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Changing from a Crawler to Speed Runner - Coyote Install

68ford

Bronco Guru
Joined
Dec 26, 2004
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2,710
Did you make the trailing arms or does someone make those?

Are you going to cut into the frame for the upper link mounts? Reason I ask is with the narrow frame, the upper links do not have much spread at the frame. Though about putting the heims inside the frame with the bolts going vertical through the frame?
 
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rcmbronc

rcmbronc

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Tomah WI
I welded the trailing arms from Ruffstuffs kit. I had to shorten them 8”.

I am putting the mounts inside the frame. The lowers also are triangulated so I think it is ok
 

68ford

Bronco Guru
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Dec 26, 2004
Messages
2,710
I welded the trailing arms from Ruffstuffs kit. I had to shorten them 8”.

I am putting the mounts inside the frame. The lowers also are triangulated so I think it is ok

I always figured if the upper mount were in the frame and the lowers angles it would be good. Curious to see what kind of numbers it cycles before the drive shaft gets upset. What stroke shocks are you running? 12 and 14? 14 and 16?
Not sure what size tires you're running or if you want to trim you wheel wells, but have you thought about c notching the frame for more uptravel?
 

markw

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So, if I may stick my nose in here, how much have you notched your frame? Any pics? I'm going to use the RuffStuff/Deaver over spring conversion and will need some room. Thanks, Mark
 

68ford

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So, if I may stick my nose in here, how much have you notched your frame? Any pics? I'm going to use the RuffStuff/Deaver over spring conversion and will need some room. Thanks, Mark

I'm assuming your asking me because I brought up C notch. My frame is not C notched, but the axle does hit it. Coincidentally, when the axle tube hits the frame and you do not have a body lift, a brand new 35in tire just contact the top most part of the inner fender. I am planning on doing a 1inch C notch and mounting a hard rubber bump stop inside it. The thing keeping me from just doing it is that 2 of the cage mounting points is a vertical tube piercing the frame and welded on the top portion and bottom portion of the frame dead center to where the C notch needs to go 😥
 
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rcmbronc

rcmbronc

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Right now just a single 14” stroke shock. Can’t afford bypass yet. Checking all the driveshaft stuff now. Wheel base is a bit long right now so have to look at that as it is hitting the rear crossmember. 35” tires. So I need to cut the housing and put on the hubs to look at all the details.
 

ntsqd

heratic car camper
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Jan 30, 2005
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3,225
Loc.
Upper SoKA
Are the lower pivots SRE's at both ends? Looks to me like the lower shock mounting bolts are on the Line of Action (the straight line from pivot to pivot) or slightly above it. If they're both SRE's than I'd expect the lowers to want to roll over. I'm hoping it is the picture rather than the reality and those holes are below the LoA.
 
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rcmbronc

rcmbronc

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Hikes are about 1/2” below centerline. Front mounts are rubber bushings. Rear are rod ends. Should be ok.

I moved some stuff around. Now here is a pic with tires when axle hits frame rail
 

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ntsqd

heratic car camper
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Upper SoKA
With rubber front pivots setting them up other than parallel means that the bushings have to distort in order to cycle the suspension. No doubt they can handle a little of this for a long time, but if excessive the life-span of the bushings will be pretty short. I've no idea where the line is between what is and isn't excessive.

An ancient thread if you haven't already found it: https://www.race-dezert.com/forum/threads/lower-links-101.4050/
 

68ford

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Dec 26, 2004
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Hikes are about 1/2” below centerline. Front mounts are rubber bushings. Rear are rod ends. Should be ok.

I moved some stuff around. Now here is a pic with tires when axle hits frame rail

Do you have a body lift? Just off your picture, my tires appear to be farther up in the wheel wells when axle hits the frame I think. Either way looks good. Assuming 14in c/o in forward mount and 16in bypass closer to the axle when the time comes?
 
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rcmbronc

rcmbronc

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I have a 1” body lift. Yes that is what I am figuring when the time comes.
 

ntsqd

heratic car camper
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Jan 30, 2005
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Upper SoKA
Suggest reading that thread that I linked. Usually those pivots are used at the chassis end of a lower link to keep it from being able to rotate about the LoA. This is important when the lower link is carrying the suspension spring and is why I asked about where the shock mount holes are relative to the LoA.
 

nvrstuk

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Just a Bronco driver for over 50 yrs!
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TS, that "old" thread has a lot of good info in it... thanks for posting it up.
 

ntsqd

heratic car camper
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Jan 30, 2005
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Upper SoKA
To be honest, it's been years since I read it all. I've probably forgotten whatever I might have contributed. I wish that the idea behind it had been employed to cover other topics as was the original intent.
 
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rcmbronc

rcmbronc

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That is why I likes the bushings. I have it at the chassis end of the lower link. The shock mount is just below the CL of the two joints, but not alot. Bushing helps keep it from rotating. I realize it will wear but I will watch it to see how bad. I read some of it. Good info.
 

ntsqd

heratic car camper
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Upper SoKA
Usually lowers like these are mounted parallel and as far outboard as is reasonably possible in a single converging linkage design. Not to say they can't be mounted differently, but that has proven to work well.
 
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rcmbronc

rcmbronc

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Mine are as far out as I can on the axle. I think mine are at about 5 degrees off parallel. That is with the outboard mounted frame brackets.
 
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