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Front taper leaf spring arc
Posted: Fri Apr 19, 2024 10:53 pm
by Craig E. Luton
Does anyone know the amount of arc the front taper leaf spring had from the factory? Thank you... Craig
Re: Front taper leaf spring arc
Posted: Sat Apr 20, 2024 11:21 am
by TRDxB2
Craig E. Luton wrote: ↑Fri Apr 19, 2024 10:53 pm
Does anyone know the amount of arc the front taper leaf spring had from the factory? Thank you... Craig
All I have is some data collected from previous discussions. It should be possible to measure the height with a main leaf by compressing its eyelet ends to the correct length (whatever that is for sure). There is agreement on the data for a height of 4-11/16" for lengths
Re: Front taper leaf spring arc
Posted: Sun Apr 21, 2024 4:42 am
by Luxford
I have a 1926 copy of an Australian spring maker setting chart which gives the measurement for a Model T Ford car front 7 leaf spring between bushing centre's as 31- 5/16 to 1/2 inch.
Re: Front taper leaf spring arc
Posted: Mon Apr 22, 2024 4:39 pm
by Craig E. Luton
Thank you....Craig
Re: Front taper leaf spring arc
Posted: Mon Apr 22, 2024 10:01 pm
by jiminbartow
Not really important. When I bent each of my spring leafs into an arch in order to strengthen the spring, I didn’t worry about how much I bent it. The spring will find its’ natural arch on its’ own once the spring is attached to the perches, which are a finite distance apart, combined with the weight of the car. Once the car is lowered onto the spring, it can only go so far and no more. The more you bend the spring leaf, the more efficient the spring will be in absorbing the shock.
Re: Front taper leaf spring arc
Posted: Wed Oct 15, 2025 12:18 am
by skyhunter
Sorry if I sound dumb but what should be the distance of the main leaf on a 7 leaf spring. Eye to Eye.
Also should that measurement be taken when it is assembled with all springs attached or by itself. On the floor or on the shackles.
Would a spring that is too long only get longer when compressed and rest on the axle if long enough and bang on bumps.
Look at this reverse eye spring. This looks like any bump in the road is going to result in the spring hitting the perch and not having much spring at all. I would think that an assembled spring attached and under weight should have the shackle at about 8 O'clock.
- drop axle copy.jpg (25.28 KiB) Viewed 259 times
Re: Front taper leaf spring arc
Posted: Wed Oct 15, 2025 1:30 am
by TRDxB2
FWIW
Leaf springs specifications are measured independently, unattached to anything, eye to eye. Several sources indicate the main for the 7 leaf is 33-1/4". Measuring leaves clamped together or under load would give a different reading.
https://mtfca.com/phpBB3/viewtopic.php?t=14560
viewtopic.php?f=2&t=2803
The method to measure an assembled used spring is different when ordering an assembled one
https://www.eatondetroitspring.com/how- ... f-springs/
Re: Front taper leaf spring arc
Posted: Wed Oct 15, 2025 6:28 am
by Jerry VanOoteghem
skyhunter wrote: ↑Wed Oct 15, 2025 12:18 am
Sorry if I sound dumb but what should be the distance of the main leaf on a 7 leaf spring. Eye to Eye.
Also should that measurement be taken when it is assembled with all springs attached or by itself. On the floor or on the shackles.
Would a spring that is too long only get longer when compressed and rest on the axle if long enough and bang on bumps.
Look at this reverse eye spring. This looks like any bump in the road is going to result in the spring hitting the perch and not having much spring at all. I would think that an assembled spring attached and under weight should have the shackle at about 8 O'clock.
drop axle copy.jpg
The eye-to-eye dimension was given above, by "Luxford". My assumption is that it would be taken on an assembled spring in the free state, (meaning not installed on the car).
Your spring shackle position looks perfectly normal.