'94 F350 Carrier Bearing Drop Spacer / 3" lift

Noiseydiesel

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Getting close to done. . .
In the final stages of initial assembly and I finally got the 2 piece drive line in and it is in dire need to drop about 3 inches at the center carrier bearing I suspect. I say three inches due to the 3 inch OEM spacers I installed on the rear axle, not to mention the 4x4 Dana 60 axle conversion the front end underwent which raised the entire vehicle.
I have been looking for a suitable spacer and nothing seems to be out there. A trip to Ace Hardware this morning found a 3 inch long round spacer that goes around the bolt. Two of those would get me up the 3 inches and they are roughly a 1 inch outer diameter.
Advisability of this? Or weld them together on either side solidifying the center? Or something else, such as what?
 

u2slow

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Perhaps revisit basic driveshaft geometry. Equal and opposite angles are ideal.

3" more block at the rear axle should not require 3" drop at the support bearing.
 

catbird7

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Didn't notice anywhere you mentioned what the original frame was prior to adding F-350 Axel's and suspension. If it was 4x4 F-250 I think you'll be fine with the stock location of the carrier bearing. The black truck in my sig started life as an F-250 and I added the same F350 components as you. Never change center carrier.
 

Old Goat

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Here is one of his threads on what he is working on. Saw it on "Similar threads" down below this one.



Goat
 

hacked89

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Didn't notice anywhere you mentioned what the original frame was prior to adding F-350 Axel's and suspension. If it was 4x4 F-250 I think you'll be fine with the stock location of the carrier bearing. The black truck in my sig started life as an F-250 and I added the same F350 components as you. Never change center carrier.

Same
 

Black dawg

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Ford typically sets these up with less than 1 degree angle at the front joint.

3 joint shafts can be a cluster to get perfect if you have changed everything.
 

u2slow

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When the rear suspension is raised with a square block (no angle) the ujoint angles on the rear driveshaft section stay equal and opposite.
 

Black dawg

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When the rear suspension is raised with a square block (no angle) the ujoint angles on the rear driveshaft section stay equal and opposite.
Yes, problem is that on most heavier pickups, there is a little extra down on the rear pinion angle to account for heavy loads. Driving unloaded it is ok becuase that little extra angle is really small and all other angles are mostly minimal. Add a bunch more driveshaft angle because of lift and stuff starts to get unhappy, even though the angle at the diff and first driveshaft section hasnt changed.

I has been my experience that pinion needs to come up some, carrier bearing down some and also t case. Or live with low speed shudder...
 

u2slow

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It depends on a lot of things.....
- Leaf spring stiffness
- Rearmost driveshaft length
- Auto vs manual (shock loading)
- Angle limits of ujoints and yokes

Bringing the pinion up tends to give me increased vibration under heavy load.

The ones with longer rear shafts are the most forgiving.
 

Noiseydiesel

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This toy started life as a 2WD vehicle. This toy has become a case of, "I should have stopped playing" at the Allison and Truetrac rear end. The 4X4 swap has become a bit of a(n expensive) PITA complete with spring swap, etc. This was just to keep the wife with an automatic.
As far as leaving it alone, that might be an option but the adapter off the back end of the Allison for the BW 1356 transfer case adds about 6 inches and creates a sharper down angle out the rear of the transfer case.

Looking at the front of the carrier bearing, it appears to already be nearly in a bind. I figured roughly a 3 inch block, without taking it down, to get a better idea of level. Considering the body lift the truck has already done via the 2WD-4X4 conversion.
I am hoping to get the front 1/2 of the shaft as close to level as possible and the rear should take care of itself. (maybe)
You must be registered for see images attach
 

Nero

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Just to throw it out there... Stock suspension height, I had a 2wd standard cab 3 piece driveline, carrier was mounted with no spacer. When I moved the driveline to my crew cab 4x4 (after extendending it) I also used no spacers on stock suspension. Many years and miles later its still just fine.
 

Black dawg

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This toy started life as a 2WD vehicle. This toy has become a case of, "I should have stopped playing" at the Allison and Truetrac rear end. The 4X4 swap has become a bit of a(n expensive) PITA complete with spring swap, etc. This was just to keep the wife with an automatic.
As far as leaving it alone, that might be an option but the adapter off the back end of the Allison for the BW 1356 transfer case adds about 6 inches and creates a sharper down angle out the rear of the transfer case.

Looking at the front of the carrier bearing, it appears to already be nearly in a bind. I figured roughly a 3 inch block, without taking it down, to get a better idea of level. Considering the body lift the truck has already done via the 2WD-4X4 conversion.
I am hoping to get the front 1/2 of the shaft as close to level as possible and the rear should take care of itself. (maybe)
You must be registered for see images attach
I would lower that carrier bearing to where there was a 1/2 degree angle on that front joint and then see how the rest works out. You want the. pinion angle to be 1 or 2 degrees lower than that first shaft. I usually don't make anything permanent, use shims, until I am happy with how it runs.
 

Noiseydiesel

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That sounds like a hella good plan.
Looking at the pic, something has to happen.
Nasty part is no one has a pre-made spacer available for this year/application. I will be pulling it apart, a rough measurement and then see what I can stuff in there temporarily while I check angles and dangles to fab something before driving it.
 

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