuff. Thanks, Roger.

I've lowered the spring and counted the leaves - there are 8..... just as is supposed to be the case. So...the correct spring and bottom plates. I have retorqued the bolts - will see if my wife agrees that it looks reasonably level.

All in all, this came down to a "leaning car" story...with much ado about not very much added by me! Thanks, everyone for their input.
 

Attachments

  • Rear Spring Sml.jpg
    Rear Spring Sml.jpg
    53.6 KB · Views: 43
New question regarding the center bottom plate, aka "rear spring clip". I just saw some material that shows and lists specs for 3 clips; the height specs are 0.53125", 0.6875" and 0.84375". Catalogs list two: 1.125" and 0.625". Can someone resolve this conundrum?

Thanks!
Dave
 
Roger V said:
A few years ago my 400A leaned to the driver's side. I "assumed" the front spring was the culprit even though it had 3000 miles on the restoration. After replacing it twice and tightening the passenger side U-bolt first, it still leaned. I thought I had checked the frame before restoration but went through measuring and comparing rail to rail every foot. Was ok. Didn't think about the stout rear spring until being the last resort. It was relatively loose! Had the right bars but may not have been torqued-up at the begining or the u-bolts allowed movement of the castle nuts. At any rate I removed the spring and disassembled it. Took a sheet of cardboard and drew a profile of each leaf and noted the position. Flipped each leaf and was amazed at the distortion on the driver's side. Since it was a NOS eight leaf I thought maybe I could re-mount it 180 degrees but a lot of effort if I end up with a passenger side lean. Next I thought maybe it would even out if I alternated every other leaf. Again, they likely would not seat to each other very well. I ended up putting a NROS spring on since its show days were long over. Resulted in eliminating the lean and is level. Did make sure the nuts were tight and cotters lined up with castle nut slots.
Click to expand...


Someone in another thread said he has found a number of rear springs with this driver's side distortion...but you're saying the one you had was a NOS.

Hmmm, maybe quality control problem at Ford rather than the rear spring being twisted over decades by more weight on the driver's side of the car? :confused:
 
M2M said:
Someone in another thread said he has found a number of rear springs with this driver's side distortion...but you're saying the one you had was a NOS.

Hmmm, maybe quality control problem at Ford rather than the rear spring being twisted over decades by more weight on the driver's side of the car? :confused:
Click to expand...

My 400A was level when it was restored. I don't for a minute believe it was manufactured that way. Could have a 50% chance of leaning to the passenger side since it can be installed either way.
 
You must log in or register to reply here.
Back
Top